Unknown TM 9 2320 272 24 1 Maintenance Manual 1998

User Manual: TM-9-2320-272-24-1-Maintenance-Manual-1998 M939 Series Trucks

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ARMY TM 9-2320-272-24-1
AIR FORCE TO 36A12-1C-1155-2-1
This publication supersedes TM 9-2320-272-20-1, October 1985, and changes 1 through 4; TM 9-2320-272-20-2,
October 1985, and changes 1 through 3; TM 9-2320-272-34-1, June 1986, and chanaes 1 through 2;
TM 9-2320-272-34-2, June 1986, and changes 1 and 2; and TM 9-2320-358-24&P, October 1992

TECHNICAL MANUAL
VOLUME 1 OF 4
UNIT, DIRECT SUPPORT, AND GENERAL SUPPORT
MAINTENANCE MANUAL
FOR
TRUCK, 5-TON, 6X6, M939, M939A1, M939A2
SERIES TRUCKS (DIESEL)

HOW TO USE THIS MANUAL

V

INTRODUCTION

l-l

SERVICE AND TROUBLESHOOTING
INSTRUCTIONS

2-l

PREVENTlVE MAINTENANCE CHECKS
AND SERVICES (PMCS)

2-2

UNIT TROUBLESHOOTING

UNIT

MAINTENANCE

2-60

3-1

TRUCK, CARGO: 5-TON, 6X6, DROPSIDE,
M923 (2320-01-050-2084) (EIC: BRY); M923Al (2320-01-206-4087) (EIC: BSS); M923A2 (2320-01-230-0307) (EIC: BS7);
M925 (2320-01-047-8769) (EIC: BRT); M925Al (2320-01-206-4088) (EIC: BST); M925A2 (2320-01-230-0308) (EIC: B58);
TRUCK, CARGO: 5-TON, 6X6 XLWB,
M927 (2320-01-047-8771) (EIC: BRV); M927A1 (2320-01-206-4089) (EIC BSW); M927A2 (2320-01-230-0309) (EIC: BS9);
M928 (2320-01-047-8770) (EIC: BRU); M928Al (2320-01-206-4090) (EIC: BSX); M928A2 (2320-01-230-0310) (EIC: BTM);
TRUCK, DUMP: 5-TON, 6X6,
M929 (2320-01-047-8756) (EIC: BTH); M929Al (2320-01-206-4079) (EIC: BSY); M929A2 (2320-01-230-0305) (EIC: BTN);
M930 (2320-01-047-8755) (EIC: BTG); M930Al (2320-01-206-4080) (EIC: BSZ); M930A2 (2320-01-230-0306) (EIC: BTO);
TRUCK, TRACTOR: 5-TON, 6X6,
M931 (2320-01-047-8753) (EIC: BTE); M931Al (2320-01-206-4077) (EIC: BS2); M931A2 (2320-01-230-0302) (EIC: BTP);
M932 (2320-01-047-8752) (EIC: BTD); M932Al (2320-01-205-2684) (EIC: BS5); M932A2 (2320-01-230-0303) (EIC: BTQ);
TRUCK, VAN, EXPANSIBLE: 5-TON, 6X6,
M934 (2320-01-047-8750) (EIC: BTB); M934A1 (2320-01-205-2682) (EIC: BS4); M934A2 (2320-01-230-0300) (EIC: BTR);
TRUCK, MEDIUM WRECKER: 5-TON, 6X6,
M936 (2320-01-047-8754) (EIC: BTF); M936Al (2320-01-206-4078) (EIC: BS6); M936A2 (2320-01-230-0304) (EIC: BTT).
DISTRIBUTION STATEMENT A - Approved for public release; distribution is unlimited.

DEPARTMENTS OF THE ARMY AND THE AIR FORCE
JUNE 1998

TM 9-2320-272-24-1

WARNING

EXHAUST GASES CAN KILL
1.
2
3.
4.
5.

6.

7.

DO NOT operate vehicle engine in enclosed area.
DO NOT idle vehicle engine with windows closed.
DO NOT drive vehicle with inspection plates or cover plates removed.
BE ALERT at all times for odors.
BE ALERT for exhaust poisoning symptoms. They are:
Headache
Dizziness
Sleepiness
Loss of muscular control
IF YOU SEE another person with exhaust poisoning symptoms:
Remove person from area
Expose to open air
Keep person warm
Do not permit person to move
Administer artificial respiration or CPR, if necessary*
* For artificial respiration, refer to FM 21-11.
BE AWARE: The field protective mask for Nuclear, Biological, or Chemical (NBC) protection will not
protect you from carbon monoxide poisoning.
THE BEST DEFENSE AGAINST EXHAUST POISONING IS ADEQUATE VENTILATION.

Warning a

TM 9-2320-272-24-1

WARNING SUMMARY
Hearing protection is required for the driver and passenger. Hearing protection is also required for
all personnel working in and around this vehicle while the engine is running (AR-40-5 and TB MED
501).
If required to remain inside vehicle during extreme heat, occupants should follow the water intake,
work/rest cycle, and other stress preventive measures (FM 21-10, Field Hygiene and Sanitation).
If NBC exposure is suspected, all air filter media should be handled by personnel wearing protective
equipment. Consult with your unit NBC officer or NBC NC0 for appropriate handling or disposal
instructions.
This vehicle has been designed to operate safely and efficiently within the limits specified in this
TM. Operation beyond these limits is prohibited by IAW AR 70-l without written approval from the
commander, U.S. Army Tank-automotive and Armaments Command, ATTN: AMCPEO-CM-S,
Warren, MI 48397-5000.
Never work under dump body unless safety braces are properly positioned. Failure to do this will
result in injury to personnel.
During winching operation, never stand between vehicles. Assistant must remain in secondary
vehicle to engage service brake if cable snaps or automatic brake fails while towing vehicle. Failure
to do this may result in injury to personnel.
Accidental or intentional introduction of liquid contaminants into the environment is in violation of
state, federal, and military regulations. Refer to Army POL (para. l-7) for information concerning
storage, use, and disposal of these liquids. Failure to do so may result in injury or death.
Cleaning solvents are flammable and toxic. Do not use near open flame and always have a fire
extinguisher nearby when solvents are used. Use only in well-ventilated places, wear protective
clothing, and dispose of cleaning rags in approved container. Failure to do this will result in injury
to personnel and/or damage to equipment.
Eyeshields must be worn when cleaning with compressed air. Compressed air source will not exceed
30 psi (207 kPa). Failure to do so may result in injury to personnel.
Extreme care should be taken when removing surge tank filler cap if temperature gauge reads
above 175°F (79°C). Steam or hot coolant under pressure will cause injury.
Alcohol used in the alcohol evaporator is flammable, poisonous, and explosive. Do not smoke when
removing alcohol evaporator or adding fluid, and do not drink fluid. Failure to do this will result in
injury or death.
Do not perform electrical circuit testing fuel tank with fill cap or sending unit removed. Fuel may
ignite, causing injury to personnel.
When performing battery maintenance, ensure batteries are seated and clamped down, all rubber
boots are installed, clamps are well down on battery posts, and all battery cables lie flat against the
top of the batteries. Failure to do this may result in injury to personnel and/or damage to
equipment.
Ensure companion seatbelts are not caught inside battery box. This will cause belts to rot which
may lead to iujury of personnel.
On M938/Al/A2 model vehicles, remove spare tire prior to changing tire and install tire in spare tire
carrier after tire change is complete. Operation of crane and/or vehicle engine while vehicle is on
jacks may result in injury to personnel or damage to equipment.
Never assemble or disassemble tire and rim assembly while inflated, use inflation to seat lockring
on split rim or tire on two-piece rim, or inflate a tire without a tire inflation cage. Injury to
personnel may result.
Do not disconnect air lines or hoses, remove safety valves or CTIS components, or perform brake
chamber repairs before draining air reservoirs. Small parts under pressure may shoot out with high
velocity, causing injury to personnel.

Warning b

TM 9-2320-272-24-1

WARNlNG SUMMARY (Contd)
Remove all jewelry when working on electrical circuits. Jewelry coming in contact with electrical
circuits may produce a short circuit, causing extreme heat, explosions, and fling particles of metal.
Failure to do so will result in injury or death and damage to equipment.
Use eyeshields and follow instructions carefully when performing assembling, disassembling, or
maintenance on this device. Components of this device are under spring tension and may shoot out
at a high velocity. Failure to do so will result in injury to personnel.
Do not remove hoses with engine running or start engine with hoses removed. High-pressure fluids
may cause hoses to whip violently and spray randomly. Failure to do so may result in injury to
personnel.
Keep hands out from between metal surfaces when removing heavy components. Failure to do so
may result in injury to personnel.
Keep personnel out from under equipment and components of equipment when supported by only a
lifting device. Sudden loss of lifting power or shift in load may result in injury or death.
Do not drain engine, transmission, or radiator fluids, or remove lines containing these fluids, when
hot. Doing so may result in injury to personnel.
Vehicle will become charged with electricity if it contacts or breaks high-voltage wires. Do not leave
vehicle while high-voltage lines are in contact with vehicle. Failure to do so may result in injury to
personnel.
Wear hand protection when handling lifting and winching cables, hot exhaust components, and
parts with sharp edges. Failure to do so may result in injury to personnel.
Do not perform fuel system procedures while smoking or within 50 ft (15.2 m) of sparks or open
flame. Diesel fuel is highly flammable and can explode easily, causing injury or death to personnel
and/or damage to equipment.
Ensure drainvalve on aftercooler is open when filling cooling system. Failure to do so may result in
injury to personnel.
Turbocharger intake fins are extremely sharp and turn at very high rpm. Keep hands and loose
items away from intake openings. Failure to do so may result in injury to personnel.
Do not place hands between frame and radiator when removing screws from trunnion or lifting
radiator. Sudden changes in support may cause the radiator to shift, causing injury to personnel.
Air pressure may create airborne debris. Use eye protection or injury to personnel may result.
Air system components are subject to high pressure. Always relieve pressure before loosening or
removing air system components.
Wear safety goggles when using a hammer.
Ether is extremely flammable. Do not perform ether start system procedures near fire. Injury to
personnel may result.

Warning c/(Warning d blank)

ARMY TM 9-2320-272-24-l
AIR FORCE TO 36A12-1C-1155-2-l
HEADQUARTERS
DEPARTMENTS OF THE ARMY AND THE AIR FORCE
Washington,D.C., 30 JUNE 1998

TECHNICAL MANUAL
NO. 9-2320-272-24-1
TECHNICAL ORDER
NO. 36A12-1C-1155-2-1

TECHNICAL MANUAL
VOLUME 1 OF 4
UNIT, DIRECT SUPPORT, AND
GENERAL SUPPORT MAINTENANCE MANUAL
FOR
TRUCK, 5TON, 6X6, M939, M939A1, M939A2 SERIES TRUCKS (DIESEL)
TRUCK

MODEL

EIC

NSN WITHOUT WINCH

Cargo, Dropside
Cargo, Dropside
Cargo, Dropside
Cargo, Dropside
Cargo, Dropside
Cargo, Dropside
Cargo
Cargo
Cargo
Cargo
Cargo
Cargo
Dump
Dump
Dump
Dump
Dump
Dump
Tractor
Tractor
Tractor
Tractor
Tractor
Tractor
Van, Expansible
Van, Expansible
Van, Expansible
Medium Wrecker
Medium Wrecker
Medium Wrecker

M923
M923Al
M923A2
M925
M925Al
M925A2
M927
M927Al
M927A2
M928
M928Al
M928A2
M929
M929Al
M929A2
M930
M930Al
M930A2
M931
M93lAl
M931A2
M932
M932Al
M932A2
M934
M934Al
M934A2
M936
M936Al
M936A2

BRY
BSS
BS7
BRT
BST
BS8
BRV
BSW
BS9
BRU
BSX
BTM
BTH
BSY
BTN
BTG
BSZ
BTO
BTE
BS2
BTP
BTD
BS5

2320-01-050-2084
2320-01-206-4087
2320-01-230-0307

BTQ

BTB
BS4
BTR
BTF
BS6
BTT

NSN WITH WINCH

2320-01-047-8769
2320-01-206-4088
2320-01-230-0308
2320-01-047-8771
2320-01-206-4089
2320-01-230-0309
2320-01-047-8770
2320-01-206-4090
2320-01-230-0310
2320-01-047-8756
2320-01-206-4079
2320-01-230-0305
2320-01-047-8755
2320-01-206-4080
2320-01-230-0306
2320-01-047-8753
2320-01-206-4077
2320-01-230-0302
2320-01-047-8752
2320-01-205-2684
2320-01-230-0303
2320-01-047-8750
2320-01-205-2682
2320-01-230-0300
2320-01-047-8754
2320-01-206-4078
2320-01-230-0304

REPORTING OF ERRORS AND RECOMMENDING IMPROVEMENTS
You can help improve this manual. If you find any mistakes or if you know of a way to improve the
procedures, please let us know. Mail your letter or DA Form 2028 (Recommended Changes to Publications
and Blank Forms), or DA Form 2028-2 located in back of this manual, directly to: Director, Armament and
Chemical Acquisition and Logistics Activity, ATTN: AMSTA-AC-NML, Rock Island, IL 61299-7630. A reply
will be furnished to you. You may also provide DA Form 2028-2 information via datafax or e-mail:
E-mail:am&a-ac-nml.@ria-emh2.army.mil
Fax: DSN 783-0726 or commercial (309) 782-0726
DISTRIBUTION STATEMENT A - Approved for public release; distribution is unlimited.
i

TM 9-2320-272-24-1
*This publication supersedes TM 9-2320-272-20-1,24 October 1985, and changes 1 through 4; TM 9-2320-272-20-2,25
October 1985, and changes 1 through 3; TM 9-2320-272-34-1, 10 June 1986, and changes 1 through 2; TM 9-2320-272-34-2,
10 June 1986, and changes 1 and 2; and TM 9-2320-358-24&P, 21 October 1992.
This publication is published in four volumes. TM 9-2320-272-24-1 contains chapters 1,2, and 3 (through
section IX). TM 9-2320-272-24-2 contains chapters 3 (sections X through XVI) and 4 (sections I through III).
TM 9-2320-272-24-3 contains chapter 4 (sections IV through XVI). TM 9-2320-272-24-4 contains chapters 5 and
6 and appendices A through H. Volume 1 contains a table of contents for the entire manual. Volumes 1,2, and 3
contain an alphabetical index covering tasks found in their respective volume. Volume 4 contains an
alphabetical index covering all tasks found in the entire manual.

TABLE OF CONTENTS
VOLUME 1 OF 4
Page

HOW TO USE THIS MANUAL
CHAPTER 1
Section I.
Section II.
Section III.
CHAPTER 2
Section I.
Section II.

INTRODUCTION

...................................................
General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Equipment Description and Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Principles of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SERVICE AND TROUBLESHOOTING INSTRUCTIONS

l-l
l-l
l-5
l-25
2-l

Repair Parts; Tools; Special Tools; Test, Measurement,
and Diagnostic Equipment (TMDE); and Support Equipment . . . . . . . . . . . . . . . . . . . . . .
ServiceUponReceipt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2-l
2-l

PREVENTIVE MAINTENANCE CHECKS AND SERVICES (PMCS)

Section IV.

UNIT TROUBLESHOOTING PROCEDURES

Section I.
Section II.
Section III.
Section IV
Section V.
Section VI.
Section VII.
Section VIII.
Section IX
Section X.
Section XI.
Section XII.
Section XIII.
Section XIV
Section XV
Section XVI.

v

..................

Section III.

CHAPTER 3

ii

........................................

UNIT MAINTENANCE

. . . . . . . . 2-2

...........................

..............................................
Engine System Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Air Intake System Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel System Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exhaust System Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cooling System Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electrical System Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Transmission and Transfer Case Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Propeller Shafts, Axles, and Suspension System Maintenance . . . . . . . . . . . . . . . . . . . . .
Compressed Air and Brake System Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wheels, Hubs, Drums, and Steering Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Frame Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Body, Cab, and Accessories Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Winch and Power Takeoff (PTO) Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Special Purpose Bodies Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Special Purpose Kits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Central Tire Inflation System (CTIS) Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2-60
3-l
3-l
3-41
3-55
3-139
3-149
3-220
3-353
3-403
3-476
3-615
3-683
3-730
3-823
3-869
3-968
3-1231

TM 9-2320-272-24-1

TABLE OF CONTENTS (Contd)
Page

CHAPTER 4
Section I.
Section II.
Section III.
Section IV
Section V
Section VI.
Section VII.
Section VIII.
Section M.
Section X.
Section XI.
Section XII.
Section XIII.
Section XIV.
Section XV
Section XVI.
CHAPTER 5
Section I.
Section II.
Section III.
Section IV.
Section V.
Section VI.
Section VII.

DIRECT SUPPORT (DS) MAINTENANCE

..............................
Direct Support (DS) and General Support (GS) Mechanical Troubleshooting . . . . . . . . . .
Power Plant Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine (M939lAl) Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine (M939A2) Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cooling System Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electrical System Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
TransmissionMaintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Transfer Case Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Front and Rear Axle Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Compressed Air and Brake System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power Steering System Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Frame Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Body, Cab, and Hood Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Special Purpose Bodies Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Winch, Hoist, and Power Takeoff (PTO) Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Special Purpose Kits Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
GENERAL SUPPORT (GS) MAINTENANCE INSTRUCTIONS

.............

Engine (M939/Al) Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine (M939A2) Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Transmission Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Transfer Case Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Front and Rear Axle Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Special Purpose Bodies Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Winch, Hoist, and Power Takeoff (PTO) Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4-l
4-1
4-35
4-117
4-271
4-352
4-388
4-465
4-504
4-548
4-584
4-605
4-681
4-691
4-715
4-808
4-1002
5-l
5-l
5-157
5-280
5-398
5432
5-463
5-606

SHIPMENT AND LIMITED STORAGE INSTRUCTIONS

6-l
6-l
6-2
6-2

APPENDIX A

REFERENCES

A-l

APPENDIX B

MAINTENANCE ALLOCATION CHART

B-l
B-l
B-4
B-25
B-26

EXPENDABLE/DURABLE SUPPLIES AND MATERIALS LIST

C-l
C-l
C-3

MANDATORY REPLACEMENT PARTS

D-l

CHAPTER 6
Section I.
Section II.
Section III.

Section I.
Section II.
Section III.
Section IV
APPENDIX C
Section I.
Section II.
APPENDIX D

.................
General Preparation of Vehicle for Shipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
LoadingandMovement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Limited Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
.....................................................

...............................
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Maintenance Allocation Chart . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tool and Test Equipment Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Remarks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
............
.
.
.
.
.
.
.
.
.
.
.
.
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Introduction
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Expendable/Durable Supplies and Materials List
...............................

iii

TM 9-2320-272-24-1

APPENDIX E

COMMON AND SPECIAL TOOL IDENTIFICATION LIST

APPENDIX F

ILLUSTRATED LIST OF MANUFACTURED ITEMS

APPENDIX G
APPENDIX

iv

H

TORQUE LIMITS

................

. . . . . . . . . . . . . . . . F-l

...................................................

SCHEMATIC AND WIRING DIAGRAMS

E-l

................... .............

G-l
H-1

TM 9-2320-272-24-l

HOW TO USE THIS MANUAL
ABOUT YOUR MANUAL
Spend some time looking through this manual. You’ll find that it has a new look, different than most
TMs you’ve been using, including its predecessors, TM 9-2320-272-20-1, TM 9-2320-272-20-2,
TM 9-2320-272-34-1, TM 9-2320-272-34-2, and TM 9-2320-358-24&P.
New features added to improve the convenience of this manual and increase your efficiency are:
a. Accessing Information - These include physical entry features such as the bleed-to-edge
indicators on the cover and edge of the manual. Extensive troubleshooting guides for specific
systems lead directly to step-by-step directions for problem solving and maintenance tasks.
b. Illustrations -A variety of methods are used to make locating and fixing components much easier.
Locator illustrations with keyed text, exploded views, and cut-away diagrams make the information
in this manual easier to understand and follow.
c. Commonality - Only items that are unique to a specific series or vehicle will be given a separate
procedure. When only minor differences occur, notes are added to tell you to alter the normal
procedure in one way or another to accommodate the differences.
d. Keying Text with Illustrations - Instructions/text are located together with illustrations of the
specific task you are performing. In most cases, the task steps and illustrations are located on
facing pages, with text on the left and illustrations on the right. Continue reading for an example of
modular text and illustration layout,

HOW TO USE THIS MANUAL
Here’s an example of how to use your manual:
Task: The unit maintenance mechanic of an M939 series vehicle reports that the engine cranks but fails to
start.
Troubleshooting steps:

1.
2.

Look at the cover of this manual. You’ll see subjects listed from top to bottom on the right-hand side.
Look at the right edge of the manual. On some of the pages you’ll see black bars (edge indicators)
that are aligned with the subject bars on the cover. These are the locations of the subjects in the
manual.

3.
4.

Look for UNIT TROUBLESHOOTING in the subject list on the cover,
Turn to the page with the edge indicator matching the subject bar for UNIT TROUBLESHOOTING.
Page numbers are also listed next to the subject titles.
An edge indicator is placed on the first page of the UNIT TROUBLESHOOTING.
NOTE
If the first page of a subject has an even-numbered page, it will
appear on your left, but the edge indicator will still be on the page to
your right. So, if the information you are looking for does not start on
the page to your right, it will on the page to your left.
Look down the list until you find ENGINE. Beneath that heading you will find the symptoms noted
by the maintenance mechanic: Engine cranks, fails to start.
Turn to the page indicated: page 2-9.
On page 2-9, steps/test relating to resolving the malfunction of “Engine cranks, fails to start,” are:
Step 1. You inspect the fuel pump shutoff valve and find it is defective and must be replaced. You
see para. 4-6 referenced.
Step 2. The rest of the inspection shows no other cause for the problem.
Locate para. 4-5, and you will find the detailed procedure for removing the old fuel pump shutoff
valve and replacing it with a new one.

5.

6.
7.
8.

9.

v

TM 9-2320-272-24-1

HOW TO USE THIS MANUAL (Contd)

10.

11.

12.

vi

NOTE
Before starting the maintenance task, look through the entire
procedure to familiarize yourself with it.
a. The entire procedure (4-5. FUEL PUMP SHUTOFF REPLACEMENT), according to the THIS
TASK COVERS header, includes: a. Removal and b. Installation.
b. The nine basic subheadings listed under INITIAL SETUP outline the task preconditions,
materials, tools, manpower requirements, and general safety instructions. They are:
APPLICABLE MODELS: Any models that require that particular maintenance task.
TEST EQUIPMENT: Test equipment needed to complete a task.
SPECIAL TOOLS : Those tools required to complete the task.
MATERIALS/PARTS: All parts or materials required to complete the task.
PERSONNEL REQUIRED: The number and type of personnel needed to accomplish a task.
NOTE
If you think you need more help to correctly or safely complete the
task (perhaps as a result of an unusual condition, etc.), alert your
supervisor and ask for help.
REFERENCES(TM): Those manuals required to complete the task.
EQUIPMENT CONDITIQN Notes the conditions that must exist before starting the task.
For (4-5. FUEL PUMP SHUTOFF REPLACEMENT), the hood must be raised and secured
(TM 9-2320-272-10), and the left splash shield removed (TM 9-2320-272-10).
SPECIAL ENVIROMENTAL CONDITIONS: Outlines specific environmental conditions
necessary to perform the task. For example: Darken an area when adjusting headlight
beams.
GENERAL SAFETY INSTRUCTIONS: Summarizes all safety warnings for the
maintenance task.
c. A step-by-step maintenance procedure follows the INITIAL SETUP.
d. At the end of the procedure, FOLLOW-ON TASK(S) will list those additional task(s) that must be
performed to complete the procedure. The follow-on tasks for 4-5. FUEL PUMP SHUTOFF
REPLACEMENT are: Start engine (TM 9-2320-272-10), check fuel pump shutoff valve for proper
operation (TM 9-2320-272-101, install left. splash shield (TM 9-2320-272-10), and lower and secure
hood (TM 9-2320-272-10X
Refer to our example procedure, 4-5. FUEL PUMP SHUTOFF REPLACEMENT as we review the
following points:
a. Modular Text: Both pages of text and illustrations are to be used together. This manual was
designed so that the two pages are visible at once, making part identification and procedure
sequence easy to follow.
b. Initial Setup: Outlines task conditions.
c. Illustrations: An exploded view of the components removed from the vehicle shows part
locations, attachments, and spatial relationships.
Refer to TM 9-2320-272-24P, Unit, Direct Support, and General Support Maintenance Repair Parts
and Special Tools List for Truck, 5-Ton, 6x6, M939, M939A1, M939A2 Series Trucks, when
requisitioning parts and special tools for Unit, Direct Support, and General Support maintenance,
Your manual is easier to use once you understand its design. We hope it will encourage you to use it
more often.

TM 9-2320-272-24-1

CHAPTER 1
INTRODUCTION
Section I.
General Information (page 1-1)
Section II. Equipment Description and Data (page l-5)
Section III. Principles of Operation (page 1-25)

Section I. GENERAL INFORMATION
1-1. SCOPE
a. This manual contains information and instructions needed to service and maintain 5-ton, 6x6, M939,
M939A1, and M939A2 (M939/A1/A2) series vehicles by unit, direct support, and general support
maintenance personnel. This manual is intended to be used in conjunction with TM 9-2320-272-10 and
TM 9-2320-272-24P for overall completion of tasks found in this manual.
b. The vehicle model numbers and description of vehicles covered in this manual are:
Table 1-1. Vehicle Cross-Reference Table.
VEHICLE DESCRIPTION
Truck, Cargo, Dropside,
Without Winch (WO/W)

M939 SERIES
M923 (EIC: BRY)

M939Al SERIES
M923Al (EIC: BSS)

M939A2 SERIES
M923A2 (EIC: BS7)

Truck, Cargo, Dropside,
With Winch (W/W)

M925 (EIC: BRT)

M925Al (EIC: BST)

M925A2 (EIC: BS8)

Truck, Cargo, Extra Long
Wheelbase (XLWB),
Without Winch (WO/W)

M927 (EIC: BRV)

M927Al (EIC: BSW)

M927A2 (EIC: BS9)

Truck, Cargo, Extra Long
Wheelbase (XLWB),
With Winch (W/W)

M928 (EIC: BRU)

M928Al (EIC: BSX)

M928A2 (EIC: BTM)

Truck, Dump,
Without Winch (WO/W)

M929 (EIC: BTH)

M929Al (EIC: BSY)

M929A2 (EIC: BTN)

Truck, Dump,
With Winch (W/W)

M930 (EIC: BTG)

M930Al (EIC: BSZ)

M930A2 (EIC: BTO

Truck, Tractor,
Without Winch (WO/W)

M931 (EIC: BTE)

M931Al (EIC: BS2)

M931A2 (EIC: BTP)

Truck, Tractor,
With Winch (W/W)

M932 (EIC: BRD)

M932Al (EIC: BS5)

M932A2 (EIC: BTQ)

Truck, Van, Expansible

M934 (EIC: BTB)

M934Al (EIC: BS4)

M934A2 (EIC: BTR)

Truck, Medium Wrecker

M936 (EIC: BTF)

M936Al (EIC: BS6)

M936A2 (EIC: BTT)

1-2. MAINTENANCE FORMS, RECORDS, AND REPORTS
Department of the Army forms and procedures used for equipment maintenance will be those prescribed
by DA Pam 738-750, The Army Maintenance Management System (TAMMS).

l-l

TM 9-2320-272-24-1

1-3. DESTRUCTION OF ARMY MATERIEL TO PREVENT ENEMY USE
Procedures for destruction of Army materiel to prevent enemy use can be found in TM 750-244-6.

1-4. PREPARATION FOR STORAGE OR SHIPMENT
Storage and shipment instructions are found in chapter 6. Additional information can be found in
TM 740-90-1, Marking, Packing, and Shipment of Supplies and Equipment: General Packaging Instructions
for Field Use.

l-5. OFFICIAL NOMENCLATURE
The nomenclature, names, and designations used in this manual are in accordance with
MIL-HDBK-63038-2.

l-6. REPORTING EQUIPMENT IMPROVEMENT RECOMMENDATIONS (EIRs);
REPORTING OF ERRORS AND RECOMMENDING IMPROVEMENTS
You can help improve this manual. If you find any mistakes or if you know of a way to improve the
procedures, please let us know. Mail your letter, DA Form 2028 (Recommended Changes to Publications and
Blank Forms), or DA Form 2028-2 located in back of this manual direct to: Commander, U.S. Army Tankautomotive and Armaments Command, ATTN: AC-NML, Rock Island, IL 61299-7630. A reply will be
furnished to you.

1-7. WARRANTY INFORMATION
The 5-ton, 6x6, M939/Al series vehicle Cummins engine (model NHC 250) and Allison transmission
(model MT564CR) are warranted in accordance with TB 9-2300-295-15/21. The warranty starts on the date
found in block 23, DA Form 2408-9, in logbook. Report all defects in material or workmanship to your
supervisor, who will take appropriate action.

1-8. ARMY PETROLEUM, OILS, AND LUBRICANTS (POL)
Proper disposal of hazardous waste material is vital to protecting the environment and providing a safe
work environment. Materials such as batteries, oils, and antifreeze must be disposed of in a safe and
efficient manner.
The following references are provided as a means to ensure proper disposal methods are followed:
Technical Guide No. 126 (from the U.S. Army Environmental Hygiene Agency)
National Environmental Policy Act of 1969 (NEPA)
Clean Air Act (CAA)
Resource Conservation and Recovery Act (RCRA)
Comprehensive Environmental Response, Compensation, and Liability Act
Emergency Planning and Community Right to Know Act (EPCRA)
Toxic Substances Control Act (TSCA)
Occupational Health and Safety Act (OHSA)
The disposal of Army Petroleum, Oils, and Lubricants (POL) products are affected by some of these
regulations. State regulations may also be applicable to POL. If you are unsure of which legislation affects
you, contact state or local agencies for regulations regarding proper disposal of Army POL.

l-2

TM 9-2320-272-24-1

1-9. USE OF METRIC SYSTEM
The equipment/system described herein contains metric common and special tools; therefore, metric units
in addition to U.S. standard units will be used throughout this publication.

1-10. LIST OF ABBREVIATIONS
AOAP - Army Oil Analysis Program
bx- box
CAGEC - Commercial and Government Entity Code
cm - centimeter
CTIS - Central Tire Inflation System
cu-ft - cubic feet
cu-yd - cubic yard
cuM - cubic Meter
ea - each
ft - feet
GM - Grease, Automotive and Artillery
GTW - Gross Towed Weight
gal. - gallon
in. inch
kg- kilograms
km/h - kilometers per hour
km/L - kilometers per liter
kPa - kiloPascal
L - liter
lb-ft - pound-feet
lb - pound
max - maximum
min - minimum

mm - millimeter
mpg - miles per gallon
mph - miles per hour
N•m - Newton meter
NATO - North Atlantic Treaty Organization
OZ - ounce
para. - paragraph
PMCS - Preventive Maintenance Checks and
Services
POL - Petroleum, Oils, and Lubricants
psi - pounds per square inch
pt - pint
PTO - Power Takeoff
qt - quart
rpm - revolutions per minute
SEA - Standard, Engineering, and Automotive
TMDE - Test, Measurement, and Diagnostic
Equipment
U/M - Unit of Measure
W/W - With Winch
WO/W - Without Winch
XLWB - Extra Long Wheelbase

1-11. GLOSSARY
APPROACH ANGLE - Angle between front tire and front bumper
DEPARTURE ANGLE - Angle between rear tire and rear bumper
FORDING - Crossing through water
GRADE - Steepness of terrain
HYDRAULIC - Operated by oil pressure
OPERATOR - Driver of vehicle
PAULIN - Canvas cover or tarpaulin (tarp)
SLAVING -Jump starting

1-3/( 1-4 blank)

TM 9-2320-272-24-1

Section II. EQUIPMENT DESCRIPTION AND DATA
l-l2. EQUIPMENT DESCRIPTION AND DATA INDEX
PARA.
NO.
1-13.
1-14.
1-15.
1-16.
1-17.

TITLE
Equipment Characteristics, Capabilities, and Features
Location and Description of Major Components
Differences Between Models
Equipment Data
Description of Data Plates

PAGE
NO.
1-5
1-16
l-20
1-22
l-24

1-13. EQUIPMENT CHARACTERISTICS, CAPABILITIES, AND FEATURES
a. The M939, M939A1, and M939A2 (M939/A1/A2) series of vehicles are varied in design and
capabilities. The M939 was a redesign and retrofit of the MS09 series of vehicles, providing enhanced
capabilities.
(1) The leading features of the M939 are:
(a) Automatic transmission (Allison MT654)
(b) Hydraulic-assisted power steering system
(c) Complete airbrake system
(d) Improved cooling system
(e) Three-crewmember cab
(f) Tilt hood
(2) Changes were incorporated into later production engines (after engine serial number 11246663)
which provided for control of exhaust gas recirculation back to the air intake manifold and the use of topstop injectors to make up a clean air configuration.
(3) The M939Al improved on the M939 by adding 14:00xR20 super-sized tires, increasing the
minimum road clearance and approach and departure angle. This necessitated a modification to the spare
tire rack and lifting device used on all series vehicles.
(4) The M939A2 incorporated a new engine (Cummins 6CTA8.3) and the Central Tire Inflation System
(CTIS).
b. The M939/A1/A2 series vehicles can be distinguished from the M809 series by the following features:
(1) On the left side, the exhaust was moved behind the cab and tilted out so exhaust gases clear the
side of the vehicle. Hood latches were installed on the sides of the hood near the mirrors. The battery box
was incorporated into the companion seat to improve battery life in cold climates. A steering-assist cylinder
was installed between the right front frame rail and the right axle hub.
(2) From the front, the hood and fenders are an assembly which tilt forward for access to the engine
compartment. A tilt handle and locking device was installed to tilt and hold the hood in a secured open
position.
(3) The air filter was moved under the driver’s door and the intake stack was brought up behind the
cab, even with the cab top.

1-5

TM 9-2320-272-24-1

1-13. EQUIPMENT CHARACTERISTICS, CAPABILITIES, AND FEATURES (Contd)
c. Cargo Trucks With Dropsides: M923/A1/A2 WO/W and M925/A1/A2 W/W.
PURPOSE: These models are used to transport cargo and troops. The vehicles have a payload rating of
10,000 lbs (4,540 kg) and provide 550 cu-ft (15.4 CuM) of cargo space. Removable dropsides and tailgate
permit hauling of extra wide loads and easy access for unloading cargo. Troop seats, bows, and canvas are
also available. The M925/A1/A2 models have front winches and can be used for recovery operation. The bed
of the M923A1/A2 and M925Al/A2 has been shifted back to facilitate a new lifting davit and spare tire
mount. When the tire is mounted in its storage location on the M923A1/A2 and M925Al/A2, the top of the
tire extends above the minimal reducible height and may need to be removed to obtain the necessary
measurement.

1-6

TM 9-2320-272-24-1

1-13. EQUIPMENT CHARACTERISTICS, CAPABILITIES, AND FEATURES

(Contd)

1-7

TM 9-2320-272-24-1

1-l3. EQUIPMENT CHARACTERISTICS, CAPABILITIES, AND FEATURES (Contd)
d. Cargo tick With Extra Long Wheelbase (XLWB): M927/A1/A2 WO/W and M928/A1/1A2 W/W.
PURPOSE: These models are used to transport troops and longer cargo loads. They have the same
characteristics as the M923/Al/A2 and M925/A1/A2, but have additional 76 in. (193 cm) of bed space that
allows an extra 194 cu-ft (5.4 cuM) of cargo space. Troop seats, bow, and tarpaulin are available. This
vehicle has permanent steel-welded sides. The M928/A1/A2 model vehicles have winches and can be used
for recovery operations. The bed of the M923A1/A2 and M925A1/A2 has been shifted back to facilitate a
new lifting davit and spare tire mount. When the tire is mounted in its storage location on the M923A1/A2
and M925A1/A2, the top of the tire extends above the minimal reducible height and may need to be
removed to obtain the necessary measurement.

1-8

TM 9-2320-272-24-1

1-13. EQUIPMENT CHARACTERISTICS, CAPABILITIES, AND FEATURES (Contd)

1-9

TM 9-2320-272-24-1

1-13. EQUIPMENT CHARACTERISTICS, CAPABILITIES, AND FEATURES (Contd)
e. Dump Truck: M929/A1/A2 WO/W and M930/A1/A2 W/W.
PURPOSE: These models are for hauling and dumping cargo. They have a capacity of 5 cu-yd
(3.84 cuM). The bodies have provisions for side racks and troop seats, and bow and tarpaulin for troop
transport. The M930/A1/A2 have front winches and can be used for recovery operations. Additional support
brackets have been designed on the M929A1/A2 and M930A1/A2 model vehicles and are available to
support the bed in a slightly raised position for removal of the 14:00xR20 spare tire.

1-10

TM 9-2320-272-24-1

1-13. EQUIPMENT CHARACTERISTICS, CAPABILITIES, AND FEATURES (Contd)

1-11

TM 9-2320-272-24-1

1-13. EQUIPMENT CHARACTERISTICS, CAPABILITIES, AND FEATURES (Contd)
f. Tractor Trucks: M931/A1/A2 WO/W and M932/A1/1A2 W/W.
PURPOSE: These vehicles are equipped with a fifth wheel and are used for hauling semitrailers. The
fifth wheel is capable of pivoting 21 degrees up, 15 degrees down, or 7 degrees sideways. The M932/A1/A2
model vehicles have front winches and can be used for recovery operations.

1-12

TM 9-2320-272-24-1

l-13. EQUIPMENT CHARACTERISTICS, CAPABILITIES, AND FEATURES (Contd)

1-13

TM 9-2320-272-24-1

1-13. EQUIPMENT CHARACTERISTICS, CAPABILITIES, AND FEATURES (Contd)
g. Expansible Vans: M934/A1/A2.
PURPOSE: These vehicles are used for electronics, maintenance, supply, power, and base station
operation. The van body can be expanded when set up in a stationary mode of operation; when mission
requires more mobile-type operation, the body is left in the retracted position.

1-14

TM 9-2320-272-24-l

1-13. EQUIPMENT CHARACTERISTICS, CAPABILITIES, AND FEATURES (Contd)
h. Medium Wrecker: M936/Al/A2.
PURPOSE: These vehicles are used for wrecker and salvage operations. They have a revolving
hydraulic crane with a self-supported extendable boom. Boom-to-ground supports and outriggers are
provided. Crane lifting capacity is 20,000 lb (9,080 kg). The vehicle has a front winch with a 20,000 lb
(9,080 kg) capacity. M936/A1 models are equipped with front anchor brackets for heavy straight and side
pulls using the front winch. All models are equipped with a 45,000 lb (20,250 kg) capacity rear winch, rear
anchor brackets for heavy straight and side pulls, and spring brake override of the Power Takeoff (PTO) air
switch for self-recovery operations.

1-15

TM 9-2320-272-24-1

1-14. LOCATION AND DESCRIPTION OF MAJOR COMPONENTS
a. Exterior Components. The components described herein are common to most vehicles covered in this
manual. Specific differences can be found in TM 9-2320-272-10 or in table 1-2, Differences Between Models
(para. 1-15), of this manual.

LIFTING SHACKLE(S)
ENGINE
TRANSMISSION
PRIMARY AND SECONDARY AIR
RESERVOIRS
TRANSFER CASE
WET TANK RESERVOIR
REAR PROPELLER SHAFT(S)
UNIVERSAL JOINT(S)
SERVICE BRAKE CHAMBER
REAR BOGIE
SPRING BRAKE CHAMBER
TOWING PINTLE
REAR DIFFERENTIAL(S)
FUEL TANK(S)
SPARE TIRE CARRIER
AIR CLEANER

1-16

TM 9-2320-272-24-1

1-14. LOCATION AND DESCRIPTION OF MAJOR COMPONENTS (Contd)
Key Item and Function
1 LIFTING SHACKLE(S) - Permit vehicle to be towed by another vehicle or used for tiedown
attachment when transporting vehicle.
2 ENGINE - There are two different Cummins model engines used, the NHC 250 (M939/A1 series
vehicles) and 6CTA8.3 diesel (M939A2 series vehicles), which provide mechanical power to the
vehicle and engine-driven subsystems.
3 TRANSMISSION - The Allison MT546CR automatic, used on all M939/A1/A2 series vehicles,
adapts the engine’s output for a varying range of operating speeds.
4 PRIMARY AND SECONDARY AIR RESERVOIRS - Provides storage of compressed air and
isolation between air subsystems.
5 TRANSFER CASE - Directs the engine and transmission output to the specified axles and/or
auxiliary equipment.
6 WET TANK RESERVOIR - Provides reserve storage of compressed air created by the air
compressor or external source when demand is low and releases it when required. This lessens the
cycling of the engine-driven air compressor.
7 REAR PROPELLER SHAFT(S) - Transmits power between transfer case and forward-rear axle
assemblies, and between forward-rear and rear-rear axles assemblies.
8 UNIVERSAL JOINT(S) - Provides a flexible point between a component and the propeller shafts.
This allows components that cannot maintain precision alignment to transfer power from one point
to another, without undue stress or breakage.
9 SERVICE BRAKE CHAMBER - Mechanical brake actuator that is activated by applying air
pressure to an expandable cylinder, causing it to apply braking force to the brakedrum.
10 REAR BOGIE - The suspension system comprised of both rear axles, upper and lower torque rods,
springs, and seats that support the rear vehicle weight.
11 SPRING BRAKE CHAMBER - Mechanical brake actuator that is spring-loaded to apply brakes
when air is low or not present. During normal vehicle operation, air piston counteracts the spring
tension and allows the brakes to release. Spring brakes can be bypassed by pushing in the spring
brake OVERRIDE switch on the instrument panel, or released using procedures found in TM 9-2320272-10.
12 TOWING PINTLE - Provides a secure quick-connect/disconnect for towing vehicles or equipment.
13 REAR DIFFERENTIAL(S) - Bi-directionally transfer power from the propeller shaft to the axles,
and provide a straight-through connection to power additional propeller shafts.
14 FUEL TANK(S) - Provides storage of fuel.
15 SPARE TIRE CARRIER - Stores spare tire.
D a v i t - Used to load and unload spare tire on M923/A1/A2, M925/A1/A2, M927/A1/A2,
M928/A1/A2, M931/A1/A2, and M9321/A1/A2 model vehicles.
Winch and Swinging Davit - Used to load and unload spare tire on M934A1/A2 model vehicles.
Optional kit is available for M934 model vehicle.
Hoist and Lifting Eye - Used to load and unload spare tire on M929/A1/A2, M930/A1/A2, and
M934 model vehicles. Optional kit is available to support dump bed in semi-raised position during
tire removal.
Vehicle Crane - Used to load and unload spare tire on M936/A1/A2 model vehicles. NOTE: On
M936/A1/A2 model vehicles, remove spare tire prior to changing tire, and install tire in spare tire
carrier after tire change is complete. Operation of crane and/or vehicle engine while vehicle is on
jacks may cause the vehicle to slip off jack.
16 AIR CLEANER - Filters air before it enters the intake manifold or turbocharger and collects dust in
removable section of filter canister.

1-17

TM 9-2320-272-24-1

1-14. LOCATION AND DESCRIPTION OF MAJOR COMPONENTS (Contd)
b. Interior Cab Components. The components described herein are common to one or more vehicles
covered in this manual. Components not found here can be found in TM 9-2320-272-10 or in table 1-2,
Differences Between Models (para. 1-15), of this manual.

Key Item and Function
1 FRONT-WHEEL DRIVE LOCK-IN SWITCH - A pneumatic switch that permits front-wheel drive
to be engaged when the transfer case is in HIGH position. Operation of switch is not required when
transfer case is in LOW position; system will automatically switch into six-wheel drive.
1-18

TM 9-2320-272-24-1

1-14 LOCATION AND DESCRIPTION OF MAJOR COMPONENTS (Contd)
Key
2
3
4
5

6
7
8
9

10

11

12

13
14
15

16
17
18
19

Item and Function
POWER TAKEOFF (PTO) SPRING BRAKE OVERRIDE SWITCH - Used during rear winch
self-recovery operations of M936/A1/A2 model vehicles only. This air control switch must be held in to
override spring brake air dump switch on transfer case PTO lever.
INSTRUMENT PANEL - Houses controls and indicators.
TRANSMISSION SELECTOR LEVER - Manual control to select driving gear.
SPRING BRAKE OVERRIDE SWITCH - Pressed in to release spring brakes independent of the
mechanical parking brake for tests and adjustments. Can be used to release spring brakes in the
event a leak or stoppage occurs in lines between primary and spring brake reservoirs, or primary
system air shutoff valve is closed.
TRANSMISSION POWER TAKEOFF (PTO) LEVER - Used on M925/A1/A2, M928/A1/A2,
M929/A1/A2, M930/A1/A2, M932/A1/A2, and M936/A1/A2 model vehicles only. Provides hydraulic
power for front winch and/or dump body operation.
WINCH CONTROL LEVER - Provides control of winch unwinding and winding operations from
inside the cab.
TRANSFER CASE SHIFT LEVER SWITCH - Used in conjunction with transmission selector
lever in NEUTRAL position to allow transfer case to be shifted between HIGH and LOW gears.
PASSENGER SEAT - Combination two-person crew seat, battery box, and storage box. Seats are
equipped with two sets of seatbelts, the battery box houses four batteries, and the storage
compartment stores technical manuals. NOTE: Ensure companion seatbelts are not caught inside
battery box.
TRANSFER CASE SHIFT LEVER - Pushed down to shift transfer case into HIGH gear, center
position for NEUTRAL, and up position for LOW gear. When transfer case is placed in LOW, it will
automatically engage six-wheel drive. In HIGH, the instrument panel-mounted front-wheel drive
lock-in switch must be used to achieve six-wheel drive operation.
SPRING BRAKE CONTROL SWITCH - Senses the position of the parking brake control lever and
signals the spring brakes to engage when the lever is up and disengage when it is down. Spring
brakes can be tested independently from parking brake by raising this switch without pulling up the
parking brake control lever (TM 9-2320-272-10).
(a) DUMP BODY CONTROL LEVER - Used on M929/A1/A2 and M930/A1/A2 to control raising
(pulled back) and lowering (pushed forward) of dump body.
(b) TRANSFER CASE POWER TAKEOFF (PTO) - Used on M936/A1/A2 to control the hydraulic
pump that delivers hydraulic pressure to the rear winch and crane. A spring brake air dump switch
is installed on the lever when used on these vehicles, which engages the spring brakes. To override
this feature during self-recovery operation with the rear winch, the driver must depress and hold the
PTO spring brake override air switch on the instrument panel.
DUMP BODY CONTROL LEVER SAFETY LATCH - Secures dump body control lever or transfer
case PTO in NEUTRAL when not in use.
FUEL TANK SELECTOR LEVER - Used on dual tank model vehicles only. NOTE: Tanks must be
switched periodically to lessen the buildup of contaminants and fungus.
PARKING BRAKE CONTROL LEVER - Pulled up to set mechanical brake on output of transfer
case and to engage the spring brakes, and down to disengage brakes. Knob on top of handle is turned
clockwise to increase braking action on the output of transfer case, and counterclockwise to decrease
braking action. Spring brakes engagement is controlled by the spring brake control switch located on
the back of the lever.
ACCELERATOR PEDAL - Foot control to vary the speed of the engine.
BRAKE PEDAL -Applies the service brakes.
DIMMER SWITCH - Depressed to change between HIGH and LOW beam setting on headlights.
FUEL GAUGE TANK SELECTOR SWITCH - Used to switch fuel gauge to read either left or right
fuel tank. Installed only on dual tank model vehicles.
1-19

TM 9-2320-272-24-1

1-15. DIFFERENCES BETWEEN MODELS
Table 1-2. Differences Between Models.
EQUIPMENT/FUNCTION

VEHICLE

BODY TYPE
M923, M923A1, M923A2, M925,
M925A1, M925A2
M927, M927A1, M927A2, M928,
M928A1, M928A2
M936, M936A1, M936A2
M929, M929A1, M929A2, M930,
M930A1, M930A2
M931, M931A1, M931A2, M932,
M932A1, M932A2
M934, M934A1, M934A2

Cargo Dropside
Cargo Fixed Side (XLWB)
Crane
Dump
Tractor
Van
CENTRAL TIRE INFLATlON SYSTEM

M923A2, M925A.2, M927A2,
M928A2, M929A2, M930A2,
M931A2, M932A2, M934A2,
M936A2
FIELD CHOCKS AND ANCHORS
Front
Rear

M936, M936Al
M936, M936A1, M936A2
FLOODLIGHTS
M936, M936A1, M936A2

FUEL TANKS
Dual Tanks 116 gal. (439.1 L)
Dual Tanks 139 gal. (526.1 L)
Single Tank 81 gal. (306.6 L)

Cargo/Personnel

HEAT/AIR CONDlTlONED BODY
OPERATIONS

Communications/Electronic Repair
Dump

Fifth Wheel
Wrecker

1-20

OPERATIONS

M929, M929A1, M929A2, M930,
M930A1, M930A2, M931, M931Al
M931A2, M932, M932A1, M932A2
M936, M936A1, M936A2
M923, M923A1, M923A2, M925,
M925A1, M925A2, M927, M927A1,
M927A2, M928, M928A1, M928A2,
M934, M934A1, M934A2
M923, M923A1, M923A2, M925,
M925A1, M925A2, M927, M927A1,
M927A2, M928, M928A1, M928A2,
M929, M929A1, M929A2, M930,
M930A1, M930A2, M934, M934A1,
M934A2
M934, M934A1, M934A2
M929, M929A1, M929A2, M930,
M930A1, M930A2
M931, M931A1, M931A2, M932,
M932A1, M932A2
M936, M936A1, M936A2

TM 9-2320-272-24-1

1-15. DIFFERENCES BETWEEN MODELS (Contd)
Table 1-2. Differences Between Models (Contd).
EQUIPMENT/FUNCTION

VEHICLE

TIRES
M923, M925, M927, M928, M929,
M930, M931, M932, M934, M936
M923A1, M923A2, M925A1,
M925A2, M927A1, M927A2,
M928A1, M928A2, M929A1,
M929A2, M930A1, M930A2,
M931A1, M93IA2, M932A1,
M932A2, M934A1, M934A2,
M936A1, M936A2

ll:00xR20
14:00xR20

WHEELBASES
M929, M929A1, M929A2, M930,
M930A1, M930A2, M931, M93IA1,
M931A2, M932, M932A1, M932A2
M923, M923A1, M923A2, M925,
M925A1, M925A2, M936, M936A1,
M936A2
M927, M927A1, M927A2, M928,
M928A1, M928A2, M934, M934A1,
M934A2

167 in. (424.2 cm)
179 in. (454.7 cm)
215 in. (546.1 cm)

WINCH
Front

Rear

M925, M925A1, M925A2, M928,
M928A1, M928A2, M930, M930A1,
M930A2, M932, M932A1, M932A2,
M936, M936A1, M936A2
M936, M936A1, M936A2

1-21

TM 9-2320-272-24-l

l-16. EQUIPMENT DATA
Vehicle performance data for the M939/A1/A2 series vehicles are listed in table 1-3. Additional
information and equipment service data are in TM 9-2320-272-10.
Table 1-3. Vehicle Performance Data.
STANDARD
1. PAYLOAD
Carried Weight:
M923, M923A1, M923A2, M925, M925A1, M925A2, M927,
M927A1, M927A2, M928, M928A1, M928A2, M929, M929A1,
M929A2, M930, M930A1, M930A2. . . . . . . . . . . . . . . . . . . . . . . . . . 10,000 lb
M934, M934A1, M934A2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5,000 lb
M936, M936A1, M936A2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7,000 lb
Towed Load on Pintle:
All (except M936, M936A1, M936A2). . . . . . . . . . . . . . . . . . . . . . . . . . 15,000 lb
M936, M936A1, M936A2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20,000 lb
On Fifth Wheel:
M929, M929A1, M929A2, M930, M930A1, M930A2 . . . . . . . . . . . . . . 15,000 lb
Semitrailer GTW:
M929, M929A1, M929A2, M930, M930A1, M930A2 . . . . . . . . . . . . . . 37,500 lb
2. CAPACITIES
Cooling System:
All Models
.... ......................................... ..... 47qt
Differentials (Each):
AllModels. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12qt

METRIC

4,540 kg
2,270 kg
3,178 kg
6,810 kg
9,080 kg
6,810 kg
17,025 kg

44.5 L
11.3 L

Engine Crankcase Only:

M939/AlSeries..............................................
23qt
M939A2Series.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 qt

21.8 L
17.0 L

Engine Crankcase and Filter:

M939/AlSeries. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27q t
M939A2Series.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2Oqt
Fuel Tank:
M923, M923A1, M923A2, M925, M925A1, M925A2, M927, M927A1,
M927A2, M928, M928A1, M928A2, M934, M934A1, M934A2
(Single Tank) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .81 gal.
M936, M936A1, M936A2 Dual Tanks. . . . . . . . . . . . . . . . . . . . . . . . . . . 116 gal.
M929, M929A1, M929A2, M930, M930A1, M930A2, M931, M931A1,
M931A2, M932, M932A1, M932A2
(DualTanks) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 3 9 g a l .
Hydraulic Tank:
M925, M925A1, M925A2, M928, M928A1, M928A2, M932, M932A1,
M932A2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 g a l .
M929,M929Al,M929A2.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 g a 1
M930, M930A1, M930A2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6.25 gal.
M936,M936Al,M936A2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100gal
Steering System:
M939/Al Series (Ross) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 q t
M939A2 Series (Sheppard). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 q t

1-22

25.5 L
18.9 L

306.6 L
439.1L
526.1L

30.3L
18.9 L
23.7 L
378.5L
4.7L
2.83L

TM 9-2320-272-24-l

l-16. EQUIPMENT DATA (Contd)
Table 1-3. Vehicle Performance Data (Contd).
STANDARD
Transmission:
AllModels(w/oPTO). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17qt
All Models (w/PTO). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 qt
All Models (w/o PTO and converter dry). . . . . . . . . . . . . . . . . . . . . . . . . . . 23 qt
All Models (w/PTO and converter dry). . . . . . . . . . . . . . . . . . . . . . . . . . . 2 5 q t
Transfer Case:
All Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.25 gal.
Winch Gear Case (Front):
AllModels(W/W) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.6pt
Winch Gear Case (Rear):
M936, M936A1, M936A2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 pt
3. ENGINE
M939/Al Series Vehicles:
Brake Horsepower. . . . . . . . . . . . . . . . . . . . . . . . . 250 horsepower @2,100 rpm
Cylinders. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 (in-line)
Fuel Consumption . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-4 mpg
Idle Speed (engine rpm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 600-650 rpm
Model. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cummins NHC 250
Mount(Front). . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . .. . . .Trunnion
Mount (Rear). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Rubber biscuit
Oil Pressure at Idle. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 psi
Operating Speed (engine rpm) . . . . . . . . . . . . . . . . . . . . . . . . . 1,500-2,100 rpm
Type . . . . . . . . . . . . . . . . . . . . . . . . . . Diesel, normally-aspirated, liquid-cooled
M939A2 Series Vehicles:
Brake Horsepower. . . . . . . . . . . . . . . . . . . . . . . . . 240 horsepower @ 2,100 rpm
Cylinders. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6 (in-line)
Fuel Consumption . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5.5-6-0 mpg
IdleSpeed. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 6 5 - 6 3 5 r p m
Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cummins 6CTA8.3
Mount(Front). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Trunnion
Mount (Rear). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Rubber biscuit
Oil Pressure at Idle. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 psi
Operating Speed (engine rpm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2,100 rpm
Type . . . . . . . . . . . . . . . . . . . . . Diesel, liquid-cooled, turbocharged, after-cooled
4. COOLING SYSTEM
M939/A1 Series Vehicles:
Coolant Operating Temperature. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175-195°F
Fan, 6-blade. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26 in.
Thermostat:
Starts to Open . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..175° F
Fully Open. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .... . . . . . . . . 185°F
M939A2 Series Vehicles:
Coolant Operating Temperature. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190-200°F
Fan, 7-blade . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26.5 in.
Thermostat:
Starts to Open. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
181°F
Fully Open. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203°F

METRIC

16.1 L
18.0 L
22.1 L
23.7 L
23.7 L
1.2 L
3.3 L

1.3-1.7 km/L

103 kPa

2.3-2.6 km/L

69 kPa

79-91°C
660 mm
79°C
85°C
88-93°C
673 mm
83°C
95°C
1-23

TM 9-2320-272-24-1

l-16. EQUIPMENT DATA (Contd)
Table 1-3. Vehicle Performance Data (Contd).

Radiator Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Crossflow
Surge Tank Cap Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 psi
5. ELECTRICAL SYSTEM
Alternator:
Ampere Output (maximum) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .60 amp
Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Voltage Output. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28 volts
Voltage Regulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Mounted internal
Batteries:
Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6TN
Number Required . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Plates Per Cell . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..2 3
Specific Gravity Full Charge. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0 70°F
Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 volts
Protective Control Box. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . WSU-4001-UT
Starter:
M o d e l. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
MES6401-CUT
Voltage.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 4 v o l t s
6. TRANSMISSION (MT654CR)
Drive Sequence. . . . . . . . . . . . . . . . . . . . . . . . . . . . Reverse, Neutral, 1,2,3,4,5
Drive Range and Shift Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Manual
Oil Pressure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 6 p s i
Oil Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . O E / H D O - 1 0
Oil Capacity:
Drain and Refill. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4.25 gal.
w/o PTO (dry) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5.75 gal.
w/PTO(dry)..............................................
6.25gal.
Oil Temperature:
Maximum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..300°F
Normal Operating Temperature. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120-220°F
Power Takeoff:
Type.............................................
Converter-driven
Mounting Flange . . . . . . . . . . . . . . . . . . . . . . . . . . . . One-opening, SAE, 6-bolt
7. TRANSFER CASE
M o d e l . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . T-1138
Type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Two-speed synchronized

97 kPa

@ 21°C

179.3 kPa

16.1 L
21.8 L
23.7 L
149°C
49-104°C

1-17. DESCRIPTION OF DATA PLATES
The location and contents of caution, data, and warning plates are provided in TM 9-2320-272-10, and a
complete list and location of all caution, data, warning, and identification plates is in TM 9-2320-272-24P If
any of these plates are worn, broken, painted over, missing, or unreadable, they must be replaced.

l-24

TM 9-2320-272-24-l

Section III. PRINCIPLES OF OPERATION
1-18. GENERAL
This section explains how components of the B-ton M939/Al/A2 series vehicles work together. A functional
description of these components and their related parts will be covered in the following paragraphs. To find
the operation of a specific system or component, see the principles of operation reference index below.

1-19. PRINCIPLES OF OPERATION REFERENCE INDEX
PARA.
NO.
l-20.
1-21.
l-22.
l-23.
l-24.
l-25.

TITLE
Control System Operation
Power System Operation
Electrical Systems Operation
Compressed Air and Brake System Operation
Hydraulic System Operation
Central Tire Inflation System (CTIS) Operation

PAGE
NO.
l-25
l-34
1-45
1-55
1-71
l-78

l-20. CONTROL SYSTEM OPERATION
The control system includes those controls and their related parts essential to the operation of the vehicle.
These controls are common to all vehicles with the exception of the transmission and transfer case Power
Takeoff (PTO) controls. All originate from the cab. Each of these controls and related parts will be described
as part of the following systems:
a. Starting and Ether Starting System Operation (page l-26).
b. Accelerator Controls System Operation (page l-28).
c. Parking Brake System Operation (page l-29).
d. Steering System Operation (page l-30).
e. Transmission Control System Operation (page l-31).
f. Transfer Case Control System Operation (page 1-32).

1-25

TM 9-2320-272-24-l

l-20. CONTROL SYSTEM OPERATION (Contd)
a. Starting and Ether Starting System Operation.
The starting system is identical on all models covered in this manual. It will start the engine in all types
of weather and has built-in protection that prevents starting components from reengaging once the engine
has been started. Major components of the starting and ether starting system are:

Key Item and Function
1 HAND THROTTLE CONTROL - Used to set engine speed without applying pressure to the
accelerator (rotated to lock).
2 BATTERY SWITCH -Activates all electrical circuits except arctic heaters.
3 IGNITION SWITCH - Has OFF, RUN, and START positions. Switch automatically returns from
START to RUN when hand pressure is released.
4 TACHOMETER - Indicates speed of engine.
5 VOLTMETER - Indicates charging condition of the battery.
6 EMERGENCY ENGINE STOP - Control used to shut down engine during emergencies (M934/A1
series vehicles must be reset by unit maintenance).
7 ETHER START SWITCH - Injects ether into engine for cold-weather starting.
1-26

TM 9-2320-272-24-l

l-20. CONTROL SYSTEM OPERATION (Contd)

Key
8
9
10
11

Item and Function
PROTECTIVE CONTROL BOX - Prevents reengagement of starter motor once engine is running.
BATTERIES - Provide 24-volt electrical current for energizing electrical circuits.
STARTER SOLENOID - Relays 24-volt battery power to energize starter motor.
STARTER MOTOR - When energized, converts electrical energy to mechanical power as it engages
flywheel to crank engine.
12 ETHER START CYLINDER - Stores ether used for cold-weather starting.
l-27

TM 9-2320-272-24-1

l-20. CONTROL SYSTEM OPERATION (Contd)
b. Accelerator Controls System Operation.

The accelerator controls system permits the operator to control vehicle speed and engine power. It is
identical on all models covered in this manual. Major components of the accelerator control system are:

Key Item and Function
1 HAND THROTTLE CONTROL - Used to set engine speed without maintaining pressure to the
accelerator (rotated to lock).
2 EMERGENCY ENGINE STOP CONTROL - Is pulled out to cut off fuel to engine. Used only in an
emergency.
3 ACCELERATOR PEDAL - Controls engine speed.
4 MODULATOR - With transmission selector lever in drive, modulator controls transmission
upshifting and downshifting as engine rpm changes.
5 CABLE - Connects modulator to fuel pump.
6 ACCELERATOR LINKAGE - Links accelerator pedal and throttle control to fuel pump.
1-28

TM 9-2320-272-24-l

l-20. CONTROL SYSTEM OPERATION (Contd)
c. Parking Brake System Operation.
A mechanical and air-actuated brake system performs the following for all vehicles covered in this
manual:
(1) Keeps vehicle from rolling once it has stopped.
(2) Slows down or stops vehicle movement.
(3) Provides emergency stopping if there is a complete air system failure.
The mechanical brake system is covered below. The compressed air function of the brake system will be
covered in a following paragraph. Major components of the parking brake system are:

Key Item and Function

7
8
9
10
11
12

PARKING BRAKE WARNING LIGHT - Illuminates when parking brake is engaged.

PARKING BRAKE CONTROL LEVER - Is positioned up to engage parking brake; down to
disengage parking brake.
PARKING BRAKE CONTROL LEVER ADJUSTING KNOB - Permits operator to make minor
tension adjustment of parking brake.
PARKING BRAKE CABLE - Links parking brake control lever to brakeshoe lever.
BRAKESHOE LEVER - Lever turns cam which pushes brakeshoes against drum.
PARKING BRAKE ADJUSTING NUT - Permits major tension adjustment between parking brake
lever and brakeshoes.
1-29

TM 9-2320-272-24-1

l-20. CONTROL SYSTEM OPERATION (Contd)
d. Steering System Operation.

The steering system is identical for all models covered in this manual. It is a hydraulically-assisted system
that provides ease of turning and control for the operator. Major components of the steering system are:

Key Item and Function
1 OIL RESERVOIR AND STEERING PUMP - Combined in one unit, the reservoir serves as an oil
fill point and the pump creates pressure.
2 ACCESSORY DRIVEBELTS - Transmit mechanical power from accessory drive pulley to steering
pump pulley to drive the steering pump.
3 STEERING WHEEL - Serves as manual steering control for operator.
4 STEERING COLUMN UNIVERSAL JOINT - Connects, at an angle, the steering wheel column
and input shaft of power steering gear.
5 POWER STEERING ASSIST CYLINDER - Receives hydraulic pressure from steering gear to
assist in turning front wheels.
6 STEERING KNUCKLE - Serves as pivot point and link for front wheels from tie rod assembly.
7 TIE ROD ASSEMBLY - Connects steering knuckles so both wheels turn at the same time.
8 STEERING ARM - Connects drag link to steering knuckle.
9 DRAG LINK - Transmits movement from steering arm to pitman arm.
10 PITMAN ARM - Transfers torque from power steering gear to drag link.
11 STEERING GEAR - Converts hydraulic pressure from steering pump to mechanical power at
pitman arm.

l-30

TM 9-2320-272-24-l

l-20. CONTROL SYSTEM OPERATION (Contd)
e. Transmission Control System Operation.
The transmission control system permits shifting of transmission, prevents starting of engine with
transmission in gear, and prevents shifting of transfer case unless transmission is in neutral. This system
also permits engagement of the transmission Power Takeoff (PTO) to provide hydraulic power for auxiliary
equipment on M925/A1/A2, M928/A1/A2, M929/A1/A2, M930/Al/A2, M932/A1/A2, and M936/A1/A2 vehicles.
Major components of the transmission control system are:

Key
12
13
14
15
16

17

Item and Function
TRANSMISSION SELECTOR LEVER - Is used to select vehicle driving gear range.
PTO CONTROL LEVER - Engages transmission power takeoff to provide power for auxiliary
equipment.
TRANSMISSION CONTROL SWITCH - Actuates transmission lockup solenoid valve when
transmission selector lever is placed in NEUTRAL and transfer case shift lever lockout switch is
pressed.
TRANSMISSION NEUTRAL START SWITCH - The neutral start switch, wired to the starter
switch, prevents the engine from being started with transmission in gear.
TRANSMISSION 5TH-GEAR LOCKUP SOLENOID VALVE -Activated by transmission control
switch and transfer case switch, the 5th-gear lockup solenoid valve directs main oil pressure of
transmission to the transmission governor system. This puts transmission in 5th-gear, creating less
drag on transfer case synchronizer which permits smoother shifting from one transfer case drive
range to another. Refer to para. l-20f, Transfer Case Control System Operation, for further details.
TRANSMISSION PTO - Driven by the transmission, the PTO drives the hydraulic pump which
provides hydraulic pressure to power the front winch on M925/A1/A2, M928/Al/A2, M930/Al/A2,
M932/Al/A2, and M936/A1/A2 vehicles, and to power the dump body on M929/A1/A2 and
M930/Al/A2 vehicles. The PTO is mounted on the right front side of the transmission.

1-31

TM 9-2320-272-24-1

l-20. CONTROL SYSTEM OPERATION (Contd)
f. Transfer Case Control System Operation.
The transfer case control system converts four-wheel driving power into six-wheel driving power,
provides smooth shifting of transfer case into high or low driving ranges while vehicle is in motion, prevents
transfer case from being shifted with transmission in gear, and provides hydraulic power for auxiliary
equipment through PTO.
(1) Six-wheel drive is achieved two different ways, depending on the drive range (high or low)
desired. In low range, the transfer case shift linkage automatically moves a cam-actuated valve which
dumps air into the front drive cylinder. This forces a piston against the transfer case clutch to engage frontwheel drive. In high range, front-wheel drive is engaged in the same manner except that the front-wheel
drive valve is manually actuated by the front-wheel drive lock-in switch on the instrument panel.
(2) In order to shift the transfer case from one driving range to another, an interlock system working
in conjunction with the 5th-gear lockup solenoid is used. This system prevents the transfer case from being
shifted unless the transmission is in neutral.
(3) With the automatic transmission, several actions must occur in order to shift transfer case from
one driving range to another. Because of the interlock system, the transmission must be placed in neutral.
The transfer case shift lever switch must also be depressed.
(4) The transfer case control system, through use of a PTO driven by the transfer case, also provides
hydraulic power to operate the crane and rear winch on M936/A1/A2 wreckers.
(5) Major components of this system are:

1-32

TM 9-2320-272-24-l

l-20. CONTROL SYSTEM OPERATION (Contd)
Key Item and Function
1 TRANSFER CASE SHIFT LEVER SWITCH - When depressed with transmission in NEUTRAL,
signals interlock solenoid valve to exhaust air pressure from interlock air cylinder and actuates
lockup solenoid.
2 TRANSFER CASE SHIFT LEVER - Is pushed down to HIGH for light load operations, and up to
LOW for heavy load operations. Six-wheel drive is achieved automatically when transfer case shift
lever is placed in LOW.
3 TRANSFER CASE PTO CONTROL LEVER - Manual control for engaging PTO.
4 TRANSFER CASE PTO - Mounted and mechanically driven at rear of transfer case, the PTO
drives a pump to supply hydraulic pressure to power the rear winch and crane on the M936/A1/A2
wreckers.
5 FRONT-WHEEL DRIVE LOCK-IN SWITCH - Manual control for activating front-wheel drive
valve to provide front-wheel drive with transfer case in HIGH drive range.

6

7
8
9

INTERLOCK AIR CYLINDER - Under air pressure, a piston in the interlock air cylinder forces a
shaft against one of three grooves in transfer case shift lever, This prevents transfer case from being
shifted with transmission in gear.
INTERLOCK SOLENOID VALVE - Releases air from interlock air cylinder when transmission is
in NEUTRAL and transfer case shift lever switch is depressed. This permits the transfer case
high/low shift shaft to move.
FRONT-WHEEL DRIVE AIR CYLINDER - When under pressure, it moves transfer case clutch
forward to engage front-wheel drive.
FRONT-WHEEL DRIVE VALVE - When tripped by a cam on transfer case shift shaft, the frontwheel drive valve routes air to front-wheel drive air cylinder.

1-33

TM 9-2320-272-24-1

1-21. POWER SYSTEM OPERATION
The power system includes components that supply all vehicles covered in this manual the power to
move. Each of these components will be described as part of the following subsystems:
a. Air Intake System Operation (page l-34).
b. Fuel System (Dual Tank) Operation (page l-36).
c. Fuel System (Single Tank) Operation (page l-38).
d. Exhaust System Operation (page l-39).
e. Cooling System Operation (page l-40).
f. Engine Oil System Operation (page l-42).
g. Powertrain System Operation (page l-44).
a. Air Intake System Operation.
The air intake system channels and cleans air going to the combustion chamber, where it mixes with fuel
from the injectors to provide power for the engine. This system is identical on all models, except where
indicated. Major components of the air intake system are:

1-34

TM 9-2320-272-24-1

1-21. POWER SYSTEM OPERATION (Contd)
Key Item and Function
1 RAIN CAP - Prevents rain and large objects from entering air intake system.
2 AIR INTAKE EXTENSION TUBE - Routes air to air intake system. Can be removed for shipping.
3 STACK-TO-AIR INTAKE EXTENSION TUBE - Routes air to air cleaner and is high enough to
keep intake opening above fording level.
4 STACK-TO-AIR CLEANER ELBOW - Flexible connection between air stack and air cleaner.
5 AIR CLEANER - Filters dirt and dust from air.
6 HUMP HOSE - Flexible connection between air cleaner and air cleaner outlet tube.
7 AIR CLEANER OUTLET TUBE - Routes air from air cleaner to intake manifold.
8 INTAKE MANIFOLD - Distributes air to combustion chambers in each cylinder head (M939/Al
series only).
9 AIR CLEANER INDICATOR - Shows red when engine air filter needs servicing.
10 TURBOCHARGER - Mounts on exhaust manifold and uses spent exhaust gases to drive impeller
and pressurize air entering aftercooler (M939A2 series only).
11 AFTERCOOLER - Distributes compressed air from turbocharger to combustion chambers while
cooling air intake out of turbocharger (M939A2 series only).

1-35

TM 9-2320-272-24-1

1-21. POWER SYSTEM OPERATION (Contd)
b. Fuel System (Dual Tank) Operation.
(1) The fuel system stores, cleans, and supplies fuel to the fuel injectors, where it is mixed with air
to initiate engine combustion.
(2) The fuel system is not identical for all models. Vehicles covered in this manual have either one or
two tanks. These tanks can also differ in capacity. See table 1-3, Vehicle Performance Data, for these
differences.
(3) A typical dual tank fuel system is described below. A single tank fuel system is described in
para. 1-21c. Both systems include fuel supply, return, and vent lines to provide fuel flow and release the
fumes throughout the system. Major components of the dual tank fuel system are:

1-36

TM 9-2320-272-24-l

1-21. POWER SYSTEM OPERATION (Contd)
Key Item and Function
1 RIGHT TANK (FRONT) VENT LINE - Vents vapors from fuel tank to vent hole in air intake
stack.
2 RIGHT TANK FILLER CAP - Covers fuel filler opening on right fuel tank.
3 RIGHT FUEL TANK - Stores fuel for vehicle use.
4 RIGHT TANK FUEL RETURN LINE - Returns unused fuel back to fuel tank.
5 RIGHT TANK (REAR) VENT LINE - Vents vapors from fuel tank to vent hole in air intake stack.
6 RIGHT TANK FUEL SUPPLY LINE - Directs fuel from tank to fuel filter.
7 RIGHT TANK FUEL LEVEL SENDING UNIT - Electrical signal registers fuel level in right tank
at gauge on instrument panel.
8 LEFT TANK FUEL LEVEL SENDING UNIT - Electrical signal registers fuel level in left tank at
gauge on instrument panel.
9 LEFT TANK FUEL SUPPLY LINE - Directs fuel from tank to fuel filter.
10 LEFT FUEL TANK - Stores fuel for vehicle use.
11 LEFT TANK (REAR) VENT LINE - Vents vapors from fuel tank to vent hole in air intake stack.
12 LEFT TANK FILLER CAP - Covers fuel filler opening on left fuel tank.
13 LEFT TANK FUEL RETURN LINE - Returns unused fuel back to fuel tank.
14 LEFT TANK (FRONT) VENT LINE - Vents vapors from fuel tank to vent hole in air intake stack.
15 FUEL SELECTOR VALVE - Manual control valve that opens fuel flow to engine from left or right
fuel tank.
16 FUEL FILTER/WATER SEPARATOR - Filters water and dirt from fuel.
17 FUEL FILTER-TO-PUMP SUPPLY LINE - Directs fuel from fuel filter to fuel pump.
18 FUEL RETURN LINE - Returns unused fuel back to fuel tanks.
19 FUEL SUPPLY LINE - Directs fuel from fuel pump to fuel injectors.
20 FUEL PUMP - Draws fuel from tank(s) and pumps it through supply line to fuel injectors.
21 FUEL PRIMER PUMP - Purges air from fuel system.

1-37

TM 9-2320-272-24-1

1-21. POWER SYSTEM OPERATION (Contd)
c. Fuel System (Single Tank) Operation.

Major components of the single tank fuel system are:

Key Item and Function
1
2
3
4
5
6
7
8
9
10
1-38

TANK (REAR) VENT LINE - Vents vapors from fuel tank to vent hole-in air intake stack.
TANK FILLER CAP - Covers fuel filler opening.
FUEL TANK - Stores fuel for vehicle use.
FUEL TANK LEVEL SENDING UNIT - Electrical signal registers fuel level in tank at gauge on
instrument panel.
TANK (FRONT) VENT LINE - Vents vapors from fuel tank to vent hole in air intake stack.
FUEL FILTER/WATER SEPARATOR - Filters water and dirt from fuel.
FUEL RETURN LINE - Returns unused fuel back to fuel tank.
FUEL PUMP - Draws fuel from tank and pumps it through supply line to fuel injectors.
FUEL SUPPLY LINE - Directs fuel from fuel pump to fuel injectors.
FUEL PRIMER PUMP - Purges air from fuel system.

TM 9-2320-272-24-1

1-21. POWER SYSTEM OPERATION (Contd)
d. Exhaust System Operation.
The exhaust system directs exhaust gases away from the vehicle for all models covered in this manual.
Major components of the exhaust system are:

Key Item and Function
11 EXHAUST STACK - Directs exhaust from muffler away from vehicle.
12 EXHAUST MANIFOLD - Collects exhaust from cylinder head ports and directs it to front exhaust
pipe.
13 FRONT EXHAUST PIPE - Directs exhaust to rear exhaust pipe.
14 FLEX PIPE - Part of rear exhaust pipe; allows flexibility for vibration and expansion in system.
15 REAR EXHAUST PIPE - Directs exhaust to muffler.
16 MUFFLER - Quiets exhaust noises.
17 MUFFLER SHIELD - Protects personnel from muffler heat.
1-39

TM 9-2320-272-24-1

1-21. POWER SYSTEM OPERATION (Contd)
e. Cooling System Operation.
This system provides cooling of the engine and transmission. It differs slightly between the M939/A1
series and M939A2 series vehicles because different engines are used. Major components of the cooling
system are:

1-40

TM 9-2320-272-24-1

1-21. POWER SYSTEM OPERATION (Contd)
Key Item and Function
1
2
3
4
5
6

7
8
9
10
11
12
13
14
15
16
17
18
19

SURGE TANK - Filling point for cooling system. On M939A2 vehicles, a float sensor monitors water
level and illuminates a light on instrument panel.
COOLANT PRESSURE CAP - Designed to depressurize cooling system and to access cooling
system for tilling.
WATER MANIFOLD - Collects coolant from cylinder heads and directs it to thermostat housing
(M939/A1 series only).
SURGE TANK-TO-WATER MANIFOLD VENT - Vents air trapped in water manifold (M939/A1
series only).
SURGE TANK-TO-RADIATOR VENT - Vents air in cooling system.
THERMOSTAT - Shuts off coolant flow to radiator until temperature reaches 175°F (79°C) on
M939/A1 series vehicles and 181°F (83°C) on M939A2 series vehicles. Coolant is then directed to the
radiator through the radiator inlet hose.
RADIATOR INLET HOSE - Directs coolant from water manifold to radiator after thermostat has
opened.
BYPASS TUBE - Directs coolant back to transmission oil cooler, where it is then recirculated
through the engine block until the thermostat opens.
RADIATOR SHROUD - Concentrates air flow through the radiator.
RADIATOR - Directs coolant through a series of fins or baffles so outside air can remove excessive
heat from coolant.
FAN CLUTCH - Regulates use of fan to control engine temperature fan to belt-driven pulley when
conditions require additional cooling.
WATER PUMP - Provides force to move coolant through engine.
FAN - Provides force to pull air through radiator.
RADIATOR DRAINVALVE - Permits coolant to be drained from radiator.
TRANSMISSION OIL COOLER HOSE - Directs coolant to transmission oil cooler.
ENGINE OIL COOLER - Reduces heat of engine oil (M939/A1 series only).
TRANSMISSION OIL COOLER - Reduces heat of transmission oil.
ENGINE OIL COOLER-TO-HEATER HOSE - Directs coolant to personnel water heater when
shutoff valve is open (M939/A1 series only).
PERSONNEL WATER HEATER - Provides heat for cab and personnel (M939/A1 only).

1-41

TM 9-2320-272-24-1

1-21. POWER SYSTEM OPERATION (Contd)
f. Engine Oil System Operation.
The engine oil system provides lubricating oil for internal moving parts. Major components of the engine
oil system are:

M939/A1 SERIES

M939A2 SERIES
1-42

TM 9-2320-272-24-1

1-21. POWER SYSTEM OPERATION (Contd)

M939/A1 SERIES

Key
1
2
3
4
5
6
7
8
9
10
11

M939A2 SERIES

Item and Function
OIL DIPSTICK - Indicates engine oil level.
CRANKCASE BREATHER - Vents hot engine oil fumes from engine and allows fresh air to enter.
ENGINE OIL COOLER - Removes heat from engine oil as coolant circulates through internal tubes
of oil cooler.
OIL FILTER - Filters out foreign particles suspended in oil.
OIL FILLER CAP - Located on rocker lever cover, cap covers engine oil fill opening.
OIL PRESSURE TRANSMITTER - Sends an electrical signal that indicates engine oil pressure to
gauge on instrument panel.
OIL PAN DRAINPLUG - Plugs engine oil drain opening.
OIL PAN - Reservoir for engine oil.
OIL SUPPLY LINE - Carries oil from oil pan to oil pump.
OIL BYPASS RETURN LINE - Returns oil from oil pump to oil pan.
OIL PUMP - Provides mechanical pressurization of oil to circulate it through oil system.
1-43

TM 9-2320-272-24-1

1-21. POWER SYSTEM OPERATION (Contd)
g. Powertrain System Operation.
The powertrain system is the same on all models in this manual except the extra-long wheelbase models,
which have an additional propeller shaft and center bearing. This system transmits engine power to the
axles to put the vehicle in motion. Major components of the powertrain system are:

Key
1
2
3
4
5
6
7
8
1-44

Item and Function
ENGINE - Provides power needed for powertrain component operation.
TRANSMISSION -Adapts engine power to meet different driving conditions.
CENTER BEARING - Provides support for propeller shaft to decrease vibration and wear on
universal joints (M927/A1/A2, M928/A1/A2, and M934/A1/A2 series only).
TRANSFER CASE - Distributes power evenly to front and rear axles.
UNIVERSAL JOINTS - Connections between two propeller shafts that permit one to drive the
other even though they may be at different angles.
DIFFERENTIALS - Distribute power to left and right axle shafts.
AXLES - Transmit power from differentials to rotate wheels.
PROPELLER SHAFTS - Serve as driving shafts that connect transmission to transfer case and
transfer case to differentials.

TM 9-2320-272-24-1

1-22. ELECTRICAL SYSTEMS OPERATION
Nearly every component of models covered in this manual is affected by the electrical system. These
components and their electrical connections are described as part of the following electrical subsystems:
a. Battery System Operation (page 1-46).
b. Starting System Operation (page 1-47).
c. Ether Starting System Operation (page 1-48).
d. Generating System Operation (page 1-49).
e. Directional Signal System Operation (page 1-50).
f. Heating System Operation (page 1-51).
g. Indicator, Gauge, and Warning System Operation (page 1-52).
h. Trailer and Semitrailer Connection System Operation (page 1-54).
Electrical Terms and Definitions.
The following electrical terms and definitions will be frequently referred to throughout this section and
should be understood before proceeding:
Alternating Current (AC signal) - Current in a circuit that flows in one direction first, then in the
other direction.
Circuit - A complete path for electric current flow between components.
Circuit Breaker - An automatic switch that interrupts current flow in a circuit when the current limit
is exceeded.
Direct Current (DC signal) - Current in a circuit that flows in one direction.
Female Connector - One-half of a connector which fits over the other half.
Ground - A common return to complete a path for current flow in a circuit.
Harness - A group of wires connected between devices that are bundled and routed together to prevent
damage and make repair and replacement easier.
Male Connector - One-half of a connector which fits the other half.
Polarity - The direction current flows in a circuit (usually positive to negative).
Relay - An electromagnetic device that operates like an automatic switch to control flow of current in
the same or different circuit.
Reverse Polarity - The condition that exists when circuit polarity is connected opposite of that which
was intended.
Sending Unit - A device that produces an electrical signal and sends this signal to the device which will
make use of it.
Sensor - An electrical sensor takes a physical condition (temperature, oil presence or absence) and
converts it into an electrical signal.
Splice - A permanent physical connection of two or more wires.
Terminal - Fastener at end of wire used to connect the wire to an electrically-powered device.

1-45

TM 9-2320-272-24-1

1-22. ELECTRICAL SYSTEMS OPERATION (Contd)
a. Battery System Operation.
The battery system is identical for all models covered in this manual and consists of the following
major components and circuits:

Key Item and Function
1 STARTER SOLENOID - Junction point for battery positive lead (circuit 6) and vehicle electrical
feed wire (circuit 81).
2 CIRCUIT 6 - Connects batteries to starting motor and to protective control box through circuit 81.
3 BATTERIES - Four 6TN batteries are connected in series parallel to provide 24-volts DC for
electrical starter system and 12-volts DC for the heater fan low speed.
4 SLAVE RECEPTACLE - Links an external power source directly to the slaved vehicle’s batteries to
assist in cranking engine when batteries are not sufficiently charged.
5 CIRCUIT 7 - Provides a ground between starter, battery, and chassis.
6 PROTECTIVE CONTROL BOX - Protects the vehicle electrical system in the event battery system
polarity is reversed. Connects battery power to vehicle electrical lead through circuit 81 and circuit 5.
Connects positive ground through circuit 94 to the starter.
7 BATTERY SWITCH - Controls a relay in protective control box through circuit 459 that connects
batteries to vehicle electrical load.

1-46

TM 9-2320-272-24-1

1-22. ELECTRICAL SYSTEMS OPERATION (Contd)
b. Starting System Operation.
The starting system is identical for all models covered in this manual and consists of the following major
components and circuitry:

Key Item and Function
8 BATTERY SWITCH - Completes circuit 459, closing a relay in the protective control box to supply
power to ignition switch through circuits 5 and 5B.
9 PROTECTIVE CONTROL BOX - Locks out starter circuit, which prevents starter from reengaging
while engine is running.
10 IGNITION SWITCH - Provides battery power to fuel solenoid through circuit 54 and the neutral
start safety switch through circuit 498.
11 NEUTRAL START SAFETY SWITCH - Prevents starter from energizing when vehicle is not in
neutral, by deenergizing circuit 499 and a relay in the protective control box, which disconnects
power from circuit 74 and the starter solenoid.
12 STARTER SOLENOID - A magnetic relay that is powered by circuit 74 to transmit 24-volt battery
power to the starter motor through circuit 6.
13 STARTER MOTOR - Cranks engine for starting. Supplied with 24-volt battery power through
circuit 6.
1-47

TM 9-2320-272-24-1

1-22. ELECTRICAL SYSTEMS OPERATION (Contd)
c. Ether Starting System Operation.
The ether starting system is identical for all models covered in this manual and consists of the following
major components and circuitry:

Key Item and Function
1 BATTERY SWITCH - Provides 24-volt battery power to protective control box through circuits 459,
81A, and 81.
2 PROTECTIVE CONTROL BOX - Energizes ether feed switch through circuits 5, 5A, 27, 5C,
and 570.
3 ETHER FEED SWITCH - Controls 24-volt power to ether pressure switch through circuit 570.
4 ETHER PRESSURE SWITCH - Connects ether feed switch to ether tank valve through circuit 570.
5 ETHER TANK VALVE - Is activated through circuit 570 when ether pressure switch is closed and
ether feed switch is pressed.

1-48

TM 9-2320-272-24-1

1-22. ELECTRICAL SYSTEMS OPERATION (Contd)
d. Generating System Operation.
The generating system is identical for all vehicles covered in this manual and consists of the following
major components and circuitry:

Key Item and Function
6 VOLTMETER - Indicates electrical system voltage. It is connected to the electrical system through
circuit 27.
7 ALTERNATOR - Rated at 26-30 volts, 60 amperes, the alternator assists and recharges batteries
during operation. A l00-ampere model is available as a kit.
8 CIRCUIT 3 - Provides a ground circuit to alternator.
9 CIRCUIT 566 - Controls a relay in protective control box that prevents starter from reactivating
while engine is running.
10 CIRCUIT 568 - Senses system voltage and excites the alternator field.
11 PROTECTIVE CONTROL BOX - Connects circuit 5 to 81 to power the electrical system and
charge the batteries.
12 CIRCUIT 5 - Conducts alternator output to charge batteries and maintain vehicle voltage.
13 BATTERY SWITCH - Closes relay in protective control box that connects battery circuits.
1-49

TM 9-2320-272-24-1

1-22. ELECTRICAL SYSTEMS OPERATION (Contd)
e. Directional Signal System Operation.
The directional signal system is identical on all models covered in this manual and consists of the
following major components and circuitry:

Key Item and Function
1 FRONT COMPOSITE LAMP - Receives power from turn signal control through circuits 460 and
461 to indicate turning direction.
2 LIGHT SWITCH - Provides battery power to directional signal switch through circuits 460 and 461
and to stoplight switch through circuit 75.
3 STOPLIGHT SWITCH - Closing this switch allows power to flow from light switch through circuit
75 to circuit 22 to directional signal switch.
4 REAR COMPOSITE LAMPS - Receive power from turn signal control through circuit 22-460 and
22-461 to indicate turning direction.
5 DIRECTIONAL SIGNAL SWITCH -A four-position switch that directs power to composite and
signal lamps through circuits 460, 461, 22-460, and 22-461 to indicate direction of turn.
6 TURN SIGNAL FLASHER - Receives power through circuit 467A and sends intermittent current
to the signal lamp through circuit 467B.
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1-22. ELECTRICAL SYSTEMS OPERATION (Contd)
f. Heating System Operation.
The electrical portion of the heating system is identical for all models covered in this manual and
consists of the following major components and circuitry:

Key Item and Function
7 PROTECTIVE CONTROL BOX - Provides 24-volt power to circuit breaker through circuits 5 and
5A and to heater switch through circuits 27 and 5C.
8 CIRCUIT BREAKER - Provides overload protection for 24-volt circuits 5, 5A, 27, and 5C leading to
the heater switch.
9 BATTERY SWITCH - Provides 12-volt battery power from circuit 569 through 569A to the heater.
10 CIRCUIT BREAKER - Provides overload protection for 12-volt circuit 569A leading to heater
switch.
11 HEATER SWITCH - Controls low and high blower motor speed and has two sources of power: 12volt power is supplied through circuit 569A from battery switch and is used to provide low speed;
24-volt power is supplied through circuit 5C from protective control box and is used to provide high
speed.
12 HEATER BLOWER MOTOR -A direct current motor controlled by heater switch through
circuit 400.
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1-22. ELECTRICAL SYSTEMS OPERATION (Contd)
g. Indicator, Gauge, and Warning System Operation.
The indicator, gauge, and warning system is comprised of several subsystems:

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1-22. ELECTRICAL SYSTEMS OPERATION (Contd)
Key Item and Function
1 VOLTMETER - Indicates system voltage and is connected to batteries through circuit 27A and to
chassis ground through instrument panel.
2 ENGINE COOLANT TEMPERATURE INDICATOR - Indicates engine coolant temperature and
receives battery power through circuit 27A. Circuit 33 completes the circuit to ground through a
coolant temperature sensor that reacts to changes in engine coolant temperature by increasing or
decreasing the resistance in ground circuit.
3 ENGINE OIL PRESSURE INDICATOR - Indicates engine oil pressure and receives battery power
through circuit 27A. Circuit 36 completes the circuit to ground through the oil pressure transmitter
located on the engine block.
4 FUEL INDICATOR - Indicates fuel level. Receives battery power through circuit 27A. Circuit 28 or
29, depending upon which position fuel selector switch is in, completes the circuit to ground through
fuel level sensor.
5 TRANSMISSION OIL TEMPERATURE INDICATOR - Indicates transmission oil temperature
and receives battery power through circuit 27A. Circuit 324 completes circuit to ground through a
temperature sensor located in transmission.
6 FRONT-WHEEL DRIVE ENGAGEMENT LIGHT - Informs the operator that front-wheel drive is
engaged. The system consists of a normally open pressure switch, which is powered through circuit
27A and an indicator lamp powered through circuit 27A.
7 HORN SYSTEM - The horn system consists of an air-operated horn that is controlled by an electric
solenoid. The solenoid is powered through circuit 26 and controlled by the horn switch through
circuit 25.
8 SPRING BRAKE WARNING SYSTEM - Warns the operator that spring brakes are applied. The
system consists of normally open pressure switch powered through circuit 37 and an indicator lamp
which is powered through circuit 37.
9 FAILSAFE WARNING SYSTEM - Intended to give the operator an audible as well as visual signal
of a malfunction in one of the primary systems. Power for the system is supplied from the ignition
switch through circuit 564. The failsafe module causes an indicator lamp to illuminate and an alarm
to sound when air pressure falls below 60 psi (414 kPa) or when parking brake is set.

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1-22. ELECTRICAL SYSTEMS OPERATION (Contd)
h. Trailer and Semitrailer Connection System Operation.
The trailer receptacle is identical on all models covered in this manual. The semitrailer receptacle is on
the tractor body only.

Key Item and Function
1 TRAILER RECEPTACLE - Provides vehicle lighting, auxiliary power, and a ground circuit for
trailers.
2 SEMITRAILER RECEPTACLE - M931/A1/A2 and M932/A1/A2 vehicles equipped with a fifth
wheel are provided with a semitrailer receptacle. This receptacle provides vehicle lighting, auxiliary
power, and a ground circuit for semitrailers.
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1-23. COMPRESSED AIR AND BRAKE SYSTEM OPERATION
The compressed air and brake system takes filtered air, compresses it, and supplies it to various
components that enable the operator to slow down or stop the vehicle. This system also supplies compressed
air to air-actuated accessories throughout the vehicle. These components and accessories will be described
as part of the following systems:
a. Medium Wrecker Automatic Brake Lock System Operation (page 1-55).
b. Air Pressure Supply System Operation (page 1-56).
c. Secondary Service Airbrake System Operation (page 1-60).
d. Spring Airbrake System Operation (page 1-62).
e. Primary Service Airbrake System Operation (page 1-63).
f. Auxiliary Air-Powered System Operation (page 1-66).
g. Air Venting System Operation (page 1-68).
h. Central Tire Inflation System (CTIS) (M939A2 series vehicles) (page 1-70).
a. Medium Wrecker Automatic Brake Lock System Operation.
The M936/A1/A2 Medium Wrecker Automatic Brake Lock System locks the service airbrakes when the
transfer case PTO lever is engaged. Major components of the automatic brake lock system are:

Key Item and Function
A TRANSFER CASE PTO LEVER - Opens the brake lock control valve through mechanical linkage
when engaged.
B BRAKE LOCK CONTROL - Allows air pressure to flow from secondary air reservoir to pressure
regulator and activate variable speed governor.
C PRESSURE REGULATOR - Reduces and regulates system air pressure to 70 psi (483 kPa) for
automatic brake lock application.
D TREADLE VALVE - Connects pressure regulator and service airbrakes.
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1-23. COMPRESSED AIR AND BRAKE SYSTEM OPERATION (Contd)
b. Air Pressure Supply System Operation.
(1) A constant air pressure supply is developed by the compressor which is regulated by the governor
to maintain 90-120 psi (621-827 kPa) for the airbrake system. Moisture within the system is controlled
through the use of either the alcohol evaporator or air dryer. The major components of the system are:

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1-23. COMPRESSED AIR AND BRAKE SYSTEM OPERATION (Contd)
Key Item and Function
A AIR DRYER - Installed in supply line to wet tank and removes moisture from inlet air to wet tank
(M939/A1 air dryer kit installed only).
B AIR COMPRESSOR - Draws in air from the intake manifold and forces it into brake system and
wet tank reservoir.
C SAFETY VALVE - Located at inlet side of wet reservoir, it prevents pressure buildup by releasing
air pressure exceeding 150 psi (1,034 kPa) when the governor fails to regulate air supplied by the
compressor.
D WET TANK RESERVOIR - Performs two functions:
l
Traps water in air reservoir to protect other air systems from freezing or corroding.
l
Stores reserve air supply enabling operator to make normal stops when engine stalls or
compressor fails.
E PRESSURE PROTECTION VALVE - Performs two functions:
l
Allows air pressure to build to 60-65 psi (414-448 kPa) before supplying air to auxiliary airpowered equipment.
l
Closes off auxiliary air system from other systems if an accessory fails and prevents loss of air
from secondary reservoir.
F ALCOHOL EVAPORATOR (M939/A1 series) - Helps protect air lines from freezing.
G WET TANK RESERVOIR DRAINVALVE - Provides a drain for moisture and air from reservoir.
H AIR DRYER - Removes moisture from inlet air to wet tank (M939A2 only).
I EXPELLO VALVE - Augments air dryer condensation blowdown by venting moisture when
compressor cycles.
J GOVERNOR - Trips valve inside compressor to regulate flow of air to the system. When pressure
builds to 120-127 psi (827-876 kPa), the governor will close valve.

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1-23. COMPRESSED AIR AND BRAKE SYSTEM OPERATION (Contd)
(2) The constant air pressure supply is distributed to the primary service airbrake system (para. e.)
and secondary airbrake system (para. c.) through a shutoff and check valve. Air pressure can either be fed
from or supplied to another vehicle through the emergency couplings.

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1-23. COMPRESSED AIR AND BRAKE SYSTEM OPERATION (Contd)
Key Item and Function
A FRONT EMERGENCY COUPLING -When vehicle is being towed, coupling receives compressed
air from towing vehicle’s brake system to charge its own brake system.
B PRIMARY AIR RESERVOIR - Stores sufficient air pressure to allow operator to make normal
brake applications if system pressure fails or engine stalls.
C PRIMARY FEED CUTOFF - Manually-operated valve used to isolate pressure leaks in primary air
system from draining wet tank (TM 9-2320-272-10).
D PRIMARY AIR RESERVOIR CHECKVALVE - Prevents backflow of air from primary tank if wet
system develops a leak.
E SECONDARY FEED CUTOFF - Manually-operated valve used to isolate pressure leaks in
secondary air system from draining wet tank (TM 9-2320-272-10).
F SECONDARY AIR RESERVOIR CHECKVALVE - Prevents backflow of air from secondary tank if
wet system develops a leak.
G REAR EMERGENCY COUPLING - When towing another vehicle, coupling allows pressurized air
from wet tank to charge towed vehicle’s wet tank.
H SECONDARY AIR RESERVOIR - Stores enough air pressure in case constant pressure system
fails or engine stalls. The operator can make normal brake application before running out of air.
PRESSURE PROTECTION VALVE - Performs two functions:
I
(1) Allows air pressure to build to 60-65 psi (414-448 kPa) before supplying air to auxiliary airpowered equipment.
(2) Closes off auxiliary air system from other systems if an accessory fails and prevents loss of air
from secondary reservoir.

1-59

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1-23. COMPRESSED AIR AND BRAKE SYSTEM OPERATION (Contd)
c. Secondary Service Airbrake System Operation.
(1) The secondary service airbrake system is made up of two subsystems:
(a) Secondary constant pressure system provides continuous air pressure to:
l Pedal valve
l Rear relay valve
l
Spring brake air reservoir
l
Spring parking brake valve
(b) Secondary signal system serves three functions:
l
Contains air pressure only when operator steps on brake pedal.
l Is regulated by various valves to control amount of braking.
l
Provides pressure to apply rear two service brakes and intermediate and rear axles
stamped with B. Service brakes on rear axle are piggybacked to spring brakes, but operate
independently of them.
(2) The secondary constant pressure system is made up of the following components:

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1-23. COMPRESSED AIR AND BRAKE SYSTEM OPERATION (Contd)
Key Item and Function
A LOW AIR PRESSURE SWITCH - Activates warning buzzer and warning lights when air pressure
goes below 60 psi (414 kPa).
B PEDAL VALVE - Allows air pressure from secondary constant pressure system to flow into
secondary signal system when operator depresses brake pedal.
C SECONDARY AIR PRESSURE GAUGE - Indicates amount of air pressure in secondary system.
D ONE-WAY CHECKVALVE -Allows air pressure to flow into secondary reservoir, but prevents it
from coming out if constant pressure system fails or engine stalls.
E SECONDARY AIR RESERVOIR - Stores enough air pressure so the operator can make five
normal brake applications before running out of air if constant pressure fails or engine stalls.
F INTERMEDIATE REAR BRAKE CHAMBERS - Converts air pressure to mechanical force which
applies intermediate rear service brake.
G DOUBLECHECK VALVE NO. 1 - Serves two functions:
l
Allows system to receive signal pressure from either pedal valve or, when towed, from brake
system of towing vehicle.
l
Serves as a tee between front and rear primary signal lines.
H SECONDARY AIR RESERVOIR DRAINVALVE - Provides a drain for moisture and air from
secondary air reservoir.
I
FRONT RELAY VALVE - Boosts signal air to rear brake chambers; regulates air pressure to rear
brake chambers so operator has control over amount of braking; and releases air pressure to rear
brake chambers directly to vent when brake pedal is released.
J STOPLIGHT SWITCH - As the brake pedal is depressed, switch receives an air pressure signal at
electrical contacts which close to activate circuits to taillights.
K DOUBLECHECK VALVE NO. 2 - Allows either primary or secondary signal air pressure to
activate stoplight switch while keeping the two systems separate.
L REAR-REAR BRAKE CHAMBERS - Converts air pressure to mechanical force which applies rearrear brakes.

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1-23. COMPRESSED AIR AND BRAKE SYSTEM OPERATION (Contd)
d. Spring Airbrake System Operation.
The spring airbrake system applies rear brakes when vehicle parking brake is applied or in event of a
major brake failure. The spring brake is located on one of the two service brake chambers at each rear
wheel. Major components of the spring airbrake system are:

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1-23. COMPRESSED AIR AND BRAKE SYSTEM OPERATION (Contd)
Key Item and Function
A SPRING BRAKE WARNING LIGHT SWITCH - Activates warning light when spring brakes are
engaged.
B SPRING BRAKE RELEASE CONTROL VALVE - Pushed in to release spring brakes
independently of mechanical parking brake. Control is also used to release spring brakes in order to
test and adjust mechanical brake.
C DOUBLECHECK VALVE NO. 4 - Allows spring brake air pressure to come from either release
control valve or spring parking brake valve directly to doublecheck valve No. 3.
D INTERMEDIATE FRONT SPRING BRAKE CHAMBER - Contains a large spring which applies
rear brakes when spring brake air pressure is released.
E ONE-WAY CHECKVALVE - Allows air pressure to flow into spring brake reservoir, but prevents it
from coming out if constant pressure system or primary system fails.
F SPRING BRAKE AIR RESERVOIR - Stores enough air pressure to release spring brakes for
emergency operation in event of primary or secondary air system failure.
G QUICK-RELEASE VALVE - Releases spring brake air pressure directly to vent if parking brake
has been set or brake system fails.
H SPRING BRAKE VALVE - Automatically sets spring brakes when parking brake is set. Valve can
be released independently of parking brake when spring brake control valve is pushed in.
SPRING BRAKE RESERVOIR DRAINVALVE - Provides a drain for moisture and air from spring
I
brake reservoir.
J DOUBLECHECK VALVE NO. 3 - Allows spring brake air pressure to come from either release
control valve or spring parking brake valve directly to doublecheck valve No. 4.
K REAR-BEAR SPRING BRAKE CHAMBER - Contains a large spring which applies rear brakes
when spring brake air pressure is released.
e. Primary Service Airbrake System Operation.
(1) The primary service airbrake system is made up of two subsystems:
(a) Primary constant pressure system provides continuous air pressure to:
l Pedal valve
l Rear relay valve
l
Spring brake air reservoir
l
Spring parking brake valve
(b) Primary signal system serves three functions:
l
Contains pressure only when operator steps on brake pedal.
l Is regulated by various valves to give operator control over amount of braking.
l Provides pressure to apply front service brakes and the front two service brakes on
intermediate and rear axles stamped with an A. Service brakes on the intermediate axle
are piggybacked to spring brakes, but operate independently of them.

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1-23. COMPRESSED AIR AND BRAKE SYSTEM OPERATION (Contd)
(2) The primary constant pressure system is made up of the following components:

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1-23. COMPRESSED AIR AND BRAKE SYSTEM OPERATION (Contd)
Key Item and Function
A PRIMARY AIR PRESSURE GAUGE - Indicates amount of air pressure in primary system.
B LIMITING VALVE - Serves three functions:
l
Regulates signal air pressure going to front brake chambers so rear brakes are applied first.
l
Regulates signal air pressure to front brake chambers so operator has control over amount of
braking.
l
Releases air pressure in front brake chambers directly to vent in the valve when brake pedal is
released.
C FRONT BRAKE CHAMBERS - Convert air pressure to mechanical force which applies front
service brakes.
D PRIMARY RESERVOIR LOW AIR PRESSURE SWITCH - Activates warning buzzer and
warning light when air pressure goes below 60 psi (414 kPa).
E PEDAL INTO VALVE - Allows air pressure from primary constant pressure system to flow into
primary signal system when operator depresses brake pedal.
F DOUBLECHECK VALVE NO. 1 - Serves two functions:
l
Allows system to receive signal pressure from either pedal valve or, when towed, from brake
system of towing vehicle.
l
Serves as a tee between front and rear primary signal lines.
G FRONT SERVICE COUPLING - When vehicle is being towed, coupling is connected to towing
vehicle so the brake systems of the two vehicles work together.
H ONE-WAY CHECKVALVE - Allows air pressure to flow into primary reservoir, but prevents it from
coming out if constant pressure system fails or engine stalls.
I
PRIMARY AIR RESERVOIR - Stores enough air pressure so the operator can make five normal
brake applications before running out of air if constant pressure fails or engine stalls.
J DOUBLECHECK VALVE NO. 2 - Allows either primary or secondary signal air pressure to
activate stoplight switch while keeping the two systems separate.
K STOPLIGHT SWITCH -As brake pedal is depressed, switch receives an air pressure signal which
closes electric contacts turning on stoplight.
L REAR SERVICE COUPLING - When towing another vehicle, coupling is connected to towed
vehicle so the brake systems of the two vehicles work together.
M INTERMEDIATE FRONT BRAKE CHAMBERS - Converts air pressure to mechanical force
which applies intermediate rear service brake.
N PRIMARY RESERVOIR DRAINVALVE - Provides a drain for moisture and air from primary air
reservoir.
O REAR RELAY VALVE - Serves three functions:
l
Boosts signal air pressure to rear brake chambers. Air signal from brake pedal opens valve to
route constant air pressure to rear brake chambers.
l
Regulates signal air pressure from brake pedal to rear brake chambers so operator has control
over amount of braking. Regulates amount of constant air pressure going to brake chambers as
the operator depresses the brake pedal.
l
Releases air pressure in rear brake chamber directly to vent system when brake pedal is
released.
P REAR FRONT BRAKE CHAMBERS - Converts air pressure to mechanical force which applies
rear service brakes.

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1-23. COMPRESSED AIR AND BRAKE SYSTEM OPERATION (Contd)
f. Auxiliary Air-Powered System Operation.
The auxiliary air-powered system consists of air-actuated vehicle accessories. All of these accessories
receive air pressure through the accessory manifold and off the pressure protection valve with the exception
of the horns. Components of the auxiliary air-powered system are:

1-66

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1-23. COMPRESSED AIR AND BRAKE SYSTEM OPERATION (Contd)
Key Item and Function
A WINDSHIELD WIPER CONTROL SWITCH - Opens air pressure valve in wiper motor to operate
wipers.
B WINDSHIELD WIPER MOTOR - Air-actuated motor powers windshield wipers.
C WINDSHIELD WASHER CONTROL - Spring-loaded valve that allows air pressure to force
washer fluid from washer reservoir to windshield.
D WINDSHIELD WASHER RESERVOIR - Container for windshield washer fluid.
E ACCESSORY MANIFOLD - Receives air pressure from the pressure protection valve and
distributes it to the various accessories.
F FRONT-WHEEL DRIVE LOCK-IN SWITCH - Air-actuated switch that engages front-wheel drive
when transfer case is in HIGH.
G WINDSHIELD WASHER NOZZLES - Direct washer fluid on windshield.
H GOVERNOR - Serves as a tee between accessory manifold and horn relay valve. It also signals the
air compressor to stop compressing air for the supply system when operating pressure has been
reached.
I
TRANSFER CASE AIR SHIFT CYLINDER - Engages front-wheel drive when it receives air
pressure from lock-in switch or engagement control valve.
J FRONT AXLE ENGAGEMENT CONTROL VALVE - Operates off cam, on transfer case shift
linkage so front-wheel drive engages automatically when transfer case is put into LOW.
K HORN RELAY VALVE - Electrical signal from horn button on steering wheel opens valve in horn
relay, allowing air pressure to sound horns.
L HORNS - Receive air pressure from horn relay valve to sound off.

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1-23. COMPRESSED AIR AND BRAKE SYSTEM OPERATION (Contd)
g. Air Venting System Operation.
The air venting system vents air from brake system and powertrain and fuel vapors from fuel system into
air intake stack where it is released into the atmosphere. The components of the air venting system are:

1-68

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1-23. COMPRESSED AIR AND BRAKE SYSTEM OPERATION (Contd)
Key Item and Function
A SPRING BRAKE RELEASE CONTROL VALVE - This valve functions as an override when a
failure in the air supply system (causing spring brakes to engage) occurs. When valve is manually
pushed in, emergency air is supplied to the spring brake chambers. This releases the spring brakes,
allowing vehicle movement.
B PEDAL VALVE - Vents primary or secondary signal air pressure when pedal is released.
C FRONT BRAKE CHAMBER VENT - Vents air pressure inside chambers when pedal valve is
released.
D LIMITING VALVE - Vents signal air pressure going to front brake chambers so rear brakes apply
first.
E STEP BOX QUICK-RELEASE VALVE - Vents air pressure from spring brake chambers when
parking brake valve has been actuated.
F REAR BRAKE CHAMBERS - Vents ports on chambers to prevent air pressure buildup.
G RELAY VALVES - Vents air pressure in rear brake chambers directly to intake tube when brake
pedal is released. Vents signal air pressure through upper port in valve.
H AIR INTAKE STACK - Venting point for the vent system.
I
TRANSMISSION VENT - Vents internal air pressure buildup due to internal heat.
J SPRING PARKING BRAKE VALVE - Vents air pressure from air and doublecheck valves No. 3
and No. 4.
K TRANSFER CASE VENT - Vents internal air pressure buildup due to internal heat.
L FUEL TANK VENTS - Vent fuel vapors to prevent partial vacuum from stopping fuel flow.

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1-23. COMPRESSED AIR AND BRAKE SYSTEM OPERATION (Contd)
h. Central Tire Inflation System (CTIS) (M939A2 Series Vehicles).
The CTIS is common to all M939A2 series vehicles. This system maintains tire air pressure depending on
which road type is selected. If this setting is changed, tires will automatically inflate or deflate to the new
setting.

Key Item and Function
1 PNEUMATIC CONTROLLER - Directs air pressure according to ECU commands.
2 PRESSURE TRANSDUCER - Mounted in pneumatic controller, it measures tire pressure and
sends information to ECU.
3 ELECTRONIC CONTROL UNIT (ECU) - Contains CTIS selector panel so that operator can
change tire inflation during vehicle operation.
4 AIR PRESSURE SWITCH - Protects air brake system for a minimum supply of 85 psi (586 kPa) of
air.
5 AIR DRYER AND FILTER - Separates moisture from compressed air system and filters impurities
from compressed air before they enter CTIS.
6 EXHAUST VALVES - Exhaust air from tires during deflation.
7 WHEEL VALVES - Isolate air pressure in tires during normal operation and for tire removal.
8 SPEED SIGNAL GENERATOR - Signals ECU to automatically inflate CTIS when vehicle speed
exceeds the top speed setting for the selected mode by 10 mph (16 kmh).
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TM 9-2320-272-24-1

1-24. HYDRAULIC SYSTEM OPERATION
Oil pressure (hydraulics) is used to provide operating power for the auxiliary equipment on the vehicles
covered in this manual. The components that provide hydraulic power are discussed in the following order:
a. Front Winch Hydraulic System Operation (page 1-71).
b. Rear Winch Hydraulic System Operation (page 1-72).
c. Dump Body Hydraulic System Operation (page 1-73).
d. Medium Wrecker Crane Hydraulic System Operation (page 1-74).
a. Front Winch Hydraulic System Operation.
A front winch is installed on M925/A1/A2, M928/A1/A2, M930/A1/A2, M932/A1/A2, and M936/A1/A2
series vehicles. The front winch hydraulic system converts mechanical power at the winch drive motor. The
basic operating principles are the same for each model. Major components of this system are:

Key Item and Function
1 CLUTCH LEVER - Manual control that engages winch drum gear to drive gear of winch motor.
2 TRANSMISSION PTO CONTROL - A manually-operated control lever located inside the cab that
permits engagement or disengagement of the transmission PTO.
3 WINCH CONTROL LEVER -An operator control that determines the hydraulic oil pressure flow
from the control valve to the winch motor. The flow of this oil determines the direction the winch
drum will turn.
4 TRANSMISSION PTO - Uses transmission driving power to provide mechanical driving power for
the hydraulic pump.
5 PTO DRIVESHAFT - Transmits mechanical power from PTO to the hydraulic pump.
6 HYDRAULIC PUMP - Driven by PTO driveshaft, it draws oil from the oil reservoir through
hydraulic hoses, then pressurizes and directs this oil to the control valve.
7 OIL FILTER - Filters used or bypassed oil from the control valve before it returns to the hydraulic
oil reservoir.
8 HYDRAULIC OIL RESERVOIR - Storage tank for hydraulic oil.
9 CONTROL VALVE - Four-port valve accepts pressurized oil from the hydraulic pump and directs
this oil to the winch motor. It also directs oil returning from the winch back to the oil reservoir. The
flow of this oil from the valve determines the directional drive of the winch motor.
10 WINCH MOTOR - Converts hydraulic power into mechanical power as hydraulic oil is forced
through the winch motor.

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1-24. HYDRAULIC SYSTEM OPERATION (Contd)
b. Rear Winch Hydraulic System Operation.
A rear winch is installed only on the M936/A1/A2 medium wrecker. It is used primarily to rescue vehicles
that have become deeply mired. The rear winch hydraulic system converts mechanical power of the engine
into fluid power through use of the hydraulic pump and back into mechanical power at the winch drive
motor. The major components of the rear winch hydraulic system are:

Key Item and Function
1 TRANSFER CASE PTO CONTROL - A manually-operated control lever located inside the cab that
permits engagement or disengagement of the PTO.
2 TRANSFER CASE PTO - Uses driving power of the transfer case to provide mechanical driving
power for the hydraulic pump.
3 PTO DRIVESHAFT - Transmits mechanical driving power from PTO to the hydraulic pump.
4 HYDRAULIC PUMP - Draws oil from hydraulic oil reservoir and directs it to the rear winch
control valve and winch drive motor.
5 OIL FILTER - Filters used or bypassed oil from the control valve before it returns to the hydraulic
oil reservoir.
6 HYDRAULIC OIL RESERVOIR - Storage tank for hydraulic oil.
7 TORQUE CONTROL LEVER - Controls the operating gear ratio of the winch drive motor. Lever is
pulled outward to HIGH for heavy loads or pushed inward to LOW for light loads.
8 WINCH DIRECTIONAL CONTROL LEVER - Manually-operated lever that controls the wind and
unwind direction of the rear winch drum. Lever does this by opening and closing the directional
control valve to the winch motor, and reversing the direction of pressurized hydraulic fluid. Lever is
pushed inward to wind and pulled outward to unwind winch cable.
9 DIRECTIONAL CONTROL VALVE - Receives pressurized hydraulic oil from the hydraulic pump
and directs it to the winch motor. The flow of hydraulic oil to and from this control valve provides
forward or reverse driving power to the winch motor. Valve also returns used oil back to the
hydraulic oil reservoir from the winch.
10 TORQUE CONTROL VALVE - Hydraulically controls the hydraulic oil pressure to engage rear
winch drum clutch in high or low gear range.
11 WINCH MOTOR - Converts hydraulic power back into mechanical power needed to turn the rear
winch drum.
12 CONTROL LINKAGE - Connects transfer case PTO control to transfer case PTO.

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TM 9-2320-272-24-1

1-24. HYDRAULIC SYSTEM OPERATION (Contd)
c. Dump Body Hydraulic System Operation.
The dump body is installed on M929/A1/A2 and M930/A1/A2 model vehicles. These models are used to
transport and deposit cargo. The dump body hydraulic system converts mechanical power from the engine
into fluid power through use of the hydraulic pump. The pump draws fluid from the oil reservoir and then
forces it into the control valve. This hydraulic pressure raises and lowers the dump body. Major components
of the dump body hydraulic system are:

Key Item and Function
13 TRANSMISSION PTO CONTROL - A manually-operated control lever located inside the vehicle
cab that permits engagement or disengagement of the transmission PTO.
14 TRANSMISSION PTO - Uses driving power of the transmission to provide mechanical driving
power for the hydraulic pump.
15 PTO DRIVESHAFT - Transmits mechanical driving power from the PTO to the hydraulic pump.
16 HYDRAULIC PUMP - Driven by the PTO driveshaft, it draws oil from oil reservoir through
hydraulic hoses, then pressurizes and directs it to the control valve.
17 HYDRAULIC OIL RESERVOIR - Storage tank for hydraulic oil.
18 DUMP BODY SAFETY LATCH - Hydraulically-operated in conjunction with the dump body
control lever, the safety latch locks dump body in the lowered position and releases it when the
control lever is pulled back to the raised position.
19 DUMP BODY CYLINDER ASSEMBLY - Consists of two piston-type hydraulic cylinder hoists.
Assembly raises and lowers dump body with hydraulic oil, forcing the cylinder upward or downward.
20 OIL FILTER - Filters used or bypassed oil from the control valve before it returns to the hydraulic
oil reservoir.
21 CONTROL VALVE - Four-port valve accepts pressurized oil from the hydraulic pump and directs
oil pressure flow from control valve to the hydraulic cylinders. It also directs oil returning from the
hydraulic cylinders back to the hydraulic oil reservoir.
22 DUMP BODY CONTROL LEVER - An operator control that determines the hydraulic oil pressure
flow from control valve to the hydraulic cylinders. The route this oil takes will determine whether the
dump will raise or lower.
23 CONTROL LINKAGE - Connects dump body control lever inside cab to the control valve.

1-73

TM 9-2320-272-24-1

1-24. HYDRAULIC SYSTEM OPERATION (Contd)
d. Medium Wrecker Crane Hydraulic System Operation.
The M936/A1/A2 medium wrecker is equipped with a hydraulically-operated crane that extends a
maximum 18 ft (5 m), elevates 45 degrees, and swings 360 degrees. It is capable of lifting loads up to
20,000 lbs (9,090 kg).
(1) The crane hydraulic system converts power of the engine into fluid power for use by the hydraulic
pump. At this pump, oil pressure is supplied to different crane control valves: BOOM, HOIST, CROWD, and
SWING. Each of these crane actions are dealt with separately. The major components for raising and
lowering the wrecker boom are:

1-74

TM 9-2320-272-24-1

1-24. HYDRAULIC SYSTEM OPERATION (Contd)
Key Item and Function
1 TRANSFER CASE PTO CONTROL - A manually-operated control lever located inside the cab that
engages and disengages the transfer case PTO.
2 TRANSFER CASE PTO LINKAGE - Connects transfer case PTO control to transfer case PTO.
3 TRANSFER CASE PTO - Receives driving power from vehicle’s engine through the transfer case to
provide mechanical driving power for the hydraulic pump.
4 PTO DRIVESHAFT - Transmits mechanical driving power from the power takeoff to the hydraulic
pump.
5 HYDRAULIC PUMP - Draws oil from hydraulic oil reservoir and directs it to valves inside the
crane control console.
6 OIL FILTER - Filters used or bypassed oil from the control valve before it returns to the hydraulic
oil reservoir.
7 HYDRAULIC OIL RESERVOIR - Storage tank for hydraulic oil.
8 SWIVEL VALVE - Permits oil to channel through pivot post while crane is swinging and eliminates
twisting of the hydraulic lines connecting reservoir to the stationary pump.
9 BOOM LIFT CYLINDER - A hydraulically-driven piston that extends upward when boom control
lever is pulled back to UP position, raising the boom. A check valve located near hydraulic oil inlet
hose prevents piston from lowering when control lever is in NEUTRAL. Oil returns through boom
control valve back to hydraulic oil reservoir allowing piston to lower when control lever is pushed
forward to DOWN position.
10 BOOM HYDRAULIC LINES - Carry the hydraulic oil to and from boom lift cylinder. Oil pumped
through the bottom lines pushes the lift cylinder piston upward. Oil pumped through the top lines
pushes the lift cylinder piston downward. When this downward action occurs, the oil that originally
pushes the cylinder upwards is returned to the hydraulic oil reservoir.
11 BOOM CONTROL LEVER - Manual control attached to the control valve that determines
hydraulic oil flow for raising and lowering action of the boom. Lever is pulled back to raise the boom
and pushed forward to lower boom.
12 CRANE CONTROL CONSOLE - Houses BOOM, HOIST, CROWD, and SWING levers and their
control valves.
BOOM
CONTROL VALVE - Located directly below boom control lever. Valve directs hydraulic oil
13
from the hydraulic pump to the boom lift cylinder for lifting, or out of the lift cylinder and back to the
hydraulic oil reservoir for lowering.

1-75

TM 9-2320-272-24-1

1-24. HYDRAULIC SYSTEM OPERATION (Contd)
(2) The major components for raising and lowering the crane cable and hook for the HOIST action are:

Key Item and Function
1 SHEAVES - Grooved wheels that guide hoist cable through boom.
2 HOIST MOTOR ASSEMBLY - Converts hydraulic power back into mechanical power needed to
turn the hoist drum.
3 UPPER ROLLER ASSEMBLY - Prevents cable from contacting inner boom during winding/
unwinding.
4 CRANE HOIST CABLE DRUM - Is turned by the worm gear in hoist motor assembly. Drum
unwinds cable when turning toward front of vehicle. Drum winds cable when turning toward rear of
vehicle.
5 HOIST CONTROL LEVER - Manual control attached to the control valve that determines
hydraulic oil flow for the raising and lowering action of the crane hoist cable and hook. Lever is
pulled back to raise cable and hook and pushed forward to lower cable and hook.
6 HOIST CONTROL VALVE - Two-way hydraulic valve located under the hoist control lever directs
fluid from the hydraulic pump to the hoist motor assembly and back through the valve to the
hydraulic oil reservoir.
1-76

TM 9-2320-272-24-1

1-24. HYDRAULIC SYSTEM OPERATION (Contd)
(3) Major components for extending and retracting the boom for the CROWD action are:

Key Item and Function
7 ROLLERS - Guide inner boom assembly and permit smooth extension and retraction of boom.
8 INNER BOOM ASSEMBLY - Extends when crowd control lever is pushed forward and retracts
when control lever is pulled back.
9 CROWD CYLINDER -A hydraulically-driven piston that extends outward when crowd control lever
is pushed forward to EXTEND position. Piston is hydraulically-driven back into the cylinder when
crowd control lever is pulled back to RETRACT position. This cylinder is contained in the inner boom
assembly.
10 CROWD CONTROL LEVER - Manual control attached to the control valve that determines oil
flow for extending and retracting the crane boom. Lever is pushed forward to extend the boom and
pulled back to retract the boom.
11 CROWD CONTROL VALVE - Two-way hydraulic valve located directly below crowd control lever.
Valve directs hydraulic oil from the hydraulic pump to the crowd cylinder to extend and retract inner
boom assembly.
1-77

TM 9-2320-272-24-1

1-24. HYDRAULIC SYSTEM OPERATION (Contd)
(4) The major components for swinging the crane left and right for the SWING action are:

Key Item and Function
1 SWING MOTOR - Converts hydraulic power back into mechanical power needed to turn the crane
turntable when hydraulic fluid is forced through its worm gear. This gear turns a large gear at the
base of the turntable to swing the crane.
2 TURNTABLE ASSEMBLY - Driven by the swing motor through a ring gear at the base of the
assembly, permits the crane to swing 360 degrees.
3 SWING CONTROL LEVER - Manual control attached to the control valve that determines
hydraulic oil flow for swinging wrecker boom to the left and to the right. Lever is pushed inward for
left boom movement, and pulled outward for right boom movement.
4 SWING CONTROL VALVE - Two-way hydraulic valve located directly below swing control lever.
Valve directs hydraulic oil from the hydraulic pump to the swing motor assembly and back through
the valve to the hydraulic oil reservoir.
1-25. CENTRAL TIRE INFLATION SYSTEM (CTIS) OPERATION
The M939A2 Central Tire Inflation System (CTIS) uses the vehicle’s air compressor system, pneumatic
valves, and a microprocessor to adjust tire pressure according to mission demands. The system needs clean,
dry air to maintain itself. The turbocharger and aftercooler help supply more compressed air when the
vehicle is loaded and operating at high rpm.
Compressed air enters air dryer, which filters dirt and ejects moisture from air. System air then enters
the wet tank and is available to airbrakes and CTIS. The brake system is protected by an 85 psi (138 kPa)
pressure switch in CTIS air line. If wet tank air pressure measures below 85 psi (138 kPa), the CTIS shuts
down until pressure switch measures 120 psi (827 kPa).
Air is then routed to pneumatic controller, which consists of three valves and solenoids working in
conjunction with the Electronic Control Unit (ECU). The ECU is a microprocessor programmed to issue
commands based on information it receives from pressure switch, pressure transducer (which tests tire
pressure), and speed signal generator (which monitors vehicle speed). The commands are electrically
received by the pneumatic controller, which affects inflation or deflation of tires through quick-exhaust
valves.
Six wheel valves isolate tire pressure during normal operation. They also open to allow tire inflation or
tire deflation through three quick-exhaust valves.
The system is automatic. The operator only needs to select the mode that best accomplishes the mission.
1-78

TM 9-2320-272-24-1

CHAPTER 2
SERVICE AND TROUBLESHOOTING INSTRUCTIONS
Repair Parts; Tools; Special Tools; Test, Measurement, and
Diagnostic Equipment (TMDE); and Support Equipment (page 2-1)
Section II. Service Upon Receipt (page 2-1)
Section III. Unit Preventive Maintenance Checks and Services (PMCS) (page 2-2)
Section IV. Unit Troubleshooting Procedures (page 2-60)
Section I.

Section I. REPAIR PARTS; TOOLS; SPECIAL TOOLS; TEST, MEASUREMENT,
AND DIAGNOSTIC EQUIPMENT (TMDE); AND SUPPORT EQUIPMENT
2-1. SCOPE
This chapter provides mechanics with Preventive Maintenance Checks and Services (PMCS). Refer to
TM 9-2320-272-10 for additional PMCS procedures.

2-2. COMMON TOOLS AND EQUIPMENT
For authorized common tools and equipment, refer to the Modified Table of Organization and Equipment
(MTOE) applicable to your unit.

2-3. SPECIAL TOOLS, TMDE, AND SUPPORT EQUIPMENT
Special tools; Test, Measurement, and Diagnostic Equipment (TMDE); and support equipment used to
maintain the components covered in this manual can be found in Appendix B, Maintenance Allocation
Chart (MAC) and TM 9-2320-272-24P.

2-4. REPAIR PARTS
Repair parts are listed and illustrated in TM 9-2320-272-24P.

Section II. SERVICE UPON RECEIPT
2-5. GENERAL
a. Upon receipt of a new, used, or reconditioned vehicle, you must determine if the vehicle has been
properly prepared for service. The following steps should be performed:
(1) Inspect all assemblies, subassemblies, and accessories to ensure they are in proper working order.
(2) Secure, clean, lubricate, or adjust as needed.
(3) Check all Basic Issue Items (BII) (TM 9-2320-272-10) to ensure every item is present, in good
condition, and is properly mounted or stowed.
(4) Follow general procedures for all services and inspections given in TM 9-2320-272-10.
b. The operator will assist when performing service upon receipt inspections.
c. Refer to TM 9-2320-272-10 when testing equipment for proper operation.

2-1

TM 9-2320-272-24-1

2-6. GENERAL INSPECTION AND SERVICING INSTRUCTIONS
The following steps should be taken while performing general inspections and services:
a. Refer to TM 9-2320-272-10 and LO 9-2320-272-12, as well as other sections of this manual, when
servicing, inspecting, and lubricating equipment.
WARNING
Drycleaning solvent is flammable and will not be used near open
flame. Keep fire extinguisher nearby. Use only in well-ventilated
places. Failure to do so may result in injury to personnel.
b. Using drycleaning solvent, clean all exterior surfaces coated with rustpreventive compounds.
c. Read Processing and Deprocessing Record of Shipment, Storage, and Issue of Vehicles and Spare
Engines tag (DD Form 1397), and follow all precautions listed. This tag should be attached to steering
wheel, shift lever, or battery switch.
NOTE
If vehicle has been driven to using unit, all the above work should
have been completed.

2-7. SPECIFIC INSPECTION AND SERVICING INSTRUCTIONS
The following steps should be taken while performing specific inspections and services:
a. Perform the semiannual, six months or 6,000 miles (9,654 kilometers), unit Preventive Maintenance
Checks and Services (PMCS) listed in section III of this chapter.
b. Lubricate the vehicle according to the instructions found in LO 9-2320-272-12. Do not lubricate
gearcases or engine unless processing tag states that the oil is unsuitable for 500 miles (805 kilometers) of
operation. If oil is suitable, just check level.
c. Schedule semiannual service on DD Form 314 (Preventive Maintenance Schedule and Record).
d. If vehicle is delivered with a dry-charged battery, activate it according to TM 9-6140-200-14.
e. Check vehicle coolant level and determine if solution is proper for climate. (Refer to TB 750-651 for
preparation of antifreeze solutions.)

Section III. UNIT PREVENTIVE MAINTENANCE CHECKS AND SERVICES (PMCS)
2-8. GENERAL
The best way to maintain vehicles covered by this manual is to inspect them on a regular basis so
minor faults can be discovered and corrected before they result in serious damage, failure of vehicle and
equipment, or injury to personnel. This section contains systematic instructions for inspection, adjustment,
and correction of vehicle components to avoid costly repairs or major breakdowns. This is referred to as
Preventive Maintenance Checks and Services (PMCS).

2-9. INTERVALS
NOTE
Designated intervals are performed under usual operating conditions. PMCS must be performed more frequently when operating
under unusual conditions.

2-2

TM 9-2320-272-24-1

2-9. INTERVALS (Contd)
a. Unit maintenance, assisted by operator/crew, will perform the checks and services contained in
table 2-1 at the following intervals:
(1) Semiannual. Every 6 months or 6,000 miles (9,654 kilometers), whichever occurs first.
(2) Annual. Every 12 months or 12,000 miles (19,308 kilometers), whichever occurs first.
(3) Biennial. Every 24 months or 24,000 miles (38,616 kilometers), whichever occurs first.
b. Perform all semiannual inspections in addition to annual inspections at the time of the annual
inspection. Perform all annual and semiannual inspections in addition to biennial inspections at the time of
the biennial inspection.

2-10. REPORTING REPAIRS
All uncorrected defects will be recorded on Equipment Inspection and Maintenance Worksheet, DA Form
2404, in accordance with DA Pam 738-750.

2-11. GENERAL SERVICE AND INSPECTION PROCEDURES
a. While performing specific PMCS procedures, ensure items are correctly assembled, secure,
serviceable, not worn, not leaking, and adequately lubricated as defined below:
(1) An item is CORRECTLY ASSEMBLED when all parts are present and in proper position.
(2) When wires, nuts, washers, hoses, or attaching hardware cannot be moved by hand, wrench, or
prybar, they are secure.
(3) An item is UNSERVICEABLE if it is worn beyond established wear limits or is likely to fail
before the next scheduled inspection.
(4) An item is WORN if there is play between joining parts, or warning and caution plates are not
readable.
(5) LEAKS. TM 9-2320-272-10 contains definitions of class I, II, and III leaks and their effect on
vehicle operation.
(6) If an item meets the requirements specified by lubrication instructions, LO 9-2320-272-12, then it
is ADEQUATELY LUBRICATED.
b. Where the instruction “tighten” appears in a procedure, you must tighten with a wrench to the given
torque value even when the item appears to be secure.
WARNING
Drycleaning solvent is flammable and will not be used near open
flame. Keep fire extinguisher nearby. Use only in well-ventilated
places. Failure to do so may result in injury to personnel.
c. Where the instruction “clean” appears in a procedure, you must use drycleaning solvent,
Type II (SD-2) (PD-680) biodegradable, to clean grease or oil from metal parts. After the item is cleaned,
rinsed, and dried, apply a light grade of oil to unprotected surfaces to prevent rusting. To clean rubber
and plastic materials, use soap and water.
2-12. SPECIFIC PMCS PROCEDURES
a. The preventive maintenance checks and services for which you are responsible are provided in
table 2-1. The checks and services listed are arranged in logical order.
b. The following columns are left to right on the PMCS schedule:
(1) Item Number. Provides logical order for PMCS performance and is used as a source number for
DA Form 2404, on which your PMCS results will be recorded.
2-3

TM 9-2320-272-24-1

2-12. SPECIFIC PMCS PROCEDURES (Contd)
(2) Interval. Indicates when check or service is to be performed (para. 2-9).
(3) Item To Check/Service.
(a) Lists the system, common name, or location of the item to be inspected.
(b) The letters RPL in this column indicate replacement parts are required to complete the
or procedure. Check mandatory replacement parts list immediately following table 2-1.
(4) Procedure. Provides instructions for servicing, inspection, replacement, or adjustment and,
some cases, having an item repaired at a higher level. If a defect is found, repair, fill, replace, or adjust
needed.
(5) Not Fully Mission Capable If:. Provides information for deadlining a vehicle when checks
services reveal a defect or deficiency of a component(s) of the vehicle.

task
in
as
or

Table 2-1. Unit Preventive Maintenance Checks and Services.
ITEM INTERVAL
NO.

ITEM TO
CHECK/
SERVICE

1

Semiannual

Starter

2

Semiannual

Accelerator
pedal and
engine

3

Semiannual

Throttle

2-4

PROCEDURE

SEMIANNUAL INSPECTION
PRIOR TO ROAD TEST
Perform all Before operation and Weekly checks
listed in TM 9-2320-272-10 PMCS in addition to
those that follow.
Start engine (TM 9-2320-272-10). While starting engine,
listen for unusual noises and difficult cranking.

NOT FULLY
MISSION
CAPABLE IF:

Starter is inoperative or makes
excessive grinding
noise.
a. Accelerator
pedal is sticking or
binding.

a. Observe response to accelerator pedal.
1. Listen for unusual noises.
2. Observe for hesitation or varying idle speed.
3. Check for sticking or binding of pedal. If
accelerator pedal binds or sticks, troubleshoot (para. 2-21).
b. Be alert for excessive vibration, fuel odor, oil, coolant
b. Engine knocks,
rattles, or smokes
or exhaust dripping, and any indication of malfunction.
excessively.
Throttle control is
Check throttle control travel and freedom of movement.
sticking or binding.
Pull throttle control all the way out, rotate, and release.
Throttle control should return to original position. If
control sticks or binds, lubricate (LO 9-2320-272-12) or
replace (para. 3-45).

TM 9-2320-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).
ITEM
NO. INTERVAL

ITEM TO
CHECK/
SERVICE

PROCEDURE

NOT FULLY
MISSION
CAPABLE IF:

ROAD TEST
Perform all During operation checks listed in
TM 9-2320-272-10 PMCS in addition to those that
follow. Drive vehicle at least 5 mi. (8 km) over varied
terrain, both on and off road. This will provide
ample time to check reported malfunctions and to
locate unreported malfunctions.
Lubrication intervals of every 1,000 mi. (1,600 km)
or monthly, and 3,000 mi. (4,800 km) or 3 months,
will be performed with maintenance or, when
practical, lubrication services will be made to
coincide with the semiannual preventive
maintenance services. For this purpose, a 10 percent
tolerance (variation) in specified lubrication point
mileage is permissible.
Brakes
a. Check brake pedal for free travel. Adjust brake pedal
if required (para. 3-196).
b. Reach a desired speed and lightly apply brake pedal
with steady force. Vehicle should slow down immediately
and stop smoothly, without side pull or chatter.
c. After stopping vehicle, and with transmission select
lever in 1-5 (drive), release brake pedal. All wheel brakes
should release immediately and without difficulty.
NOTE
Engine
Ensure engine tachometer does not exceed
maximum governed speed of 2,400 rpm with no
load.
a. Check engine throughout the range of operating
speeds. Refer to TM 9-2320-272-10.
b. Check engine instruments. Refer to TM 9-2320-272-10
for proper readings.
a. Oil temperTransmisa. Check transmission oil temperature gauge. Normal
ature exceeds
range is 120o-220°F (49o-104°C).
sion
300°F (149°C).
b. Check for response to shifting and smoothness of
operation in all speed ranges. Refer to TM 9-2320-272-10
for proper shifting speed ranges.

3

SemiThrottle
annual (Contd)

4

Semiannual

5

Semiannual

6

Semiannual

7

SemiTransfer
annual case

8

Semiannual

Suspension

Shift transfer case lever between HI and LOW positions to
ensure proper operation. Observe for smoothness of
engagements. Refer to TM 9-2320-272-10 for proper
shifting speed ranges and operation.
Observe how vehicle responds to road shock. Constant
bouncing or swaying from side-to-side is an indication of a
malfunction.

2-5

TM 9-2320-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).
ITEM INTERVAL
NO.
9

Semiannual

ITEM TO
CHECK/
SERVICE
Emergency
engine stop
control

PROCEDURE
NOTE
Before M939/A1 series vehicles can be restarted,
fuel shutoff valve control lever under the hood
must be reset.
l This check will be performed with engine running,
transmission in N (neutral), and parking brake
applied.
Check emergency engine stop control:
1. Pull emergency engine stop control out until engine
stops. If engine does not stop before emergency engine stop
control is pulled completely out, place battery switch in the
OFF position, and troubleshoot (para. 2-21).
2. Push emergency engine stop control in until original
position is obtained.
l

AFTER ROAD TEST
Perform all After operation, Weekly, and Monthly
checks in TM 9-2320-272-10, then make the
following inspections in the order given, including
kit items on vehicles so equipped.
10

Semiannual

Air filter

WARNING
If NBC exposure is suspected, all filter media should
be handled by personnel wearing protective
equipment. Consult your unit NBC officer or NBC
NCO for appropriate handling or disposal instructions.
a. Inspect filter element for tears and presence of dirt
and oil.
1. If dirt is present, clean filter element
(TM 9-2320-272-10).
2. If oil is present, replace filter element.
b. Check for oil in air cleaner manifold. If present:
1. Check oil level in transmission and transfer case. If
oil levels are excessive, drain excess (para. 3-133).
2. Check for fuel diluting the oil. If necessary, change
oil and filters (para. 3-133).
3. If oil levels are low, check transfer case interlock
air cylinder for leaks (para. 3-143).

2-6

NOT FULLY
MISSION
CAPABLE IF:

Engine fails to shut
off.

TM 9-2320-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).

ITEM INTERVAL
NO.
11 Semiannual

ITEM TO
CHECK/
SERVICE

PROCEDURE

Batteries

WARNING

NOT FULLY
MISSION
CAPABLE IF:

Wear safety glasses or goggles when checking
batteries. Always check electrolyte level with engine
stopped. Do not smoke or use exposed flame when
checking batteries; explosive gases are present, and
severe injury to personnel can result.
l Remove all jewelry such as rings, dog tags,
bracelets, etc. If jewelry contacts battery terminal, a
direct short may result in instant heating of tools,
damage to equipment, and injury or death to
personnel.
l Remove or disconnect batteries, and turn master
battery disconnect switch off prior to performing
maintenance in immediate area or working on
electrical system. Such disconnections prevent
electrical shock to personnel and equipment.
l Ensure seatbelts do not come in contact with
electrolyte. Damage to strapping will result, leading
to injury or death.
l Ensure seatbelts are not caught inside battery box
when closing cover. Failure to do so will result in
injury or death.
a. Clean and inspect batteries (para. 3-125). Replace if
required.
b. Inspect battery box for security of mounting and
completeness of assembly (para. 3-128).
c. Inspect battery cables and terminals for frays, splits, and
security Repair battery cables or terminals (para. 3-131), or
replace as necessary (para. 3-124).
e. Inspect slave receptacle and wiring for security of
mounting and damage. Repair (para. 3-131), or replace if
damaged (para. 3-127).
f. Lightly coat battery terminals and slave receptacle
contacts with grease.
l

[RPL]

EXPECTED TEMPERATURES
LUBRICANTS

ABOVE 15°F
(ABOVE -9oC)

GAA
Grease, automotive and
artillery (MIL-G-10924)

+40oF TO -15°F
(+4oC TO -26°C)

+40oF TO -65°F
(+4oC TO -54°C)

All temperatures

g. Inspect seatbelts for serviceability and security of
mounting. Replace seatbelts if unserviceable or show signs of
contact with electrolyte (para. 3-289).

2-7

TM 9-2320-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).

ITEM INTERVAL
NO.

ITEM TO
CHECK/
SERVICE

11 SemiBatteries
annual (Contd)

NOT FULLY
MISSION
CAPABLE IF:

PROCEDURE

h. Lubricate hinges on battery box cover and map
compartment every 1,000 mi. (1,600 km) or monthly,
whichever occurs first.
EXPECTED TEMPERATURES

LUBRICANTS
OE/HDO
Lubricating oil, internal
combustion engine
(MIL-L-2104)
OEA
Lubricating oil, internal
combustion engine (arctic)
(MIL-L-46167)

ABOVE 15°F
(ABOVE -9oC)
OE/HDO 30

+40oF TO - 15°F
(+4oC TO -26oC)
OE/HDO 10

OEA

i. Inspect battery box cover and map compartment cover
and seals on both for condition and security of installation.
Replace seal(s) on battery box cover and/or map
compartment cover if damaged (para. 3-123).
12 Semiannual

Cab components

WARNING
If transmission oil temperature is above 220°F (104oC),
allow transmission oil to cool before removing dipstick.
CAUTION
Do not remove transmission dipstick before
cleaning dirt away from access plate, filler tube,
and dipstick. Dirt may enter and damage
transmission.
l
Do not overfill transmission. Internal
transmission component damage will result.
l
Change transmission oil when contamination by
fuel, water, and other foreign materials is evident.
Failure to do so may result in failure of internal
transmission components.
l
Shut off engine if transmission oil temperature
exceeds 300°F (149°C). Continuing to operate
transmission under these conditions may result in
failure of internal transmission components.
NOTE
Steps a. through c. apply to M939/A1 series vehicles
only. Transmission dipstick and temperature sending
unit cannot be accessed through cab floor on M939A2
series vehicles.
l

2-8

+40oF TO -65oF
(+4oC TO -54oC)

TM 9-2320-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).

ITEM INTERVAL
NO.

12 Semiannual

ITEM TO
CHECK/
SERVICE

Cab components
(Contd)

NOT FULLY
MISSION
CAPABLE IF:

PROCEDURE

a. Open access door in floor of cab. Lubricate access
door hinge every 1,000 mi. (1,600 km) or monthly,
whichever occurs first.
EXPECTED TEMPERATURES

LUBRICANTS

o

OE/HDO
Lubricating oil, internal
combustion engine
(MIL-L-2104)
OEA
Lubricating oil, internal
combustion engine (arctic)
(MIL-L-46167)

ABOVE 15 F
(ABOVE -9oC)
OE/HDO 30

+40oF TO -15°F
(+4oC TO -26oC)
OE/HDO 10

+40oF TO -65oF
(+4oC TO -54°C)

OEA

b. Inspect transmission dipstick and oil:
1. Check for evidence of metal particles. Notify
your supervisor if metal particles are found.
2. Check for evidence of dilution from coolant. If oil
is diluted by coolant, refer to para. 2-21, mechanical
troubleshooting.
3. Check oil level in transmission. If oil levels are
excessive, drain the excess (para. 3-133).
c. Inspect transmission temperature sending unit for
security of mounting and wiring for frays, splits, breaks,
and missing insulation.
d. On vehicles with winch, lubricate winch and Power
Takeoff (PTO) control levers every 1,000 mi. (1,600 km) or
monthly, whichever occurs first.
e. Lubricate power brake treadle with 3-4 drops of
oil every 1,000 mi. (1,600 km) or monthly, whichever
occurs first.
EXPECTED TEMPERATURES
LUBRICANTS
OE/HDO
Lubricating oil, internal
combustion engine
(MIL-L-2104)
OEA
Lubricating oil, internal
combustion engine (arctic)
(MIL-L-46167)

o

ABOVE 15 F
(ABOVE -9oC)
OE/HDO 30

+40oF TO -15oF
(+4oC TO -26°C)
OE/HDO 10

+40oF TO -65oF
(+4oC TO -54oC)

OEA

2-9

TM 9-2320-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).

ITEM INTERVAL
NO.
12 Semiannual

ITEM TO
CHECK/
SERVICE
Cab components
(Contd)

NOT FULLY
MISSION
CAPABLE IF:

PROCEDURE

f. Lubricate transfer case shift linkage pins every
1,000 mi. (1,600 km) or monthly, whichever occurs first.
g. On M929/A1/A2 and M930/A1/A2 vehicles, lubricate
dump lever and crossshaft every 1,000 mi. (1,600 km) or
monthly, whichever occurs first (LO 9-2320-272-12).
EXPECTED TEMPERATURES

LUBRICANTS
GAA
Grease, automotive and
artillery (MIL-G-10924)
OE/HDO
Lubricating oil, internal
combustion engine
(MIL-L-2104)

13 Semiannual

Front
winch

ABOVE 15oF
(ABOVE -9oC)

+40oF TO -15oF
(+4oC TO -26°C)
All temperatures

OE/HDO 30

OE/HDO 10

+40oF TO -65oF
(+4oC TO -54oC)

h. Inspect instrument panel cluster and cab portion of
front wiring harness for frays, splits, missing or damaged
insulation, or poor connections. Repair or replace affected
wiring (para. 3-131).
a. Inspect winch for security of mounting, loose or missing
mounting bolts, and broken or missing parts (para. 3-329).
WARNING
Wire rope can become frayed or contain broken
wires. Wear heavy leather-palmed work gloves
when handling wire rope. Frayed or broken wires
can injure hands.
l Never let moving wire rope slide through hands,
even when wearing gloves. A broken wire could
cut through glove and cut hand.
b. Unwind entire cable, soak and clean with new oil, and
inspect for kinks, frays, and wear. Refer to TM 9-2320-272-10
for operation.
l

EXPECTED TEMPERATURES
LUBRICANTS
CW
Lubricating oil (VV-L-751)
Oil lubricating, multipurpose
(MIL-L-2105) GO-75

ABOVE
+80°F(+27oC)
CW-11C

o

o
+80 F TO +30
F +30oF TO -30oF
-30’
TO -65o
o
o
(27°C TO -1 C) (-1°C TO -34°C) (-34 TO -54°C)
CW-11A
CW-11B

c. On M936/A1 vehicles, lubricate sheave bearing (1),
swivel fitting (3), trolley wheel (4), and level wind frame (2)
every 3,000 mi. (4,800 km) or 6 months, whichever comes
first. If operation is frequent, continuous, or under severe
conditions, service weekly (LO 9-2320-272-12).
2-10

GO-75

TM 9-2320-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).
ITEM TO
ITEM INTERVAL C H E C K /
NO.
SERVICE

PROCEDURE

NOT FULLY
MISSION
CAPABLE IF:

d. Lubricate tensioner sheave pins (5), vertical cable
rollers (6), and horizontal cable rollers (7) every
3,000 mi. (4,800 km) or 6 months, whichever occurs first.
If operation is frequent, continuous, or under severe
conditions, service weekly (LO 9-2320-272-12).
EXPECTED TEMPERATURES
LUBRICANTS
+40°F TO -65°F
+40°F TO -15°F
ABOVE 15°F
(+4°C TO -54°C)
(+4°C TO -26°C)
(ABOVE -9°C)
All temperatures
GAA
Grease, automotive and

13 Semiannual

Front
winch
(Contd)

2-11

TM 9-2320-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).

ITEM INTERVAL
NO.

13

Semiannual

ITEM TO
CHECK/
SERVICE

Front
winch
(Contd)

NOT FULLY
MISSION
CAPABLE IF:

PROCEDURE

e. Check gearcase level.
1. Clean around and remove oil level sight plug (6),
and check oil level.
NOTE
Perform steps 2 through 4 only if oil level is low.
2. Clean around and remove gearcase fill plug (2). If
necessary to drain, remove drain plug (7) and reinstall.
3. Fill to bottom opening of oil level sight plug (6).
4. Install filler plug (2) and oil level sight plug (6).
f. Check end frame oil level.
1. Clean around and remove end frame level plug (8)
and fill plug (1) and check end frame gearcase oil level.
NOTE
Perform steps 2 and 3 only if oil level is low.
2. Fill to opening of level plug (8) and install level
plug (8).
3. Install filler plug (1).
g. Check sight plug (6) and filler plug (2) on gearcase and
filler plug (1), level plug (8), and drain plug (9) on end
frame for tightness.
EXPECTED TEMPERATURES

LUBRICANTS
Oil, lubricating, multipurpose
(MIL-L-2105) GO-80/90
Oil, lubricating, multipurpose
(MIL-L-2105) GO-75

ABOVE 15°F
(ABOVE -9°C)
GO-80/90

+4O°F TO -15°F
(+4°C TO -26°C)
GO-80/90

+4O°F TO -65°F
(+4°C TO -54°C)

GO-75

h. On M936/A1 model vehicles, lubricate trolley lock (3)
every 1,000 mi. (1,600 km) or monthly, whichever occurs
first.
i. Lubricate drum lock (4), and tensioner control lever
lock (5) every 1,000 mi. (1,600 km) or monthly, whichever
occurs first.
EXPECTED TEMPERATURES
LUBRICANTS
OE/HDO
Lubricating oil, internal combustion engine (MIL-L-2104)
OEA
Lubricating oil, internal combustion engine (arctic) (MIL-L-46167)

2-12

ABOVE 15°F
(ABOVE -9°C)
OE/HDO 30

+40°F TO -15°F
(+4°C TO -26°C)
OE/HDO 10

+40°F TO -65°F
(+4°C TO -54°C)

OEA

TM 9-2320-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).
ITEM TO
ITEM INTERVAL C H E C K /
NO.
SERVICE

PROCEDURE

NOT FULLY
MISSION
CAPABLE IF:

2-13

TM 9-2320-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).

ITEM INTERVAL
NO.

ITEM TO
CHECK/
SERVICE

13 Semiannual

Front
winch
(Contd)

14

Hood

Semiannual

NOT FULLY
MISSION
CAPABLE IF:

PROCEDURE

j. Test drag brake for proper operation (para. 3-324).
k. Test winch automatic brake for proper operation
(para. 3-323).
a. Inspect hood support bar and locking pins for
condition and security of mounting. If support bar or
locking pins are defective, repair or replace as required
(para. 3-269).
b. Inspect hood stop cables for condition and security of
mounting. If stop cables are defective, repair or replace as
required (para. 3-270).
c. Lubricate hood trunnion every 3,000 mi. (4,800 km) or
3 months, whichever occurs first.
EXPECTED TEMPERATURES

LUBRICANTS

ABOVE 15°F
(ABOVE -9°C)

+40°F TO -15°F
(+4°C TO -26°C)

+40°F TO -65°F
(+4°C TO -54°C)

All temperatures

GAA
Grease, automotive and
artillery (MIL-G-10924)

d. Lubricate hood hinges every 1,000 mi. (1,600 km) or
monthly, whichever occurs first.
EXPECTED TEMPERATURES
LUBRICANTS
OE/HDO
Lubricating oil, internal
combustion engine
(MIL-L-2104)
OEA
Lubricating oil, internal
combustion engine (arctic)
(MIL-L-46167)
15

Semiannual

16

Semiannual

2-14

Front
lights and
cable
assembly
Motor
mount
trunnions

ABOVE 15°F
(ABOVE -9°C)

+40°F TO -15°F
(+4°C TO -26°C)

OE/HDO 30

OE/HDO 10

Inspect front light cable assembly wiring for frays,
splits, missing or damaged insulation, or poor
connections. Repair affected wiring (para. 3-131).
a. Check two front engine mounting trunnion screws
for tightness. If engine mounting trunnion screws are
loose, notify your supervisor.
b. Tighten five lower trunnion mount screws 65-75 lb-ft
(88-102 N·m).
c. On M939A2 series vehicles, check two front mounting
locknuts for tightness. Tighten mounting locknuts
75-85 lb-ft (102-115 N·m).

+40°F TO -65°F
(+4°C TO -54°C)

OEA

TM 9-2320-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).

ITEM INTERVAL
NO.

17

18

Semiannual

Semiannual

ITEM TO
CHECK/
SERVICE

Emergency
and service
compressed
air systems

PROCEDURE

NOT FULLY
CAPABLE IF:

a. Inspect front emergency and service air and dummy
couplings for serviceability and seals.

NOTE
Inspection of emergency and service air lines and
fittings will be accomplished over complete vehicle.
Tighten, repair, and/or replace components of these
compressed air systems as required. If maintenance is
required at a higher level, records should reflect closest
point of reference to ensure proper identification of
components requiring service.
b. Inspect air lines, fittings, and emergency shutoff valve
for security of mounting, tightness of connections, and
damage that could cause air leaks (para. 2-15).
c. Ensure front emergency shutoff valve is closed and
emergency and service air and dummy couplings are securely
fastened (TM 9-2320-272-10).
NOTE
Inspection of crossmembers, bolts, and rivets will be
accomplished over complete vehicle. Tighten, repair,
and/or replace components of the frame as required.
If maintenance is required at a higher level, records
should reflect closest point of reference to ensure
proper identification of components requiring service.
Frame and Inspect crossmembers for missing rivets, screws,
Screws or rivets are
crossobstructions to other components, and breaks
loose or missing.
members
(TM 9-2320-247-40).
1. Using a 0.001 in. feeler gauge, check for space
between rivet head and the riveted frame members.
Penetration of the feeler gauge between the rivet head
and riveted member is reason to suspect the riveted
connection and/or rivet should be replaced.
2. Thoroughly clean, grease, and oil rivet. Using an oil
can, apply lubricating oil around the connection. Allow
approximately 10-20 seconds for oil to penetrate. Wipe
rivet and riveted connection free of oil. Tap rivet with an
8-pound hammer. Any indication of oil around the
rivet indicates a loose rivet. Replace all loose rivets
(TM 9-2320-247-40). Check all riveted connections for
signs of movement, such as bare or shiny spots or other
indications of movement between rivet and frame. If
movement is indicated, rivet and connection are loose.

2-15

TM 9-2320-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).

ITEM INTERVAL
NO.

19

Semiannual

ITEM TO
CHECK/
SERVICE

Front
wheels,
hubs, and
drums

PROCEDURE

FRONT WHEELS, HUBS, DRUMS, BRAKES,
SPRINGS, AXLE, AND STEERING
WARNING
· Completely deflate tire before removing from axle
if there is obvious damage to wheel components.
Injury or death to personnel may result from
exploding wheel components.
· Use caution when inflating tires. Ensure tire is in
a tire cage and properly seated on rim before
inflating. An improperly seated tire can burst
with explosive force. Failure to comply can cause
death or serious injury to personnel.
· Do not work on any component supported only by
lift jacks or hoist. Always use blocks or proper
stands to support the component prior to any
work. Equipment may fall and cause injury or
death to personnel.
· Air in system is under pressure. Ensure engine is
shut down and all air reservoirs are drained
before disconnecting CTIS components to prevent
serious injury to personnel.
NOTE
· Similar left and right side components are
inspected in the same manner and will be
accomplished simultaneously. Procedures cover
left side only.
· When documenting discrepancies for similar left
and right side components, indicate which side is
affected.
· To simplify maintenance, perform items 19a
through 19g simultaneously with items 20a
through 20c.
a. On M939 series vehicles, inspect split locking ring (2)
for dents or breaks that could cause them to pop off. If
ring is loose, break wheel (4) down and inspect for damage
to rim (1) or tire (3). Replace any damaged wheel
components (para. 3-221).
b. On M939A1/A2 series vehicles, inspect wheels (4) for
loose or missing rim nuts (5). Tighten rim nuts (5)
210-240 lb-ft (285-325 N·m). Replace any rim stud (6)
that is broken or has stripped threads (para. 3-222).
c. Inspect axle drive companion flange for oil leaks. If oil
appears to be leaking from expansion plug (8) on axle
drive companion flange (7), notify your supervisor.

2-16

NOT FULLY
MISSION
CAPABLE IF:

TM 9-2320-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).

ITEM INTERVAL
NO.

ITEM TO
CHECK/
SERVICE

PROCEDURE

NOT FULLY
MISSION
CAPABLE IF:

2-17

TM 9-2320-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).
ITEM TO
ITEM INTERVAL CHECK/
NO.
SERVICE
19

Semiannual

CAUTION

Front
wheels,
hubs, and
drums
(Contd)

[RPL]

NOT FULLY
MISSION
CAPABLE IF:

PROCEDURE

On M939A2 series vehicles, use care not to damage
CTIS air seals when removing axle components.
Failure to do so may result in further damage to
axle and wheel bearings, in addition to improper
operation of CTIS system.
NOTE
Lugnuts on left side have left-hand threads and can
be identified by an L, while lugnuts on right side
have right-hand threads, and can be identified by
an R.
d. Clean, inspect, and lubricate axle shaft and universal
joints (para. 3-154).
EXPECTED TEMPERATURES

LUBRICANTS

ABOVE 15°F
(ABOVE -9°C)

All temperatures

GAA
Grease, automotive and
artillery (MIL-G-10924)

[RPL]

+40°F TO -15°F
(+4°C TO -26°C)

1. Check bearing sleeve inside spindle for signs of
damage. If bearing sleeve is damaged, notify DS
maintenance.
2. Replace drive flange gasket with RTV sealant.
e. On M939A2 series vehicles, replace filter in wheel
valves (para. 3-448).
WARNlNG
Do not allow grease or oil to contact brake linings.
Linings can absorb grease and oil, causing early
glazing and very poor braking action. Failure to
comply could cause serious injury or death to
personnel.
f. Check brakeshoes for condition and brakeshoe-to-drum
clearance (para. 3-179). Replace brakeshoes if worn beyond
chamfer on linings (para. 3-180).
g. Inspect CV boots for rips, cracking, punctures, and
other damage that could cause a loss of lubrication around
CV joint. Replace CV boots if ripped, cracked, punctured,
or damaged (para. 3-223).

2-18

+40°F TO -65°F
(+4°C TO -54°C)

TM 9-2320-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).
ITEM TO
ITEM INTERVAL CHECK
NO.
SERVICE

20 Semiannual

21

Semiannual

PROCEDURE

NOT FULLY
MISSION
CAPABLE IF:

Air lines
a. Inspect front service brake air lines and fittings
and brake for loose connections, cracks, splits, or damage that could
chambers cause potential air leaks. Tighten loose air lines and
fittings connections, and replace any air line or fitting that
has cracks, splits, or damage that could cause potential
air leaks.
b. Inspect front service brake chambers for condition and
security of mounting. Replace any service brake chamber
that is damaged, defective, or inoperative (para. 3-181).
NOTE
Inspection of CTIS air lines and fittings will be
accomplished over complete vehicle. Tighten, repair,
and/or replace components of the compressed air
system as required. If maintenance is required at a
higher level, records should reflect closest point of
reference to ensure proper identification of
components requiring service.
c. On M939A2 series vehicles, inspect CTIS air lines and
fittings for loose connections, cracks, splits, or damage
that could cause potential air leaks.
a. Inspect steering knuckles, steering gear, tie rod
Steering
system
assembly, steering arms, drag link, pitman arm, lower
steering gear shaft, and power steering cylinder for breaks,
cracks, rust, wear, and signs of unserviceable condition.
1. Treat for corrosion of steering knuckles, tie rod
assembly, steering arms, drag link, pitman arm, or
steering gear shaft.
2. Replace tie rod assembly, drag link, pitman arm,
lower steering gear shaft, or power steering cylinder if
broken, cracked, worn, or signs of an unserviceable
condition are present.
3. If steering knuckles, steering arms, or steering
gear are broken, cracked, worn, or have other signs of an
unserviceable condition, notify DS maintenance.

2-19

TM 9-2320-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).
ITEM TO
ITEM INTERVAL CHECK/
NO.
SERVICE

21

Semiannual

Steering
system
(Contd)

PROCEDURE

NOT FULLY
MISSION
CAPABLE IF:

NOTE
Lubricate grease fittings every 3,000 mi. (4,800 km)
or 3 months, whichever occurs first. When practical,
lubrication services will be made to coincide with
the semiannual preventive maintenance service. For
this purpose, a 10 percent tolerance (variation) in
specified lubrication point mileage is permissible.
b. Lubricate at steering knuckle grease fittings (1), tie
rod assembly grease fittings (4), steering shaft grease
fittings (7) and (8), drag link grease fittings (2), and power
steering assist cylinder grease fittings (6).
EXPECTED TEMPERATURES

LUBRICANTS
GAA
Grease, automotive and
artillery (MID-G-10924)

ABOVE 15°F
(ABOVE -9°C)

+40°F TO -15°F
(+4°C TO -26°C)
All temperatures

+40°F TO -65°F
(+4°C TO -54°C)

NOTE
An assistant is required to perform the following
step.
c. Inspect steering stops for presence and security.
If any stop is missing or has broken welds, notify DS
maintenance.
d. With engine shut off, turn steering wheel slowly
d. Movement
right and left.
between cross and
1. Inspect steering gear U-joints while steering wheel cap is present.
is rotated.
2. Check for free play between steering knuckles
and tie rod ends, power assist cylinder, and drag link and
pitman arm to drag link. If free play is present, tighten
four steering knuckle nuts (5) and drag link-to-pitman arm
nut (3) 140-180 lb-ft (190-244 N·m). Tighten to minimum
torque and continue to tighten as needed to align slot in
nut and cotter pin hole. Do not tighten over 275 lb-ft
(373 N·m).
3. Repeat step 2. If free play is still present, notify
DS maintenance.
e. Inspect power steering assist assembly.
1. Remove stone shield (para. 3-231).
2. Inspect power steering assist cylinder for
condition and security of mounting (para. 3-233).

2-20

TM 9-2320-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).
ITEM TO
ITEM
INTERVAL CHECK/
NO.
SERVICE

21 Semiannual

Steering
system
(Contd)

PROCEDURE

NOT FULLY
MISSION
CAPABLE IF:

3. Inspect hydraulic hoses and fittings between frame
and cylinder for loose connections, cracks, splits, or damage
that could cause hydraulic leaks. Tighten hydraulic lines
and fittings connections. Replace ant hydraulic line or
fitting that has cracks, splits, or damage that could cause
hydraulic leaks (para. 3-232).
4. Install stone shield (para. 3-231).

2-21

TM 9-2320-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).

ITEM
NO. INTERVAL

21

2-22

Semiannual

ITEM TO
CHECK/
SERVICE

Steering
system
(Contd)

PROCEDURE

f. Inspect power steering pump for security of mounting,
leaks, and signs of damage. Tighten loose mounting
hardware.
g. On M939/A1 series vehicles, inspect power steering
pump belts for tension and serviceability (para. 3-230).
h. Inspect power steering pressure and return hoses and
fittings for loose connections, cracks, splits, or damage
that could cause potential hydraulic leaks. Tighten loose
hydraulic lines and fittings, and replace any hydraulic line
or fitting that has cracks, splits, or damage that could
cause potential hydraulic leaks. Refer to para. 3-234 for
Ross steering gear, or para. 3-235 for Sheppard
steering gear.
i. Inspect power steering hydraulic lines between steering
gear and steering assist cylinder and fittings for security of
mounting, loose connections, cracks, splits, or damage that
could cause hydraulic leaks. Tighten loose hydraulic lines and
fittings, and replace any hydraulic line or fitting that has
cracks, splits, or damage that could cause hydraulic leaks
(para. 3-239).
j. Inspect steering gear for security of mounting and
signs of leaks.
1. Loosen bracket mounting screws (1).
2. Tighten steering gear mounting locknuts (2)
260-280 lb-ft (353-380 N·m).
3. Tighten locknuts (3) 60-70 lb-ft (81-95 N·m).

NOT FULLY
MISSION
CAPABLE IF:

TM 9-2320-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).
ITEM INTERVAL
NO.

22

Semiannual

ITEM TO
CHECK/
SERVICE

Front
springs,
propeller
shaft,
universal
and slip
joints,
and axle

PROCEDURE

NOT FULLY
MISSION
CAPABLE IF:

a. Inspect axle (4) for security of mounting on springs (7).
Tighten nuts (5) on spring U-bolts (3) 350-400 lb-ft
(475-542 N·m).
b. Inspect springs (7) and shackles (8) for cracks,
breaks, and security of mounting. Tighten spring
shackle mounting nuts (6) 70 lb-ft (95 N·m).
CAUTION
Wipe fittings clean before servicing to prevent
damage to shackle pins and bushings.
c. Lubricate spring U-bolts (3) and shackles (8) every
3,000 mi. (4,800 km) or 6 months, whichever occurs first.

2-23

TM 9-2320-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).

ITEM INTERVAL
NO.

22

Semiannual

ITEM TO
CHECK/
SERVICE

Front
springs,
propeller
shaft,
universal
and slip
joints,
and axle
(Contd)

PROCEDURE

NOT FULLY
MISSION
CAPABLE IF:

1. Apply lubricant to spring pins (1) until it
appears between front spring pin (1) and bushing (3) at
both ends of shackle (2). If spring pin (1) does not accept
lubricant, remove spring pin (1).

EXPECTED TEMPERATURES
LUBRICANTS

ABOVE 15°F
(ABOVE -9°C)

GAA
Grease, automotive and
artillery MIL-G-10924)

+40°F TO -15°F
(+4°C TO -26°C)
All temperatures

2. Inspect front spring pin (1) and bushing (3) at
both ends of shackle (2) (para. 3-163).

2-24

+40°F TO -65°F
(+4°C TO -54°C)

TM 9-2320-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).

ITEM INTERVAL
NO.

12 Semiannual

ITEM TO
CHECK/
SERVICE

Front
springs,
propeller
shaft,
universal
and slip
joints,
and axle
(Contd)

NOT FULLY
MISSION
CAPABLE IF:

PROCEDURE

NOTE
Lubrication of universal and slip joints will be
accomplished while performing other inspection
tasks in that same area. Tighten, repair, and/or
replace components of universal, slip joints, and
propeller shafts when found to be damaged or worn,
as required. If maintenance is required at a higher
level, records should reflect closest point of reference
to ensure proper identification of components
requiring service.
d. Lubricate universal and slip joints on transfer
case-to-front axle propeller shaft adapter every 3,000 mi.
(4,800 km) or 3 months, whichever occurs first.
e. Inspect universal and slip joints on transfer
case-to-front axle propeller shaft for damage or worn
components. Replace worn components (para. 3-149).
CAUTION
Breathers and axle around breathers must be wiped
clean before servicing to prevent damage to axle
from contamination.
f. Remove, clean, and lubricate axle breathers every
1,000 mi. (1,600 km) or monthly, whichever occurs first
(para. 3-154).
EXPECTED TEMPERATURES

LUBRICANTS
OE/HDO
Lubricating oil, internal
combustion engine
(MIL-L-2104)
OEA
Lubricating oil, internal
combustion engine (arctic)
(MIL-L-46167)

ABOVE 15°F
(ABOVE -9°C)
OE/HDO 30

+40°F TO -15°F
(+4°C TO -26°C)
OE/HDO 10

+40°F TO -65°F
(+4°C TO -54°C)

OEA

2-25

TM 9-2350-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).

ITEM INTERVAL
NO.

22

Semiannual

ITEM TO
CHECK/
SERVlCE

Front
springs,
propeller
shaft,
universal
and slip
joints,
and axle
(Contd)

NOT FULLY
MISSION
CAPABLE IF:

PROCEDURE

g. Remove differential fill plug (1) and check oil level
in differential (4) every 3,000 mi. (4,800 km) or 3 months,
whichever occurs first. Fill if necessary. Level should be
within 1/2 in. (12.7 mm) from hole of fill plug (1) when oil
is cold, and to the hole of fill plug when hot.

EXPECTED TEMPERATURES
LUBRICANTS
Oil, lubricating, multipurpose,
(MIL-L-2105): GO-80/90
Oil, lubricating, multipurpose,
(MIL-L-2105): GO-75

ABOVE 15°F
(ABOVE -9°C)
GO-80/90

+40°F TO -15°F
(+4°C TO -26°C)
GO-80/90

h. Inspect differential drainplug (3) and fill plug (1) for
tightness and signs of leakage. Tighten drainplug (3)
35-60 lb-ft (47-81 N·m) and fill plug (1) 80-135 lb-ft
(108-183 N·m).
i. Inspect differential seals (2) for leaks.

23 Semiannual

2-26

Underside a. Inspect underside of engine for fuel, water, and
of engine oil leaks.
and trans- b. Inspect oil pan and drainplug for leaks. If oil pan is
m i s s i o n loose or if leaks are present, tighten oil pan screws
35-40 lb-ft (47-54 N•m). If drainplug is loose or if leaks are
present, tighten drainplug 100 lb-ft (136 N•m) (M939/A1
vehicles), 60 lb-ft (80 N•m) (M939A2 vehicles). Notify your
supervisor if leaks still occur.
c. Inspect transmission body for cracks or loose bolts that
could cause leaks.
d. Inspect transmission shift linkage for bends, cracks,
and wear that could cause failure.
e. Tighten transmission oil pan mounting bolts 5 lb-ft
(7 N•m). Tighten oil pan drainplug 15-20 lb-ft (20-27 N•m).

+40°F TO -65°F
(+4°C TO -54°C)

GO-75

TM 9-2320-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).

ITEM INTERVAL
NO.

24

Semiannual

ITEM TO
CHECK/
SERVICE

Cooling
system

PROCEDURE

NOT FULLY
MISSION
CAPABLE IF:

a. Inspect coolant lines, hoses, and fittings for loose
connections, cracks, frays, wear, and damage that could
cause leaks. Tighten loose connections. Replace any oil
line, hose, or fitting that is cracked, frayed, worn, or
damaged and could cause leaks.
b. Inspect fan actuator and sensor for security of
mounting. Inspect air hoses and fittings for loose
connections, cracks, frays, wear, and damage that could
cause leaks. Tighten loose connections. Replace any air
line, hose, or fitting that is cracked, frayed, worn, or
damaged and could cause leaks.
c. Inspect radiator core for clogged or bent fins, leaks,
and protruding debris, Clean clogged core and remove
debris (para. 2-15).
d. On M939A2 series vehicles, inspect power steering
cooler core for clogged or bent fins, leaks, and protruding
debris. Clean clogged core and remove debris (para. 2-15).
e. Inspect water pump vent/drain for obstructions.
f. Inspect water pump pulley and fan for play.
g. Check drivebelt(s) for proper tension.
1. For M939A2 series vehicles, check belt tensioner
for security of mounting 30 lb-ft (41 N•m) and condition
of fan drivebelt (para. 3-71).
2. For M939/A1 series vehicles, check fan drivebelt
tension and adjust as required (para. 3-70).
3. For M939/A1 series vehicles, check power steering
pump drivebelt tension (para. 3-230).
4. For M939/A1 series vehicles, check water pump
drivebelt tension and adjust as required (para. 3-67).
5. For M939/A1 series vehicles, check alternator
drivebelt tension (para. 3-78).
h. Inspect fan blade for security, breaks, missing or loose
screws and rivets, and damage which could cause an
out-of-balance condition. For M939/A1 series vehicles,
refer to para. 3-72, and for M939A2 series vehicles, refer
to para. 3-64. Replace fan blade as required.
i. Inspect surge tank, water manifold, thermostat
housing, radiator, engine oil cooler, transmission oil cooler,
and hoses for leaks, condition, and security of mounting(s).
j. Inspect temperature sending unit for security of
mounting. Inspect sending unit wiring for frays, splits,
breaks, and worn or missing insulation.
k. Check antifreeze protection temperature and adjust
if necessary to meet environmental conditions (para. 3-53).

2-27

TM 9-2320-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).
ITEM TO
ITEM INTERVAL C H E C K /
TO
SERVICE

25

Semiannual

26

Semiannual

2-28

Compressor

PROCEDURE

a. Check compressor for security of mounting and leaks.
l. If M939/A1 series engine-mounted compressor is
loose, notify DS maintenance.
2. If M939A2 series engine-mounted compressor is
loose, replace locknut and tighten to 55 lb-ft (77 N•m).
b. Check condition and security of cooling lines to air
compressor. Tighten cooling lines, if loose. Replace cooling
lines if split, cracked, or damaged in such a manner as
to cause leaks (para. 3-55).
c. On M939A2 series engines, check condition of
compressor oil line and fittings. Tighten fittings and oil
line if loose. Replace oil line if split, cracked, worn, or
damaged in such a manner as to cause leaks (para. 3-206).
d. Check condition and security of input tube and hoses,
output air line, and governor control air line. Tighten
output and governor control air lines, if loose. Replace
input tube or hoses if split, cracked, collapsed, distorted,
or damaged in such a manner as to prevent a tight seal or
restrict incoming air (para. 3-55).
a. Inspect all engine oil lines, hoses, and fittings for
Engine
lubrication
loose connections, cracks, frays, wear, and damage
system and that could cause leaks. Tighten loose connections, and
oil lines
replace any oil lines, hoses, and fittings that are cracked,
frayed, worn, or damaged and could cause leaks.
NOTE
• Oil filter is located on lower front left side of
engine on M939/A1 series vehicles and lower front
right side of engine on M939A2 series vehicles.
• M939/A1 series vehicles utilize an element-type
engine oil filter, while M939A2 series vehicles use
one of two styles of cartridge-type engine oil
filters.
b. Inspect M939/A1 series vehicles for security of oil
filter housing. Ensure filter center bolt is tight. If center
bolt is loose, tighten 25-35 lb-ft (34-48 N•m).
c. Inspect M939A2 series vehicles for security of oil
filter head. Ensure spin-on oil filter is tight. If spin-on oil
filter is loose, hand-tighten, then tighten an additional
3/4 turn with a wrench.
d. Check engine oil and dipstick for metal particles.
Notify DS maintenance if metal particles are found.

NOT FULLY
MISSION
CAPABLE IF:

TM 9-2320-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).

ITEM
NO.

16

INTERVAL

Semiannual

ITEM TO
CHECK/
SERVICE

Engine
lubrication
system and
oil lines
(Contd)

PROCEDURE

NOT FULLY
MISSION
CAPABLE IF:

WARNING
Accidental or intentional introduction of liquid
contaminants into the environment is in violation of
state, federal, and military regulations. Refer to
Army POL (para. 1-8) for information concerning
storage, use, and disposal of these liquids. Failure to
do so may result in injury or death.
NOTE
• Sample oil every 60 days or 1,000 mi. (1,600 km),
whichever occurs first. Army Reserve units will
sample oil every 120 days or 1,000 mi. (1,600 km).
• When AOAP laboratory support is not available,
change engine oil every 6,000 mi. (9,600 km) or
6 months, whichever occurs first.
• Engine AOAP sampling valve on M939/A1 series
vehicles is located on right side of engine attached
to oil cooler, On M939A2 series vehicles, valve is
located near starter on left side of engine.

e. Collect engine oil sample (para. 3-10) or change oil
(para. 3-5) as required.
EXPECTED TEMPERATURES
LUBRICANTS
+40°F TO -65°F
+40°F TO -15°F
ABOVE 15°F
(+4°C TO -26°C) (+4°C TO -54°C)
(ABOVE -9°C)
OE/HDO 10
OE/HDO 30
OE/HDO
Lubricating oil, internal
combustion engine
(MIL-L-2104)
OEA
OEA
Lubricating oil, internal
combustion engine (arctic)
(MIL-L-46167)
f. Inspect valve cover(s) and gasket(s) for evidence of
leaks. Notify DS maintenance if leak(s) are detected.
[RPL]

2-29

TM 9-2320-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).
ITEM TO
ITEM INTERVAL CHECK/
NO.
SERVICE

1 7 Semiannual

Fuel
system
engine

[RPL]

[RPL]

[RPL]

NOT FULLY
MISSION
CAPABLE IF:

PROCEDURE

NOTE
• Steps a. and b. apply to M939A1series vehicles
and step e. applies to M939A2 series vehicles.
All other steps are common to both vehicles.
• Replace fuel filter every 3,090 mi. (4,800 km) or
3 months, whichever occurs first.
a. Replace filter in standard AFC fuel pump on all
M939/A1 series vehicles except M936/A1 models
(para. 3-31) or in VS fuel pump on M936/A1 models
(para. 3-32).
b. Inspect fuel filter/water separator mounting and
housing for dents and cracks, and damage to inlet, outlet,
and bleeder fittings that could cause leaks (para. 2-15).
c. Install new fuel filter element on M939/A1 series
vehicles, or new fuel filter on M939A2 series vehicles
(para. 3-30).
d. Inspect fuel lines for tightness of connections
(para. 3-29).
e. Check fuel system components of M939A2 series
vehicles.
1. Inspect fuel injector lines, injector pump lines, and
manifold line and screws for leaks and damage. Tighten
fuel injector lines, injector pump lines, and manifold line
and screws if leaking, and replace if damaged (para. 3-18).
2. Inspect injector line holddown screws for security
of mounting. If loose, tighten (para. 3-18).
3. Replace in-line fuel filter (para. 3-30).
f. Check fuel priming pump on M939/A1 series vehicles
or fuel priming/transfer pump on M939A2 series vehicles
for security of mounting and proper operation.
g. Lubricate throttle control and modulator linkages.
EXPECTED TEMPERATURES

LUBRICANTS
OE/HDO
Lubricating oil, internal
combustion engine
(MIL-L-2104)
OEA
Lubricating oil, internal
combustion engine (arctic)
(MIL-L-46167)

2-30

ABOVE 15°F
(ABOVE -9°C)
OE/HDO 30

+40°F TO -15°F
(+4°C TO -26°C)
OE/HDO 10

+40°F TO -65°F
(+4°C TO -54°C)

OEA

TM 9-2320-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).
ITEM TO
ITEM INTERVAL
CHECK/
NO.
SERVICE

28

Semiannual

29

Semiannual

30

Semiannual

31

Semiannual

PROCEDURE

NOT FULLY
MISSION
CAPABLE IF:

Protective Inspect control box and quick-disconnect for security
control box of mounting and connection. Tighten control box mounting
screws and/or quick-disconnect, if loose (para. 3-115).
Inspect all engine compartment wiring for frays, splits,
Engine
compart- missing or damaged insulation, or poor connections.
Repair or replace affected wiring (para. 3-131).
ment
electrical
wiring
NOTE
Fuel lines
On dual tank fuel systems, inspect left side of tank
and tank
when performing other tasks conducted in that area
of the vehicle. Ensure any problem found while
inspecting right and left side component systems is
noted in maintenance forms.
a. Inspect fuel tank(s) for dents, cracks, and broken
welds that could cause leaks.
b. Visually inspect fuel sending unit(s) and wiring for
loose connections, presence, frays, splits, and missing
insulation (para. 3-131). Repair or replace wiring
that is missing or shows signs of frayed, split, or missing
insulation. Tighten loose connections (para. 3-92).
c. Visually inspect tube(s) and hose(s) at fuel tank(s) for
loose connections, cracks, and splits. Replace fuel tank
tube(s) and hose(s) that are cracked or split (para. 3-26).
Tighten loose fuel tank tube(s) and hoses connections.
d. Inspect fuel tank selector valve on dual tank model
vehicles for freedom of operation and security of mounting,
and check flex lines for leaks (para. 3-24).
e. Check fuel tank selector valves for proper operation
(TM 9-2320-272-10).
TransmisWARNING
sion and
• If transmission oil temperature is above 220°F
transfer
(104°C), allow transmission oil to cool before
case
removing dipstick.
• Accidental or intentional introduction of liquid
contaminants into the environment is in violation
of state, federal, and military regulations. Refer
to Army POL (para. 1-8) for information concerning storage, use, and disposal of these liquids.
Failure to do so may result in injury or death.

2-31

TM 9-2320-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).

ITEM INTERVAL
NO.

31

Semiannual

ITEM TO
CHECK/
SERVICE

Transmission and
transfer
case
(Contd)

NOT FULLY
MISSION
CAPABLE IF:

PROCEDURE

CAUTION
• Do not remove transmission dipstick before
cleaning dirt away from access plate, filler tube,
and dipstick. Dirt may enter and damage
transmission.
• Do not overfill transmission. Internal
transmission component damage will result.
• Change transmission oil when contamination by
fuel, water, or other foreign materials is evident.
Failure to do so may result in failure of internal
transmission components.
NOTE
When AOAP laboratory support is not available,
change transmission oil every 24,000 mi. (38,000 km)
or 24 months, whichever occurs first.
a. On M939A2 series vehicles, inspect transmission
dipstick and oil.
1. Check for evidence of metal particles. Notify
your supervisor if metal particles are found.
2. Check for evidence of dilution by coolant. If oil is
diluted by coolant, refer to para. 2-21, mechanical
troubleshooting.
3. Check oil level in transmission. If oil levels are
excessive, drain excess (para. 3-133).
EXPECTED TEMPERATURES

LUBRICANTS
OE/HDO
Lubricating oil, internal
combustion engine
(MIL-L-2104)
OEA
Lubricating oil, internal
combustion engine (arctic)
(MIL-L-46167)

ABOVE 15°F
(ABOVE -9°C)
OE/HDO 30

+40°F TO -15°F
(+4°C TO -26°C)
OE/HDO 10

b. Inspect transmission oil lines, hoses, and fittings for
loose connections, cracks, frays, wear, and damage that
could cause leaks. Tighten loose connections, or notify
DS maintenance if any oil line, hose, or fitting is cracked,
frayed, worn, or damaged and could cause leaks.
c. Inspect transmission oil filter housing for security of
mounting. Ensure spin-on oil filter is tight. If spin-on oil
filter is loose, hand-tighten, then tighten an additional
3/4 turn by hand. If leak continues, replace filter
(para. 3-139).

2-32

+40°F TO -65°F
(+4°C TO -54°C)

OEA

TM 9-2320-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).

PROCEDURE

31

Semiannual

Transmission and
transfer
case
(Contd)

NOT FULLY
MISSION
CAPABLE IF:

d. For M939A2 series vehicles, inspect transmission
temperature sending unit for security and signs of leaks,
and wiring for frays, splits, breaks, and missing insulation.
Tighten temperature sending unit if loose or leaking.
Replace if necessary (para. 3-97). Repair or replace wiring
that is missing, or shows signs of frayed, split, or missing
insulation. Tighten loose connections (para. 3-97).
e. Inspect transmission PTO unit (winch models and
dump trucks only).
1 .Inspect for security of mounting and leaks. Notify
DS maintenance if mounting is loose or leakage is present.
2. Inspect oil line and fittings between transmission
and PTO unit for loose connections, cracks, frays,
wear, and damage that could cause leaks. Notify DS
maintenance if mounting is loose or leakage is present.
3. Inspect hydraulic pump for security of mounting,
leaks, and signs of damage that could cause leaks. Notify
DS maintenance if mounting is loose or leakage is present.
4. Inspect hydraulic lines and fittings for loose
connections, cracks, frays, wear, and damage that could
cause leaks. Notify DS maintenance if mounting is loose
or leakage is present.
f. Remove transfer case fill plug and check oil level in
transfer case every 3,000 mi. (4,800 km) or 3 months,
whichever comes first. Fill if necessary. Level should be
within 1/2 in. (12.7 mm) from fill hole when oil is cold, or
to the fill hole when hot.
g. Inspect transfer case drainplug and fill plug for
tightness and signs of leakage.
h. Inspect transfer case for leaks. Notify DS maintenance
if leaks are detected.
i. Inspect shift linkage for cracks, bends, and wear.
j. Inspect transfer case PTO unit (M936/A1/A2 only).
1. Inspect for security of mounting and leaks.
2. Inspect oil and air lines and fittings on transfer
case and PTO for loose connections, cracks, frays, wear,
and damage that could cause leaks. Tighten loose connections. Replace any oil or air line, hose, or fitting that is
cracked, frayed, worn, or damaged and could cause leaks.
3. Inspect hydraulic pump for security of mounting,
leaks, and signs of damage that could cause leaks. Tighten
mounting of hydraulic pump (para. 3-393).
4. Inspect hydraulic lines and fittings for loose
connections, cracks, frays, wear, and damage that could
cause leaks. Tighten loose connections. Replace any oil
line, hose, or fitting that is cracked, frayed, worn, or
damaged and could cause leaks (para. 3-387).

2-33

TM 9-2320-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).
NOT FULLY
MISSION
CAPABLE IF:

PROCEDURE

12

Semiannual

Propeller
shafts, and
universal
and slip
joints

a. On front winch and M929/A1/A2 model vehicles only,
lubricate transmission PT0 universal joint
every 3,006 mi. (4,800 km) or 3 months, whichever occurs
first.
EXPECTED TEMPERATURES

LUBRICANTS
GAA
Grease, automotive and
artillery (MIL-G-10924)

33 Semiannual

2-34

ABOVE 15°F
(ABOVE -9°C)

+40°F TO -15°F
+40°F TO -65°F
(+4°C TO -26°C)
(+4°C TO -54°C)
All temperatures

b. On M936/A1/A2 series vehicles, lubricate transfer
case PTO universal joint every 3,000 mi. (4,800 km) or
3 months, whichever occurs first.
NOTE
Lubrication of universal and slip joints will be
accomplished while performing other inspection tasks
in that same area. Tighten, repair, and/or replace
components of universal, slip joints, and propeller
shafts when found to be damaged or worn, as required.
If maintenance is required at a higher level, records
should reflect closest point of reference to ensure
proper identification of components requiring service.
c. Lubricate universal and slip joints on transmissionto-transfer case, transfer case-to-differential, differentialto-differential propeller shafts, and speedometer adapter
every 3,000 mi. (4,800 km) or 3 months, whichever occurs
first.
d. Inspect universal and slip joints on transmission
PTO, transfer case FTO, and transfer case-to-front axle,
transmission-to-transfer case (para. 3-148), transfer
case-to-differential (para. 3-150 or 3-151), and
differential-to-differential (para. 3-144) propeller shafts
for damaged or worn components.
Air intake a. Inspect vent lines for serviceability and security of
connections (para. 2-15).
tubes
b. Inspect air intake piping and air cleaner assembly for
condition and security of mounting. Replace defective
components and secure loose mountings (para 3-14).
c. Test air cleaner indicator for proper operation
(para. 3-12).

TM 9-2320-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).
NOT FULLY
MISSION
CAPABLE IF:

PROCEDURE

34

35

a. Inspect reservoir tanks, doublecheck valves, and
Air
reservoir fittings for leaks (para. 2-15).
and
b. Inspect condition of reservoir tank for damage that
doublecheck could cause leaks (para. 2-15).
valves
Check hydraulic oil level in tank. If low, fill to top notch
SemiWinch
annual reservoir on dipstick.
Semiannual

EXPECTED TEMPERATURES
LUBRICANTS
OE/HDO
Lubricating oil, internal
combustion engine
(MIL-L-2104)
OEA
Lubricating oil, internal
combustion engine (arctic)
(MIL-L-46167)
16 Semiannual

Rear
wheels
and hubs,
and
suspension

ABOVE 15°F
(ABOVE -9°C)
OE/HDO 30

+40°F TO -15°F
(+4°C TO -26°C)
OE/HDO 10

+40°F TO -65°F
(+4°C TO -54°C)

OEA

WARNING
• Completely deflate tire before removing from axle
if there is obvious damage to wheel components.
Injury or death to personnel may result from
exploding wheel components.
• Use caution when inflating tires. Ensure tire is in
a tire cage and properly seated on rim before
inflating. An improperly seated tire can burst
with explosive force. Failure to comply can result
in death or serious injury to personnel.
• Do not work on any component supported only
by lift jacks or hoist. Always use blocks or proper
stands to support the component prior to any
work. Equipment may fall and cause injury or
death to personnel.
• Air in system is under pressure. Ensure engine
is shut down and all air reservoirs are drained
before disconnecting CTIS components to prevent
serious injury to personnel.
• Do not allow grease or oil to contact brake linings.
Linings can absorb grease and oil, causing early
glazing and very poor braking action. Failure to
do so could cause serious injury or death to
personnel.

2-35

TM 9-2320-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).

PROCEDURE

36

Semiannual

Rear
wheels
and hubs,
and
suspension
(Contd)

[RPL]

2-36

NOTE
• Similar left and right side, and forward-rear and
rear-rear components are inspected in the same
manner and will be accomplished simultaneously,
although procedures are written for left side only.
• When documenting discrepancies for similar left
and right side, and forward-rear and rear-rear
components, indicate which area is affected.
• Lugnuts on left side have left-hand threads and
can be identified by an L, while lugnuts on right
side have right-hand threads and can be
identified by an R.
a. On M939 series vehicles, inspect split locking ring for
dents or breaks that could cause them to pop off. If ring is
loose, break tire down, and inspect for damage to rim or
tire. Replace any damaged wheel components (para. 3-221).
b. On M939A1/A2 series vehicles, inspect wheels for any
loose or missing rim nut. Tighten rim nuts 210-240 lb-ft
(285-325 N•m). Replace any rim stud that is broken or has
stripped threads (para. 3-222).
c. Clean, inspect, and lubricate inner and outer rear
wheel bearings (3-225).
d. Inspect service and service/spring brake air lines
and fittings for loose connections, cracks, splits, or
damage that could cause air leaks. Tighten loose air lines
and fittings and replace any air line or fitting that has
cracks, splits, or damage that could cause air leaks
(para. 3-174).
e. Check brakeshoe-to-drum clearance and condition of
brakeshoes (para. 3-179). If clearance is more than 0.06 in.
(1.5 mm), manually adjust brakes or notify your supervisor
of inoperative adjusters. Replace brakeshoes if worn
beyond chamfer on linings (para. 3-180).
f. Inspect service brake chambers for condition and
security of mounting. Replace service brake chambers
and/or component parts if condition could impair operation
of brakes (para. 3-181).
g. Inspect service/spring brake chambers for condition
and security of mounting. Replace service/spring brake
chambers and/or component parts if condition could impair
operation of brakes (para. 3-182).
h. Inspect rear relay valve for condition and security of
mounting and air lines and fittings for loose connections.
Replace rear relay valve and/or component parts if
condition could impair operation of brakes (para. 3-188).
Tighten loose air lines and fittings.

NOT FULLY
MISSION
CAPABLE IF:

TM 9-2320-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).
NOT FULLY
MISSION
CAPABLE IF:

PROCEDURE

36

Semiannual

Rear
i. Inspect air manifold tee for condition and security of
wheels
mounting and air lines and fittings for loose connections.
and hubs, Replace air manifold tee and/or component parts if
and
condition could impair operation of brakes (para. 3-189).
suspension Tighten loose air lines and fittings.
(Contd)
j. Inspect M939A2 series vehicles CTIS air lines and
fittings for loose connections, cracks, splits, or damage that
could cause air leaks. Tighten loose air lines and fittings.
k. Lubricate spring trunnion bearings every 3,000 mi.
(4,800 km) or 3 months, whichever occurs first.
EXPECTED TEMPERATURES
LUBRICANTS

GAA
Grease, automotive and
artillery (MIL-G-10924)

[RPL]

ABOVE 15°F
(ABOVE -9°C)

+40°F TO -15°F
(+4°C TO -26°C)
All temperatures

+40°F TO -65°F
(+4°C TO -54°C)

l. Visually inspect spring leaves, retaining clips, and
center screws for cracks, breaks, and security of mounting.
Replace spring leaves, retaining clips, or center screws if
cracked or broken (para. 3-167). Secure mounting if loose.
m. Inspect torque rods.
l. Visually inspect rubber for cracks, splits, or out-ofround condition. Replace torque rods if rubber is cracked
or out-of-round (para. 3-170).
2. Check torque rod nuts for tightness. For inspection
purposes, torque rod nuts should be 350-700 lb-ft
(475-949 N•m). If loose, tighten torque rod nuts
350-400 lb-ft (475-542 N•m). Continue to tighten until
cotter pins can be installed.
n. Inspect both front and rear wearpads for wear. Replace
if wearpads are rubbing the spring bracket (para. 3-168).
o. Tighten nuts on spring U-bolts 300-400 lb-ft
(407-542 N•m).
CAUTION
Clean breathers and axle around breathers before
servicing to prevent damage to axle from
contamination.

2-37

TM 9-2320-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).
NOT FULLY
MISSION
CAPABLE IF:

PROCEDURE

36

Semiannual

Rear
p. Remove, clean, and lubricate axle breathers every
wheels
1,000 mi. (1,600 km) or monthly, whichever occurs first.
and hubs,
and
suspension
(Contd)
EXPECTED TEMPERATURES
LUBRICANTS

OE/HDO
Lubricating oil, internal
combustion engine (MIL-L-2104)
OEA
Lubricating oil, internal
combustion engine (arctic)
(MIL-L-46167)
[RPL]

ABOVE 15°F
(ABOVE -9°C)
OE/HDO 30

+40°F TO -15°F
(+4°C TO -26°C)
OE/HDO 10

+40°F TO -65°F
(+4°C TO -54°C)

OEA

q. Remove fill plug (3) on forward-rear and rear-rear
differential (1) and check oil level in differential (1) every
3,000 mi. (4,800 km) or 3 months, whichever occurs first. If
necessary, fill differential (1). Level in differential (1)
should be within 1/2 in. (12.7 mm) from hole of fill plug (3)
when oil is cold, and to hole of fill plug (3) when hot.
EXPECTED TEMPERATURES

LUBRICANTS
Oil, lubricating, multipurpose
(MIL-L-2105) GO-80/90
Oil, lubricating, multipurpose
(MIL-L-2105) GO-75

[RPL]

2-38

ABOVE 15°F
(ABOVE -9°C)
GO-80/90

+40°F TO -15°F
(+4°C TO -26°C)
GO-80/90

r. Inspect differential drainplug (2) and fill plug (3)
for tightness and signs of leakage. Tighten drainplug (2)
35-60 lb-ft (47-81 N•m) and fill plug (3) 80-135 lb-ft
(108-183 N•m).
s. Inspect differential seals for leaks.
t. On M939A2 series vehicles, replace filter and install
wheel valves (para. 3-458).

+40°F TO -65°F
(+4°C TO -54°C)

GO-75

TM 9-2320-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).
NOT FULLY
MISSION
CAPABLE IF:

PROCEDURE

37

Semiannual

Towing
Lubricate towing pintle every 3,000 mi. (4,800 km) or
3 months, whichever occurs first.
pintle
and glad
hand
connections
EXPECTED TEMPERATURES

LUBRICANTS

ABOVE 15°F
(ABOVE -9°C)

GAA
Grease, automotive and
artillery (MIL-G-10924)
38

Semiannual

39 Semiannual

40 Semiannual

+40°F TO -15°F
(+4°C TO -26°C)
All temperatures

+40°F TO -65°F
(+4°C TO -54°C)

Glad
hand and
air lines

a. Inspect emergency and service air and dummy
couplings for serviceability and tightness of seal. Replace
emergency or service air or dummy coupling(s) that are
broken, bent, cracked, or have seals that leak (para. 3-208).
b. Inspect emergency and service air lines, fittings, and
shutoff valves for security of mounting, tightness of
connections, and damage that could cause air leaks
(para. 3-208).
Rear light- Inspect rear lights, trailer receptacle, and wiring for
ing and
damage. Repair if damaged (para. 3-131).
trailer
receptacle
a. For M927/A1/A2 and M928/A1/A2 vehicles, lubricate
Special
body items propeller shaft center bearing every 3,000 mi. (4,800 km) or
3 months, whichever occurs first.
EXPECTED TEMPERATURES
LUBRlCANTS

ABOVE 15°F
(ABOVE -9°C)

GAA
Grease, automotive and
artillery (MIL-G-10924)

+40°F TO -15°F
(+4°C TO -26°C)
All temperatures

+40°F TO -65°F
(+4°C TO -54°C)

WARNING
Support weight of dump body on safety braces when
performing maintenance on hoist mechanism with
dump body in raised position.
b. For M929/A1/A2 and M930/A1/A2 model vehicles:
l. Lubricate safety latch, lifting arm, cylinder
crosshead, body hinge pins, lifting arm rollers, and trunnion
pins every 3,000 mi. (4,800 km) or 6 months, whichever
occurs first.

2-39

TM 9-2320-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).
NOT FULLY
MISSION
CAPABLE IF:

PROCEDURE

40

semiannual

Special
body items
(Contd)

2. Lubricate tailgate bearings every 1,000 mi. (1,600 km)
or monthly, whichever occurs first.
EXPECTED TEMPERATURES

LUBRICANTS

ABOVE 15°F
(ABOVE -9°C)

GAA
Grease, automotive and
artillery (MIL-G-10924)

+40°F TO -15°F
(+4°C TO -26°C)
All temperatures

+40°F TO -65°F
(+4°C TO -54°C)

c. For M931/A1/A2 and M932/A1/A2 vehicles:
1. Lubricate bushing pins, coupler jaw pin, and
walking beam every 1,000 mi. (1,600 km) or monthly,
whichever occurs first.
2. Lubricate lock plunger shaft every 1,000 mi.
(1,600 km) or monthly, whichever occurs first.
EXPECTED TEMPERATURES
LUBRICANTS
OE/HDO
Lubricating oil, internal
combustion engine
(MIL-L-2104)
OEA
Lubricating oil, internal
combustion engine (arctic)
(MIL-L-46167)

ABOVE 15°F
(ABOVE -9°C)
OE/HDO 30

+40°F TO -15°F
(+4°C TO -26°C)
OE/HDO 10

+40°F TO -65°F
(+4°C TO -54°C)

OEA

d. For M934/A1/A2 model vehicles:
1. Perform a general inspection of van body (para. 2-15).
2. Inspect and operate heater, air conditioner, and
ventilators to ensure proper operation (TM 9-2320-272-10).
3. Lubricate propeller shaft center bearing every
3,000 mi. (4,800 km) or 3 months, whichever occurs first.
4. Lubricate ratchets and paw1 plungers every 6,000 mi.
(9,600 km) or 6 months, whichever occurs first.
EXPECTED TEMPERATURES
LUBRICANTS
GAA
Grease, automotive and
artillery (MIL-G-10924)

2-40

ABOVE 15°F
(ABOVE -9°C)

+40°F TO -15°F
(+4°C TO -26°C)
All temperatures

+40°F TO -65°F
(+4°C TO -54°C)

TM 9-2320-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).
NOT FULLY
MISSION
CAPABLE IF:

PROCEDURE

e. For M936/A1/A2 model vehicles:
Special
body items
1. Test rear winch automatic brake for proper operation
(Contd)
(para. 3-331).
2. Unwind cable completely and inspect for kinks, frays,
and wear (TM 9-2320-272-10).
3. Lubricate upper, lower, and vertical cable guide
rollers every 3,000 mi. (4,800 km) or 6 months, whichever
occurs first. If operation is frequent, continuous, or under
severe conditions, service weekly.
EXPECTED TEMPERATURES
LUBRICANTS
+40°F TO -65°F
+40°F TO -15°F
ABOVE 15°F
(+4°C TO -26°C) (+4°C TO -54°C)
(ABOVE -9°C)

40 semiannual

All temperatures

GAA
Grease, automotive and
artillery (MIL-G-10924)

4. Lubricate winch and hoist cables every 6,000 mi.
(9,600 km) or 6 months, whichever occurs first. Unwind
entire cable; soak and clean and soak with new OE/HDO 30.
Wipe off excess and coat cable and drum with lubricating oil
before rewinding (TM 9-2320-272-10). If operation is
frequent, continuous, or under severe conditions, service
weekly.
EXPECTED TEMPERATURES
LUBRICANTS
C W
Lubricating oil (VV-L-751)
Oil lubricating, multipurpose
(MIL-L-2105) GO-75

+80°F TO +30°F +30°F TO -30°F -30” TO -65”
ABOVE
+8O°F(+27°C) (27°C TO -1°C) (-1°C TO -34°C) (-34” TO -54°C)
CW-11A
CW-11B
CW-11C
GO-75

5. Lubricate hoist cable sheaves, boom hinge pins, boom
cylinder pins, boom sheave pins, block sheave pins, block
hook, cable guide rollers, boom winch drum shaft bearings,
and tumable gear every 3,000 mi. (4,800 km) or 6 months,
whichever occurs first. If operation is frequent, continuous,
or under severe conditions, service weekly. Rotate turntable
through full range of travel while lubricating turnable gear.
EXPECTED TEMPERATURES
LUBRICANTS
Oil, lubricating, multipurpose
(MIL-L-2105) GO-80/90
Oil, lubricating, multipurpose
(MIL-L-2105) GO-75

ABOVE 15°F
(ABOVE -9°C)
GO-80/90

+40°F TO -15°F
(+4°C TO -26°C)
GO-80/90

+40°F TO -65°F
(+4°C TO -54°C)

GO-75

2-41

TM 9-2320-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).
NOT FULLY
MISSION
CAPABLE IF:

PROCEDURE

40

Semiannual

6. Lubricate level wind frame, end frame bearing, and
Special
body items sheave frame pin bearing every 3,000 mi. (4,800 km) or
6 months, whichever occurs first. If operation is frequent,
(Contd)
continuous, or under severe conditions, service weekly.
7. Lubricate tensioner sheave pins, level wind sheave
bearing, and level wind trolley wheels every 1,000 mi.
(1,600 km) or monthly, whichever occurs first.
EXPECTED TEMPERATURES

LUBRICANTS

ABOVE 15°F
(ABOVE -9°C)

GAA
Grease, automotive and
artillery (MIL-G-10924)

+40°F TO -15°F
(+4°C TO -26°C)
All temperatures

+40°F TO -65°F
(+4°C TO -54°C)

8. Lubricate level wind trolley lock and tensioner rocker
lever pins every 1,006 mi. (1,600 km) or monthly, whichever
occurs first.
EXPECTED TEMPERATURES
LUBRICANTS
OE/HDO
Lubricating oil, internal
combustion engine
(MIL-L-2104)
OEA
Lubricating oil, internal
combustion engine (arctic)
(MIL-L-46167)

ABOVE 15°F
(ABOVE -9°C)
OE/HDO 30

+40°F TO -15°F
(+4°C TO -26°C)
OE/HDO 10

+40°F TO -65°F
(+4°C TO -54°C)

OEA

9. Lubricate turntable bearings every 6,000 mi.
(4,800 km) or 6 months, whichever occurs first. Rotate
turntable through full range of travel while lubricating
turntable bearings.
EXPECTED TEMPERATURES
LUBRICANTS
GAA
Grease, automotive and
artillery (MIL-G-10924)

2-42

ABOVE 15°F
(ABOVE -9°C)

+40°F TO -15°F
(+4°C TO -26°C)
All temperatures

+40°F TO -65°F
(+4°C TO -54°C)

TM 9-2320-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).
NOT FULLY
MISSION
CAPABLE IF:

PROCEDURE

40

Semiannual

10. Drain and fill hoist gearcase with new oil every
Special
body items 6,000 mi. (9,600 km) or 6 months, whichever occurs first.
Remove level plugs, fill plugs, drainplugs, and drain
(Contd)
gearcases. Install drainplugs and fill to level plugs. Install
level plugs and fill plug.
EXPECTED TEMPERATURES

LUBRICANTS
Oil, lubricating, multipurpose
(MIL-L-2105) GO-80/90
Oil, lubricating, multipurpose
(MIL-L-2105) GO-75

ABOVE 15°F
(ABOVE -9°C)
GO-80/90

+40°F TO -15°F
(+4°C TO -26°C)
GO-80/90

+40°F TO -65°F
(+4°C TO -54°C)

GO-75

11. Check hydraulic oil reservoir for proper level every
1,000 mi. (1,600 km) or monthly, whichever occurs first.
Fill as required.
EXPECTED TEMPERATURES
LUBRICANTS
OE/HDO
Lubricating oil, internal
combustion engine
(MIL-L-2104)
OEA
Lubricating oil, internal
combustion engine (arctic)
(MIL-L-46167)
41 Semiannual
42

Semiannual
43 Semiannual
44

Semiannual

ABOVE 15°F
(ABOVE -9°C)
OE/HDO 30

+40°F TO - 15°F
(+4°C TO -26°C)
OE/HDO 10

+40°F TO -65°F
(+4°C TO -54°C)

OEA

a. Check rifle top and lower mounts for looseness,
binding, and damage.
b. Check handle for excessive looseness and damage.
Refer to TM 9-1005-245-14 for Preventive Maintenance
Machine
gun mount Checks and Services (PMCS).
Refer to TM 3-6665-225-12 for PMCS.
M-8
chemical
alarm
Refer to TM 3-4230-204-12&P for PMCS.
M-11
decontamination
unit
Rifle
mounting
kit

2-43

TM 9-2320-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).

PROCEDURE

45

Annual

46

Annual

2-44

FINAL ROAD TEST
After all services and inspections have been completed,
perform a short road test to ensure all corrections have
been implemented. Correct any defects or malfunctions
that may occur during this test.
ANNUAL INSPECTION
NOTE
• Lubricate vehicle in accordance with
LO 9-2320-272-12.
• Perform all semiannual checks listed in this table.
a. Check front end alignment with toe-in gauge. Correct
Front end
toe-in is 1/16-3/16 in. (1.588-4.763 mm). When toe-in is
correct, tighten crossshaft screws and nuts 35-55 lb-ft
(47-75 N•m) (para. 3-152).
b. Inspect axle housings and differentials for cracks.
c. Inspect shock absorbers and mounting brackets for
looseness, wear, cracks, serviceability, and leaks. Replace
leaking shock absorbers if more than a class I leak is
detected (para. 3-166).
d. Check each tire using tire depth gauge. Tread depth
should be at least 1/8 in. (3 mm) or as indicated on tire
depth gauge.
a. Inspect front cab mounting brackets for security, wear,
Engine
compart- cracks, splits, broken welds, loose bushings, and missing
ment and screws. Replace front cab mounting brackets if worn,
cracked, split, or welds are broken. Replace loose
cab
insulators and missing screws (para. 3-304).
b. Inspect rear cab mounting brackets for security, wear,
cracks, splits, broken welds, loose bushings, and missing
screws. Replace front cab mounting brackets if worn,
cracked, split, or welds are broken. Replace loose
bushings and missing screws (para. 3-305).
c. Tighten front cab mounting screws.
d. Check the following items on M939A2 vehicles:
1. Inspect front and rear engine mounting brackets for
security, wear, cracks, splits, broken welds, loose bushings,
and missing bolts (para. 2-15).

NOT FULLY
MISSION
CAPABLE IF:

TM 9-2320-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).

PROCEDURE

46

Annual Engine
compartment and
cab
(Contd)

4 7 Annual

2. Check left-side engine mounting locknuts (1) and
right-side engine mounting screws (6) for looseness. If loose,
tighten 120-140 lb-ft (163-190 N•m).
3. Check two upper locknuts (4) securing left engine
mount (2). If loose, tighten 90 lb-ft (122 N•m). Check two
lower locknuts (3) for looseness. If loose, tighten 60 lb-ft
(82 N•m).

4. Check two upper locknuts (7) securing right engine
mount (5) for looseness. If loose, tighten 90 lb-ft (122 N•m).
Check two lower locknuts (8) for looseness. If loose, tighten
60 lb-ft (81 N•m).
a, Inspect forward-rear and rear-rear axle housings and
Rear
suspension differentials for cracks.

WARNING
Do not allow grease or oil to contact brake linings.
Linings can absorb grease and oil, causing early
glazing and very poor braking action. Failure to
comply could cause serious injury or death to
personnel.
b. Tighten forward-rear and rear-rear axle drive flange
screws 80-105 lb-ft (108-142 N•m).
c. Ensure all differential companion flange mounting
screws and U-joint mounting screws are tight. Tighten
companion flange mounting screws 30-40 lb-ft (41-54 N•m)
and U-joint mounting screws 90-110 lb-ft (122-149 N•m).
d. Test spring seat bearing free play by placing jack under
spring seat bracket. Raise vehicle so spring moves freely
up and down in guide brackets. Put prybar between U-bolt
saddle and lift pin. Pull up on prybar. If there is free play,
adjust spring seat bearing (para. 3-169).

2-45

TM 9-2320-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).

PROCEDURE

48

Annual

ComCheck for faulty check valves at the primary and secondary
pressed air air tanks and crossed hoses. Crossed hoses occur from A
treadle valve air supply hoses at the primary and secondary
system
air tanks, and B primary and secondary air gauge lines at
the treadle valve.
• Chock vehicle wheels. Failure to do so may result
in injury or death to personnel.
• Wear safety goggles while performing inspection.
Line is under pressure. Failure to do so may result
in injury to personnel from flying parts or debris.

2-46

NOT FULLY
MISSION
CAPABLE IF:

TM 9-2320-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).

PROCEDURE

NOT FULLY
MISSION
CAPABLE IF:

2-47

TM 9-2320-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).

PROCEDURE

49

Wiring
Inspect spare tire carrier for security, completeness of
harnesses assembly, and proper operation.
and compressed air
lines
50 Annual Spare tire Inspect starter mounting bolts and starter wiring for
corrosion and loose connections. Tighten starter mounting
carrier
bolts 55 lb-ft (75 N•m).
51 Annual
Parking
Inspect brake lever travel (para. 3-172). Replace brakeshoes
if brake lever travel is greater than 2 in. (5.1 cm)
brake
(para. 3-180).
52 Annual Air dryer
a. Inspect air dryer, two purge valves, and check valve for
security of mounting and signs of damage that could cause
system
leaks.
NOTE
Air dryer will whistle when filter needs to be
replaced.
b.
Replace filter in air dryer (3-465).
[RPL]
c. Inspect filter in water separator (para. 3-466).
d. Inspect all tubes and fittings for damage or cracks that
could cause leaks.
Check operation of towing pintle hook. Inspect pintle and
5 3 Annual Towing
bracket for cracks, breaks, wear, and play of 0.003-0.017 in.
pintle
(0.07-0.43 mm) (para. 3-241 or 3-242).

2-48

Annual

NOT FULLY
MISSION
CAPABLE IF:

TM 9-2320-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).

PROCEDURE

54 Annual Special
body items

NOT FULLY
MISSION
CAPABLE IF:

a. M929/A1/A2 and M930/A1/A2.
WARNING
• Support weight of dump body on safety braces
when performing maintenance on hoist mechanism
with dump body in raised position.
• Do not drain oil from dump hydraulic pump,
reservoir, or cylinder or remove lines containing oil
when dump body is supported by hydraulic
cylinder. Doing so may result in injury to
personnel.
• Do not drain oil from dump hydraulic pump,
reservoir, or cylinder or remove lines containing oil
when oil is hot. Doing so may result in injury to
personnel.
• Do not remove hoses while engine is running or
start engine with hoses removed. High-pressure
fluids may cause hoses to whip violently and spray
randomly. Failure to do so may result in injury to
personnel.
• Accidental or intentional introduction of liquid
contaminants into the environment is in violation
of state, federal, and military regulations. Refer to
Army POL (para. 1-8) for information concerning
storage, use, and disposal of these liquids. Failure
to do so may result in injury or death.
1. Inspect dump body for completeness of assembly.
Ensure dump body is aligned with frame.
2. Inspect dump hydraulic lines, hoses, and fittings for
leaks and splits. Check hydraulic pump for tightness of
mounting.
3. Inspect transmission PTO, hydraulic pump
propeller shaft, and hydraulic pump for tight mounting and
leaks.
4. Ensure tailgate control rod hand lever locks and
unlocks tailgate lower latch. Inspect control linkage for
security, bends, and binding.
5. Operate dump body and observe for smooth raising
and lowering of dump body.
6. With dump body raised, inspect cylinder piston rods
for scoring and wear.

2-49

TM 9-2320-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).
NOT FULLY
MISSION
CAPABLE IF:

PROCEDURE

4

Annual

Special
body items
(Contd)
[RPL]

CAUTION
Remove filler plug slowly to release pressure. Do not
overfill.
7. Drain, clean, and fill winch hydraulic oil reservoir
and replace filter (para. 3-336) every 12 months.
EXPECTED TEMPERATURES

LUBRICANTS
OE/HDO
Lubricating oil, internal
combustion engine (MIL-L-2104)
OEA
Lubricating oil, internal
combustion engine (arctic)
(MIL-L-46167)

ABOVE 15°F
(ABOVE -9°C)
OE/HDO 30

+40°F TO -15°F
(+4°C TO -26°C)
OE/HDO 10

+40°F TO -65°F
(+4°C TO -54°C)

OEA

b. On M934/A1/A2 model vehicles:
1. Expand van body and inspect for damaged or
broken hinges, fasteners, and latches (para. 2-15).
2. Check for bent or binding of components or
damaged seals or panels that would allow light to shine
through or prevent a tight seal. Repair or replace defective
components (para. 2-15).
3. Lubricate worm gear, worm, winch handle shaft,
wire rope, winch barrel shaft, and swing davit base every
12,000 mi. (19,000 km) or 12 months, whichever occurs first.
EXPECTED TEMPERATURES
LUBRICANTS
C W
Lubricating oil (VV-L-751)
Oil lubricating, multipurpose
(MIL-L-2105): GO-75

ABOVE
+80°F(+27°C)
CW-11C

+80°F TO +30°F +30°F TO -30°F
(27°C TO -1 “C) (-1°C TO -34°C)
CW-11B
CW-11A

-30° TO -65’
(-34° TO -54°C)

GO-75

4. Lubricate support rollers, end rollers, retractor
beams, sprocket, and sprocket bushings every 12,000 mi.
(19,606 km) or 12 months, whichever occurs first.
EXPECTED TEMPERATURES
LUBRICANTS
GM
Grease, automotive and
artillery (MIL-G-10924)

2-50

ABOVE 15°F
(ABOVE -9°C)

+40°F TO -15°F
(+4°C TO -26°C)
All temperatures

+40°F TO -65°F
(+4°C TO -54°C)

TM 9-2320-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).

PROCEDURE

54

Annual

Special
body items
(Contd)

NOT FULLY
MISSION
CAPABLE IF:

c. On M936/A1/A2 model vehicles:
WARNING
• Do not drain oil from wrecker hydraulic pump,
reservoir, cylinders, or motors, or remove lines
containing oil when oil is hot. Doing so may result
in injury to personnel.
• Do not remove hoist or winch hydraulic hoses
when engine is running or start engine with hoist
or winch hydraulic hoses removed. High pressure
fluids may cause hoses to whip violently and spray
randomly. Failure to do so may result in injury to
personnel.
• Do not drain oil from wrecker hydraulic pump,
reservoir, or cylinders or remove lines containing
oil when crane boom is supported by hydraulic
cylinder, or hoist or winch cables are supporting a
load. Doing so may result in injury to personnel.
• Accidental or intentional introduction of liquid
contaminants into the environment is in violation
of state, federal, and military regulations. Refer to
Army POL (para. 1-8) for information concerning
storage, use, and disposal of these liquids. Failure
to do so may result in injury or death.
1 . Inspect rear winch and winch controls for loose
mounting and broken or missing parts. If mounting is loose,
tighten. If parts are missing or broken, replace (para. 3-332).
2. Inspect hydraulic pump for leaks. If leaks are
present, notify DS maintenance.
3. Test automatic hoist drum brake for proper
operation (para. 3-323).
4. With boom raised, inspect crane cylinder piston
rods for bends and scoring. If crane cylinder piston rods are
bent or scored, notify DS maintenance.
5. While operating crane, observe that fuel pump
governor is maintaining 1,250-1,300 rpm during hoisting
operation. Notify DS maintenance if engine is surging
erratically (TM 9-2320-272-10).
6. Inspect and clean hydraulic tank swing motor and
hoist crane motor breather caps (para. 2-15).
7. Inspect reservoir filter case for leaks. Replace filter
element (para. 3-336).
8. Drain, clean, and fill hydraulic oil reservoir every
12 months (LO 9-2320-272-12).

2-51

TM 9-2320-272-24-1
Table 2-1. Unit Preventive Maintenance Checks and Services (Contd).
NOT FULLY
MISSION
CAPABLE IF:

PROCEDURE

55

Biennial Transmission

NOTE
Perform item 55 only if AOAP laboratory support is
not available.
Change transmission oil, and internal, external, and
governor oil filters every 24,000 mi. (38,000 km) or
24 months, whichever occurs first (para. 3-133).
EXPECTED TEMPERATURES

LUBRICANTS
OE/HDO
Lubricating oil, internal
combustion engine
(MIL-L-2104)
OEA
Lubricating oil, internal
combustion engine (arctic)
(MIL-L-46167)
56

Transfer
case

+40°F TO -15°F
(+4°C TO -26°C)
OE/HDO 10

Inspect tightness of transfer case mounting bolts and
mounting brackets. Tighten three transfer case mounting
bracket-to-frame bolts 50-60 lb-ft (68-81 N•m) Tighten
seven transfer case-to-mounting bracket bolts 125-135 lb-ft
(170-183 N•m).
57 Biennial Special
a. On M929/A1/A2 and M930/A1/A2 model vehicles,
body items tighten all dump body mounting bolts 240 lb-ft
(325 N•m).
b. On M931/A1/A2 and M932/A1/A2 model vehicles,
inspect fifth wheel for completeness of assembly. Ensure
mounting screws are tightened 160-170 lb-ft
(217-231 N•m).

2-52

Biennial

ABOVE 15°F
(ABOVE -9°C)
OE/HDO 30

+40°F TO -65°F
(+4°C TO -54°C)

OEA

TM 9-2320-272-24-1

PMCS MANDATORY REPLACEMENT PARTS LIST
The following is a list of parts required when performing semiannual PMCS. The semiannual parts list
contains the mandatory replacement parts for one semiannual PMCS. The annual parts list contains the
mandatory replacement parts for one semiannual PMCS and the peculiar replacement parts for one annual
PMCS.

SEMIANNUAL (6,000 MILE) PMCS MANDATORY REPLACEMENT PARTS LIST
ITEM
NO.
1
2
3
4
5
6
*
7
**
8
**
9
** 10
** 11
** 12
** 13
** 14
15
16
*** 17
*
18
**** 19
*
20
** 21
** 22
** 23
** 24
** 25
** 26
** 27
** 28
** 29
** 30
** 31
*
32
*
33
*
34
*
35
*
36
37
38
** 39
*
*

PART
NUMBER
MS35338-46
MS35338-48
7979374
MS35335-33
10935405
1229-S-513-C
5139123
1229-U-1009
MS28775-206
A-1205-Z-2132
2297-N-5630
2208-S-1033
A-1205-N-2120
599791
MS35769-21
C2AZ9324C
154088
146483
145504
256476
3313281
FF-5079
A3994-1
131245
10947447-2
A-1205-Z-2132
1229-U-1009
A-1205-N-2120
A-1205-D-2162
3286-P-1056
10947447
5139123
741344
12375801
7409553
MS24665-500
MS35769-21
599791

NSN
5310-00-722-5658
5310-00-003-4094
5310-00-209-0786
5340-00-450-57 18
5310-01-062-3384
5310-00-700-7069
5310-00-321-9974
5330-01-133-5858
5330-01-271-9410
4730-01-272-0582
5330-01-272-1148
5330-01-272-1147
4460-01-284-2344
5330-01-352-7768
4720-00-845-0630
5330-00-013-7806
5310-00-291-9490
5330-01-051-4243
2910-00-152-2033
2940-01-157-6309
4330-01-309-6189
4720-01-279-3034
5330-01-271-9410
5310-00-321-9974
5330-01-272-1147
5330-01-308-0175
2530-01-285-3563
5310-00-700-7089
5330-01-444-8350
2590-00-740-9553
5315-00-187-9567
5330-01-352-7768
4460-01-284-2344

NOMENCLATURE
QTY
10
Lockwasher
20
Lockwasher
Seal, plain, encased
2
Lockwasher
20
Protective caps
A/R
Lockwasher
8
2
Keyway insert
2
Keyway insert
2
O-ring
2
Seal, plain, encased
2
Seal, conical, flared
2
Gasket
4
Retainer, oil seal (air seals)
2
Filter element, fluid
1
Gasket
Hose, nonmetallic
1
1
Seal, cap
1
Filter element
1
Packing, preformed
1
Kit, fluid pressure
1
Filter element, fluid
1
Filter, fluid, in-line
4
O-ring (wheel valve-to-axle)
O-ring (wheel valve filter)
4
8
Locknut
40
Locknut
Oil seal, axle
4
4
Keyway insert
4
Retainer, oil seal (rear air seals)
Retainer, oil seal (front air seals)
4
Slinger ring
4
Locknut
40
4
Keyway insert
4
Seal assembly
4
Seal assembly
4
Wiper
12
Cotter pin
Gasket
4
4
Filter element, fluid

STEP
NUMBER
lla
19d
19d
19d
19d
19d
19d
19d
19d
19d
19d
19d
19d
19e
22g
26e
27a
27a
27a
27c
27c
27e3
36c
36c
36c
36c
36c
36c
36c
36c
36c
36c
36c
36c
36c
36c
36m2
36q
36t

ANNUAL (12,000 MILE) PMCS MANDATORY REPLACEMENT PARTS LIST
M929/A1/A2 and M930/A1/A2
ITEM
NO.
*****40

PART
NUMBER
PF297

NSN

* M939/A1

** M939A2

*** M936/A1

NOMENCLATURE
Filter element

QTY
1

STEP
NUMBER
7

**** M939/A1 only (except M936/A1)
2-53

TM 9-2320-272-24-1

2-13. GENERAL MAINTENANCE PROCEDURES INDEX
PARA.
NO.

TITLE
Cleaning
Inspection
Repair
Disassembly
Assembly

2-14.
2-15.
2-16.
2-17.
2-18.

PAGE
NO.
2-54
2-56
2-57
2-58
2-58

2-14. CLEANING
a. General Instructions. Cleaning procedures are the same for the majority of parts and components
which compose the vehicle subassemblies. General cleaning procedures are detailed in steps b. through o.
WARNING
Improper cleaning methods and use of unauthorized cleaning
solvents may result in injury to personnel.
CAUTION
When cleaning any CTIS components or parts, special care must
be taken not to contaminate the system’s mating surfaces, tubes,
hoses, or passages. Damage to components may result.
b. The Importance of Cleaning. Great care and effort are required in all cleaning operations. The
presence of dirt and foreign material is a constant threat to satisfactory vehicle operation and maintenance.
The following instructions will apply to all cleaning operations.
CAUTION
Keep all related parts and components together. Do not mix parts.
Failure to comply may result in damage to parts.
(1) Clean all parts before inspection, after repair, and before assembly.
(2) Hands must be kept free of any accumulation of grease which can collect dust and grit.
(3) After cleaning, all parts must be covered or wrapped in plastic or paper to protect them from
dust and/or dirt.
c. Disassembled Parts Cleaning. Place all disassembled parts in wire baskets for cleaning.
(1) Dry and cover all cleaned parts.
(2) Place on or in racks and hold for inspection or repair.
(3) All parts subject to rusting must be lightly oiled and wrapped.
d. Castings.
WARNING

(1)
(2)

2-54

Drycleaning solvent is flammable and will not be used near open
flame. Use only in well-ventilated places and keep tire extinguisher
nearby. Failure to do so may result in injury to personnel.
Clean all inner and outer areas subject to grease and oil with drycleaning solvent (TM 9-247).
Use a stiff brush to remove sludge and gum deposits.

TM 9-2320-272-24-1

2-14. CLEANING (Contd)
Compressed air source will not exceed 30 psi (207 kPa). When
cleaning with compressed air, eyeshields must be worn. Failure to
do so may result in injury to personnel.
(3) Use compressed air to blow out all tapped screw holes and to dry castings after cleaning.
e. External Engine Cleaning. All electrical equipment and other parts that could be damaged by
steam-cleaning or moisture must be removed and all openings must be covered before cleaning. Dry with
compressed air.
f. Oil Passages. Particular attention must be given to all oil passages in castings and machined
parts. Oil passages must be clean and free of any obstructions.
(1) Clean passages with wire probes to break up any sludge or gum deposits.
(2) Wash passages by flushing with solvent (TM 9-247).
Compressed air source will not exceed 30 psi (207 kPa). When
cleaning with compressed air, eyeshields must be worn. Failure
to do so may result in injury to personnel.
(3) Dry passages with compressed air.
g. Seals, Electrical Cables, and Flexible Hoses. Clean with soap and water.
h. Bearings.
(1) Bearings require special cleaning. After removing surface oil and gum deposits, wipe bearings
dry; do not use compressed air. After cleaning, coat bearings with oil, wrap, and hold for inspection.
(2) Refer to TM 9-214 for more information on care of bearings.
WARNING
• Drycleaning solvent is flammable and will not be used near open
flame. Use only in well-ventilated places and keep fire
extinguisher nearby. Failure to do so may result in injury to
personnel.
• Compressed air source will not exceed 30 psi (207 kPa). When
cleaning with compressed air, eyeshields must be worn. Failure
to do so may result in injury to personnel.
i . Machined Tooled Parts. Clean with drycleaning solvent and dry with compressed air.
j. Machined Surfaces. Clean with drycleaning solvent and dry with lint-free cloth.
WARNING

k.
solvent.

l.
m.
n.
o.

Eyeshields must be worn when cleaning with a wire brush. Flying
rust and metal particles may cause injury to personnel using a
wire brush.
Mated Surfaces. Remove old gasket and/or sealing compound using wire brush and drycleaning
NOTE
All parts subject to rusting must be lightly oiled and wrapped
before being stored.
Rusted Surfaces. Clean all rusted surfaces using wire brush and crocus cloth.
Oil-bathed Internal Parts. Wipe clean with lint-free cloth.
Air-actuated Internal Parts. Wipe clean with lint-free cloth.
External Exposed Parts. Wash with soap and water. Rinse thoroughly and air-dry.
2-55

TM 9-2320-272-24-1

2-15. INSPECTION
a. General Instructions. Procedures for inspections will be the same for many parts and components
which make up the vehicle subassemblies. General procedures are detailed in steps b. through q.
Dimensional standards for parts have been fixed at extremely close tolerances, so use specification tables.
Use specified inspection equipment for inspection where cracks and other damage cannot be spotted
visually. Exercise extreme care in all phases of inspection.
b. Castings.
(1) Inspect all ferrous and nonferrous castings for cracks using a magnifying glass and strong
light.
(2) Refer to MIL-L-6866, Inspection, Liquid Penetrant Methods, and MIL-L-6868, Inspection
Process, Magnetic Particles.
(3) Particularly inspect areas around studs, pipe plugs, threaded inserts, and sharp corners.
Replace all cracked castings.
(4) Inspect machined surfaces for nicks, burrs, or raised metal. Mark damaged areas for repair or
replacement.
(5) Inspect all pipe plugs, pipe plug openings, screws, and screw openings for damaged or stripped
threads. Replace or repair damaged or stripped threads.
(6) Using a straightedge or surface plate, check all gasket mating surfaces, flanges on housings,
and supports for warpage. Inspect mating flanges for discolorations which may indicate persistent oil
leakage. Replace damaged parts.
(7) Check all castings for conformance to applicable repair standards. Replace damaged castings.
c. Bearings. Refer to TM 9-214 for inspection of bearings. Check all bearings for conformance to
applicable standards.
d. Studs, Bolts, and Screws. Replace if threads are damaged, bent, or stripped.
e. Gears.
(1) In strong light, inspect all gears for cracks. No cracks are allowed.
(2) Inspect gear teeth for wear, sharp edges, burrs, and galled or pitted surfaces.
(3) Check keyway slots for wear and/or damage.
f. Oil Seals. Oil seals are mandatory replacement items.
g. Engine Bearings.
NOTE
• Engine connecting rods and main bearings are serviced in sets.
If one bearing fails, all bearings must be replaced.
• Old and new style engine components must be used in sets and
not intermixed.
h. Bushings and Bushing-Type Bearings.
(1) Check all bushings and bushing-type bearings for secure fit, evidence of overheating, wear,
burrs, nicks, and out-of-round condition.
(2) Check for dirt in lubrication holes or grooves. Holes and grooves must be clean and free from
damage.
l. Expansion Plugs. Inspect for leakage. Replace plugs when leakage is present.
j. Machined Tooled Parts. Inspect for cracks, breaks, elongated holes, wear, and chips.
k. Machined Surfaces. Inspect for cracks, evidence of wear, galled or pitted surface, burrs, nicks, and
scratches.
leakage.
m. Rusted Surfaces. Inspect for pitting, holes, and severe damage.
n. Oil-bathed Internal Parts. Inspect for cracks, nicks, burrs, evidence of overheating, and wear.
2-56

TM 9-2320-272-24-1

2-15. INSPECTION (Contd)
o.
p.
q.

Air-actuated Internal Parts. Inspect for cracks, nicks, burrs, evidence of overheating, and wear.
Externally Exposed Parts. Inspect for breaks, cracks, rust damage, and wear.
Rivets. Inspect for loose, broken, and missing rivets in accordance with TM 9-450.

a . General Instructions. Repair of most parts and components is limited to general procedures
outlined in applicable maintenance instructions and the following detailed procedures, steps b. through h.
CAUTION
Repaired items must be thoroughly cleaned to remove metal chips
and abrasives to prevent them from entering working parts of
vehicle. Special care must be taken with CTIS parts, or damage to
components may result.
b. Castings.
(1) All cracked castings will be replaced.
(2) Only minor repairs to machined surfaces, flanges, and gasket mating surfaces are permitted.
Remove minor nicks, burrs, and/or scratches with:
(a) Fine mill file.
(b) Crocus cloth dipped in cleaning solvent.
(c) Lapping across a surface plate.
(3) Remachining of machined surfaces to repair damage, warpage, or uneven surfaces is not
permitted. Replace castings.
(4) Repair damaged threaded pipe plug and/or screw holes with a tap. Repair oversize holes with
threaded inserts.
c. Bearings. Refer to TM 9-214.
d. Studs. Replace all bent and stretched studs. Repair minor thread damage with a thread die.
Replace studs having stripped or damaged threads as outlined below:
(1) Remove studs using a stud remover. Back studs out slowly to avoid heat buildup and seizure
which can cause stud to break off.
NOTE
If welding method is used, refer to TM 9-237 for proper
instructions.
(2) If studs break off too short to use a stud remover or a stud extractor, use welding method.
(3) Broken studs can be removed by welding bar stock or a nut to stud and removing with wrench.
(4) Standard studs may have a coarse thread on one end and a fine thread on the other end. The
coarse thread end is installed in aluminum casting. Studs having coarse threads on both ends are used in
some applications. The shorter threaded end goes into the casting. Refer to appendix D for correct part
number.
(5) Replacement studs have a special coating and must have a small amount of antiseize
compound (Appendix C, Item 10) applied on the threads before stud is installed. Install replacement stud
slowly to prevent heat buildup and snapping off.
e. Gears.
(1) Remove gears using pullers.
(2) Use the same method described in step b. for castings to remove minor nicks, burrs, or
scratches on gear teeth.

2-57

TM 9-2320-272-24-1

2-16. REPAIR (Contd)
(3) If keyways are worn or enlarged, replace gear.
f. Bushings and Bushing-type Bearings. When bushings and bushing-type bearings seize to a
shaft and spin in the bore, the associated part must also be replaced.
g. Oil Sears.
(1) Using proper oil seal removal tool, remove oil seals without damaging casting or adapter bore.
(2) Always install new seal in bore using proper seal replacement tool.
h. Rivets. Replace rivets in accordance with TM 9-450.

2-17. DISASSEMBLY
a. The work area for disassembly of any item must be kept as clean as possible. This will prevent
contamination of internal parts. This is especially true when working with fuel and air systems or CTIS
components.
b. All gaskets, O-rings, and seals removed during repair will be discarded and replaced with new
parts. These items are usually damaged during removal. Lockwire, lockwashers, cotter pins, and like items
should be discarded during disassembly.
c. When removing gaskets, preformed packings, or seals, do not use any metal tools that will scratch
the sealing surfaces next to these items.
d. Before disassembling any item, study the illustration carefully, noting the relationship of internal
parts. Knowing the details of construction will speed up disassembly and help avoid mistakes.

2-18. ASSEMBLY
a. Cleanliness is essential in all assembly operations. Dirt and dust, even in small quantities, are
abrasive. Parts must be cleaned as specified and kept clean. Wrap or cover parts and components when
assembly procedures are not completed immediately.
b. Lubricate all metal parts with lubricant used during operation (LO 9-2320-272-12).
c. Installation of cotter pins and lockwire shall be accomplished as specified in assembly procedures.
d. Critical torque values are specified in the assembly procedure. When not specified, tighten bolts,
screws, and nuts in accordance with standard dry torque values (Appendix G).
e. All fuel, air, and hydraulic components must be kept thoroughly clean at all times. Plug all open
ports until the component is installed in the vehicle.
f. All pressing operations should be accomplished using a suitable press and adapters unless
otherwise specified.

2-58 (2-59 blank)

TM 9-2320-272-24-1

Section IV. UNIT TROUBLESHOOTING PROCEDURES

WARNING
Operation of a deadlined vehicle without preliminary inspection
may cause injury to personnel and/or damage to equipment.
NOTE
If malfunction corrective action does not correct malfunction,
notify direct support maintenance.
a . This section provides information needed to diagnose and correct malfunctions of mechanical,
electrical, CTIS, and compressed air and brake system at the unit level of maintenance.
b. The troubleshooting procedures in this section cannot give all the answers or correct all vehicle
malfunctions encountered. However, these procedures are a step-by-step approach to a problem that directs
tests and inspections toward the source of a problem and a successful solution.
c . Each malfunction symptom given for an individual component or system is followed by step(s) to
determine the cause and corrective action you must take to remedy the problem.
d . Before taking any corrective action for a possible malfunction, the following rules should be
followed:
(1) Question operator to obtain any additional information that might help you to determine the
cause of the problem.
(2) Never overlook the chance the problem could be of a simple origin. The problem could require
only a minor adjustment.
(3) Use all senses to observe and locate troubles.
(4) Use test instruments and gauges to help you determine and isolate problems.
(5) Always isolate the system where the malfunction occurs and locate the defective component.
(6) Use standard automotive theories and principles when troubleshooting the vehicles covered in
this manual.
e . This section cannot list all malfunctions that may occur. If a malfunction occurs that is not listed in
the tables, notify Direct Support CDS) maintenance.

2-60

TM 9-2320-272-24-1

2-20. UNIT TROUBLESHOOTING INDEX
PARA.
NO.

PAGE
NO.

TITLE

2-21.
2-22.

Mechanical Troubleshooting
Electrical System Troubleshooting

2-23.
2-24.

Compressed Air and Brake System Troubleshooting
STE/ICE Troubleshooting

2-25.

Central Tire Inflation System (CTIS) Troubleshooting

2-61
2-92
2-177
2-219
2-267

2-21. MECHANICAL TROUBLESHOOTING
NOTE
If malfunction corrective action does not correct malfunction,
notify direct support maintenance.
a . This section provides information to diagnose and correct malfunctions of the mechanical system at
the unit maintenance level.
b. This section cannot list all mechanical malfunctions that may occur. If a malfunction occurs that is
not listed in table 2-2, notify direct support maintenance.

MECHANICAL TROUBLESHOOTING SYMPTOM INDEX
MALFUNCTION
NO.

1.
2.
3.
4.
5.
6.
7.
8.
9:
10.
11.
12.
13.
14.
15.
16.

17.
18.
19.
20.
21.

MALFUNCTION

TROUBLESHOOTING
PROCEDURE
PAGE

ENGINE
Engine will not crank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine cranks but will not start. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Starter cranks engine slowly, hard to start. . . . . . . . . . . . . . . . . . . . . . . .
Engine stops during normal operation . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine stops when accelerator is returned to idle position . . . . . . . . . . .
Engine fails to stop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine misfires during operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Engine idle rough, erratic (M939A2 only). . . . . . . . . . . . . . . . . . . . . . . . .
Poor acceleration and/or lack of power . . . . . . . . . . . . . . . . . . . . . . . . . . .
Enginesurges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Excessive engine oil loss or consumption . . . . . . . . . . . . . . . . . . . . . . . . .
Engine oil pressure too low or too high at normal operating temperature
Engine oil contaminated . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Excessive vibrating or clunking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Excessive fuel consumption. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ETHER START SYSTEM
Engine cranks but will not start in cold weather
(fuel system operating properly) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
EXHAUST SYSTEM
Exhaust color blue during normal operation . . . . . . . . . . . . . . . . . . . . . .
Exhaust color white during normal operation and idle . . . . . . . . . . . . . .
Exhaust color black during normal operation and idle. . . . . . . . . . . . . . .
Excessive exhaust noise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exhaust fumes in cab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2-64
2-64
2-66
2-66
2-66
2-66
2-67
2-67
2-67
2-68
2-68
2-69
2-70
2-70
2-70

2-71
2-71
2-72
2-72
2-72
2-73
2-61

TM 9-2320-272-24-1

MECHANICAL TROUBLESHOOTING SYMPTOM INDEX
MALFUNCTION
NO.

22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.
38.
39.
40.
41.
42.
43.
44.
45.
46.
47.
48.
49.
50.
51.
52.
53.
54.
55.
56.
57.
58.
2-62

MALFUNCTION

TROUBLESHOOTING
PROCEDURE
PAGE

COOLING SYSTEM
Engine does not reach normal operating temperature . . . . . . . . . . . . . . .
Engine overheats as indicated by engine coolant temperature gauge . . .
Loss of coolant. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Contaminated coolant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
TRANSMISSION
Excessive noise during shifting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Low transmission oil pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Transmission oil leaking. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
No response to shift lever movement . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rough shifting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Transmission overheats as indicated by transmission temperature gauge
Dirt or metal particles in transmission oil . . . . . . . . . . . . . . . . . . . . . . . .
Oil thrown from transmission dipstick tube. . . . . . . . . . . . . . . . . . . . . . .
Transmission oil dirty, foamy, and/or milky . . . . . . . . . . . . . . . . . . . . . . .
TRANSFER CASE
Hard shifting of transfer case. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Transfer case leaking oil. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Excessive noise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Excessive vibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PROPELLER AND DRIVESHAFTS
Excessive noise or vibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
FRONT AND REAR AXLES
Continuous axle or wheel noise. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oil leaking from front wheel drive lock-in switch. . . . . . . . . . . . . . . . . . .
Differential noisy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Differential clunks during turns or initial takeoff . . . . . . . . . . . . . . . . . .
Differential vibrates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Differential leaks oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
WHEELS AND TIRES
Uneven tire wear. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wheel shimmy or wobble . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
STEERING
Hardsteering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Vehicle wanders or pulls to one side. . . . . . . . . . . . . . . . . . . . . . . . . . .
Excessive play in steering wheel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Shimmy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
FRAME AND BRACKETS
Towing pintle does not latch or lock . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pintle hook does not turn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Excessively loose lifting shackle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Loose spare tire carrier. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SPRINGS AND SHOCK ABSORBERS
Continuous wandering or swaying (poor control) . . . . . . . . . . . . . . . . . . .
Harsh or hard ride . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Spring leaf defect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2-73
2-74
2-75
2-75
2-75
2-75
2-75
2-76
2-76
2-76
2-76
2-76
2-77
2-77
2-78
2-78
2-78
2-78
2-79
2-79
2-79
2-79
2-80
2-80
2-80
2-80
2-81
2-81
2-82
2-82
2-83
2-83
2-83
2-83
2-83
2-84
2-84

TM 9-2320-272-24-1

MECHANICAL TROUBLESHOOTING SYMPTOM INDEX
MALFUNCTION
NO.

MALFUNCTION

TROUBLESHOOTING
PROCEDURE
PAGE

59.
60.
61.
62.
63.
64.
65.
66.

WINCH
Winch does not operate. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Winch operates in one direction only . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Drag brake does not operate. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Winch will not hold load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Automatic brake overheats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Front winch operates at one speed only . . . . . . . . . . . . . . . . . . . . . . . . . .
Rear winch cable tensioner will not operate. . . . . . . . . . . . . . . . . . . . . . .
Vehicle rolls while operating rear winch. . . . . . . . . . . . . . . . . . . . . . . . . .

2-84
2-85
2-86
2-86
2-86
2-86
2-86
2-87

67.
68.
69.

POWER TAKEOFF (PTO)
Excessive noise at power takeoff. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Hard shifting of power takeoff . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Leaking lubricant at power takeoff. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2-87
2-87
2-87

78.
79.
80.
81.
82.

INSTRUMENTS AND GAUGES
Speedometer or tachometer noisy or erratic. . . . . . . . . . . . . . . . . . . . . . .
Air pressure gauge inoperative. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Oil pressure gauge inoperative (oil level is correct) . . . . . . . . . . . . . . . . .
RADIO INTERFERENCE SUPPRESSION
Interference while vehicle in motion. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Interference only when engine is running . . . . . . . . . . . . . . . . . . . . . . . .
FIFTH WHEEL
Trailer will not hitch to fifth wheel. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
MEDIUM WRECKER (M936)
Hydraulic system does not operate. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Hydraulic pump noisy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DUMP BODY (M929, M930)
Dump body will not raise . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Dump body will not lower. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Dump body will not hold in raised position . . . . . . . . . . . . . . . . . . . . . . .
Hydraulic pump noisy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tailgate will not open . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

83.
84.
85.
86.
87.

EXPANSIBLE VAN (M934, M935)
Side panels hard to retract or expand. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Side panel cannot be locked in retracted position. . . . . . . . . . . . . . . . . . .
Van body not waterproof or lighttight. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Door lock will not operate. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Heater will not ignite . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

70.
71.
72.
73.
74.
75.
76.
77.

2-87
2-88
2-88
2-88
2-88
2-88
2-89
2-89
2-89
2-90
2-90
2-90
2-90
2-90
2-90
2-91
2-91
2-91

2-63

TM 9-2320-272-24-1
Table 2-2. Mechanical Troubleshooting.
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION

ENGINE
1. ENGINE WILL NOT CRANK
NOTE
If STE/ICE is available, perform NG20 - No Crank - No Start Test
(para. 2-24).
Step 1. Check battery and starting systems (Electrical Troubleshooting, para. 2-22).
Step 2. Remove starter (para. 2-82) and visually check starter drive and flexplate ring gear for
broken and missing teeth.
a. Replace starter if teeth are missing (para. 3-82).
b. If flexplate ring gear is damaged, notify DS maintenance.
c. Install starter (para. 3-82) if vehicle evacuation is required.
Step 3. Check belt-driven engine accessories for seizure.
a. Remove alternator, fan, water pump, and power steering pump drivebelts (para. 3-78,
3-70, 3-71, 3-67, and 3-230).
b. Manually turn drive pulley of each accessory.
c. Replace component if any accessory drive pulley will not turn (para. 3-80, 3-81, 3-71,
3-68, 3-67, and 3-236).
NOTE
Perform step 4 for M939A2 series vehicles.
Step 4. Check air compressor for seizure.
a. Remove air compressor (para. 3-206).
b. Rotate drive gear of air compressor. If drive gear does not turn, replace air compressor
(para. 3-206).
c. Attempt to crank engine. If engine will not crank, notify DS maintenance.
Step 5. Check engine for fluid-locked pistons.
Remove turbocharger exhaust and air intake tubes (para. 3-21). If water is present, notify
DS maintenance.
END OF TESTING !
2. ENGINE CRANKS BUT WILL NOT START
NOTE
If STE/ICE is available, perform NG30 Engine Cranks No Start
Test (para. 2-24).
Step 1. Ensure emergency engine stop control is in all the way.
Step 2. Press accelerator pedal all the way down to floor and hold, then restart engine.
Step 3. Check air cleaner indicator for air restriction indications.
a. If red appears at indicator window, inspect air intake stack for restrictions and, if
necessary, replace air cleaner element (TM 9-2320-272-10).
b. Reset air cleaner indicator by pressing button down.
NOTE
Perform steps 4 through 6 for M939A2 series vehicles.

2-64

TM 9-2320-272-2491
Table 2-2. Mechanical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Step 4. Check for white smoke during cranking.
a, If white smoke is seen, air may be in fuel system.
Prime fuel system (para. 2-22),
b. If white smoke is seen, coolant may be in combustion chambers.
Remove dipstick. If coolant is present, notify DS maintenance.
WARNING
Eyeshields must be worn when cleaning with compressed air.
Compressed air source will not exceed 30 psi (207 kPa). Failure
to do so may result in injury to personnel.
l Diesel fuel is highly flammable. Do not perform fuel system
procedures near open flame. Injury to personnel may result.
Check fuel transfer pump for proper operation.
a. Check for loose fuel supply hose at fuel filter head.
b. Operate hand primer on the fuel transfer pump and check for fuel.
If fuel is present, replace fuel transfer pump (para. 3-20).
Check for fuel leaking from fuel pressure transducer. If fuel is present:
a. Check fuel transfer pump for proper operation (refer to step 5).
b. Check for clogged fuel injector supply line.
If clogged, clear with compressed air or sturdy wire.
Inspect fuel filter for dirty and/or clogged condition (para. 3-30).
Replace fuel filter if clogged or dirty (para. 3-30).
Inspect fuel lines and connections for leaks, breaks, obstructions, or damage.
a. Visually check for leaks. If leaks are present at connection, tighten.
b. If leaks are result of cracked, split, or damaged tubing, replace fuel line(s) (TM 9-243).
C. Disconnect fuel line at both ends. If fuel line is clogged, clear with compressed air or
sturdy wire.
d. Reconnect fuel line.
e. Replace fuel filter (para. 3-30).
f. Prime fuel system (para. 3-22).
g. If not corrected, notify DS maintenance.
Check for fuel contamination.
a. Open drainvalve on fuel filter/water separator and drain approximately 1 pt (0.478 L) of
fuel into a glass container.
b. If contamination is present, continue to drain fuel up to 1 qt (0.946 L).
c. If contamination is still present, drain fuel tank(s) (para. 3-27).
d. Clean and flush fuel system. Dry with compressed air.
e. Replace fuel filter (para. 3-30).
f. Refill tank(s) with fuel (TM 9-2320-272-10).
g. Prime fuel system (para. 3-22).
l

Step 5.

Step 6.

Step 7.
Step 8.

Step 9.

2-65

TM 9-2320-272-24-1
Table 2-2. Mechanical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
WARNING
Ether is extremely flammable. Do not perform ether start
system testing procedures near fire. Injury to personnel may
result.
l Eyeshields must be worn when cleaning with compressed air.
Compressed air source will not exceed 30 psi (207 kPa). Failure
to do so may result in injury to personnel.
Step 10. Check ether start system.
Perform malfunction 16.
END OF TESTING!
3. STARTER CRANKS ENGlNE SLOWLY, HARD TO START
Step 1. Press accelerator pedal all the way to floor and hold, then restart engine.
Step 2. In cold weather, ensure proper engine oil is being used.
Add or replace oil (LO 9-2320-272-12).
NOTE
If STE/ICE is available, perform NG80-Starter Circuit Tests
(para. 2-24).
Step 3. Check starting system (Electrical Troubleshooting, para. 2-22).
END OF TESTING!
4. ENGlNE STOPS DURlNG NORMAL OPERATION
Step 1. Perform malfunction 2, steps 2, 8, and 9.
Step 2. Check for restrictions in exhaust system.
Ensure exhaust system is not bent, restricted, or damaged.
Replace exhaust system component(s) if bent, restricted, or damaged (paras. 3-48, 3-49,
3-50, or 3-51).
END OF TESTING!
5. ENGlNE STOPS WHEN ACCELERATOR IS RETURNED TO IDLE POSlTlON
Step 1. Check accelerator linkage adjustment.
If necessary, adjust accelerator linkage (para. 3-42 or 3-43).
Step 2. Check if engine idle is too low.
If idle speed is below 600 rpm, notify DS maintenance.
END OF TESTING!
6. ENGlNE FAILS TO STOP
Step 1. Inspect emergency stop control cable for damage and proper adjustment.
Adjust or replace emergency stop control cable (para. 3-44).
NOTE
Perform step 2 for M939A2 series vehicles.
Step 2. Check for proper operation of throttle control solenoid and linkage.
Replace throttle control solenoid or linkage if not operating properly (para. 3-46).
END OF TESTING!
l

2-66

TM 9-2320-272-24-1
Table 2-2. Mechanical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
7. ENGINE MISFIRES DURING OPERATION
NOTE
If STE/ICE is available, perform NG90 - Governor/Power Test
Fault Isolation (para. 2-24).
Step 1. Perform malfunction 4, steps 1 and 2.
Step 2. Check accelerator linkage and modulator cables for proper operation and adjustment.
a. If accelerator linkage does not operate properly, adjust or replace as necessary
(para. 3-42 or 3-43).
b. Replace modulator cable if binding, broken, or sticking (para. 3-145).
c. If not corrected, notify DS maintenance.
END OF TESTING!
8. ENGINE IDLE ROUGH, ERRATIC (M939A2 ONLY)
Check for loose, plugged, or cracked injector tubes.
a. If loose, tighten injector tubes.
b. If cracked, replace (para. 3-19) (M939A2 only).
WARNING
Eyeshields must be worn when cleaning with compressed air.
Compressed air source will not exceed 30 psi (207 kPa). Failure to
do so may result in injury to personnel.
c. If plugged, remove and clear tubes with compressed air .
d. If not corrected, notify DS maintenance.
END OF TESTING!
9. POOR ACCELERATlON AND/OR LACK OF POWER
Step 1. Perform malfunction 4.
Step 2. Inspect accelerator pedal and throttle lever for full travel.
Adjust accelerator pedal and throttle lever travel (para. 3-42 or 3-43).
NOTE
Perform steps 3 through 7 for M939A2 series vehicles.
Step 3. Check Air Fuel Control (AFC) tube for leaks and/or restrictions.
a. If loose, tighten fittings.
b. If restricted, replace AFC tube if necessary (para. 3-18).
Step 4. Check for air leaks.
a. Check crossover tube and aftercooler for leaks.
b. Tighten all hose clamps.
c. Replace aftercooler gasket (para. 3-76).
d. Check for exhaust leaks at turbocharger and exhaust manifold. If exhaust leaks are
present, notify DS maintenance.
e. Replace turbocharger gasket (para. 3-21).

2-67

TM 9-2320-272-24-1
Table 2-2. Mechanical Troubleshooting (Contd).
MALFUNCTlON
TEST OR INSPECTION
CORRECTIVE ACTION
Step 5.

Check fuel transfer pump for proper operation.
Refer to malfunction 2, step 5.
Step 6. Check for fuel leaking from fuel pressure transducer.
Refer to malfunction 2, step 6.
WARNING
Turbocharger intake fans are extremely sharp and turn at very
high rpms. Keep hands and loose items away from intake opening.
Failure to do so may cause injury to personnel.
Step 7. Check turbocharger for proper operation.
a. Remove air intake tube from turbocharger inlet (para. 3-14).
b. Start engine (TM 9-2320-272-10) and check turbocharger intake fan for free rotation.
c. If turbocharger intake fan does not rotate freely, replace turbocharger (para. 3-21).
d. If poor acceleration or lack of power exists, notify DS maintenance.
NOTE
If STE/ICE is available, perform NC90 - Governor/Power Test
Fault Isolation (para. 2-24).
END OF TESTING!
10. ENGINE SURGES
Step 1. Perform malfunction 2, step 8.
Step 2. Check accelerator linkage and modulator cables for proper operation and adjustment.
a. If accelerator linkage does not operate properly, adjust or replace as necessary
(para. 3-42 or 3-43).
b. Replace modulator cable if binding, broken, or sticking (para. 3-145).
Step 3. If engine surge continues, notify DS maintenance.
END OF TESTING!
11. EXCESSIVE ENGlNE OIL LOSS OR CONSUMPTION
NOTE
If STE/ICE is available, perform NG90 - Governor/Power Test
Fault Isolation (para. 2-24).
Step 1. Check engine oil for overfilling (TM 9-2320-272-10).
If dipstick has been read correctly and indicates excessive oil, drain crankcase to safe
operating level (LO 9-2320-272-12). Recheck oil level (TM 9-2320-272-10).
Step 2. Check for external oil leaks.
a. Wipe off edge of rocker arm cover, oil pan, oil filter, and other external surfaces.
b. Start engine (TM 9-2320-272-10) and observe for leaks.
c. Tighten any loose connections or loose screws. If leaking continues, replace defective
component or notify DS maintenance.

2-68

TM 9-2320-272-24-1
Table 2-2. Mechanical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
NOTE
Perform step 3 for M939A2 series vehicles.
Step 3. Check turbocharger for oil leaking into air intake or exhaust.
a. Remove air intake tube from turbocharger inlet.
b. If oil is present in air intake, or excessive smoke is seen, replace turbocharger
(para. 3-21).
END OF TESTING!
12. ENGINE OIL PRESSURE TOO LOW OR TOO HIGH AT NORMAL OPERATING TEMPERATURE
Step 1. Check engine oil level (TM 9-2320-272-10).
If dipstick has been read correctly and indicates low or excessive oil, refill or drain
crankcase to proper operating level (TM 9-2320-272-10).
Step 2. Check oil supply lines for cracks, splits, leaks, damage, or obstructions.
a. Tighten loose fittings and connections.
b. Replace cracked, split, or damaged oil lines.

Eyeshields must be worn when cleaning with compressed air.
Compressed air source will not exceed 30 psi (207 kPa). Failure to
do so may result in injury to personnel.
c. Clear clogged or obstructed lines with compressed air or sturdy wire.
Step 3. Inspect oil filter for leaks.
a. Tighten oil filter.
b. If leaking persists, replace oil filter (para. 3-5).
NOTE
If STE/ICE is available, perform NG05 - Low Oil Pressure Check
(para. 2-24).
Step 4. Check oil pressure gauge, sending unit, and electrical lead for malfunction.
a. Refer to electrical troubleshooting (para. 2-22).
b. If defective, replace oil pressure sending unit (para. 3-91).
c. If defective, replace oil pressure gauge (para. 3-86).
NOTE
Perform step 5 for M939A2 series vehicles.
Step 5. Check oil pressure regulator plunger and ensure it moves freely.
a. Remove oil filter head (para. 3-4).
b. Remove oil pressure regulator plunger and spring from oil filter head (para. 3-4).
c. Clean oil pressure regulator plunger and ensure it moves freely in bore.
d. If restricted, replace oil pressure regulator plunger.
e. If low oil pressure is not corrected, notify DS maintenance.
END OF TESTING!

2-69

TM 9-2320-272-24-1
Table 2-2. Mechanical Troubleshooting (Contd).

13. ENGINE OIL CONTAMINATED
Step 1. Take oil sample to determine type of contamination(s) (para. 3-10).
Step 2. If excessive sludge is present in engine oil:
a. Review oil and filter change intervals (LO 9-2320-272-12).
b. Drain and refill engine crankcase (LO 9-2320-272-12).
NOTE
Perform step 3 for M939A2 series vehicles.
Step 3. If fuel is present in engine oil (thin, black oil is an indication):
a. Check transfer pump for leaking seal.
b. If leaking, replace transfer pump seal (para. 3-20).
Step 4. If coolant is present in engine oil (milky color):
NOTE
l During engine operation, oil pressure will be higher than
coolant pressure. A leak in oil cooler will indicate oil in coolant.
But, after engine is shut down, residual pressure in cooling
system will cause coolant to leak into oil.
l Perform step b. for M939A2 series vehicles.
a. Repair or replace oil cooler if leaking (para. 3-4, or notify DS maintenance).
b. Repair or replace aftercooler if leaking (para. 3-76).
Step 5. Check if metal particles are present in engine oil.
If metal particles are present, notify DS maintenance.
END OF TESTING!
14. EXCESSIVE VlBRATlNG OR CLUNKING
Step 1. Check engine mounting brackets and pads for looseness or damage.
a. If loose, tighten.
b. If engine mounting pad(s) are damaged, notify DS maintenance.
Step 2. Check vibration damper for looseness.
If vibration damper is loose, notify DS maintenance.
END OF TESTING!
15. EXCESSIVE FUEL CONSUMPTION
Step 1. Check air cleaner indicator for indication of air restriction.
a. If red appears at indicator window, inspect air intake stack for restrictions and, if
necessary, replace air cleaner element (TM 9-2320-272-10).
b. Beset air cleaner indicator by pressing button down.
Step 2. Inspect fuel lines and connections for leaks, breaks, obstructions, or damage.
a. Visually check for leaks. If leaks are present at connection, tighten.
b. If leaks are result of cracked, split, or damaged tubing, replace fuel line(s) (TM 9-243).
Step 3. Check fuel return line for bends and kinks.
Straighten or replace fuel return lines if bent or kinked.
END OF TESTING!
2-70

TM 9-2320-272-24-1
Table 2-2. Mechanical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION

ETHER START SYSTEM

Ether is extremely flammable. Do not perform ether start system
testing procedures near fire. Injury to personnel may result.
16. ENGINE CRANKS BUT WILL NOT START IN COLD WEATHER (FUEL SYSTEM OPERATING PROPERLY)
Step 1. Check ether cylinder.
a. Remove ether cylinder from valve, shake cylinder, and listen for liquid splashing inside
cylinder (para. 3-35).
b. If empty, replace ether cylinder (para. 3-35).
Step 2. Check ether valve for proper operation.
a. Disconnect tubing at ether valve (para. 3-35).
b. Press ether start switch. A small amount of ether should be released at ether valve.
c. If ether is not evident, check electrical system (Electrical Troubleshooting, para. 2-22).
d. If electrical system operates properly, replace ether valve (para. 3-35).
Step 3. Check thermal close valve and thermal close valve tubing for restrictions.
a. Disconnect ether valve to thermal close valve tubing at ether valve. Disconnect thermal
close valve-to-atomizer tubing at thermal close valve.
b. With thermal close valve cold, blow compressed air into tubing at ether valve end to
determine if system is restricted.
c. If restricted, disconnect tubing from thermal close valve and check for restrictions in
tubing.
d. If tubing is not restricted, replace thermal close valve (para. 3-405).
e. If tubing is restricted, replace tubing (para. 3-405).
Step 4. Check atomizer and atomizer tubing for restrictions,
a. Disconnect tubing between thermal close valve and atomizer at thermal close valve.
b. Blow compressed air into tubing at thermal close valve to determine if system is
restricted.
C. If restricted, disconnect tubing from atomizer and check for restrictions in tubing.
d. If tubing is not restricted, replace ether atomizer (para. 3-37 or 3-38).
e. If tubing is restricted, replace tubing (para. 3-39).
END OF TESTING!

EXHAUST SYSTEM
17. EXHAUST COLOR BLUE DURING NORMAL OPERATION
NOTE
Blue exhaust indicates presence of excess engine oil in cylinder
combustion chamber.
Step 1. Check that engine oil grade is correct for vehicle use and climatic conditions
(LO 9-2320-272-121.
If oil grade is incorrect, replace engine oil and oil filter (LO 9-2320-272-12).
2-71

TM 9-2320-272-24-1
Table 2-2. Mechanical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Check that engine fuel grade is correct for vehicle use and climatic conditions
(TM 9-2320-272-10).
If fuel grade is incorrect, drain complete fuel system and replace with correct grade of fuel
(TM 9-2320-272-10).
END OF TESTING!
18. EXHAUST COLOR WHITE DURING NORMAL OPERATION AND IDLE
CAUTION
Step 2.

Thick white smoke indicates coolant is present in engine combustion chambers during operation. When this condition is evident,
shut engine down immediately and determine cause. Continued
engine operations may result in permanent damage to engine.
Step 1. Check engine temperature. Ensure engine temperature is within normal operating range
175°-200°F (79°-93°C).
If temperature is above normal operating range, perform malfunction 23.
Step 2. Check for presence of water in fuel.
If water is present, drain fuel system, replace fuel filter (para. 3-30), and refill fuel tanks
(TM 9-2320-272-10).
Step 3. If problem still exists, notify DS maintenance.
END OF TESTING!
19. EXHAUST COLOR BLACK DURING NORMAL OPERATION AND IDLE
Step 1. Check air cleaner indicator for indication of air restriction,
a. If red appears at indicator window, inspect air intake stack for restrictions and, if
necessary, replace air cleaner element (TM 9-2320-272-10).
b. Reset air cleaner indicator by pressing button down.
Step 2. Check for fuel contamination.
a. Open drainvalve on fuel filter/water separator and drain approximately 1 pt (0.473 L) of
fuel into a glass container.
b. If contamination is present, continue to drain fuel up to 1 qt (0.946 L).
c. If contamination is still present, drain fuel tank(s) (para. 3-26).
d. Clean and flush fuel system. Dry with compressed air.
e. Replace fuel filter (para. 3-30).
f. Refill tank(s) with fuel (TM 9-2320-272-10).
g. Prime fuel system (para. 3-22).
END OF TESTING!
20. EXCESSIVE EXHAUST NOISE
WARNING
Do not touch hot exhaust system components with bare hands.
Severe injury to personnel may result.

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TM 9-2320-272-24-1
Table 2-2. Mechanical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Step 1.

Inspect exhaust piper, stack, and muffler for secure connections, cracks, breaks, and
excessive rust.
a. If loose, tighten.
b. If leaking at pipe connection, replace gasket(s) (para. 3-48).
c. If cracked, broken, or rusted, replace (para, 3-48). If loose, tighten.
Step 2. Check exhaust manifold for leaks. If leaking, notify DS maintenance.
NOTE
Perform step 8 for M989A2 series vehicles,
Step 3. Inspect turbocharger for secure mounting and exhaust leaks.
If turbocharger mounting is loose or leaks exhaust, notify DS maintenance.
21. EXHAUST FUMES IN CAB
Inspect exhaust pipes, stack, and muffler for secure connections, cracks, breaks, and excessive rust.
a. If loose, tighten.
a. If leaking at pipe connection, replace gasket(s) (para. 3-48).
b. If cracked, broken, or rusted, replace (para. 3-48).
END OF TESTING!

COOLING SYSTEM
22. ENGINE DOES NOT REACH NORMAL OPERATING TEMPERATURE
WARNING
Extreme care should be taken when removing surge tank filler cap
if temperature gauge reads above 175°F (79°C). Steam or hot
coolant under pressure may cause injury.
NOTE
If STE/ICE is available, perform NG31 - Gauge Test (para. 2-24).
Step 1. Start engine (TM 9-2320-272-10). Remove surge tank cap and visually check coolant for
proper circulation.
Stop engine. If coolant is seen circulating and temperature is below 175°F (79°C), replace
thermostat (para. 3-65 or 3-66).
Step 2. Test coolant temperature gauge, sending unit, and electrical leads for malfunction
(Electrical Troubleshooting, para. 2-22).
a. Replace coolant temperature gauge if defective (para. 3-86).
b. Replace coolant temperature sending unit if defective (para. 3-93).
NOTE
Perform step 3 for M939A2 series vehicles.
Step 3. Observe fan clutch and actuator for proper operation.
Replace fan clutch and/or actuator if defective (para. 3-74).
END OF TESTING!

2-73

TM 9-2320-272-24-1
Table 2-2. Mechanical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
23. ENGINE OVERHEATS AS INDICATED BY ENGINE COOLANT TEMPERATURE GAUGE
WARNING
Extreme care should be taken when removing surge tank filler cap
if temperature gauge reads above 175°F (79°C). Steam or hot
coolant under pressure may cause injury.
Step 1. Check coolant level (TM 9-2320-272-10).
CAUTION
Do not add coolant to engine when hot. Internal damage to
engine could result.
l On M939A2 series vehicles, ensure drainvalve on aftercooler is
open. Failure to do so may result in damage to equipment.
If coolant level is low, fill to proper level (para. 3-53).
Check engine oil level (TM 9-2320-272-10).
If oil level is low, fill to correct level (LO 9-2320-272-12).
Inspect drivebelts and tensioner (M939A2) for looseness, absence, and worn conditions.
a. If loose, tighten.
b. Replace drivebelt if worn or damaged (paras. 3-67, 3-68, 3-71, 3-80, 3-81, or 3-236).
Inspect radiator, hoses, hose connections, and drainvalves for leaks.
a. Tighten loose hose clamps and fittings.
b. Tighten or close drainvalves.
c. Replace defective cooling system components (chapter 3, section V).
Check cooling system for clogging.
If clogged, flush and clean cooling system (para. 3-53).
Inspect fan for cracked or missing blades.
If blades are cracked or missing, replace fan (para. 3-64 or 3-72).
Check radiator for airflow obstructions.
Remove obstructions from front of radiator (TM 750-254).
Observe fan clutch and actuator for proper operation.
If defective, replace fan clutch and actuator (para. 3-73 or para. 3-74).
Check water pump for leaks and proper operation.
a. Start engine (TM 9-2320-272-10). Remove surge tank cap and visually check coolant for
proper circulation.
b. Stop engine. If coolant is seen circulating and temperature is below 175°F (79°C)
replace thermostat (para. 3-65 or 3-66).
NOTE
If STE/ICE is available, perform NG31 - Gauge Test (para. 2-24).
Test temperature gauge for proper operation (TM 9-2320-272-10).
If not correct, notify DS maintenance.
END OF TESTING!
l

Step 2.
Step 3.

Step 4.

Step 5.
Step 6.
Step 7.
Step 8.
Step 9.

Step 10.

2-74

TM 9-2320-272-24-1
Table 2-2. Mechanical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
24. LOSS OF COOLANT
Step 1. Check for leaks in cooling system.
a. Inspect radiator, hoses, hose connections, and drainvalves for leaks.
b. Tighten loose hose clamps and fittings.
c. Tighten or close drainvalves.
d. Replace defective cooling system components (chapter 3, section V).
Step 2. Check for coolant in transmission oil.
a. Check transmission oil for presence of coolant.
b. If coolant is present in transmission oil, check transmission oil cooler for damage and
leaks.
c. If damaged or leaking, replace transmission oil cooler (para. 3-140 or 3-141).
d. Drain and flush cooling system (para. 3-53).
END OF TESTING!
25. CONTAMINATED COOLANT
Step 1. If coolant appears rusty, drain and flush cooling system (para. 3-53).
Step 2. If transmission oil is present in coolant, perform malfunction 24, step 2.
Step 3. If engine oil is present in coolant, notify DS maintenance.
END OF TESTING!

TRANSMISSION
26. EXCESSIVE NOISE DURING SHIFTING
Step 1. Check transmission fluid level (TM 9-2320-272-10).
Drain or fill fluid as necessary (LO 9-2320-272-12).
Step 2. Check propeller shaft flanges for loose mounting bolts.
If loose, tighten mounting bolts 30-40 lb-ft (41-54 N-m).
Step 3. Inspect propeller shaft universal joints for looseness, wear, and damage.
a. If loose, tighten universal joint screws 90-110 lb-ft (122-149 N•m).
b. Replace worn or damaged universal joints (para. 3-154).
END OF TESTING!
27. LOW TRANSMISSION OIL PRESSURE
Step 1. Check transmission fluid level (TM 9-2320-272-10).
Drain or fill fluid as necessary (LO 9-2320-272-12).
Step 2. Replace transmission oil filter (para. 3-133).
END OF TESTING!
28. TRANSMISSION OIL LEAKING
Step 1. Inspect for leak at output shaft.
If output shaft oil seal is leaking, notify DS maintenance.
a. If loose, tighten drainplug.
b. If leak continues, notify DS maintenance.
2-75

TM 9-2320-272-24-1
Table 2-2. Mechanical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Step 2.

Inspect transmission oil pan gasket for leaks.
a. If loose, tighten mounting screws 10-15 lb-ft (14-20 N•m).
b. If leak continues, replace oil pan gasket (para. 3-133).
Step 3. Inspect transmission housing for leaks.
If leaking, notify DS maintenance.
END OF TESTING!
29. NO RESPONSE TO SHIFT LEVER MOVEMENT
Step 1. Check transmission fluid level (TM 9-2320-272-10).
Drain or fill fluid as necessary (LO 9-2320-272-12).
Step 2. Check for broken or disconnected shift cable.
If broken or disconnected, notify DS maintenance.
END OF TESTING!
30. ROUGH SHlFTlNG
Step 1. Check transmission fluid level (TM 9-2320-272-10).
Drain or fill fluid as necessary (para. 3-133).
Step 2. Check transmission select lever and shift cable for proper operation.
a. If select lever is damaged, notify DS maintenance.
b. If shift cable is bent, kinked, broken, or frayed, notify DS maintenance.
END OF TESTING!
31. TRANSMISSION OVERHEATS AS INDICATED BY TRANSMISSION TEMPERATURE GAUGE
Step 1. Check transmission fluid level (TM 9-2320-272-10).
Drain or fill fluid as necessary (para. 3-1331.
Step 2. Check for clogged or restricted transmission oil cooler.
If clogged or restricted, replace transmission oil cooler (para. 3-140 or 3-141).
Step 3. Check transmission temperature sending unit (Electrical Troubleshooting, para. 2-24).
Step 4. Check for clogged or restricted transmission oil cooler hoses.
If clogged or restricted, replace transmission oil cooler (para. 3-140 or 3-141).
Step 5. Test transmission temperature gauge for proper operation using a gauge known to be good.
If test gauge does not indicate overheating, replace transmission temperature gauge
(para. 3-86).
END OF TESTING!
32. DIRT OR METAL PARTICLES IN TRANSMISSION OIL
Take transmission oil sample. Submit oil sample in accordance with TB 43-0210.
END OF TESTING!
33. OIL THROWN FROM TRANSMlSSlON DIPSTICK TUBE
Step 1. Check transmission fluid level for overfilling (TM 9-2320-272-10).
Drain fluid to proper level (LO 9-2320-272-12). Recheck transmission for proper fluid level
(TM 9-2320-272-10).

2-76

TM 9-2320-272-24-1
Table 2-2. Mechanical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Step 2.

Check for loose dipstick tube.
If loose, tighten.

NOTE
Perform step 3 if deep water was forded.
Step 3. Remove vent line from transmission. Start vehicle and build up air pressure. If air is coming
from line, notify DS maintenance.
END OF TESTING!
34. TRANSMISSION OIL DIRTY, FOAMY, AND/OR MILKY
NOTE
Dirt/grit in transmission oil indicates oil needs to be changed
(step 2). Foaminess indicates contamination by air or water
(step 3). Milkiness indicates contamination by coolant (step 4).
Step 1. Check oil filter tube seal for damage and leaks.
a. If damaged, replace seal (para. 3-133).
b. If leaking, tighten.
Step 2. Check for dirt/grit.
a. Replace transmission internal oil filter (para. 3-133).
b. Replace transmission external oil filter (para. 3-133).
c. Notify DS maintenance for transmission replacement,
Step 3. Check for excessive foaming.
Ensure transmission fluid is at proper level (TM 9-2320-272-10). Drain or fill fluid as
necessary (LO 9-2320-272-12).
Step 4. Check for coolant in transmission fluid.
If coolant is present in transmission oil, perform malfunction 24, step 2.
END OF TESTING!

TRANSFER CASE
35. HARD SHIFTING OF TRANSFER CASE
Step 1. Check transfer case fluid level (LO 9-2320-272-12).
Fill or drain to proper level as necessary (LO 9-2320-272-12).
Step 2. Inspect transfer case shift linkage for proper lubrication.
Lubricate linkage as necessary (LO 9-2320-272-12).
Step 3. Inspect shift linkage for bends, breaks, and missing parts.
If shift linkage is bent, broken, or has missing parts, notify DS maintenance.
Step 4. Check wire 586 for good ground.
Repair or replace wire (para. 3-131).
END OF TESTING!

2-77

TM 9-2320-272-24-1
Table 2-2. Mechanical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
36. TRANSFER CASE LEAKING OIL
Step 1. Inspect drainplugs for leaks and looseness.
If loose and leaking, tighten drainplugs 35 lb-ft (48 N•m).
Step 2. Inspect transfer case housing for leaks.
If leaking, notify DS maintenance.
END OF TESTING!
37. EXCESSIVE NOISE
Check transfer case fluid level (LO 9-2320-272-12).
a. Fill to proper fluid level as necessary (LO 9-2320-272-12).
b. Tighten filler plug 35 lb-ft (48 N-m).
c. If problem still exists, notify DS maintenance.
END OF TESTING!
38. EXCESSIVE VIBRATION
Step 1. Check transfer case fluid level (LO 9-2320-272-12).
a. Fill to proper fluid level as necessary (LO 9-2320-272-12).
b. Tighten filler plug 35 lb-ft (48 N•m).
Step 2. Check yoke companion flange screws for proper torque.
Tighten screws 32-40 lb-ft (43-54 N•m).
END OF TESTING!

PROPELLER AND DRIVESHAFTS
39. EXCESSIVE NOISE OR VlBRATlON
Step 1. Check universal joints for proper lubrication.
Lubricate universal joints as necessary (LO 9-2320-272-12).
Step 2. Check torque of all propeller shaft flange yoke screws.
Tighten screws 32-40 lb-ft (43-54 N•m).
Step 3. Inspect propeller shafts for wear and damage.
Replace any worn or damaged propeller shafts (chapter 3, section VIII).
NOTE
Perform step 4 for M927 and M928 model vehicles.
Step 4. Inspect center bearing for looseness and damage.
a. Tighten center bearing-to-forward rear axle propeller shaft yoke to transfer-to-center
bearing rear flange screws 32-40 lb-ft (43-54 N•m).
b. If damaged, replace center bearing assembly (para. 3-150).
END OF TESTING!

2-78

TM 9-2320-272-24-1
Table 2-2. Mechanical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION

FRONT AND REAR AXLES
40. CONTINUOUS AXLE OR WHEEL NOlSE
Step 1. Check to see if front wheel drive is engaged.
Disengage front wheel drive when traveling on hard surfaces.
Step 2. Check for loose or missing wheel stud nuts.
a. Tighten stud nuts 400-425 lb-ft (542-576 N•m).
b. Replace missing stud nuts (para. 3-224).
Step 3. Check lubrication level in axle housing and differential (LO 9-2320-272-12).
Fill axle housing or differential to proper level if necessary (LO 9-2320-272-12).
Step 4. Check for loose or damaged wheel bearings.
a. Raise vehicle wheels off ground and support with jack stands.
b. Use prybar to lift up on bottom of tire. Excessive play indicates improperly adjusted or
damaged bearings.
c. If excessive play is present, adjust or replace wheel bearings (para. 3-225).
END OF TESTING!
41. OIL LEAKlNG FROM FRONT WHEEL DRIVE LOCK-IN SWITCH
Step 1. Disconnect air line from cylinder and check for oil in line.
Step 2. If oil is present in line, notify DS maintenance.
END OF TESTING!
42. DlFFERENTlAL NOISY
Step 1. Perform malfunction 40.
Step 2. Check differential operation. Remove differential propeller shaft(s) (para. 3-148, 3-149,
3-150, or 3-151). Raise wheels (TM 9-2320-272-10), manually turn wheels, and observe
differential operation.
a. If tires will not rotate, check brakeshoe condition and operation (para. 3-176).
b. Remove brakedrums (para. 3-177). If brake system components are defective, repair or
replace (chapter 3, section IX), or notify DS maintenance.
c. If tires will still not rotate, notify DS maintenance.
d. If tire rotation drags at some points during full rotation, remove and inspect axle shafts
(para. 3-154 or 3-157).
e. If defective, replace axle shafts (para. 3-154 or 3-157).
END OF TESTING!
43. DlFFERENTlAL CLUNKS DURING TURNS OR INlTlAl TAKEOFF
Step 1. Check condition of differential propeller shaft(s) and universal joint(s) (para. 3-154, 3-148,
3-149, 3-150, or 3-151).
Repair or replace defective components (para. 3-154, 3-148, 3-149, 3-150, or 3-151).
Step 2. Check front axle shafts and universal joints for defects (para. 3-154).
Repair or replace defective components (para. 3-154).
Step 3. If internal problem exists in differential, notify DS maintenance.
END OF TESTING!
2-79

TM 9-2320-272-24-1
Table 2-2. Mechanical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
44. DlFFERENTlAL VlBRATES
Step 1. Check condition of tires and rims. Repair or replace defective components (para. 3-219 or 3-220).
Step 2. Perform malfunction 43, steps 1 and 2.
Step 3. If internal problems in differential exist, notify DS maintenance.
END OF TESTING!
45. DIFFERENTIAL LEAKS OIL
Step 1. Check condition of axle seals. Inspect brakedrum for presence of gear oil.
If gear oil is present in or around brakedrums, replace axle seals (para. 3-160).
Step 2. Check through-shaft for free play.
Place end of prybar between differential housing and companion flange. Apply pressure to
prybar.
Step 3. If companion flange moves, notify DS maintenance.
END OF TESTING!

WHEELS AND TIRES
NOTE
A broken or separated radial belt will cause symptoms as outlined
in malfunctions 46, 47, 49, and 51.
46. UNEVEN TIRE WEAR
Step 1. Check for loose or missing wheel stud nuts and wheel studs.
a. Tighten loose wheel stud nuts 400-425 lb-ft (542-576 N•m).
b. Replace missing wheel stud nuts and/or wheel studs (para. 3-218, 3-219, or 3-222).
Step 2. Check for improper wheel alignment adjustment if wear is on front tires.
Adjust alignment if necessary (para. 3-152).
Step 3. Check wheel bearings for proper adjustment and damage. Raise wheels off ground. Use
prybar to lift up on bottom of tire. Excessive play indicates improperly adjusted or damaged
bearings.
a. Adjust wheel bearings (para. 3-225).
b. Replace damaged bearings (para. 3-223, 3-224, 3-460, or 3-461).
c. Check that tires are properly inflated (TM 9-2320-272-10).
END OF TESTING!
47. WHEEL SHlMMY OR WOBBLE
Step 1. Inspect wheels for bends and damage.
Replace bent or damaged wheels (para. 3-218 or 3-219).
Step 2. Check wheel bearings for proper adjustment and damage. Raise wheels off ground. Use prybar
to lift up on bottom of tire. Excessive play indicates improper adjustment or damaged bearings,
a. Adjust wheel bearings (para. 3-225).
b. Replace damaged bearings (para. 3-223, 3-224, 3-460, or 3-461).
c. Check that tires are properly inflated (TM 9-2320-272-10).
END OF TESTING!
2-80

TM 9-2320-272-24-1
Table 2-2. Mechanical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
STEERING
48. HARD STEERING
step 1. Inspect all hydraulic lines and hoses for leaks.
Tighten loose fittings and replace leaking lines (chapter 3, section X).
step 2. Inspect steering linkage for binding, damage, and improper lubrication.
a. Repair or replace binding or damaged linkage (chapter 3, section X).
b. Lubricate linkage (LO 9-2320-272-12).
step 3. Inspect steering knuckles for binding. Raise front wheels off ground. Disconnect drag link at
pitman steering arm (para. 3-227 or 3-228). Turn wheels from side to side to determine
binding.
Notify DS maintenance if wheels do not turn from side to side without binding.
step 4. Check spring U-bolts for tightness.
Tighten U-bolt(s) 350-400 lb-ft (475-542 N•m).
step 6. Check front wheel alignment.
a. Check front tires for underinflation and uneven tire pressure. Inflate tires to proper
pressure (TM 9-2320-272-10).
b. Adjust alignment to specifications (para. 3-152).
END OF TESTING!
49. VEHICLE WANDERS OR PULLS TO ONE SIDE
Step 1. Check front tires for underinflation and uneven tire pressure.
Inflate tires to proper pressure (TM 9-2320-272-10).
Step 2. Check tires for uneven wear (indicates improper wheel alignment).
Adjust front wheel alignment (para. 3-152).
Step 3. Check for dragging brakes. Raise wheels off ground. Spin wheels by hand. Wheels should
turn with slight drag when properly adjusted.
Refer to compressed air and brake system troubleshooting (table 2-4, malfunction 4).
Step 4. Check wheel bearings for proper adjustment and damage. Raise wheels off ground. Use
prybar to lift up on bottom of tire. Excessive play indicates improper adjusted or damaged
bearings.
a. Adjust wheel bearings (para. 3-225).
b. Replace damaged bearings (para. 3-223, 3-224, 3-225, 3-460, or 3-461).
c. Check that tires are properly inflated (TM 9-2320-272-10).
Step 5. Inspect steering assist cylinder for damage and improper adjustment.
Replace or adjust steering assist cylinder (para. 3-233).
Step 6. Inspect tie rod for looseness and damage.
Tighten or replace tie rod (para. 3-163).
Step 7. Check for loose steering gear mounting bolts.
Tighten mounting bolts 260-280 lb-ft (353-380 N-m).

2-81

TM 9-2320-272-24-1
Table 2-2. Mechanical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Step 8.

Check for worn pitman arm.
If worn, replace pitman arm (para. 3-227 or 3-228).
Step 9. Check front spring shackle pins for damage and breaks.
If damaged or broken, replace front spring shackle pins (para. 3-162).
Step 10. Check wheel alignment for proper adjustment.
Adjust wheel alignment if necessary (para. 3-152).
END OF TESTING!
50. EXCESSIVE PLAY IN STEERING WHEEL
Step 1. Check steering wheel free play. With engine running, place stiff wire long enough to touch
steering wheel rim against dash. Turn steering wheel left, then right, until there is resistance.
Mark the points on steering wheel where the travel ends. Then measure the distance between
these points. If there is more than 2-1/2 in. (6.3 cm) of play, proceed to step 2.
Step 2. Check drag link for looseness and damage.
Tighten or replace drag link (para. 3-229).
Step 3. Inspect tie rod for damage and loose ends. No free play is allowable.
Tighten or replace tie rod (para. 3-153).
Step 4. Inspect pitman arm for damage.
Replace pitman arm if damaged (para. 3-227 or 3-228).
Step 5. Inspect steering assist cylinder for improper adjustment and damage.
Replace or adjust steering assist cylinder (para. 3-233).
Step 6. If 2-1/2 in. (6.4 cm) of play still exists, notify DS maintenance.
END OF TESTING!
51. SHIMMY
Step 1. Check for loose or missing wheel stud nuts and wheel studs.
a. Tighten loose wheel stud nuts 400-425 lb-ft (542-576 N•m).
b. Replace missing wheel stud nuts and/or wheel studs (para. 3-218, 3-219, or 3-222).
Step 2. Inspect wheels for bends and damage.
Replace bent or damaged wheels (para. 3-218 or 3-219).
Step 3. Check wheel bearings for proper adjustment and damage. Raise wheels off ground. Use
prybar to lift up on bottom of tire. Excessive play indicates improperly adjusted or damaged
bearings.
a. Adjust wheel bearings (para. 3-225).
b. Replace damaged bearings (para. 3-223, 3-224, 3-225, 3-460, or 3-461).
c. Check that tires are properly inflated (TM 9-2320-272-10).
Step 4. Check front wheel alignment.
a. Check front tires for underinflation and uneven tire pressure. Inflate tires to proper
pressure (TM 9-2320-272-10).
b. Adjust alignment to specifications (para. 3-152).

2-82

TM 9-2320-272-24-1
Table 2-2. Mechanical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Step 5.

Check for loose front axle steering knuckle(s). Raise wheels off ground. Turn wheels from
side to side to observe for loose steering knuckle.
If steering knuckle is loose, notify DS maintenance.
END OF TESTING!

FRAME AND BRACKETS
52. TOWlNG PINTLE DOES NOT LATCH OR LOCK
Step 1. Inspect pintle hook for lubrication.
Lubricate pintle hook (LO 9-2320-272-12).
Step 2. Check pintle hook lock for proper operation.
Replace defective pintle hook (para. 3-242).
END OF TESTING!
53. PINTLE HOOK DOES NOT TURN
Step 1. Inspect pintle hook for lubrication.
Lubricate pintle hook (LO 9-2320-272-12).
Step 2. Check clearance between thrust washer and mounting bracket housing with feeler gauge.
Clearance should be 0.003 in. - 0.017 in. (0.07 mm - 0.43 mm).
a. If clearance is the same completely around, but not 0.003 in. - 0.017 in. (0.07 mm 0.43 mm), adjust clearance (para. 3-242).
b. If clearance is the same completely around, go to step 3.
Step 3. Inspect pintle hook shaft for bends.
Replace pintle hook if shaft is bent (para. 3-242).
END OF TESTING!
5-54. EXCESSIVELY LOOSE LIFTING SHACKLE
Inspect shackle and shackle pin for bends, wear, and proper size.
If worn, bent, or size is improper, replace shackle and/or shackle pin (para. 3-241).
END OF TESTING!
55. LOOSE SPARE TIRE CARRIER
Step 1. Check for missing and worn mounting bolts.
If worn or missing, replace mounting bolts.
Step 2. Inspect carrier frame for damage.
If damaged, replace any unserviceable carrier component (chapter 3, section XI).
END OF TESTING!

SPRINGS AND SHOCK ABSORBERS
56. CONTINUOUS WANDERING OR SWAYING (POOR CONTROL)
Step 1. Inspect front leaf springs for breaks.
If broken, replace main leaves (para. 3-161).
Step 2. Inspect shock absorbers for leaks and damage.
If leaking or damaged, replace shock absorbers (para. 3-166).
2-83

TM 9-2320-272-24-1
Table 2-2. Mechanical Troubleshooting (Contd).

Step 3.

Inspect spring U-bolts for looseness and damage.
a. Tighten loose spring U-bolts 350-400 lb-ft (475-542 N•m).
b. If damaged, replace U-bolts (para. 3-161).
Step 4. Check steering system (malfunction 48).
END OF TESTING!
57. HARSH OR HARD RlDE
Step 1. Check lubrication of springs, pivots, and shackle pins.
Lubricate springs, pivots, and shackle pins (LO 9-2320-272-12).
Step 2. Check spring shackles for frozen condition.
Free shackles and lubricate (LO 9-2320-272-12).
Step 3. Check for defective shock absorbers.
a. Remove shock absorber from top mounting.
b. Pull up and down on shock absorber to test resistance.
c. If there is little or no resistance, replace shock absorber (para. 3-166).
END OF TESTING!
58. SPRING LEAF DEFECT
Step 1. Inspect for loose and damaged front spring shackles.
If loose or damaged, replace shackles (para. 3-162).
Step 2. Inspect spring U-bolts for looseness and damage.
a. Tighten loose spring U-bolts 350-400 lb-ft (475-542 N•m).
b. If damaged, replace U-bolts (para. 3-161).
Step 3. Inspect front leaf springs for breaks.
If broken, replace main leaves (para. 3-161).
END OF TESTING!

WINCH
59. WINCH DOES NOT OPERATE
Step 1. Check hydraulic oil reservoir for proper fluid level.
a. Fill hydraulic oil reservoir to proper oil level (LO 9-2320-272-12).
b. Check for evidence of oil leaks and damage to reservoir.
c. If leaks are found, tighten any loose connections or fittings.
d. If damaged, replace reservoir (para. 3-337 or 3-338).
Step 2. Check PTO and winch controls for kinks, damage, breaks, and improper lubrication (front
winch).
a. Lubricate if necessary (LO 9-2320-272-12).
b. If winch or PTO cable is kinked, damaged, or broken, notify DS maintenance.

2-84

TM 9-2320-272-24-1
Table 2-2. Mechanical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Step 3. Check all oil lines for damage and leaks.
a. Tighten loose fittings.
b. Replace leaking or damaged hoses.
Step 4. Check winch oil filter for leaks and clogs (front winch).
a. Remove center bolt, filter housing, filter, and gasket from filter head.
b. Check filter and filter head for clogs. Replace filter if clogged; clean filter head if clogged.
c. Install filter, gasket, and filter housing on filter head with center bolt. Tighten center
bolt 30-35 lb-ft (41-48 N•m).
Step 5. Check winch pump for leaks and overheating.
a. If loose, tighten winch pump connections.
b. If winch pump is defective, notify DS maintenance.
Step 6. Check winch motor for leaks.
a. If loose, tighten winch motor connections.
b. If winch motor is defective, notify DS maintenance.
NOTE
Assistant will help with step 7.
Step 7. Check control valve for proper operation and leaks (front winch).
a. While assistant operates winch control lever, observe control valve for proper operation.
b. If control valve is defective, notify DS maintenance.
c. Tighten any loose fittings.
Step 8. Check if drum clutch is engaged (front winch).
a. Engage drum clutch (TM 9-2320-272-10).
b. If drum clutch does not engage, replace front winch (para. 3-329).
Step 9. Check if drum lock is pulled out (front winch).
a. Pull out drum lock (TM 9-2320-272-10).
b. If drum lock does not pull out, replace front winch (para. 3-329).
END OF TESTING!
60. WINCH OPERATES IN ONE DIRECTION ONLY
Step 1. Check PTO and winch controls for kinks, damage, breaks, and improper lubrication (front
winch).
a. Lubricate if necessary (LO 9-2320-272-12).
b. If winch or PTO cable is kinked, damaged, or broken, notify DS maintenance.
NOTE
Assistant will help with step 2.
Step 2. Check control valve for proper operation and leaks (front winch).
a. While assistant operates winch control lever, observe control valve for proper operation.
b. If control valve is defective, notify DS maintenance.
c. Tighten loose fittings.

2-85

TM 9-2320-272-24-1
Table 2-2. Mechanical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Step 3.

Check if air-operated tensioner is released (rear winch).
Release tensioner (TM 9-2320-272-10).
Step 4. Check if torque control lever is engaged (rear winch).
Engage torque control lever (TM 9-2320-272-10).
END OF TESTING!
61. DRAG BRAKE DOES NOT OPERATE
Check drag brake adjustment.
a. Adjust drag brake (para. 3-324 or 3-330).
b. If drag brake is defective, replace winch (para. 3-329 or 3-332).
END OF TESTING!
62. WlNCH WILL NOT HOLD LOAD
Step 1. Check torque control lever position (rear winch).
Reposition torque control valve lever to HIGH or LOW position.
Step 2. Check automatic brake adjustment (para. 3-323).
Adjust automatic brake screw (para. 3-323 or 3-330).
END OF TESTING!
63. AUTOMATIC BRAKE OVERHEATS
Step 1. Check weight limit of winch. Adjust size of load.
Step 2. Check automatic brake adjustment (para. 3-323).
Turn automatic brake screw counterclockwise one-quarter turn. Recheck winch for
overheating.
END OF TESTING!
64. FRONT WINCH OPERATES AT ONE SPEED ONLY
Step 1. Check control valve for proper operation and leaks (front winch).
a. While assistant operates winch control lever, observe control valve for proper operation.
b. If control valve is defective, notify DS maintenance.
Step 2. Check winch controls for kinks, damage, breaks, and improper lubrication (front winch).
a. Lubricate if necessary (LO 9-2320-272-12).
b. If winch cable is kinked, damaged, or broken, notify DS maintenance.
Step 3. Check throttle control cable for damage (front winch).
If throttle control cable is damaged, notify DS maintenance.
END OF TESTING!
65. REAR WINCH CABLE TENSIONER WILL NOT OPERATE
Check air supply lines for leaks.
a. Tighten loose fittings.
b. If leaks persist, notify DS maintenance.
END OF TESTING!

2-86

TM 9-2320-272-24-1
Table 2-2. Mechanical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
66. VEHICLE ROLLS WHILE OPERATING REAR WlNCH
Step 1. Check parking brake for proper adjustment.
Adjust parking brake (TM 9-2320-272-10).
Step 2. Check spring brake caging.
Release spring brake cage (TM 9-2320-272-10).
Step 3. Check field chock positioning.
Position chocks facing load for direct pulls (TM 9-2320-272-10).
END OF TESTING!

POWER TAKEOFF (PTO)
67. EXCESSIVE NOISE AT PTO
Step 1. Inspect PTO universal joint for insufficient lubrication.
If necessary, lubricate universal joint (LO 9-2320-272-12).
Step 2. Inspect propeller shaft for bends.
If bent, replace propeller shaft (para. 3-334 or 3-393).
END OF TESTING!
68. HARD SHIFTING OF PTO
Inspect PTO shift linkage for bends, cracks, and improper lubrication.
a. Lubricate shift linkage if necessary (LO 9-2320-272-12).
b. If bent or cracked, notify DS maintenance.
END OF TESTING!
69. LEAKING LUBRICANT AT PTO
Inspect mounting screws for security.
a. Tighten loose mounting screws.
b. If leak continues, notify DS maintenance.
END OF TESTING!

INSTRUMENTS AND GAUGES
70. SPEEDOMETER OR TACHOMETER NOISY OR ERRATIC
Step 1. Inspect tachometer or speedometer flexible shaft for binding and kinks.
If binding or kinked, replace flexible shaft(s) (para. 3-89 or 3-90).
Step 2. Inspect tachometer or speedometer for proper operation.
a. Test operation of tachometer or speedometer by replacing them with a speedometer or
tachometer known to be good (para. 3-88).
b. If test speedometer or tachometer operate properly, replace defective speedometer or
tachometer (para. 3-88).
END OF TESTING!

2-87

TM 9-2320-272-24-1
Table 2-2. Mechanical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
71. AIR PRESSURE GAUGE INOPERATlVE
Replace air gauge with one known to be good (para. 3-87).
If test gauge works properly, replace defective air gauge (para. 3-87).
END OF TESTING!
72. OIL PRESSURE GAUGE INOPERATIVE (OIL LEVEL IS CORRECT)
Check oil pressure sending unit for proper operation.
a. Replace oil pressure sending unit with one known to be good (para. 3-86).
b. If oil pressure gauge does not work properly, replace oil pressure gauge (para. 3-86).
END OF TESTING!

RADIO INTERFERENCE SUPPRESSION
73. INTERFERENCE WHILE VEHICLE IN MOTlON
Inspect wiring for loose connections and frayed or broken wiring.
a. Tighten all loose connections,
b. Replace or repair frayed or broken wiring (para. 3-131).
END OF TESTING!
74. INTERFERENCE ONLY WHEN ENGINE IS RUNNING
Inspect alternator for defects.
If defective, replace alternator (para. 3-79 or 3-80).
END OF TESTING!

FIFTH WHEEL
75. TRAllER WILL NOT HITCH TO FIFTH WHEEL
Inspect coupling jaws for bends and breaks.
If coupling jaws are bent or broken, replace fifth wheel (para. 3-248).
END OF TESTING!

MEDIUM WRECKER (M936)
76. HYDRAULIC SYSTEM DOES NOT OPERATE
Step 1. Check hydraulic oil reservoir for proper fluid level (LO 9-2320-272-12).
Fill oil reservoir to proper fluid level if necessary (LO 9-2320-272-12).
Step 2. Check if PTO is engaged.
a. Engage PTO control (TM 9-2320-272-10).
b. If PTO does not engage, perform malfunction 67,
Step 3. Check all hydraulic lines for damage and leaks.
a. Tighten loose fittings.
b. If hoses are leaking or damaged, notify DS maintenance.

2-88

TM 9-2320-272-24-1
Table 2-2. Mechanical Troubleshooting (Contd).
MALFUNCTlON
TEST OR INSPECTION
CORRECTIVE ACTION
Step 4.

Check reservoir drainplug and valve for leaks.
a. Close valve.
b. Tighten drainplug.
END OF TESTING!
77. HYDRAULIC PUMP NOISY
Check hydraulic oil reservoir for proper fluid level (LO 9-2320-272-12),
Fill oil reservoir to proper fluid level if necessary (LO 9-2320-272-12).
END OF TESTING!

DUMP BODY (M929, M930)
WARNlNG
When dump body is in raised position, oil in filter system is under
pressure. Any movement of the control valve or leakage at the
hydraulic cylinder line or hose connection will cause dump body to
drop to subframe. Never work under dump body unless safety
braces are properly positioned.
78. DUMP BODY WILL NOT RAISE
Step 1. Check if PTO is engaged.
a . Engage PTO control (TM 9-2320-272-10).
b. If PTO does not engage, perform malfunction 68.
Step 2. Check all hydraulic lines for damage and leaks.
a. Tighten loose fittings.
b. Replace leaking or damaged hoses (para. 3-131).
NOTE
Assistant will help with step 3.
Step 3. Check control valve for proper operation and leaks (front winch).
a. While assistant operates winch control lever, observe control valve for proper operation.
b. Tighten loose fittings.
c. If control valve is defective, notify DS maintenance.
Step 4. Check control valve shaft movement.
If shaft does not move freely, notify DS maintenance.
Step 6. Inspect pump housing for leaks and signs of overheating when PTO is engaged.
a. Tighten loose fittings.
b. Notify DS maintenance.
END OF TESTING!

2-89

TM 9-2320-272-24-1
Table 2-2. Mechanical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
79. DUMP BODY WILL NOT LOWER
Step 1. Check for raised safety braces under dump body.
Lower and stow safety braces (TM 9-2320-272-10).
NOTE
Assistant will help with step 2.
Step 2. Check control valve for proper operation and leaks (front winch).
a. While assistant operates winch control lever, observe control valve for proper operation.
b. Tighten loose fittings.
c. If control valve is defective, notify DS maintenance.
END OF TESTING!
80. DUMP BODY WILL NOT HOLD IN RAISED POSITION
Step 1. Check all hydraulic lines for damage and leaks.
a. Tighten loose fittings.
b. If hoses are cracked or leaking, notify DS maintenance.
Step 2. Check control valve shaft movement.
If shaft does not move freely, notify DS maintenance.
END OF TESTING!
81. HYDRAULIC PUMP NOISY
Check hydraulic oil reservoir for proper fluid level (LO 9-2320-272-12).
Fill oil reservoir to proper fluid level if necessary (LO 9-2320-272-12).
END OF TESTING!
82. TAILGATE WILL NOT OPEN
Check for bent or broken linkage.
If bent or broken, replace linkage (para. 3-349).
END OF TESTING!

EXPANSIBLE VAN (M934, M935)
83. SIDE PANELS HARD TO RETRACT OR EXPAND
Step 1. Check for dirt and other foreign material in sprocket assembly.
a. Clean and lubricate sprocket assembly (LO 9-2320-272-12).
b. If sprocket will not turn or engage properly, notify DS maintenance.
Step 2. Check for corroded, dirty, and damaged rollers.
Clean corroded or dirty rollers. If damaged, notify DS maintenance.
END OF TESTING!
84. SIDE PANEL CANNOT BE LOCKED IN RETRACTED POSITION
Step 1. Visually inspect front edge of side panel to see if it is retracted.
Place heavy block of wood (2 in. x 4 in., or 4 in. x 4 in.) against rub rail at front of panel,
Strike block with heavy hammer.

2-90

TM 9-2320-272-24-1
Table 2-2. Mechanical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Step 2. Visually check to see if top side panel is too far out to engage edge of roof.
Place heavy block of wood against flat surface of seal retainer, opposite locking bar at top of
side panel. Strike block with heavy hammer.
END OF TESTING!
85. VAN BODY NOT WATERPROOF OR LIGHTTIGHT
step 1. Visually inspect lower part of side panel for tightness against van body.
Place heavy block of wood (2 in. x 4 in., or 4 in. x 4 in.) against rub rail at end of side panel
where leaks occurs. Strike block with heavy hammer.
step 2. Check for sagging end panel.
Add rubber seal material (appendix D, item 632) to seal on outer edge of hinged roof until
seal meets top edge of panel door.
step 3. Check lip of block seal at inner rear corner of hinge roof to see if it is out of position.
Move side panel out to disengage corner block seal. Push seal lip up into correct position so
end panel door properly engages seal when side panel is retracted.
step 4. Check for loose or worn seal at top of rear doors.
If worn, recover worn or loose area with sealing material (appendix D, item 632).
END OF TESTING!
86. DOOR LOCK WILL NOT OPERATE
Step 1. Check for jammed lock bolt.
If lock bolt is jammed, repair lock assembly (para. 3-364).
Step 2. Check alignment of lock bolt to striker plate.
Add or remove shims behind lock until bolt properly engages striker plate (para. 3-364).
END OF TESTING!
87. HEATER WILL NOT IGNITE
Check electrical system (Electrical Troubleshooting, para. 2-22).
END OF TESTING!

2-91

TM 9-2320-272-24-1

2-22. ELECTRICAL SYSTEM TROUBLESHOOTING
a. This section provides information to diagnose and correct malfunctions of the electrical system.
Because of the complexity, the electrical system is divided into the following functional systems:
l Engine and Vehicle Electrical System (page 2-95)
l Battery System (page 2-97)
l Starting System (page 2-101)
l Generating System (page 2-118)
l Lighting System (page 2-124)
l Directional Signal System (page 2-135)
l Ether Start System (page 2-141)
l Indicator, Gauge, and Warning System (page 2-145)
l Trailer Connection System (page 2-163)
l Heater System (page 2-165)
l 100-Amp Alternator Kit (page 2-169)
l Transfer Case System (page 2-174)
l Protective Control Box Assembly (page 2-176)
b. Principles of operation showing wiring diagrams for each system can be found in chapter 1. The
wiring schematic (appendix H) shows the interrelationship of these systems. Both should be utilized as
references when performing electrical troubleshooting (table 2-3).
c. Each malfunction symptom given for an individual component or system is followed by step(s) that
should be taken to determine the cause and then corrective action that must be taken to remedy the
problem.
d. Before taking any action to correct a possible malfunction, the following rules should be followed:
(1) Question the vehicle operator to obtain any information that might help determine the cause of
the problem.
(2) Never overlook the chance that the problem could be of a simple origin. The problem could be
corrected with minor adjustment.
(3) Use all senses to observe and locate troubles.
(4) Use test instrument or gauges to help determine and isolate problems.
(5) Always isolate the system where the malfunction occurs and then locate the defective
component.
(6) Use Principles of Automotive Vehicles, TM 9-8000, when troubleshooting vehicles covered in
this manual.
e. Table 2-3 lists electrical malfunctions that may occur in individual units or systems of the vehicle.
This table covers electrical troubleshooting only. Troubleshooting procedures for the mechanical systems can
be found in table 2-1, para. 2-21.
f. This section cannot list all the electrical malfunctions that may occur. If a malfunction occurs that is
not listed in table 2-3, notify DS maintenance.

2-92

TM 9-2320-272-24-1

ELECTRICAL TROUBLESHOOTING SYMPTOM INDEX
MALFUNCTION
NO.

MALFUNCTION

TROUBLESHOOTlNG
PROCEDURE
PAGE

2.
3.
4.
5.

ENGINE AND VEHICLE ELECTRICAL SYSTEM
Engine and vehicle electrical system malfunctioning . . . . . . . . . . . . . . . . . . . .
BATTERY SYSTEM
Batteries are hot, electrolyte is boiling, or excessive use of water. . . . . . . . . . .
Specific gravity will not increase to 1.280 under charge . . . . . . . . . . . . . . . . . .
Engine will not crank; some electrical systems inoperative or weak . . . . . . . .
All vehicle electrical systems inoperative. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6.
7.
8.

STARTING SYSTEM
Starter motor inoperative. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Solenoid operates, starter operates, but engine cranks slowly. . . . . . . . . . . . . .
Starter motor inoperative; no solenoid thump. . . . . . . . . . . . . . . . . . . . . . . . . .

1.

9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20
21.
22.
23.
24.
25.

26.
27.
28.
29.
30.
31.
32.
33.
34.

GENERATING SYSTEM
Batteries hot or boiling; correct specific gravity of all cells is 1.280 . . . . . . . . .
Batteries use excessive water. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Batteries run down in service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
No alternator output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Alternator output voltage low . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Alternator adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Battery indicator gauge in red position . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
LIGHTING SYSTEM
Lamps will not light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Headlamp (one side) inoperative . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Headlamp (both sides) inoperative. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Blackout drive or blackout marker light inoperative. . . . . . . . . . . . . . . . . . . . .
Stoplight inoperative . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rear lights inoperative. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
One or more trailer lights inoperative . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DIRECTIONAL SIGNAL SYSTEM
Individual lights do not light with directional signal lever in any position. . . .
No lights operate with directional signal control lever in any position . . . . . . .
System operates incorrectly in one or more positions of directional
signal control lever. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ETHER START SYSTEM
Engine cranks but will not start (fuel available) . . . . . . . . . . . . . . . . . . . . . . . .
INDICATOR, GAUGE, AND WARNING SYSTEM
All gauges inoperative . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
One gauge inoperative . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Temperature gauge inoperative (coolant). . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel gauge inoperative . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Battery/alternator gauge inoperative. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Horn inoperative . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Low air pressure warning buzzer will not shut off
(air pressure gauges at normal system pressure). . . . . . . . . . . . . . . . . . . . . . .
Low air pressure warning buzzer will not shut off and
parking brake warning light flashes with hand/parking
brake in any position (air pressure normal). . . . . . . . . . . . . . . . . . . . . . . . . . .

2-95
2-97
2-98
2-98
2-99
2-101
2-103
2-109
2-118
2-120
2-120
2-120
2-123
2-123
2-124
2-125
2-127
2-128
2-130
2-131
2-132
2-133
2-135
2-138
2-140
2-141
2-145
2-149
2-150
2-151
2-153
2-154
2-158
2-161

2-93

TM 9-2320-272-24-1

ELECTRICAL TROUBLESHOOTING SYMPTOM INDEX (Contd)
MALFUNCTION
NO.
35.

36.
37.
38.
39.
40.
41.
42.
43.
44.
45.
46.

2-94

MALFUNCTION

TROUBLESHOOTING
PROCEDURE
PAGE

Spring brake warning light inoperative with spring brake override
engaged . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
TRAILER CONNECTION SYSTEM
One or more lighting systems do not light on trailer. . . . . . . . . . . . . . . . . . . . .
HEATER SYSTEM
Heater will not operate with switch in LOW position
(HIGH position operation normal) . . . . . . . . . . : . . . . . . . . . . . . . . . . . . . . . . .
Heater will not operate with switch in HIGH position
(LOW position operation normal). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Heater will not operate in LOW or HIGH position . . . . . . . . . . . . . . . . . . . . . .
100-AMP ALTERNATOR KIT
Batteries hot or boiling; correct specific gravity of all cells is 1.280 . . . . . . . . .
Batteries use excessive water. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Batteries run down in service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
No alternator output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
TRANSFER CASE SYSTEM
Transfer case control lever will not shift from LOW to HIGH or HIGH to LOW
when vehicle is in motion. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Transfer case shifts hard while engine is running. . . . . . . . . . . . . . . . . . . . . . .
PROTECTIVE CONTROL BOX ASSEMBLY
Protective control box assembly test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2-161
2-163

2-165
2-167
2-168
2-169
2-170
2-170
2-170

2-174
2-175
2-176

TM 9-2320-272-24-1

Table 2-3. Electrical Troubleshooting.
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION

ENGINE AND VEHICLE ELECTRICAL SYSTEM
1. ENGINE AND VEHICLE ELECTRlCAL SYSTEM MALFUNCTlONlNG
Test 1. Check alternator output.
Step 1. Remove two screws (2), lockwashers (3), and terminal cover (1) from alternator (4).
Step 2. Connect black test lead to ground and red test lead to lead 5.
Step 3. Check alternator output (malfunction 9). Multimeter should indicate 26.5-29.5 volts.
Step 4. If voltage is within range, go to step 6.
Step 5. If voltage is not within range, adjust alternator (4). Perform malfunction 14.
Step 6. Install terminal cover (1) on alternator (4) with two lockwashers (3) and screws (2).
Test 2. Check vehicle ground straps.
a. Ensure ground straps are securely fastened and no paint is under starwasher.
b. Remove paint as necessary.

2-95

TM 9-2320-272-24-1

Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Test 3.
Step
Step
Step

Check protective control box,
1. Unplug harness (2) from bottom of protective control box (1).
2. Listen for protective control box relay to reset.
3. If reset is heard, replace protective control box (1) (para. 3-116).

END OF TESTING!
2-96

TM 9-2320-272-24-1

Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION

BATTERY SYSTEM

2. BATTERlES ARE HOT, ELECTROLYTE IS BOILING, OR EXCESSIVE USE OF WATER
NOTE
If STE/ICE is available, perform NG50 - Charging Circuit Tests
(para. 2-24).
Check electrolyte temperature and specific gravity and note reading (TM 9-6140-200-14).
a. If temperature is over 120°F (49°C) and specific gravity is 1.280 or greater, batteries
are being overcharged. Go to generating system troubleshooting (malfunction 9,
test 1).
b. If battery temperature is over 120°F (49°C), but specific gravity is 1.236-1.260,
recharge batteries (TM 9-6 140-200-14).
END OF TESTING!

2-97

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
3. SPECIFIC GRAVITY WILL NOT INCREASE TO 1.280 UNDER CHARGE
NOTE
If STE/ICE is available, perform NG50 - Charging Circuit Tests
(para. 2-24).
Check rate of charging:
Place battery on charge, assuring that cells are gassing freely (TM 9-6140-200-14). Maintain
charge rate slightly below heavy gassing.
If specific gravity does not recover to 1.280 in 25 hours of charging, replace battery
(para. 3-125).
END OF TESTING!
4. ENGINE WILL NOT CRANK; SOME ELECTRICAL SYSTEMS INOPERATIVE OR WEAK
Test 1. Perform the following steps to inspect batteries:
Step 1. Visually check batteries for cracks, leaks, and corroded or broken terminal posts.
a. Replace any cracked, leaking, corroded, or broken batteries, or batteries with loose or
broken terminal posts (para. 3-125).
b. Clean corroded terminal posts to bright metal.
Step 2. Check for loose, broken, or worn terminals and cables.
a. Tighten any loose terminal or cable (para. 3-124 or 3-126).
b. If any terminal or cable is broken or worn, replace (para. 3-124 or 3-126).
Step 3. Check electrolyte level in each cell (TM 9-6140-200-14).
Fill each cell to fill ring with distilled water (TM 9-6140-200-14).
Step 4. Perform a specific gravity test (TM 9-6140-200-14). Batteries must be 1.225 or greater,
temperature corrected, and each cell in a battery must test within 25 points of the
others.
a. Charge all batteries not meeting requirements, and check specific gravity again
(TM 9-6140-200-14).
b. If 25-point variation still exists, replace battery(ies) (para. 3-125).
Step 5. Attempt to crank engine for 15 seconds, then turn battery switch to OFF position. Check
batteries for overheating by feeling terminal connections. If battery terminal(s) is hot,
loose or corroded connections are indicated.
a. Tighten all loose connections at batteries.
b. Tighten battery ground wire (lead 7) at vehicle chassis ground. Tighten battery
positive wire (lead 6) at starter solenoid.
NOTE
If STE/ICE is available, perform NG20 - No Crank - No Start
(para. 2-24).
Test 2. Test batteries under load to determine adequate current capability and voltage drop during
a 15-second amperage load.

2-98

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Step 1.
Step 2.

Set multimeter to 50-volt range.
Connect multimeter positive lead to starter solenoid terminal 6 and negative lead to
ground strap. Multimeter should indicate voltage.
Step 3. Place headlight and battery switch on ON position for 15 seconds (headlights on high
beam). Multimeter should register 1-volt drop from step 2 reading.
Recharge batteries when voltage reading is low (TM 9-6140-200-14).

END OF TESTING!
5. ALL VEHICLE ELECTRICAL SYSTEMS INOPERATIVE
Test 1. Check connection of battery cables.
Ensure battery cables are correctly connected to batteries. (See wiring diagram in Appendix H.)
If not correctly connected, secure battery cables (para. 3-124 or 3-126).
Test 2. Inspect batteries (malfunction 4, test 1).

2-99

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION

Test 3.
Step
Step
Step
Step
Step

NOTE
If STE/ICE is available, perform NG81 - Battery Tests
(para. 2-24).
Check protective control box continuity from pin C to pin D.
1. Place battery switch to OFF position.
2. Disconnect harness connector from protective control box.
3. Set multimeter to RX1 for continuity reading.
4. Apply battery voltage to pin A of control box.
5. Touch negative multimeter lead to pin C and positive lead to pin D on control box.
a. Continuity should be indicated between pins C and D.
b. If continuity is not indicated, replace protective control box (para. 3-115).

END OF TESTING!
2-100

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION

STARTING SYSTEM

6. STARTER MOTOR INOPERATIVE
NOTE
If STE/ICE is available, perform NG80 - Starter Circuit Tests
(para. 2-24).
2-101

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Check starter solenoid operation.
Step 1. Turn starter switch to START position and listen for starter solenoid to engage.
a. If thump of starter solenoid energizing is heard, perform malfunction 7.
b. If thump of starter solenoid is not heard, proceed to step 2.
Step 2. Set multimeter to 50-volt range.
Step 3. Connect multimeter positive lead to starter solenoid terminal lead 74 and negative lead
to starter ground as shown.
Step 4. Turn starter switch to START position and observe multimeter for a 24-volt reading.
a. If battery voltage is not indicated, perform malfunction 7.
b. If battery voltage is indicated, replace starter (para. 3-82).

END OF TESTING!

2-102

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
7. SOLENOlD OPERATES, STARTER OPERATES, BUT ENGINE CRANKS SLOWLY
NOTE
If STE/ICE is available, perform NG80 - Starter Circuit Tests
(para. 2-24).
Test 1. Check batteries for overheating. Crank engine for 15 seconds. Check batteries for
overheating by feeling battery terminal connections. If battery terminal is hot, a loose or
corroded connection is indicated.
a. Clean corroded connection to bright metal.
b. Tighten all loose connections at batteries, ground, and starter.
Test 2. Perform a specific gravity test (TM 9-6140-200-14). Batteries must be 1.225 or greater,
temperature corrected, and each cell in a battery must test within 25 points of the others.
a. Charge all batteries not meeting requirements, and check specific gravity again
(TM 9-6140-200-14).
b. If 25-point variation still exists, replace battery(ies) (para. 3-125).
Test 3. Test starter voltage.
Step 1. Set multimeter to 50-volt range.
Step 2. Connect multimeter positive lead to positive terminal stud of starter and negative lead
to terminal stud on end plate of starter.
Step 3. Crank engine and observe voltage reading on multimeter. Voltage reading should exceed
22 volts.
If voltage reading is low, clean and tighten connections.

2-103

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Test 4. Test starter-to-solenoid strap.
Step 1. Set multimeter to 10-volt range.
Step 2. Connect multimeter negative lead to positive terminal stud of starter and positive lead
to terminal stud of solenoid.
Step 3. Crank engine and observe multimeter. A voltage reading exceeding 0.1 volt indicates bad
connection at starter terminal stud and terminal stud of solenoid.
Clean and tighten connections.

2-104

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Test 5. Test starter solenoid contractors.
Step 1. Set multimeter to 10-volt range.
Step 2. Connect multimeter between starter solenoid terminals.
Step 3. Crank engine and observe multimeter. A voltage reading exceeding 0.4 volt indicates
defective starter solenoid.
a. Replace starter (para. 3-82).
b. If malfunction still exists, go to tests 6, 7, and 8.

2-105

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Test 6. Test negative cable 7 voltage drop from batteries to starter.
Step 1. Set multimeter to lo-volt range.
Step 2. Connect multimeter positive lead to terminal stud on end plate of starter and negative
lead to grounding point at batteries.
Step 3. Crank engine and observe multimeter. A voltage reading exceeding 0.4 volt indicates
loose or corroded connection(s).
Clean and tighten connections at batteries, starter, and chassis (para. 3-124).

2-106

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Test 7. Test positive cable 6 from batteries to starter solenoid.
Step 1. Set multimeter to lo-volt range.
Step 2. Connect multimeter positive lead to positive terminal point on batteries and negative
lead to positive terminal on starter solenoid.
Step 3. Crank engine and observe multimeter. A voltage reading exceeding 0.4 volt indicates
loose or corroded connection.
Clean and tighten connections at batteries, starter, and chassis (para. 3-124).

2-107

Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Test 8. Test battery voltage after cranking load is applied.
Step 1. Set multimeter to 50-volt range.
Step 2. Connect multimeter directly across battery terminal posts: positive lead to positive post,
and negative lead to negative post.
Step 3. Engage emergency stop control and crank engine for 15 seconds (TM 9-2320-272-10).
Voltage reading should be 20 volts or more after cranking has stopped.
a. If battery voltage is less than 20 volts, perform malfunction 2.
b. If battery voltage exceeds 20 volts, replace starter (para. 3-82).
Step 4. Disengage emergency stop control and crank engine (TM 9-2320-272-10).
If engine still cranks slowly, notify DS maintenance.

END OF TESTING!
2-108

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTlON
TEST OR INSPECTION
CORRECTIVE ACTION
8. STARTER MOTOR INOPERATIVE; NO SOLENOID THUMP
Test 1. Test battery and starter systems (malfunctions 2, 3, 4, 6, and 7).
Test 2. Test starter lockout reset.
Step 1. Disconnect harness connector from protective control box.
Step 2. Connect harness connector to protective control box to reset starter lockout switch.
Step 3. Start engine (TM 9-2320-272-10).
a. If engine fails to start, go to test 3.
b. If engine starts, replace alternator (para. 3-79 or 3-80).
Test 3. Test battery switch for voltage.
Step 1. Set multimeter to 50-volt range.
Step 2. Disconnect lead 81A (pin A) from battery switch.
Step 3. Connect multimeter positive lead to contact end of lead 81A and negative lead to ground.
a. Multimeter should indicate battery voltage. If voltage is not indicated, repair broken
lead 81A/81 (para. 3-131).
b. If voltage is indicated, go to step 4.

2-109

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Step
Step
Step
Step
Step

2-110

4.
5.
6.
7.
8.

Connect lead 81A to battery switch pin A.
Disconnect lead 459 (pin B) at battery switch.
Place battery switch to ON position.
Connect multimeter positive lead to contact end of pin B.
Connect multimeter negative lead to ground.
a. Multimeter should indicate battery voltage. If voltage is not indicated, replace
battery switch (para. 3-107).
b. If voltage is indicated, connect lead 459 to battery switch (pin B), place battery switch
to OFF position, and go to test 4.

TM 9-2320-272-24-1

Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Test 4.
Step
Step
Step
Step

Test voltage input to protective control box.
1. Set multimeter to 50-volt range.
2. Disconnect harness connector at protective control box.
3. Place battery switch to ON.
4. Connect multimeter positive lead to pin A (lead 459) at harness connector and negative
lead to ground.
a. Multimeter should indicate voltage. If voltage is not indicated, repair broken lead
459 (para. 3-131).
b. If voltage is indicated, go to step 5.
Step 5. Place battery switch to OFF position.
Step 6. Connect multimeter positive lead to pin C (lead 81) at harness connector and negative
lead to ground.
a. Multimeter should indicate voltage. If voltage is not indicated, repair broken lead 81
(para. 3-131).
b. If voltage is indicated, go to test 5.

2-111

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Cantd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Test 5.
Step
Step
Step
Step

Test continuity of protective control box harness.
1. Dirconnect battery ground cables (para. 3-126).
2. Set multimeter to RX1 for continuity reading.
3. Disconnect lead 74 at starter solenoid.
4. Connect multimeter positive lead to pin B (lead 74) at harness connector and negative
lead to lead 74 at starter solenoid.
a. Multimeter should indicate continuity. If continuity is not indicated, repair broken
lead 74 (para. 3-131).
b. If continuity is indicated, go to step 5.
Step 5. Connect lead 74 at starter solenoid.

2-112

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Step 6.
Step 7.

Disconnect lead 5B (pin B) at starter switch.
Connect multimeter positive lead to pin D at harness connector and negative lead to
contact end of lead 5B at starter switch.
a. Multimeter should indicate continuity. If continuity is not indicated, repair broken
lead 5A/5B (para. 3-131).
b. If continuity is indicated, go to test 6.

2-113

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTlON
CORRECTlVE ACTION
Test 6.
Step
Step
Step

2-114

Test starter switch for continuity.
1. Disconnect lead 498 (pin S) at starter switch.
2. Connect multimeter positive lead to pin B and negative lead to pin S.
3. Place stark switch to START position and hold.
a. Multimeter should indicate continuity. If continuity is not indicated, replace starter
switch (para. 3-107).
b. If continuity is indicated, connect lead 5B to starter switch (pin B) and go to test 7.

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Test 7.
Step
Step
Step
Step

Test continuity of protective control box harness.
1. Set parking brake (TM 9-2320-272-10).
2. Place transmission in neutral.
3. Disconnect lead 498 at neutral start switch.
4. Connect multimeter positive lead to contact end of lead 498 and negative lead to contact
end of lead 498 at neutral start switch.
a. Multimeter should indicate continuity. If continuity is not indicated, repair broken
lead 498 (para. 3-131).
b. If continuity is indicated, connect lead 498 to start switch (pin S) and go to step 5.
Step 5. Disconnect lead 499 at neutral start switch.
Step 6. Connect multimeter positive lead to neutral start switch contact end of lead 499 and
negative lead to neutral start contact end of lead 498.
a. Multimeter should indicate continuity. If continuity is not indicated, replace neutral
start switch (para. 3-98).
b. If continuity is indicated, connect lead 498 to neutral start switch and go to
step 7.

2-115

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Step 7. Disconnect harness connector at protective control box.
Step 8. Connect multimeter positive lead to contact end of lead 499 and negative lead to pin E
at harness connector.
a. Multimeter should indicate continuity. If continuity is not indicated, repair broken
lead 499 (para. 3-131).
b. If continuity is indicated, connect leads 499 and 498 to neutral start switch and go to
test 8.

2-116

TM 9-2320-272-24-1

Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Test 8. Test continuity of protective control box harness.
NOTE
Sealant must be removed before removing leads.
Step 1. Disconnect lead 566 at alternator.
a. Remove two screws (2), lockwashers (3), and terminal cover (1) from alternator (4).
b. Remove nut (7), washer (6), lockwasher (5), and lead 566 from alternator (4).
Step 2. Connect multimeter positive lead to pin F at harness connector and negative lead to
contact end of lead 566 at alternator.
a. Multimeter should indicate continuity. If continuity is not indicated, repair broken
lead 566 (para. 3-131).
b. If continuity is indicated, connect harness connector to protective control box. DO
NOT connect lead 566 to alternator. Go to test 9.

Test 9. Test starter lockout signal.
Attempt to start engine with lead 566 disconnected from alternator.
a. If engine fails to start, replace protective control box (para. 3-115).
b. If engine starts, replace alternator (para. 3-79 or 3-80).
END OF TESTING!
2-117

TM 9-2320-272-24- 1

Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
GENERATING SYSTEM

9. BATTERIES HOT OR BOILING; CORRECT SPECIFIC GRAVTY Of ALL CELLS IS 1.280
NOTE
If STE/ICE is available, perform NG50 - Charging Circuit Tests
(para. 2-24).

2-118

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Test charging voltage.
Step 1. Set multimeter to 50-volt range.
Step 2. Connect multimeter directly across battery terminal posts: positive lead to positive post
and negative lead to negative post.
Step 3. Start engine (TM 9-2320-272-10) and allow engine to stabilize at 700-800 rpm.
Multimeter should indicate 26.5-29.5 volts. If not, replace alternator (para. 3-79 or 3-80).

END OF TESTING!
2-119

TM 9-2320-272-24-1

Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION

10. BATTERIES USE EXCESSIVE WATER
NOTE
If STE/ICE is available, perform NG81 - Battery Tests or NG50 Charging Circuit Tests (para. 2-24).
Test charging voltage (malfunction 9).
END OF TESTING !
11. BATTERIES RUN DOWN IN SERVICE
NOTE
If STE/ICE is available, perform NG50 - Charging Circuit Tests
(para. 2-24).
Test 1. Check for loose, broken, or missing alternator or fan drivebelts.
a. Adjust loose drivebelts (M939/A1) (para. 3-78).
b. Replace broken or missing drivebelts (para. 3-78 or 3-71).
Test 2. Test charging voltage (malfunction 9).
If proper voltage is indicated, problem is not in generating system. Perform battery system
troubleshooting, malfunctions 2 through 5.
END OF TESTING!
12. NO ALTERNATOR OUTPUT
NOTE
If STE/ICE is available, perform NG50 - Charging Circuit Teats
(para. 2-24).
Test 1. Check for loose, broken, or missing alternator or fan drivebelts.
a. Adjust loose drivebelts (M939/A1) (para. 3-78).
b. Replace broken or missing drivebelts (para. 3-78 or 3-71).
Test 2. Test alternator lead 568 for voltage.
Step 1. Disconnect lead 568 at alternator.
Step 2. Set multimeter to 50-volt range.
Step 3. Connect multimeter positive lead to lead 568 and negative lead to vehicle chassis
ground.
Step 4. Place battery switch to ON position.
a. Multimeter should indicate battery voltage.
b. If battery voltage is indicated, place battery switch to OFF position and replace
alternator (para. 3-79 or 3-80).
c. If battery voltage is not indicated, go to step 5.

2-120

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION

Step 5. Touch multimeter positive lead to lead 5 of alternator terminal.
a. Multimeter should indicate battery voltage.
b. If battery voltage is indicated, repair broken lead 568 (para. 3-131).
c. If battery voltage is not indicated, go to step 6.

2-121

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTlVE ACTION
Step 6. Set multimeter to RX1 for continuity reading.
Step 7. Disconnect battery ground cable (para. 3-126).
Step 8. Connect multimeter positive lead to lead 568 and negative lead to lead 5 of alternator
terminal.
Step 9. Multimeter should indicate continuity. If continuity is not indicated, there is an open
lead.
Repair broken lead 568 (para. 3-131).

END OF TESTING!

2-122

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
13. ALTERNATOR OUTPUT VOLTAGE LOW
NOTE
If STE/ICE is available, perform NG50 - Charging Circuit Tests
(para. 2-24).
Test 1. Check for loose, broken, or missing alternator or fan drivebelts.
a. Adjust loose drivebelts (M939/A1) (para. 3-78).
b. Replace broken or missing drivebelts (para. 3-78 or 3-71).
Test 2. Test battery voltage (malfunction 9).
END OF TESTING!
14. ALTERNATOR ADJUSTMENT
NOTE
Sealant must be removed from terminals before testing alternator
output.
Step 1. Remove two screw-assembled lockwashers (2) and terminal cover (1) from alternator (4).
Step 2. Start engine (TM 9-2320-272-10) and raise engine speed above normal idle 600-650 rpm
(M939/A1), 565-635 rpm (M939A2).
Step 3. Put a load on alternator (4) by operating driving lights (TM 9-2320-272-10).
Step 4. Using multimeter, check alternator (4) output voltage. Connect black test lead to
ground 3. Connect red test lead to lead 5. Output voltage should be 26.5 to 29.5 volts. If
adjustment is required, go to step 5. If no adjustment is required, go to step 8.
Step 5. Remove pipe plug (3) from alternator (4).
Step 6. Turn adjusting screw counterclockwise to increase voltage; clockwise to decrease voltage.
Step 7. Apply sealing compound (Appendix C, Item 65) to threads of pipe plug (3). Using hexhead driver, install pipe plug (3) on alternator (4) and tighten to 30-40 lb-in. (3-4 N•m).
Step 8. Turn off driving lights and stop engine (TM 9-2320-272-10).
Step 9. Seal terminal connections with adhesive sealant (Appendix C, Item 4).
Step 10. Install terminal cover (1) on alternator (4) with two screw-assembled lockwashers (2).

END OF TESTING!
2-123

T-M 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
15. BATTERY INDICATOR GAUGE IN RED POSITION
NOTE
If STE/ICE is available, perform NG50 - Charging Circuit Tests
(para. 2-24).
Test 1. Test battery voltage (malfunction 9).
Test 2. Check alternator for overheating.
Step 1. Run engine for approximately 10 minutes.
Step 2. With engine off, check alternator for high temperature by holding hand near alternator.
Step 3. If alternator is hot, disconnect lead 568 at alternator and allow alternator to cool.
Step 4. Connect lead 568 to alternator and start engine. If battery indicator returns to high red
position and alternator heats up again, replace alternator (para. 3-79 or 3-80).
END OF TESTING!
LIGHTING SYSTEM

NOTE: Broken lines indicate turn signal circuits.
2-124

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
16. LAMPS WILL NOT LIGHT
Test 1. Check for defective bulb.
a. Replace bulb with one known to be good.
b. If bulb does not light, go to test 2.
Test 2. Check for corrosion or dirt in sockets or on terminals.
a. Clean corroded connections.
b. Clean dirt from sockets and terminals.
Test 3. Check lamp holders for loose connections and broken wire terminals.
a. Tighten all loose connections.
b. Repair or replace broken wire terminals (para. 3-131).
Test 4. Test lighting system harness connector voltage.
Step 1. Place battery switch to OFF position.
Step 2. Remove light switch from instrument panel (para. 3-108).
Step 3. Place battery switch to ON position.
Step 4. Set multimeter to 50-volt range.
Step 5. Connect multimeter negative lead to vehicle chassis ground and positive lead to
connector socket pin F.
a. If battery voltage is not indicated, go to step 6.
b. If battery voltage is indicated at socket pin F, connect a jumper wire from socket
pin F to socket of faulty lead as shown.
c. If lamps lights with jumper wire connected, replace light switch (para. 3-108).
Step 6. Check wiring harness for loose connections.
a. Tighten all loose connections.
b. Repair broken wiring harness (para. 3-131).
CAUTION
Lead 15 or wire 15 is hot whenever the batteries are connected.

2-125

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION

SOCKET WIRE NO.
A
B
C
D
E
F
H
J
K
L
M
N

75
40
22
19
20-24
15
21
460-461
75
491
16
23

CIRCUIT
STOPLIGHT SWITCH
PANEL LIGHTS
DIRECTIONAL CONTROL
B.O DRIVING LIGHT
B.O. MARKER LIGHTS
BATTERY POS. 24 VOLTS
SERVICE REAR LIGHTS
DIRECTIONAL INDICATOR
STOPLIGHT SWITCH
SERVICE PARKING LIGHTS
SERVICE HEADLIGHTS
B.O. STOPLIGHT

END OF TESTING !
2-126

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
17. HEADLAMP (ONE SlDE) INOPERATIVE
Test 1. Test headlamp connector voltage.
Step 1. Place battery switch to OFF position.
CAUTION
Step 2.
Step 3.
Step 4.
Step 5.
Step 6.

Step 7.

Lead 15 or wire 15 is hot whenever the batteries are connected.
Disconnect leads 18 and 91 at headlights.
Place battery switch to ON position.
Place light switch to SERVICE LIGHT position and depress high-beam selector switch
to LOW BEAM position.
Set multimeter to 50-volt range.
Connect multimeter positive lead to lead 18 and negative lead to lead 91.
a. Multimeter should indicate battery voltage. If battery voltage is not indicated,
reposition selector lever switch from SERVICE DRIVE to OFF and back to SERVICE
DRIVE.
b. If malfunction is not cleared, wiring harness from headlamp to selector switch or the
switch itself is defective. Perform malfunction 18.
c. If voltage is present and malfunction is not cleared, perform malfunction 18, test 2.
Visually inspect headlamp body pin connector for corrosion and loose connections.
a. Clean corroded parts.
b. Tighten loose connections.
c. If malfunction is not cleared, perform malfunction 18, test 2.

LIGHT SWITCH

END OF TESTING!
2-127

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
18. HEADLAMP (BOTH SIDES) INOPERATIVE
Test 1. Test headlamps connector voltage for both sides (malfunction 17, test 1).
Test 2. Test headlamp high-beam selector switch.
Step 1. Place battery and light switch to OFF’ position.
CAUTION
Step 2.
Step 3.
Step 4.
Step 5.
Step 6.
Step 7.

Step 8.

2-128

Lead 15 or wire 16 is hot whenever batteries are connected.
Disconnect leads 17 and 18 at high-beam selector switch.
Place battery and light switch to ON position.
Connect multimeter positive lead to terminal 17 on high-beam selector switch and
negative lead to vehicle chassis ground.
Note multimeter voltage reading.
With multimeter negative lead connected to ground, connect positive lead to exposed
terminal 18 on high-beam selector switch.
Note multimeter voltage reading,
a. If battery voltage was indicated at terminals 17 or 18 on switch, but not at
headlamps, the wiring harness is defective. Notify DS maintenance.
b. If battery voltage was not indicated at terminals 17 or 18 on switch, go to step 8.
Operate high-beam selector switch. Repeat steps 4 through 7.
a. If battery voltage was indicated at terminals 17 and 18 alternately as switch was
operated, but not at the headlamps, wiring harness is defective. Notify DS
maintenance.
b. If battery voltage was not indicated at terminals 17 or 18 alternately as switch was
operated, go to step 9.

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Step 9.
Step 10.
Step 11.
Step 12.

Place battery switch and light switch to OFF position.
Disconnect lead 16 from high-beam selector switch,
Place battery switch to ON position and light switch to SERVICE DRIVE position.
With negative lead of multimeter connected to ground, connect positive lead of
multimeter to lead 16 (not switch terminals), Multimeter should indicate battery
voltage.
a, If battery voltage is indicated, replace high-beam selector switch (para. 3-112).
b. If battery voltage is not indicated, perform malfunction 16, test 4.
CAUTION
Lead 15 or wire 15 is hot whenever the batteries are connected.

WIRE NO.
16
17
18

CIRCUIT
LIGHT SWITCH TO
SELECT OR SWITCH
HIGH BEAM
LOW BEAM

END OF TESTING!
2-129

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
19. BIACKOUT DRlVE OR BLACKOUT MARKER LIGHT INOPERATIVE
Test front blackout lamp connector voltage.
Step 1. Place battery switch to OFF position,
CAUTION
Step 2.
Step
Step
Step
Step

3.
4.
5.
6.

Lead 15 or wire 15 is hot whenever the batteries are connected.
Disconnect lead 19 at blackout drive light. Disconnect lead 20 at both left and right front
composite lights.
Place battery switch to ON position.
Place light switch to B.O. DRIVE position.
Set multimeter to 50-volt range.
Connect multimeter negative lead to vehicle chassis ground. Touch positive lead to each
of disconnected lead wires and note voltage indication through each wire.
a. If voltage was indicated, replace blackout light or lamp (para. 3-117).
b. If battery voltage is not indicated, perform malfunction 16, test 4.

END OF TESTING!
2-130

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
20. STOPLIGHT INOPERATIVE
Test stoplight switch voltage.
Step 1. Place battery switch to OFF position.
CAUTION
Step 2.
Step 3.

Step 4.
Step 5.

Lead 15 or wire 15 is hot whenever the batteries are connected.
Disconnect both leads 75 at stoplight switch.
Place battery switch to ON position and light switch to STOPLIGHT position.
NOTE
For stoplight lead test, brake pedal must be depressed and air
pressure maintained.
Set multimeter to 50-volt range.
Connect multimeter negative lead to good ground and positive lead to each exposed lead
75 and note voltage indicated.
a. Meter should indicate battery voltage through one of the leads 75. If no voltage is
present, perform malfunction 16, test 4. If voltage is indicated, connect that wire to
one terminal of stoplight switch.
b. With brake pedal depressed, connect multimeter positive lead to exposed stoplight
switch terminal. Multimeter should indicate battery voltage.
c. If battery voltage is indicated, stoplight switch is operational. If no voltage is
indicated, replace stoplight switch (para. 3-111).

2-131

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
21. REAR LIGHTS INOPERATIVE
Test rear lamp connector voltage.
Step 1. Place battery switch to OFF position.
CAUTION
Lead 15 or wire 15 is hot whenever the batteries are connected.
Step 2. Disconnect lead wire corresponding to inoperative rear lamp.
Step 3. Place battery switch to ON position.
Step 4. Place light switch to position corresponding to disconnected lead wire.
NOTE
For stoplight lead test, brake pedal must be depressed and air
pressure maintained.
Step 5. Set multimeter to 50-volt range.
Step 6. Connect multimeter negative lead to vehicle chassis ground and positive lead to
disconnected lead wire. Light switch must be in the corresponding position. Note voltage
indication.
a. If voltage was indicated, replace bulb (para. 3-118). If new bulb fails to operate,
perform malfunction 16, test 2.
b. If battery voltage is not indicated, perform malfunction 16, test 4.

2-132

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
22. ONE OR MORE TRAILER LIGHTS INOPERATIVE
Test 1. Test trailer receptacle voltage.
Step 1. Place battery switch to ON position.
CAUTION
Lead 15 or wire 15 is hot whenever the batteries are connected.
Place light switch to position corresponding to inoperative lamp.
NOTE
For stoplight lead test, brake pedal must be depressed and air
pressure maintained.
Step 3. Set multimeter to 50-volt range.
Step 4. Connect multimeter negative lead to socket terminal pin L on receptacle. Touch positive
lead to appropriate connector socket of lead being tested. Light switch must be in the
corresponding position.
a. Battery voltage should be indicated at connector socket being tested.
b. If voltage was not indicated at one or more of pins being tested, go to test 2.
c . If voltage is indicated, disconnect and reconnect male connector to ensure positive
connection. If trailer lamps still do not light, check male connection for corrosion.
d. If trailer lamps still do not light, check trailer lighting system.

Step 2.

2-133

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Test 2. Check trailer receptacle ground.
Step 1. Set multimeter on Rx1 for continuity reading.
CAUTION
Lead 15 or wire 15 is hot whenever the batteries are connected.
Step 2. Connect multimeter positive lead to lead 90 at socket (receptacle terminal L and then D)
and negative lead to good ground. Multimeter should indicate continuity from both
terminal L and D to ground.
a. If continuity was indicated, perform malfunction 16, test 4.
b. If continuity was not indicated, repair broken lead 90 (para. 3-131).

END OF TESTING!
2-134

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
DIRECTIONAL SIGNAL SYSTEM

23. INDIVIDUAL LIGHTS DO NOT LIGHT WITH DIRECTIONAL SIGNAL LEVER IN ANY POSITION
Test 1. Check for defective lamp.
Step 1. Place battery switch to ON position and light switch to STOP TURN position.
Step 2. With air pressure maintained, depress brake pedal.
a. If stop signal lamp lights, go to test 2.
b. If stop signal lamp does not light, replace defective lamp (para. 3-118).
Test 2. Test wiring harness voltage.
Step 1. Place battery switch to OFF position.
Step 2. Disconnect leads 460, 461, 22-460, and 22-461 from lights.
Step 3. Place battery switch to ON position.
Step 4. Place light switch to STOP TURN position.
Step 5. Place directional signal control lever to HAZARD warning position.
2-135

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Step 6.
Step 7.

Set multimeter to 50.volt range.
Connect multimeter negative lead to vehicle chassis ground. Touch positive lead to
center contact of leads 460,461, 22-460, or 22-461.
a. Multimeter needle should deflect at a rate of 1 to 2 cycles per second. If multimeter
deflects, clean light socket.
b. If multimeter does not deflect, go to test 3.

Test 3. Test wiring harness continuity.
Step 1. Place battery switch to OFF position.
Step 2. Disconnect wire connector from control unit and disconnect wire from defective light at
lamp base.
Step 3. Place jumper wire from disconnected light wire at light to ground.
Step 4. Set multimeter on RX1 for continuity reading.
Step 5. Connect multimeter negative lead to vehicle chassis ground. Touch positive lead to
control unit harness connector socket point for wire that was jumped to ground.
2-136

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Step 6. Multimeter should read continuity. If continuity is not read, check wiring harness for
broken, frayed, or pinched wires.
a. Repair broken, frayed, or pinched wires (para. 3-131).
b. If system is still not operational, go to test 4.
Test 4. Test wiring harness for short,
Step 1. Remove jumper wire from light wire to ground that was connected in test 3, step 3.
Step 2. With multimeter set for continuity, and wires disconnected as in step 1, connect
multimeter negative to vehicle chassis ground. Touch positive lead to wire corresponding
to defective lead.
Step 3. Multimeter should not read continuity (infinite reading). If there is a reading, the wiring
harness has a shorted lead.
Step 4. Check harness for short lead by visually locating frayed or pinched wires.
a. Repair frayed or pinched wires (para. 3-131).
b. If system is still not operational, perform malfunction 24.

END OF TESTING!
2-137

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
24. NO LIGHTS OPERATE WITH DIRECTIONAL SIGNAL CONTROL LEVER IN ANY POSlTlON
Test 1. Test control unit voltage feed.
Step 1. Place battery switch to OFF position.
Step 2. Disconnect connector control unit harness from directional signal control unit.
Step 3. Place battery switch to ON position.
Step 4. Place light switch to STOP TURN position.
Step 5. Set multimeter to 50-volt range.
Step 6. Connect multimeter negative lead to vehicle chassis ground and positive lead to
connector terminal point G.
a. Multimeter should indicate battery voltage. If battery voltage is not indicated,
perform malfunction 16, test 4.
b. If battery voltage is indicated, go to test 2.

2-138

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Test 2. Test flasher harness continuity.
Step 1. Set multimeter to RX1 for continuity reading, and connect positive lead to terminal A of
flasher unit. Connect negative lead to terminal H of control unit cable, and observe
multimeter for continuity.
Step 2. Connect multimeter negative lead to terminal F of control unit socket and positive lead
to terminal B of flasher unit. Observe multimeter for continuity.
Step 3. Connect multimeter positive lead to terminal C of flasher unit connector. Connect
negative lead to ground, and observe multimeter for continuity.
a. If any lead does not have continuity, repair (para. 3-131).
b. If all leads have continuity and turn signals still do not work, replace flasher
(para. 3- 114).
c. If turn signals still do not work, perform malfunction 25.

END OF TESTING!
2-139

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
25. SYSTEM OPERATES INCORRECTLY IN ONE OR MORE POSITIONS OF DIRECTIONAL SIGNAL CONTROL LEVER
Test directional signal control unit continuity.
Step 1. Place battery switch to OFF position.
Step 2. Remove harness connector from control unit.
NOTE
Remove indicator lamp before making tests.
Step 3. Remove indicator lamp from directional signal control (para. 3-113).
Step 4. Set multimeter to RX1 for continuity reading.
Step 5. Set control lever in each of four operating positions and test.
If any lead does not test as shown in tables below, replace directional signal control unit
(para. 3-113).

A. DIRECTIONAL SIGNAL CONTROL LEVER
IN NEUTRAL POSITION
FROM PIN
TO PIN
CONTINUITY
INDICATED
H
A
Open
B
H
Open
C
H
Open
E
H
Open
C
D
Shorted
E
D
Shorted
G
F
Open

C. DIRECTIONAL SIGNAL CONTROL LEVER
IN RIGHT TURN POSITION
FROM PIN
TO PIN
CONTINUITY
INDICATED
F
G
Shorted
H
A
Shorted
H
E
Shorted
H
B
Open
H
C
Open
D
C
Shorted
D
E
Open

B. DIRECTIONAL SIGNAL CONTROL LEVER
IN LEFT TURN POSITION
FROM PIN
TO PIN
CONTINUITY
INDICATED
B
H
Shorted
C
Shorted
H
A
Open
H
E
Open
H
G
Shorted
F
D
E
Shorted
D
C
Open

D. DIRECTIONAL SIGNAL CONTROL LEVER
IN HAZARD WARNING POSITION
FROM PIN
TO PIN
CONTINUITY
INDICATED
A
H
Shorted
B
H
Shorted
C
H
Shorted
H
E
Shorted
D
E
Open
D
C
Open
G
F
Shorted

END OF TESTING!
2-140

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
ETHER START SYSTEM

26. ENGINE CRANKS BUT WILL NOT START (FUEL AVAILABLE)
Test 1. Check ether cylinder.
Remove ether cylinder from ether valve (para. 3-35); shake and listen for liquid splashing inside
cylinder.
a. Replace cylinder if empty (para. 3-35) and try to restart engine.
b. If cylinder is full, reinstall (para. 3-35) and go to test 2.
2-141

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Test 2. Check ether start system electrical source.
Operate personnel heater blower motor with switch in HIGH position (TM 9-2320-272-10).
a. If personnel heater blower motor does not operate, perform malfunction 39.
b. If personnel heater blower motor operates, go to test 3.
Test 3. Test lead 570 for voltage at ether valve.
Step 1. Disconnect lead 570 at ether valve.
Step 2. Set multimeter to 50-volt range. Connect positive lead to disconnected lead 570 and
multimeter negative lead to ground.
Step 3. Turn battery switch to ON position.
Step 4. Crank engine, depress ether start switch, and observe multimeter.
a. If meter indicates battery voltage and ether valve does not function, replace ether
valve (para. 3-35).
b. If no voltage is indicated, go to test 4.

2-142

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Test 4. Test lead 570 for voltage at ether start pressure switch.
Step 1. Disconnect lead 570 to ether valve from ether start pressure switch.
Step 2. Connect positive lead to lead 570 terminal on ether start pressure switch and negative
lead to chassis ground.
Step 3. Crank engine, depress ether start switch, and observe multimeter.
a. If meter indicates battery voltage, repair lead 570 to ether valve (para. 3-131).
b. If no voltage is indicated, go to step 4.
Step 4. Disconnect lead 570 at ether start switch.
Step 5. Connect multimeter positive lead to lead 570 from ether start switch and negative lead
to chassis ground.
Step 6. Crank engine, depress ether start switch, and observe multimeter.
a. If multimeter indicates battery voltage, replace ether start pressure switch
(para. 3-33).
b. If no voltage is indicated, go to test 5.

2-143

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECT ACTION
Test 5. Test lead 570 for voltage at ether start switch.
Step 1. Dieconned lead 570 to ether start pressure switch from ether start switch.
Step 2. Connect multimeter positive lead to lead 570 ether start switch connector and negative
lead to chassis ground.
Step 3. Depress ether start switch and observe multimeter.
a. If meter indicates battery voltage, replace lead 570 to ether start pressure switch
(para. 3-131).
b. If no voltage is indicated, proceed to step 4.
Step 4. Dieconnect lead 570 to lead 5C from ether start switch.
Step 6. Connect multimeter positive lead to lead 570 and negative lead to chassis ground.
a. If meter indicates battery voltage, replace ether start switch (para. 3-33).
b. If no voltage is indicated, replace lead 570 to lead 5C connector.

END OF TESTING!
2-144

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
INDICATOR, GAUGE, AND WARNING SYSTEM

27. ALL GAUGES INOPERATIVE

Test 1.
Step
Step
Step
Step

NOTE
If STE/ICE is available, perform NG31 - Gauge Test (para. 2-24).
Test instrument cluster voltage feed.
1. Place battery switch to OFF position.
2. Disconnect lead 5A at circuit breaker.
3. Place battery switch to ON position.
4. Set multimeter to 50-volt range.

2-145

TM 9-2320-272-24-1
Table 2-3. Electrical Doubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Step 5.

Step
Step
Step
Step

2-146

6.
7.
8.
9.

Connect multimeter negative lead to vehicle chassis ground and positive lead to lead 5A
Multimeter should indicate battery voltage.
a. If battery voltage is indicated, go to step 6.
b. If battery voltage is not indicated, perform malfunctions 1, 2, 3, 5, and 6.
Place battery switch to OFF position.
Connect lead 5A and disconnect lead 27 at circuit breaker.
Place battery switch to ON position.
With multimeter negative lead connected to ground, touch positive lead to circuit 27
terminal of circuit breaker. Multimeter should indicate battery voltage.
a. If battery voltage is not indicated, replace defective circuit breaker (para. 3-105).
b. If battery voltage is indicated, go to test 2.

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Test 2.
Step
Step
Step
Step
Step

Test instrument cluster for short circuit.
1. Place battery switch to OFF position.
2. Remove instrument cluster panel (para. 3-83).
3. Disconnect lead 27 from each gauge.
4. Place battery switch to ON position.
5. Connect one lead of a 24-volt test lamp to lead 27 disconnected from engine temperature
gauge and other lead to ground. Reconnect each lead 27 to its appropriate gauge, one at
a time, and note lamp indication. Test lamp should remain lit each time.
Step 6. Disconnect lead 27 at oil pressure gauge. Connect one lead of test lamp to lead 27
disconnected from oil pressure gauge and other lead to ground. Reconnect lead 27 to
engine temperature gauge. Test lamp should light.
If test lamp is dim, blinks on and off, or goes out when lead is connected to gauge,
replace oil pressure gauge (para. 3-86).

2-147

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Test 3.
Step
Step
Step
Step
Step
Step

Test instrument cluster voltage feed.
1. Place battery switch to OFF position.
2. Remove instrument cluster panel (para. 3-83).
3. Disconnect lead 27 from each gauge.
4. Place battery switch to ON position.
5. Set multimeter to 50-volt range.
6. Connect multimeter negative lead to vehicle chassis ground and positive lead to lead 27.
Multimeter should indicate battery voltage.
If battery voltage is not indicated, disconnect instrument cluster wiring harness lead 27
from power source lead 27 and go to step 7.
Step 7. With multimeter negative lead connected to ground, touch positive lead to circuit 27
connector at instrument cluster, Multimeter should indicate battery voltage.
a. If battery voltage is indicated, replace instrument cluster wiring harness
(para. 3-130).
b. If battery voltage is not indicated, and voltage was correct in test 1, step 9, repair
power source lead 27 (para. 3-131).

END OF TESTING!
2-148

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
28. ONE GAUGE INOPERATlVE
NOTE
If STE/ICE is available, perform NG31 - Gauge Test (para. 2-24).
Test individual gauge voltage.
Step 1. Place battery switch to OFF position.
Step 2. Remove instrument cluster panel (para. 3-83).
Step 3. Disconnect lead 27 from inoperative gauge.
Step 4. Place battery switch to ON position.
Step 5. Set multimeter to 50-volt range.
Step 6. Connect multimeter negative lead to vehicle chassis ground and positive lead to
disconnected lead 27. Multimeter should indicate battery voltage.
a. If battery voltage is not indicated, replace instrument cluster wiring harness
(para. 3-130).
b. If battery voltage is indicated, replace defective gauge (para. 3-86).

END OF TESTING!
2-149

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
29. TEMPERATURE GAUGE INOPERATIVE (COOLANT)
NOTE
If STE/ICE is available, perform NG31 - Gauge Test (para. 2-24).
Test 1. Test temperature gauge voltage. Perform malfunction 27.
Test 2. Test coolant temperature gauge sending unit.
Step 1. Allow engine to cool.
Step 2. Set multimeter to RX4 for resistance reading.
Step 3. Disconnect lead 33 from temperature sending unit.
Step 4. Start engine (TM 9-2320-272-10).
Step 5. Connect multimeter negative lead to vehicle engine ground and connect positive lead to
sending unit terminal 33. The multimeter reading should decrease as engine
temperature increases.
If resistance does not show any decrease as temperature increases, replace temperature
sending unit (para. 3-93).
Test 3. Test lead 33 continuity.
Step 1. Disconnect lead 33 from temperature gauge and temperature sending unit.
Step 2. Attach temperature gauge end of lead 33 to chassis ground,
Step 3. Set multimeter to RX1 for continuity reading.
Step 4. Connect multimeter negative lead to vehicle chassis ground and positive lead to sending
unit end of lead 33. Multimeter should read continuity.
If continuity is not present, repair lead 33 (para. 3-131).

END OF TESTING!
2-150

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
30. FUEL GAUGE INOPERATIVE
WARNING

Test 1.
Test 2.
Step
Step
Step
Step
Step

Do not perform testing near fuel tank with fill cap or sending unit
removed. Fuel may ignite, causing injury to personnel.
NOTE
If STE/ICE is available, perform NG31- Gauge Test (para. 2-24).
Test fuel level gauge voltage (malfunction 28).
Test fuel level sending unit.
1. Disconnect lead 28 (left-hand tank) or lead 29 (right-hand tank) from fuel level sending
unit.
2. Place battery switch to ON position.
3. Place fuel selector switch (if equipped) to affected fuel tank.
4. Set multimeter on 50-volt range.
5. Connect multimeter negative lead to chassis ground and positive lead to disconnected
lead. Multimeter should indicate battery voltage.
If battery voltage is indicated, replace fuel level sending unit (para. 3-92).

2-151

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Test 3. Test circuit wire of affected tank.
Step 1. Dieconnect lead 28 (left-hand tank, pin B) or lead 29 (right-hand tank, pin D) from fuel
selector switch.
Step 2. Place battery switch to ON position.
Step 3. Place fuel selector switch (if equipped) to affected fuel tank.
Step 4. Set multimeter on 50-volt range.
Step 5. Connect multimeter negative lead to chassis ground and positive lead to pin B or pin D
on selector switch. Multimeter should indicate battery voltage.
a. If battery voltage is indicated, repair lead from switch to sending unit (para. 3-131).
b. If battery voltage is not indicated, go to test 4.
Test 4. Test fuel selector switch.
Step 1. Dieconnect lead 28 from pin A of fuel selector switch.
Step 2. Place battery switch to ON position.
Step 3. Set multimeter to 50-volt range.
Step 4. Connect multimeter negative lead to vehicle chassis ground and positive lead to
connector of disconnected lead 28. Multimeter should indicate battery voltage.
a. If battery voltage is indicated, replace fuel selector switch (para. 3-109).
b. If battery voltage is not indicated, repair lead 28 (para. 3-131).

END OF TESTING!
2-152

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
31. BATTERY/ALTERNATOR GAUGE INOPERATIVE
NOTE
If STE/ICE is available, perform NG31 - Gauge Test (para. 2-24).
Test 1. Test battery/altamator gauge voltage. Perform malfunction 28.
Test 2. Check battery/alternator gauge for continuity.
CAUTION
Place battery switch to OFF position. If ground is open and
battery voltage is present, the multimeter may be damaged.
Step 1. Set multimeter to RX1 for continuity reading.
Step 2. Connect multimeter negative lead to vehicle chassis ground and positive lead to
indicator case. Multimeter should read continuity.
a. If multimeter doer not read continuity, clean and tighten indicator mounting points.
b. If multimeter doer read continuity, replace battery/alternator gauge (para. 3-86).

END OF TESTING!
2-153

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
32. HORN INOPERATIVE
Test 1. Test horn circuit breaker voltage.
Step 1. Place battery switch to OFF position.
Step 2. Disconnect lead 10 from circuit breaker.
Step 3. Place battery switch to ON position.
Step 4. Set multimeter to 50-volt range.
Step 5. Connect multimeter negative lead to vehicle chassis ground and positive lead to lead 10.
Multimeter should indicate battery voltage.
a. If battery voltage is not indicated, perform malfunctions 2, 3,4, 6, and 7.
b. If battery voltage is indicated, go to step 6.

2-154

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Step
Step
Step
Step

6.
7.
8.
9.

Place battery switch to OFF position.
Connect lead 10 and disconnect lead 26 from circuit breaker.
Place battery switch to ON position.
Connect multimeter negative lead to vehicle chassis ground and positive lead to lead 26.
Multimeter should indicate battery voltage.
If battery voltage is not indicated, replace circuit breaker (para. 3-105).

2-155

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Test 2.
Step
Step
Step

2-156

Test horn circuit voltage.
1. Disconnect leads 25 and 26 from horn solenoid.
2. Set multimeter to 50-volt range.
3. Connect multimeter negative lead to vehicle chassis ground and positive lead to lead 26.
Multimeter should indicate battery voltage.
a. If battery voltage is not indicated, repair or replace lead 26 (para. 3-131).
b. If battery voltage is indicated, proceed to step 4.

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Step 4. Connect lead 26 to horn solenoid, Connect a jumper wire to vehicle chassis ground and
the other end to lead 25 terminal on horn solenoid. Horn should sound.
a. If horn does not sound, replace horn solenoid (para. 3-103).
b. If horn sounds, connect lead 26 and go to test 3.

Test 3. Test horn switch.
Step 1. Disconnect lead 25 from horn switch.
Step 2. Connect one end of a jumper wire to vehicle chassis ground and touch opposite end to
lead 25 connector. Horn should sound.
If horn sounds, replace horn switch (para. 3-104).

END OF TESTING!
2-157

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
33. LOW AIR PRESSURE WARNING BUZZER WILL NOT SHUT OFF (AIR PRESSURE GAUGES AT NORMAL SYSTEM
PRESSURE)
Test 1. Test resistance at low air pressure switches.
Step 1. Start engine (TM 9-2320-272-10) and allow air pressure to reach normal operating
pressure.
Step 2. Disconnect leads 578 and 578A from low air pressure switch A.
Step 3. Set multimeter to RX4 for resistance reading.
Step 4. Touch positive lead of multimeter to contact end of pressure switch A.
Step 5. Touch negative lead of multimeter to other contact end of pressure switch A.
a. If resistance is 300 ohms or less, go to step 6.
b. If resistance is more than 300 ohms, replace low air pressure switch (para. 3-86).
Step 6. Connect leads 578 and 578A to low air pressure switch A.
Step 7. Disconnect leads 57 and 578A from low air pressure switch B.
Step 8. Touch positive lead of multimeter to contact end of pressure switch B.
Step 9. Touch negative lead of multimeter to other contact end of pressure switch B.
a. If resistance is 300 ohms or less, stop engine, connect leads, and go to test 2.
b. If resistance is more than 300 ohms, replace low air pressure switch (para. 3-86).

2-158

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Test 2. Test continuity at air pressure switches.
Step 1. Start engine (TM 9-2320-272-10) and allow air pressure to reach normal operating
pressure.
Step 2. Set multimeter to RX1 for continuity reading.
Step 3. Disconnect lead 57 at air pressure switch B.
Step 4. Touch positive lead of multimeter to contact end of lead 57 and negative lead of
multimeter to frame ground.
a. If continuity is present, go to step 5.
b. If continuity is not present, replace lead 57 (para. 3-131).
Step 5. Connect lead 57 to air pressure switch B.
Step 6. Disconnect lead 578 from air pressure switch A.
Step 7. Touch positive lead of multimeter to contact end of lead 578 and negative lead of
multimeter to frame ground.
a. If continuity is present, go to step 8.
b. If continuity is not present, replace lead 578 (para. 3-131).

2-159

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Step 8. Connect lead 578 to air pressure switch A.
Step 9. Disconnect wiring harness at failsafe warning control module.
Step 10. Touch positive lead of multimeter to pin F (lead 578) and negative lead of multimeter to
frame ground.
a. If continuity is present, go to step 11.
b. If continuity is not present, replace lead 578 (para. 3-131).
Step 11. Touch positive lead of multimeter to pin H (lead 57) and negative lead of multimeter to
frame ground.
a. If continuity is present, go to step 12.
b. If continuity is not present, replace lead 57 (para. 3-131).
Step 12. Touch positive lead of multimeter to pin D (lead 350) and negative lead of multimeter to
frame ground.
a. If continuity is present, go to step 13.
b. If continuity is not present, replace lead 350. (Refer to Digest Article, Engine
Overheating Warning System.)
Step 13. Ensure parking brake is engaged (TM 9-2320-272-10).
Step 14. Touch positive lead of multimeter to pin I (lead 584) and negative lead of multimeter to
frame ground.
If low air warning buzzer will not shut off, replace.
a. If continuity is not present, replace lead 584 (para. 3-131).

END OF TESTING!
2-160

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
34. LOW AIR PRESSURE WARNING BUZZER WILL NOT SHUT OFF AND PARKING BRAKE WARNING LIGHT
FLASHES WITH HAND/PARKING BRAKE IN ANY POSITION (AIR PRESSURE NORMAL)
Step 1. Set multimeter to RX1 for continuity reading.
Step 2. Disconnect lead 584 from parking brake switch (under cab).
Step 3. Check for continuity through parking brake switch to ground lead 584 (with parking
brake released).
Step 4. If continuity is not present, replace parking brake switch (para. 3-107).
END OF TESTING!
35. SPRING BRAKE WARNING LIGHT INOPERATIVE WITH SPRING BRAKE OVERRIDE ENGAGED
Test 1. Check spring brake override warning light.
Replace lamp with one known to be good (para. 3-84).
Test 2. Test spring brake pressure switch.
Step 1. Place battery switch to ON position.
Step 2. Disconnect two leads 37 from spring brake pressure switch.
Step 3. Connect a jumper wire to both leads 37. Warning light should operate.
If warning light is on, replace spring brake pressure switch (para. 3-100).

Test 3.
Step
Step
Step
Step
Step

Test spring brake override warning light circuit breaker voltage.
1. Place battery switch to OFF position.
2. Disconnect lead 10 from circuit breaker.
3. Place battery switch to ON position.
4. Set multimeter to 50-volt range.
5. Connect multimeter negative lead to vehicle chassis ground and positive lead to lead 10.
Multimeter should indicate battery voltage.
If battery voltage is not indicated, perform malfunctions 2, 3, 4, 6, and 7.

2-161

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Step
Step
Step
Step

6.
7.
8.
9.

Place battery switch to OFF position.
Connect lead 10 and disconnect lead 37 from circuit breaker.
Place battery switch to ON position.
Connect multimeter negative lead to vehicle chassis ground and positive lead to
lead 37 terminal of circuit breaker. Multimeter should indicate battery voltage.
If battery voltage is not indicated, replace defective circuit breaker (para. 3-105).

END OF TESTING!
2-162

TM 9-2320-272-24-l
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION

TRAILER CONNECTION SYSTEM

36. ONE OR MORE LIGHTING SYSTEMS DO NOT LIGHT ON TRAILER
Test 1. Test trailer connecting receptacle voltage (malfunction 22).
Test 2. Test trailer connecting cable continuity.
Step 1. Remove connecting cable from vehicle.
Step 2. Place both ends of cable at a convenient point near each other. Open and lock hinged
covers on each end.
Step 3. Set multimeter to RX1 for continuity reading.
Step 4. Connect multimeter leads from socket letter A on one connector to socket letter A on
other connector. Note multimeter reading.
NOTE
Wires M and N are not used and continuity is not required.
2-163

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Test 3. Test each wire the same until all 10 wires have been tested. Continuity should be read on
each wire.
a. If continuity is not read on any wire, replace cable.
b. If continuity is read, plug cable into vehicle receptacle and test receptacle voltage at
trailer end of cable. Perform malfunction 22.

END OF TESTING!
2-164

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION

HEATER SYSTEM

37. HEATER WILL NOT OPERATE WITH SWITCH IN LOW POSITION (HIGH POSITION OPERATION NORMAL)
Test 1. Test lead 569A for voltage.
Step 1. Place battery switch to OFF position.
Step 2. Disconnect lead 569A from heater switch.
Step 3. Place battery switch to ON position.
Step 4. Set multimeter to 50-volt range.
Step 5. Connect multimeter negative lead to vehicle chassis ground and positive lead to lead
569A. Multimeter should indicate 12 to 13-volts.
a. If battery voltage is not indicated, go to test 2.
b. If battery voltage is indicated, replace defective heater switch (para. 3-107).
2-165

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION

Test. 2. Test circuit breaker.
Step 1. Disconnect lead 569A to heater switch from circuit breaker.
Step 2. Set multimeter to 50-volt range, connect negative lead to vehicle chassis ground, and
positive lead to exposed circuit breaker terminal.
Step 3. Place battery switch to ON position and observe multimeter.
Step 4. Disconnect lead 569A to battery switch from circuit breaker. Connect multimeter
positive lead to wire and observe multimeter.
a. If multimeter indicated 12-13 volts in step 3, repair or replace lead 569A between
circuit breaker and heater switch (para. 3-131).
b. If multimeter indicated 12-13 volts in step 4, replace circuit breaker (para. 3-105).

END OF TESTING!

2-166

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
38. HEATER WILL NOT OPERATE WITH SWITCH IN HIGH POSITION (LOW POSITION OPERATION NORMAL)
Step 1. Place battery to OFF position.
Step 2. Disconnect lead 5C from heater switch.
Step 3. Place battery switch to ON position.
Step 4. Set multimeter to 50-volt range.
Step 5. Connect multimeter negative lead to vehicle chassis ground and positive lead to
lead 5C. Multimeter should indicate 12-13 volts.
a. If battery voltage is not indicated, perform malfunction 27, test 1.
b. If battery voltage is indicated, replace defective heater switch (para. 3-107).

END OF TESTING!
2-167

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
39. HEATER WILL NOT OPERATE IN LOW OR HIGH POSITION
Step 1. Place battery to OFF position.
Step 2. Disconnect lead 400 from heater switch.
Step 3. Place battery switch to ON position.
Step 4. Set multimeter to 50-volt range.
Step 5. Connect multimeter negative lead to vehicle chassis ground. Touch positive lead to lead
400 terminal on heater switch and note voltage reading. Multimeter should indicate
12-13 volts with heater switch in LOW or HIGH position.
a. If battery voltage is not indicated, replace heater switch (para. 3-107).
b. If battery voltage is indicated, clean and tighten heater ground point connection.
c. If heater still does not operate, replace heater (para. 3-292).

END OF TESTING!
2-168

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION

100-AMP ALTERNATOR KIT

40. BATTERIES HOT OR BOILING; CORRECT SPECIFIC GRAVITY OF ALL CELLS IS 1.280
NOTE
If STE/ICE is available, perform NG50 - Charging Circuit Tests
(para. 2-24).
Test charging voltage (malfunction 9).
END OF TESTING!
2-169

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
41. BATTERIES USE EXCESSIVE WATER
NOTE
If STE/ICE is available, perform NG81 - Battery Tests or NG50 Charging Circuit Tests (para. 2-24).
Test charging voltage (malfunction 9).
END OF TESTING!
42. BATTERIES RUN DOWN IN SERVICE
NOTE
If STE/ICE is available, perform NG50 - Charging Circuit Tests
(para. 2-24).
Test 1. Check for loose, broken, or missing alternator or fan drivebelts.
a. Adjust loose drivebelts (M939/A1) (para. 3-78).
b. Replace broken or missing drivebelts (para. 3-79 or 3-80).
Test 2. Test charging voltage (malfunction 9).
a. If proper voltage is indicated, problem is not in generating system. Refer to battery
system troubleshooting.
b. If proper voltage is not indicated, perform malfunction 44.
END OF TESTING!
43. NO ALTERNATOR OUTPUT
NOTE
If STE/ICE is available, perform NG50 - Charging Circuit Tests
(para. 2-24).
Test 1. Check for loose, broken, or missing alternator or fan drivebelts.
a. Adjust loose drivebelts (M939/A1) (para. 3-78).
b. Replace broken or missing drivebelts (para. 3-79 or 3-80).
Test 2. Test continuity of alternator harness.
Step 1. Disconnect quick-disconnect for lead 566.
Step 2. Disconnect voltage regulator harness connector at alternator and voltage regulator.
Step 3. Set multimeter to RX1 for continuity reading.
Step 4. Connect multimeter negative lead to contact end of lead 566 and positive lead to pin F.
Continuity should be present.
a. If continuity is present, go to step 5.
b. If continuity is not present, replace voltage regulator harness (para. 3-131).
Step 5. Connect multimeter positive lead to contact end of pin D at voltage regulator harness
connector and negative lead to contact end of pin B at alternator harness connector.
Continuity should be present.
a. If continuity is present, go to step 6.
b. If continuity is not present, replace voltage regulator harness (para. 3-131).

2-170

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Step 6.

Connect multimeter positive lead to contact end of pin E at voltage regulator harness
connector and negative lead to contact end of pin E at alternator harness connector.
Continuity should be present.
a. If continuity is present, go to step 7.
b. If continuity is not present, replace voltage regulator harness (para. 3-131).
Step 7. Connect multimeter positive lead to contact end of pin C at voltage regulator harness
connector and negative lead to contact end of pin C at alternator harness connector.
Continuity should be present.
a. If continuity is present, go to step 8.
b. If continuity is not present, replace voltage regulator harness (para. 3-131).
Step 8. Connect multimeter positive lead to contact end of pin B at voltage regulator harness
connector and negative lead to contact end of pin D at alternator harness connector.
Continuity should be present.
a. If continuity is present, go to test 3.
b. If continuity is not present, replace voltage regulator harness (para. 3-131).

2-171

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Test 3.
Step
Step
Step
Step

Test continuity of starter harness.
1. Disconnect quick-disconnect from lead 568.
2. Disconnect voltage regulator harness connector at voltage regulator.
3. Disconnect voltage regulator harness at starter motor and starter solenoid.
4. Connect multimeter positive lead to contact end of lead 81 at starter solenoid and
negative lead to pin B at voltage regulator harness connector. Continuity should be
present.
a. If continuity is present, go to step 5.
b. If continuity is not present, replace voltage regulator harness (para. 3-131).
Step 5. Connect multimeter positive lead to contact end of lead 81 at starter solenoid and
negative lead to pin A at voltage regulator harness connector. Continuity should be
present.
a. If continuity is present, go to step 6.
b. If continuity is not present, replace voltage regulator harness (para. 3-131).
Step 6. Connect multimeter negative lead to contact end of pin C at voltage regulator harness
connector and positive lead to contact end of lead at starter motor. Continuity should be
present.
a. If continuity is present, go to step 7.
b. If continuity is not present, replace voltage regulator harness (para. 3-131).
Step 7. Connect multimeter positive lead to contact end of lead 568 and negative lead to contact
end of pin F at voltage regulator harness connector. Continuity should be present.
a. If continuity is present, notify DS maintenance.
b. If continuity is not present, replace voltage regulator harness (para. 3-131).

2-172

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION

END OF TESTING!
2-173

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION

TRANSFER CASE SYSTEM
44. TRANSFER CASE CONTROL LEVER WILL NOT SHIFT FROM LOW TO HIGH OR HIGH TO LOW WHEN VEHICLE
IS IN MOTION
Test 1. Test transfer case control circuit breaker (malfunction 35, test 3).
Test 2. Test transfer case control switch.
Step 1. Place battery switch to OFF position.
Step 2. Disconnect lead 585 from transfer case control switch.
Step 3. Place battery switch to ON position.
Step 4. Set multimeter to 50-volt range.
Step 5. Connect multimeter negative lead to vehicle chassis ground and positive lead to lead
585. Multimeter should indicate battery voltage.
a. If battery voltage is not indicated, repair or replace lead 585 (para. 131).
b. If battery voltage is indicated, connect lead 585 and disconnect lead 586 from control
switch.
Step 6. Place transmission control lever to NEUTRAL position. With negative lead of meter
connected to ground and, with transfer case switch button depressed, touch positive lead
to lead 586 terminal on control switch. Multimeter should indicate battery voltage.
If battery voltage is not indicated, notify DS maintenance.

END OF TESTING!
2-174

TM 9-2320-272-24-1
Table 2-3. Electrica1 Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
45. TRANSFER CASE SHIFTS HARD WHILE ENGINE IS RUNNING
Test transfer case switch lever for voltage.
Step 1. Set multimeter to 24-volt range.
Step 2. Disconnect lead 586 from transfer case shift lever switch.
Step 3. Touch positive lead of multimeter to contact end of transfer case shift lever switch and
negative lead to ground.

END OF TESTING!

2-175

TM 9-2320-272-24-1
Table 2-3. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION

Step 4.

NOTE
Assistant will help with step 4.
Have assistant position ignition switch to ON and push transfer case shift lever button.
Voltage should be present.
a. If voltage is present, linear valve is defective. Notify DS maintenance.
b. If voltage is not present, transfer case shift lever switch or wiring is defective. Notify
DS maintenance.

PROTECTIVE CONTROL BOX ASSEMBLY
46. PROTECTIVE CONTROL BOX ASSEMBLY TEST
Initial check - front wiring harness disconnected at box.
Step 1. Confirm that continuity exists between pin E and ground.
Step 2. Confirm that continuity exists between pins B and D, pins C and D, pin A and ground,
pin B and ground, pin C and ground, and pin D and ground.
Step 3. Apply 24 volts to pin A. Confirm that continuity exists between pins C and D, but not
between pins B and D.
Step 4. If findings are other than as indicated, protective control box is malfunctioning. Replace
protective control box (para. 3-115).

END OF TESTING!
2-176

TM 9-2320-272-24-1

2-23. COMPRESSED AIR AND BRAKE SYSTEM TROUBLESHOOTING
a. This section contains troubleshooting information and tests for locating and correcting malfunctions
which may develop in the compressed air and brake system on vehicles covered in this manual. Each
symptom or malfunction given for an individual component or system is followed by step(s) you should take
to determine the cause and corrective action needed to remedy the problem. Compressed air and brake
system is divided into the following functional systems:
l
Parking Brake (page 2-179)
l
Service Brakes (page 2-180)
l
Compressed Air Supply (page 2-197)
l
Air-operated Accessories (page 2-213)
b. This troubleshooting guide is used to keep your vehicle operating and trouble-free as much as
possible in the quickest, easiest way.
(1) When a malfunction occurs, start at the source of the trouble and keep working back to
eliminate elements that are not defective to isolate the parts of the system that are. When found, this part,
line, or element is repaired, replaced, or otherwise corrected to get your vehicle running again.
(2) In the compressed air and brake system, emphasis in the troubleshooting guide is placed on
leaks, blockages in tubing and hoses, and correct pressure for operating various air-operated devices. Leaks
and blockages are easily determined using methods indicated in the tests.
(3) Correct air pressure requires a gauge of known accuracy, which is a special tool, to test
whether an element of the system is functioning or operating properly when supplied with the correct air
pressure.
c. Before taking any corrective action to correct a possible malfunction, the following rules should be
followed:
(1) Question operator to obtain any additional information that might help you to determine the
cause of the problem.
(2) Never overlook the chance the problem could be of a simple origin. The problem could require
only a minor adjustment.
(3) Use all senses to observe and locate troubles.
(4) Use test instruments and gauges to help you determine and isolate problems.
(5) Always isolate the system where the malfunction occurs and locate the defective component.
(6) Use standard automotive theories and principles when troubleshooting the vehicles covered in
this manual
(7) Operate the vehicle yourself to ensure the operator’s description of the problem is correct.
(8) Always wear eyeshields when troubleshooting the compressed air system.
d. The compressed air schematic (Appendix H) shows the interrelationship of the compressed air and
brake system, and should be used as a reference when performing troubleshooting procedures. Table 2-4
lists malfunctions of the compressed air and brake system that may occur.
e. This section cannot list all compressed air and brake system malfunctions that may occur. If a
malfunction occurs that is not listed in table 2-4, notify DS maintenance.
WARNING
l

l

Do not disconnect air lines before draining air reservoirs. Small
parts under pressure may shoot out with high velocity, causing
injury to personnel.
Hearing protection is required for the driver and passenger.
Hearing protection is also required for all personnel working in
and around the vehicle while the engine is running. (Refer to
AR 40-5 and TB MED 501.)

2-177

TM 9-2320-272-24-1

COMPRESSED AIR AND BRAKE SYSTEM TROUBLESHOOTING INDEX
MALFUNCTION
NO.

1.
2.
3.
4.
5.
6.
7.
8.

9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.

20.
21.
22.
23.
24.

2-178

MALFUNCTION

TROUBLESHOOTING
PROCEDURE
PAGE

PARKING BRAKE
Parking brake does not hold vehicle on grade . . . . . . . . . . . . . . . . . . . . . . . . . .
Parking brake drags, as indicated by smoking or burning smell. . . . . . . . . . . .
SERVICE BRAKES
Insufficient brakes (vehicle stopping distance too long, no apparent
air system failure with gauges at normal operating pressure,
warning buzzer not sounding) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Vehicle pulls right or left when applying brakes . . . . . . . . . . . . . . . . . . . . . . . .
Vehicle rear brakes grab or drag . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Vehicle vibrates, chatters, or bounces when brakes are applied . . . . . . . . . . . .
Brakes squeal
...................................................
Warning buzzer sounds when brakes are applied (primary and secondary
gauge pressure drops below 55-65 psi (379-448 kPa). . . . . . . . . . . . . . . . . . . .
COMPRESSED AIR SUPPLY
No air pressure (warning buzzer sounding, air pressure not building to
normal operating range as indicated by gauges) . . . . . . . . . . . . . . . . . . . . . . .
Air pressure does not build to normal operating pressure
(above 80 psi (552 kPa)) according to gauges. . . . . . . . . . . . . . . . , . . . . . . . . .
Air pressure builds slowly (takes excessive amount of time to build to
100 psi (690kPa)
...............................................
Air pressure exceeds maximum (gauges show over 130 psi (896 kPa)),
safety valve opens to release pressure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Primary pressure gauge reads no pressure, low pressure, or builds to
normal operating pressure slowly. Secondary pressure gauge reads normal
(engine idling, brake pedal not applied). . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Secondary pressure gauge reads no pressure, low pressure, or builds to
normal operating pressure slowly. Primary pressure gauge reads normal
(engine idling, brake pedal not applied). . . . . . . . . . . . . . . . . . . . . . . . . , . . . .
Primary air system fails to maintain pressure (no major leaks, air can be
heard escaping into air intake stack, parking brake applied) . . . . . . . . . . . . .
Secondary air system fails to maintain pressure (no major leaks, air can be
heard escaping into air intake stack, parking brake applied) . . . . . . . . . . . . .
Warning buzzer fails to sound or fails to shut off on low pressure
(below 55-65 psi (379-448 kPa)), air pressure system operating normally. . . .
Spring brakes do not release (vehicle brakes grab or drag). . . . . . . . . . . . . . . .
Spring brakes do not set (gauges at normal operating pressures, air
exhausting not heard when parking brake applied). . . . . . . . . . . . . . . . . . . . .
AIR-OPERATED ACCESSORIES
All air-operated accessories do not operate (horn, windshield wipers,
windshield washers, transfer case controls), gauges at normal operating
pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cooling fan does not operate, engine temperature above 200°F (93°C) as
indicated by temperature gauge. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cooling fan does not stop running, engine temperature below normal
operating range (override bolt not installed) . . . . . . . . . . . . . . . . . . . . . . . . . .
Front wheel drive does not engage (front wheel drive lock-in switch
engaged and transfer case shift lever in HIGH position). . . . . . . . . . . . . . . . .
Horn does not work (gauges at normal operating pressure, warning buzzer
not sounding)
..................................................

2-179
2-179

2-180
2-194
2-196
2-196
2-196
2-196

2-197
2-200
2-200
2-200
2-202
2-206
2-208
2-208
2-210
2-210
2-212

2-213
2-213
2-214
2-214
2-218

TM 9-2320-272-24-1
Table 2-4. Compressed Air and Brake System Troubleshooting.
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION

PARKING BRAKE
1. PARKING BRAKE DOES NOT HOLD VEHICLE ON GRADE
Test 1. Check parking brake adjustment.
a. Release spring brakes (TM 9-2320-272-10).
b. Turn knob (1) on parking brake lever (2) clockwise to increase braking action.
c. If adjustment does not correct malfunction, perform test 2.
Test 2. Inspect parking brake cable (3) for binding or breaks.
a. Replace cable (3) if binding or broken (para. 3-175).
b. If cable (3) is not damaged, perform test 3.
Test 3. Inspect parking brakeshoes (6) for wear.
a. Push brakeshoe lever (4) clockwise by hand and measure brakeshoe lever travel.
b. If travel is more than 2 in. (5) mm), replace parking brakeshoes (6) (para. 3-176).
Test 4. Inspect for broken or faulty actuating plate (7).
a. Move brakeshoe lever (4) back and forth. Observe operation of brakeshoe lever (4),
spring (5), and actuating plate (7).
b. If actuating mechanism is defective, notify DS maintenance.
c. If actuating mechanism is serviceable, perform malfunction 19.
END OF TESTING!
2. PARKING BRAKE DRAGS, AS INDICATED BY SMOKING OR BURNING SMELL
Ensure parking brake lever (2) is not partially engaged.
a. Fully release parking brake.
b. If parking brake still drags, perform malfunction 1, tests 1, 2, and 4.

END OF TESTING!
2-179

TM 9-2320-272-24-1
Table 2-4. Compressed Air and Brake System Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION

SERVICE BRAKES
3. INSUFFICIENT BRAKES (VEHICLE STOPPING DISTANCE TOO LONG, NO APPARENT AIR SYSTEM FAILURE WITH
GAUGES AT NORMAL OPERATING PRESSURE, WARNING BUZZER NOT SOUNDING)
NOTE
Assistant will help with this procedure.
Test 1. Check lines and hoses for leaks.
Direct assistant to fully apply service brakes.
a. If air leaks are found, repair as necessary.
b. If no air leaks in lines and hoses are found, perform test 2.
Test 2. Check service brake chambers (1) for leaks through vent lines (2).
WARNING

Step
Step

Test 3.
Step
Step
Step
Step
Step
Step
Step
Step

2-180

Do not look in service chamber vent port when performing test.
Injury to personnel may result.
1. Disconnect vent line (2) from service brake chamber (1).
2. Direct assistant to apply service brakes and feel for evidence of escaping air at vent
port (3).
a. If air is escaping, air is present. Notify DS maintenance.
b. If no air is escaping, install vent line (2) on service brake chamber (1).
c. Check all remaining vent lines (2) on service brake chambers (1) before proceeding to
test 3.
Check front service brake chambers (1) for proper pressure.
1. Stop engine and open all drainvalves (4), in sequence shown, until brake system air
pressure is vented.
2. Close drainvalves (4).
3. Disconnect delivery line (5) from service brake chamber (1).
4. Remove adapter fitting (7) from service brake chamber (1).
5. Connect tee (6) to service brake chamber (1) and connect test gauge and delivery
line (5) to tee (6).
6. Direct assistant to start engine and build air supply to normal operating pressure.
7. Direct assistant to fully apply and hold service brakes.
8. Check test gauge reading and compare with reading on instrument panel primary air
pressure gauge.
a. If readings from both front service brake chambers are the same as reading from
primary air pressure gauge, stop engine, drain air, remove test gauge, connect lines,
and proceed to test 4.
b. If test gauge readings are nonexistent or far less than primary air pressure gauge,
stop engine, drain air, remove test gauge, connect lines, and perform tests 6
through 10.

TM 9-2320-272-24-1
Table 2-4. Compressed Air and Brake System Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION

\

DRAINVALVE SEQUENCE
2-181

TM 9-2320-272-24-1
Table 2-4. Compressed Air and Brake System Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Test 4. Check service brake chambers (2) and (3) for proper pressure.
NOTE
Air pressure to service brake chambers must be compared with
reading on primary air pressure gauge. Air pressure to spring and
service brake chambers must be compared with reading on
secondary air pressure gauge.
Step 1. Install test gauge on service brake chambers (2) and (3) and check for proper pressure as
outlined in test 3, steps 1 through 7.
Step 2. Check test gauge reading and compare with reading on instrument panel primary air
pressure gauge.
a. If reading on all four service brake chambers (2) and (3) are the same as reading
from primary air pressure gauge, stop engine, drain air, remove test gauge, connect
lines, and proceed to test 5.
b. If reading from two forward-rear rear service brake chambers (2) are not the same, stop
engine, drain air, remove test gauge, connect lines, and perform test 11.
c. If reading from two rear-rear forward service brake chambers (3) are not the same, stop
engine, drain air, remove test gauge, connect lines and perform test 12.
d. If reading from all service brake chambers (2) and (3) are not the same, stop engine,
drain air, remove test gauge, connect lines, and perform test 13.
Test 5. Check spring and service brake chambers (1) and (4) for proper pressure.
Step 1. Install test gauge on spring and service brake chambers (1) and (4) and check for proper
pressure as outlined in test 3, steps 1 through 7.
Step 2. Check test gauge reading and compare with reading on instrument panel secondary air
pressure gauge.
a. If reading on all four spring and service brake chambers (1) and (4) are the same as
reading on secondary air pressure gauge, stop engine, drain air, remove test gauge,
connect lines, and proceed to test 17.
b. If reading from two forward-rear forward spring and service brake chambers (1) are
not the same, stop engine, drain air, remove test gauge, connect lines, and perform
test 14.
c. If reading from only two rear-rear rear spring and service brake chambers (4) are not
the same, stop engine, drain air, remove test gauge, connect lines, and perform
test 15.
d. If reading from all four spring and service brake chambers (1) and (4) are not the
same, stop engine, drain air, remove test gauge, connect lines, and perform test 16.
Test 6. Check limiting valve (7) for venting (front service brake chambers test low or nonexistent
air pressure).
WARNING
Do not look into limiting valve vent port when performing test.
Injury to personnel may result.
Step 1. Direct assistant to apply and hold service brake pedal.
Step 2. Disconnect vent line (5) from limiting valve vent port (6).
Step 3. Feel for escaping air at limiting valve vent port (6).
a. If air is felt, replace limiting valve (7) (para. 3-190).
b. If no air is felt, reconnect vent line (5) and proceed to test 7.
2-182

TM 9-2320-272-24-1

Table 2-4. Compressed Air and Brake System Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION

2-183

TM 9-2320-272-24-1
Table 2-4. Compressed Air and Brake System Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Test 7. Check limiting valve (3) for proper air delivery pressure (front service brake chambers test
low or nonexistent air pressure).
Step 1. Stop engine and open all drainvalves (1), in sequence shown, until brake system air
pressure is vented.
Step 2. Close drainvalves (1).
Step 3. Disconnect air delivery lines (6) and (4) and remove tee (5) from limiting valve (3).
Step 4. Connect test gauge to delivery port (2) of limiting valve (3).
Step 5. Direct assistant to start engine and allow air pressure to build to normal operating
pressure.
Step 6. Direct assistant to fully apply and hold service brakes.
Step 7. Check reading on test gauge.
a. If test gauge reads normal operating pressure, check air delivery lines (6) and (4) for
blockage. Repair or replace lines (6) and (4) as necessary (TM 9-243).
b. If pressure is below normal or nonexistent, stop engine, drain air, connect lines to
limiting valve (3), and proceed to test 8.

DRAINVALVE SEQUENCE

2-184

TM 9-2320-272-24-1
Table 2-4. Compressed Air and Brake System Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Test 8. Check limiting valve (3) for proper air supply pressure (front service brake chambers test
low or nonexistent air pressure).
Step 1. Stop engine and open all drainvalves (1), in sequence shown, until brake system air
pressure is vented.
Step 2. Close drainvalves (1).
Step 3. Disconnect air supply line (7) from limiting valve (3).
Step 4. Connect test gauge to air supply line (7).
Step 5. Direct assistant to start engine and allow air pressure to built to normal operating
pressure.
Step 6. Check reading on test gauge.
a. If test gauge reads normal operating pressure, replace defective limiting valve (3)
(para. 3-190).
b. If pressure is below normal or nonexistent, check air supply line (7) for blockage.
Repair or replace as necessary. If no blockage is present, stop engine, drain air,
remove test gauge, connect air supply line (7), and proceed to test 9.

DRAINVALVE SEQUENCE
2-185

TM 9-2320-272-24-1
Table 2-4. Compressed Air and Brake System Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Test 9. Test doublecheck valve No. 1(2) supply pressure (front service brake chambers test low or
nonexistent air pressure).
WARNING

Step 1.
Step 2.
Step 3.
Step 4.
Step 5.

2-186

Do not depress service brake pedal during installation of test
gauge. This may result in injury to personnel.
Direct assistant to keep foot off service brake pedal (6).
Disconnect air supply line (1) from doublecheck valve No. 1 (2).
Connect test gauge to air supply line (1). Direct assistant to start engine and allow air
pressure to build to normal operating pressure.
Depress service brake pedal (6).
Check reading on test gauge.
a. If pressure reads normal and delivery line (3) is not blocked (as determined by
test 8), replace defective doublecheck valve No. 1 (2) (para. 3-212).
b. If pressure is below normal or nonexistent, stop engine, drain air, remove test gauge,
connect delivery line (3), and perform test 10.

TM 9-2320-272-24-1
Table 2-4. Compressed Air and Brake System Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Test 10. Check service brake pedal primary air system delivery port (4) (front service brake
chambers test low or nonexistent air pressure).
WARNING
Do not depress service brake pedal during removal of plug
and/or installation of test gauge. Doing so may result in injury
to personnel.
l
Remove correct plug only. Removal of incorrect plug may result
in injury to personnel.
Remove plug (7) from service brake pedal primary air system delivery port (4) on brake
pedal valve (5).
Connect test gauge to delivery port (4). Direct assistant to start engine and allow air
pressure to build to normal operating pressure.
Depress service brake pedal (6).
Check test gauge.
a. If air test gauge reads normal, check delivery line (1) to doublecheck valve No. 1 (2)
for blockage. Clear blockage as necessary.
b. If air pressure is below normal or nonexistent, remove test gauge and replace service
brake pedal valve (5) (para. 3-197 or 3-198).
l

Step 1.
Step 2.
Step 3.
Step 4.

2-187

TM 9-2320-272-24-1
Table 2-4. Compressed Air and Brake System Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Test 11. Check primary air system relay valve (3) for proper pressure (forward-rear rear service
brake chambers (1) test low or nonexistent air pressure).
Step 1. Stop engine and open all drainvalves (2), in sequence shown, until brake system air
pressure is vented.
Step 2. Close drainvalves (2).
Step 3. Disconnect delivery line (4) from forward-rear rear service brake chambers (1) and
remove elbow (5) from delivery port (6) on relay valve (3).
Step 4. Connect test gauge to delivery port (6).
Step 5. Direct assistant to start engine and allow air system to build to normal operating
pressure.
Step 6. Direct assistant to fully apply and hold service brakes.
Step 7. Check reading on test gauge.
a. If pressure is below normal, stop engine, drain air, remove test gauge, connect air
line, and proceed to test 12.
b. If pressure is normal, inspect relay valve to service brake chamber delivery lines (4)
for blockage. Repair or replace as necessary (TM 9-243).
c. Stop engine, drain air, remove test gauge, and connect delivery lines (4).

2-188

TM 9-2320-272-24-1
Table 2-4. Compressed Air and Brake System Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Test 12. Check primary air system relay valve (3) for proper pressure (rear-rear forward service
brake chambers (7) test low or nonexistent air pressure).
Step 1. Stop engine and open all drainvalves (2), in sequence shown, until brake system air
pressure is vented.
Step 2. Close drainvalves (2).
Step 3. Disconnect delivery line (9) from rear-rear forward service brake chambers (7) and
remove elbow (10) from relay delivery valve port (11) on relay valve (3).
Step 4. Connect test gauge to delivery valve port (11).
Step 5. Direct assistant to start engine and allow air system to build to normal operating
pressure.
Step 6. Direct assistant to fully apply and hold service brakes.
Step 7. Check reading on test gauge.
a. If pressure is below normal, proceed to test 13.
b. If pressure is normal, inspect relay valve to service brake chamber delivery lines (9)
for blockage. Repair or replace as necessary (TM 9-243).
c. Stop engine, drain air, remove test gauge, and connect delivery lines (9).

2-189

TM 9-2320-272-24-1
Table 2-4. Compressed Air and Brake System Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Test 13. Check primary air tank to relay valve supply line (3) (all four primary air system service
brake chambers test low or nonexistent air pressure).
Step 1. Stop engine and open all drainvalves (1), in sequence shown, until brake system air
pressure is vented.
Step 2. Close drainvalves (1).
Step 3. Disconnect supply line (3) from primary air system relay valve (2).
Step 4. Connect test gauge to supply line (3).
Step 5. Direct assistant to start engine and allow air system to build to normal operating
pressure.
Step 6. Direct assistant to fully apply and hold service brakes.
Step 7. Check reading on test gauge.
a. If pressure is below normal, inspect supply line (3) for blockage. Repair or replace as
necessary.
b. If pressure is normal, replace defective primary air system relay valve (2) (para. 3-187
or 3-188).
c. Stop engine, drain air, remove test gauge, and connect supply line (3).

DRAINVALVE SEQUENCE
2-190

TM 9-2320-272-24-1

Table 2-4. Compressed Air and Brake System Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Test 14. Check secondary air system relay valve (5) for proper pressure (only spring and service
brake chambers (4) test low or nonexistent air pressure).
Step 1. Stop engine and open all drainvalves (1), in sequence shown, until brake system air
pressure is vented.
Step 2. Close drainvalves (1).
Step 3. Disconnect delivery line (8) from service brake chambers (4) and remove elbow (7) from
relay valve (6).
Step 4. Connect test gauge to delivery port (6).
Step 5. Direct assistant to start engine and allow air system to build to normal operating
pressure.
Step 6. Direct assistant to fully apply and hold service brakes.
Step 7. Check reading on test gauge.
a. If pressure is below normal, proceed to test 16.
b. If pressure is normal, repair or replace blocked delivery line (8).
c. Stop engine, drain air, remove test gauge, and connect delivery line (8).

DRAINVALVE SEQUENCE
2-191

TM 9-2320-272-24-1
Table 2-4. Compressed Air and Brake System Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Test 16. Check secondary air system relay valve (3) for proper pressure (only spring and service
brake chambers (1) test low or nonexistent air pressure).
Step 1. Stop engine and open all drainvalves (2), in sequence shown, until brake system air
pressure is vented.
Step 2. Close drainvalves (2).
Step 3. Disconnect delivery line (6) from service brake chambers (1) and remove elbow (5) from
relay valve (3).
Step 4. Connect test gauge to delivery port (4).
Step 6. Direct assistant to start engine and allow air system to build to normal operating
pressure.
Step 6. Direct assistant to fully apply and hold service brakes.
Step 7. Check reading on test gauge.
a. If pressure is below normal, proceed to test 16.
b. If pressure is normal, repair or replace blocked delivery line (6).
c. Stop engine, drain air, remove test gauge, and connect delivery line (6).

2-192

TM 9-2320-272-24-1

Table 2-4. Compressed Air and Brake System Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Test 16. Check secondary air tank to relay valve supply line (7) (all four secondary air system
spring and service brake chambers (1) test low or nonexistent air pressure).
Step 1. Stop engine and open all drainvalves (2), in sequence shown, until brake system air
pressure is vented.
Step 2. Close drainvalves (2).
Step 3. Disconnect supply line (7) from secondary air system relay valve (3).
Step 4. Connect test gauge to supply line (7).
Step 6. Direct assistant to start engine and allow air system to build to normal operating
pressure.
Step 6. Direct assistant to fully apply and hold service brakes.
Step 7. Check reading on test gauge.
a. If pressure is below normal, inspect supply line (7) for blockage. Repair or replace as
necessary.
b. If pressure is normal, replace secondary air system relay valve (3) (para. 3-187 or 3-188).
c. Stop engine, drain air, remove test gauge, and connect supply line (7).

DRAINVALVE SEQUENCE
2-193

TM 9-2320-272-24-1
Table 2-4. Compressed Air and Brake System Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Test 17. Inspect service brakes.
Step 1. Remove brake dustcovers (para. 3-178).
Step 2. Inspect chamfer (2) on lining of brakeshoes (1) for wear.
If brakeshoes (1) are worn to depth of chamfer (2) or less than 5/16 in. (7.94 mm),
replace brakeshoe (para. 3-180).
Step 3. Inspect for oil on brakeshoes (1) or drum.
a. If oil is found, replace brakeshoes (1) (para. 3-180).
b. Replace front axle oil seal (para. 3-160) and clean hub and drum.
Step 4. Inspect actuator seals (3) for rotted, tom, or worn condition. If defective, notify DS
maintenance.
END OF TESTING!
4. VEHICLE PULLS RIGHT OR LEFT WHEN APPLYING BRAKES
NOTE
Vehicle pulling to right or left indicates a malfunction in one of
two front wheel service brakes.
Test 1. Determine which brake is grabbing.
Step 1. In a safe test area, bring vehicle to a hard, sudden stop.
Step 2. Inspect front wheels for excessive heat on wheel and drum. Inspect for smoke or skid
marks.
a. If grabbing is found, go to test 3.
b. If no signs of grabbing are present, perform test 2.
Test 2. Check front service brake chambers for proper air pressure. Perform malfunction 3, test 3.
Test 3. Remove front brake dustcovers (para. 3-178) and inspect service brake.
Step 1. Perform malfunction 3, test 17.
Step 2. Inspect brakeshoe lining to drum clearance (para. 3-179).
Test, 4. Perform mechanical troubleshooting (para. 2-21, malfunction 47).

2-194

TM 9-2320-272-24-1

Table 2-4. Compressed Air and Brake System Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION

END OF TESTING!
2-195

TM 9-2320-272-24-1
Table 2-4. Compressed Air and Brake System Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTION ACTION
5. VEHICLE REAR BRAKES GRAB OR DRAG
Test 1. Inspect rear brakes to isolate malfunction.
Step 1. Inspect for signs of locking, smoke, skid marks, and excessive heat on wheels and
drums.
a. If locking is found, perform malfunction 4, test 3 on rear brakes.
b. If no sign of locking is found, go to step 2.
Step 2. Inspect for leaks. Apply brakes, listen, and locate any defective lines or fittings.
a. If leakage is indicated, repair or replace defective lines or fittings as necessary
(TM 9-243).
b. If no leakage is found, go to test 2.
Test 2. Check rear brake chambers for proper air pressure. Perform malfunction 3, tests 4 and 5.
END OF TESTING!
6. VEHICLE VIBRATES, CHATTERS, OR BOUNCES WHEN BRAKES ARE APPLIED
Perform malfunction 5.
END OF TESTING!
7. BRAKES SQUEAL
Inspect for glazed and worn brake linings.
Step 1. Remove brakedrums (paras. 3-223 and 3-224).
Step 2. Perform malfunction 4, test 3.
Step 3. Inspect for glazed lining. Lining should appear dull.
If lining is shiny, remove glaze with wire brush.
Step 4. Inspect for dirt or metal trapped in brakeshoes.
Clean out with wire brush.
END OF TESTING!
8. WARNING BUZZER SOUNDS WHEN BRAKES ARE APPLIED (PRIMARY AND SECONDARY GAUGE PRESSURE
DROPS BELOW 55-65 PSI (379-448 kPa)
NOTE
This malfunction indicates a major leak in air delivery system.
Listen and locate leaks.
Step 1. Direct assistant to start engine and allow air system to build to normal operating
pressure.
Step 2. Direct assistant to fully apply and hold service brakes.
Step 3. Inspect for leaks.
Locate and repair leaks as necessary.
END OF TESTING!

2-196

TM 9-2320-272-24-1
Table 2-4. Compressed Air and Brake System Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION

COMPRESSED AIR SUPPLY
9. NO AIR PRESSURE (WARNING BUZZER SOUNDING, AIR PRESSURE NOT BUILDING TO NORMAL OPERATING
RANGE AS INDICATED BY GAUGES)
Test 1. Check for leaks.
Step 1. Direct assistant to start engine.
Step 2. Listen and locate leaks.
a. If leakage is found, repair lines or fittings as necessary.
b. If no leakage is found, go to test 2.
Test 2. Check air compressor (1) with engine running.
Step 1. Loosen and bleed air from governor signal line (2) to air compressor (1).
Step 2. Feel if air compressor outlet line (3) is hot.
a. If air compressor (1) is operating normally, outlet line (3) will be hot (under great
pressure). Proceed to test 3 if outlet line (3) is hot.
b. If outlet line (3) is not hot, proceed to step 3.

2-197

TM 9-2320-272-24-1
Table 2-4. Compressed Air and Brake System Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
WARNING

Step

Test 3.

Test 4.
Step
Step
Step
Step
Step
Step

Test 5.
Step
Step

Step

2-198

Loosen outlet line at air compressor very slowly. Stop procedure
and tighten fitting the moment air begins to escape. Injury to
personnel may result if line is accidentally disconnected from a
serviceable operating compressor.
3. Carefully loosen fitting (2) until air is heard escaping.
a. If air is heard, tighten fitting and proceed to test 3.
b. If air is not present, notify DS maintenance of defective air compressor (1).
Inspect outlet line (3) for damage that could restrict airflow.
a. If damage is present, repair or replace outlet line (3) (TM 9-243).
b. If no damage is present, perform test 4.
Check outlet line for blockage.
1. Stop engine and open all drainvalves (6), in sequence shown, until brake system air
pressure is vented.
2. Close drainvalves (6).
3. Disconnect outlet line (3) at wet supply tank (5) and install tee (4) between tank (5) and
outlet line (3).
4. Connect test gauge to tee (4).
5. Direct assistant to start engine and allow air system to build to normal operating
pressure.
6. Compare test gauge reading with gauge readings on instrument panel.
a. If readings compare (below 80 psi (552 kPa)), perform test 5.
b. If test gauge reads normal operating pressure, test instrument panel gauges for
proper operation. Perform malfunctions 13 and 14.
c. Stop engine, drain air, remove test gauge, and connect outlet line (3).
Check air governor.
1. Replace governor with one known to be good (para. 3-207).
2. Start engine and allow air pressure to reach normal operating pressure.
a. If air pressure is normal, governor was defective.
b. If air pressure remains below 80 psi (552 kPa), air compressor (1) is defective.
Notify DS maintenance.
3. Check primary air system relay valve; perform test 12.

TM 9-2320-272-24-1

Table 2-4. Compressed Air and Brake System Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION

DRAINVALVE SEQUENCE
END OF TESTING!
2-199

TM 9-2320-272-24-1
Table 2-4. Compressed Air and Brake System Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
10. AIR PRESSURE DOES NOT BUILD TO NORMAL OPERATING PRESSURE (ABOVE 80 PSI (552 kPa))
ACCORDING TO GAUGES
Test 1. Inspect for leaks.
Listen and locate leakage.
a. If leakage is indicated, repair or replace lines or fittings as necessary.
b. If no leakage is indicated, perform test 2.
Test 2. Adjust air governor (para. 3-207).
Test 3. Check air compressor for proper operation (malfunction 9, tests 2, 3, and 4).
END OF TESTING!
11. AIR PRESSURE BUILDS SLOWLY (TAKES EXCESSIVE AMOUNT OF TIME TO BUILD TO 100 PSI (690 kPa))
Perform malfunction 10.
END OF TESTING!
12. AIR PRESSURE EXCEEDS MAXIMUM (GAUGES SHOW OVER 130 PSI (896 kPa)), SAFETY VALVE OPENS TO
RELEASE PRESSURE
Test 1. Check for air loss through air accessories. Perform malfunction 20.
Test 2. Check governor signal line (1) for leaks, bends, and clogs.
Step 1. If leaking, bent, or clogged, repair or replace governor signal line (1) (TM 9-243).
Step 2. If not leaking, bent, or clogged, proceed to test 3.
Test 3. Check governor signal line (1) pressure.
Step 1. Stop engine and open all drainvalves (5), in sequence shown, until brake system air
pressure is vented.
Step 2. Close drainvalves (5).
Step 3. Disconnect governor signal line (1) from air governor (2).
Step 4. Connect adapter fitting (4) to air governor (2) and tee (3) to adapter (4).
Step 5. Connect test gauge to tee (3).
Step 6. Direct assistant to start engine and allow air system to build to normal operating
pressure.
Step 7. Compare test gauge reading with gauge readings on instrument panel.
a. If air pressure readings are the same on test and instrument panel gauges, notify DS
maintenance.
b. If air pressure reading is below 80 psi (552 kPa), replace air governor (2)
(para. 3-207).
c. Stop engine, drain air, remove test gauge, and connect signal line (1).

2-200

TM 9-2320-272-24-1

Table 2-4. Compressed Air and Brake System Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION

DRAINVALVE SEQUENCE
END OF TESTING!
2-201

TM 9-2320-272-24-1
Table 2-4. Compressed

Air

and Brake System Troubleshooting (Contd).

MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
13. PRIMARY PRESSURE GAUGE READS NO PRESSURE, LOW PRESSURE, OR BUILDS TO NORMAL OPERATING
PRESSURE SLOWLY. SECONDARY PRESSURE GAUGE READS NORMAL (ENGINE IDLING, BRAKE PEDAL NOT
APPLIED)
Test 1. Check for leaks.
Listen and locate leakage.
a. If leakage is indicated, repair or replace air lines or fittings as necessary.
b. If no leakage is indicated, perform test 2.
Test 2. Check primary air pressure gauge (3).
Step 1. Stop engine and open all drainvalves (1), in sequence shown, until brake system air
pressure is vented.
Step 2. Close drainvalves (1).
Step 3. Disconnect air line (2) from primary air pressure gauge (3).
Step 4. Connect test gauge to air line (2).
Step 5. Direct assistant to start engine and allow air system to build to normal operating
pressure.
Step 6. Check test gauge reading.
a. If test gauge reads normal operating pressure, replace primary air pressure gauge (3)
(para. 3-207).
b. If test gauge reads no pressure, low pressure, or pressure is building slowly, perform
test 3.
c. Stop engine, drain air, remove test gauge, and connect air line (2).
Test 3. Check air pressure at brake pedal valve supply port (7).
Step 1. Stop engine and open all drainvalves (1), in sequence shown, until brake system air
pressure is vented.
Step 2. Close drainvalves (1).
Step 3. Disconnect primary pressure gauge air line (5) from pedal valve (4).
Step 4. Connect test gauge to supply port (6) of pedal valve (4).
Step 5. Direct assistant to start engine and allow air system to build to normal operating
pressure.
Step 6. Check test gauge reading.
a. If test gauge reads normal operating pressure, repair or replace clogged primary
pressure gauge air line (5).
b. If test gauge reads no pressure, low pressure, or pressure is building slowly, perform
test 4.
c. Stop engine, drain air, remove test gauge, and connect air line (5).

2-202

TM 9-2320-272-24-1
Table 2-4, Compressed Air and Brake System Troubleshooting (Contd).

MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION

2-203

TM 9-2320-272-24-1
Table 2-4. Compressed Air and Brake System Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Test 4. Check primary reservoir air pressure.
Step 1. Stop engine and drain primary air reservoir at drainvalve (6).
Step 2. Remove drainvalve (6) from primary drain line (5).
Step 4. Connect test gauge to primary drain line (5).
Step 5. Direct assistant to start engine and allow air system to build to normal operating
pressure.
Step 6. Check test gauge reading.
a. If test gauge reads normal operating pressure, stop engine, drain air, remove test
gauge, connect drain line (5), and perform test 5.
b. If test gauge reads no pressure, low pressure, or pressure is building slowly, perform
test 6. Remove test gauge and install drainvalve (6) in primary drain line (5).
Test 5. Check primary air system supply line (3) from primary air reservoir to brake pedal valve (1).
Step 1. Stop engine and open remaining drainvalves (7), in sequence shown, until brake system
air pressure is vented.
Step 2. Disconnect primary air system supply line (3) from brake pedal valve fitting (4) and
connect test gauge to supply line (3).
Step 3. Direct assistant to start engine and allow air system to build to normal operating
pressure.
Step 4. Check test gauge reading.
a. If test gauge reads normal operating pressure, replace brake pedal valve (1)
(para. 3-197 or 3-198).
b. If test gauge reads no pressure, low pressure, or pressure is building slowly, repeat
steps 1 and 2, reinstall primary air system supply line (3), and proceed to
test 6.
Test 6. Check one-way check valve (2).
Step 1. Stop engine and open all drainvalves (6) and (7) until brake system air pressure is
vented.
Step 2. Remove one-way check valve (2) (para. 3-186).
Step 3. Inspect check valve (2) for clogging and damage.
a. If clogging or damage is indicated, replace defective one-way check valve (2)
(para. 3-186).
b. If no clogging or damage is present, repair or replace clogged primary air supply
line (3).

2-204

TM 9-2320-272-24-1

Table 2-4. Compressed Air and Brake System Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION

END OF TESTING!
2-205

TM 9-2320-272-24-1
Table 2-4. Compressed Air and Brake System Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
14. SECONDARY PRESSURE GAUGE READS NO PRESSURE, LOW PRESSURE, OR BUILDS TO NORMAL
OPERATING PRESSURE SLOWLY. PRIMARY PRESSURE GAUGE READS NORMAL (ENGINE IDLING, BRAKE
PEDAL NOT APPLIED)
Test 1. Perform malfunction 13, test 1.
Test 2. Check secondary air pressure gauge (3).
Step 1. Stop engine and open all drainvalves (1), in sequence shown, until brake system air
pressure is vented.
Step 2. Close drainvalves (1).
Step 3. Disconnect air line (2) from secondary air pressure gauge (3).
Step 4. Connect test gauge to air line (2).
Step 5. Direct assistant to start engine and allow air system to build to normal operating
pressure.
Step 6. Check test gauge reading.
a. If test gauge reads normal operating pressure, replace secondary air pressure
gauge (3) (para. 3-87).
b. If test gauge reads no pressure, low pressure, or pressure is building slowly, perform
test 3.
c. Stop engine, drain air, remove test gauge, and connect air line (2).

DRAINVALVE SEQUENCE

2-206

TM 9-2320-272-24-1
Table 2-4. Compressed Air and Brake System Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Test 3. Check air pressure at brake pedal valve supply port (5).
Step 1. Stop engine and open all drainvalves (1), in sequence shown, until brake system air
pressure is vented.
Step 2. Close drainvalves (1).
Step 3. Disconnect secondary pressure gauge air line (6) from pedal valve supply port (5).
Step 4. Connect test gauge to supply port (5) of pedal valve (4).
Step 5. Direct assistant to start engine and allow air system to build to normal operating
pressure.
Step 6. Check test gauge reading.
a. If test gauge reads normal operating pressure, repair or replace clogged air line (6) to
secondary air pressure gauge (3) on instrument panel.
b. If test gauge reads no pressure, low pressure, or pressure is building slowly, perform
test 4.

2-207

TM 9-2320-272-24-1

Table 2-4. Compressed Air and Brake System Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Test 4.
Step
Step
Step
Step

Check secondary reservoir air pressure.
1. Stop engine and drain secondary air reservoir at drainvalve (4).
2. Remove drainvalve (4) from secondary drain line (6).
3. Connect test gauge to secondary drain line (6).
4. Direct assistant to start engine and allow air system to build to normal operating
pressure.
Step 6. Check test gauge reading.
a. If test gauge reads normal operating pressure, perform test 5.
b. If test gauge reads no pressure, low pressure, or pressure is building slowly,
perform test 6.
c. Stop engine, drain air, remove test gauge, and install drainvalve (4).
Test 6. Check supply line (1) from secondary air reservoir to brake pedal valve.
Step 1. Stop engine and open all drainvalves (3), (4), and (5), in sequence shown, until brake
system air pressure is vented.
Step 2. Disconnect secondary air system supply line (1) from brake pedal valve fitting (2) and
connect test gauge to supply line (1).
Step 3. Direct assistant to start engine and allow air system to build to normal operating
pressure.
Step 4. Check test gauge reading.
a. If test gauge reads normal operating pressure, replace brake pedal valve
(para. 3-197 or 3-198).
b. If test gauge reads no pressure, low pressure, or pressure is building slowly, repeat
steps 1 and 2, install secondary air system supply line (1), and proceed to
test 6.
Test 6. Check one-way check valve.
Step 1. Stop engine and open all drainvalves (3), (4), and (5) in sequence shown, until brake
system air pressure is vented.
Step 2. Remove one-way check valve (para. 3-186).
Step 3. Inspect check valve for clogging and damage.
a. If clogging or damage is indicated, replace defective one-way check valve
(para. 3-186).
b. If no clogging or damage is present, repair or replace clogged secondary air supply line (1).
END OF TESTING!
15. PRIMARY AIR SYSTEM FAILS TO MAINTAIN PRESSURE (NO MAJOR LEAKS, AIR CAN BE HEARD ESCAPING
INTO AIR INTAKE STACK, PARKING BRAKE APPLIED)
Perform malfunction 3, test 2.
END OF TESTING!
16. SECONDARY AIR SYSTEM FAILS TO MAINTAIN PRESSURE (NO MAJOR LEAKS, AIR CAN BE HEARD
ESCAPING INTO AIR INTAKE STACK, PARKING BRAKE APPLIED)
Test 1. Check secondary relay valve. Perform malfunction 3, tests 14 and 15.
Test 2. Check brake pedal valve. Perform malfunction 14, test 3.

2-208

TM 9-2320-272-24-1

Table 2-4. Compressed Air and Brake System Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION

DRAINVALVE SEQUENCE

END OF TESTING!

2-209

TM 9-2320-272-24-1
Table 2-4. Compressed Air and Brake System Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
17. WARNING BUZZER FAILS TO SOUND OR FAILS TO SHUT OFF ON LOW PRESSURE (BELOW 55-65 PSI
(379-448 kPa)), AIR PRESSURE SYSTEM OPERATING NORMALLY
See Electrical Troubleshooting, para. 2-22.
END OF TESTING!
18. SPRING BRAKES DO NOT RELEASE (VEHICLE BRAKES GRAB OR DRAG)
NOTE
If only one spring brake chamber fails to release, perform
malfunction 5.
Test 1. Isolate malfunction.
Full out emergency spring brake release control (1) and move vehicle forward to determine if
spring brakes release.
a. If spring brakes release, perform test 2.
b. If spring brakes do not release, perform tests 2, 3, and 4.
Test 2. Check supply pressure to parking brake valve (4).
Step 1. Inspect parking brake valve (4) to determine if mechanical actuator (2) is stuck in
engage position.
a. If actuator (2) is sticking, pull back rubber boot (3) and apply a few drops of light
machine oil (Appendix C, Item 47) to actuator (2).
b. If malfunction continues, go to step 2.
Step 2. Start engine and allow air system to build to normal operating pressure.
WARNING
Loosen supply line at valve very slowly. Stop procedure and
tighten fitting of supply line the moment air begins to escape.
Injury to personnel may result if line is accidentally disconnected
from valve.
a. Slowly loosen supply line (5) to check for air pressure.
b. If pressure is not present, proceed to test 3.
c. If pressure is present, proceed to test 4.

2-210

TM 9-2320-272-24-1
Table 2-4. Compressed Air and Brake System Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Test 3. Check quick-release valve (10).
With engine idling and parking brake released, listen for sounds of air escaping through air
intake stack (7).
a. If escaping air is present, replace quick-release valve (10) (para. 3-216).
b. If escaping air is not present, inspect line (9) between quick-release valve (10) and
doublecheck valve (8). If clogged, repair or replace line (9). If not clogged, replace
doublecheck valve (8) (para. 3-216).
WARNING
Loosen delivery line at valve very slowly. Stop procedure and
tighten fitting of delivery line the moment air begins to escape.
Injury to personnel may result if delivery line is accidentally
disconnected from valve.
Test 4. Check parking brake valve (4) delivery pressure (supply pressure confirmed in test 2). With
engine running and parking brake released, slowly loosen delivery line (6).
a. If escaping air is not present, adjust or replace parking brake valve (4) (para. 3-194).
b. If escaping air is present, spring brake diaphragms are defective. Notify DS
maintenance.

END OF TESTING!
2-211

TM 9-2320-272-24-1
Table 2-4. Compressed Air and Brake System Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
19. SPRING BRAKES DO NOT SET (GAUGES AT NORMAL OPERATING PRESSURES, AIR EXHAUSTING NOT
HEARD WHEN PARKING BRAKE APPLIED)
Test 1. Ensure spring brake release control (1) is not out.
Test 2. Ensure parking brake is fully applied.
Test 3. Inspect for crimping in air lines (3) on quick-release valve (2).
a. Replace air line(s) (3) if crimped.
b. If no damage to lines (3) is apparent, perform test 4.
Test 4. Check parking brake valve (4).
Step 1. Disconnect vent line (6) from parking brake valve vent port (5).
Step 2. With engine running and parking brake released, apply parking brake.
Step 3. Feel for air venting through parking brake valve vent port (5).
a. If escaping air is present, replace parking brake valve (4) (para. 3-194).
b. If escaping air is not present, replace quick-release valve (2) (para. 3-216).

2-212

TM 9-2320-272-24-1
Table 2-4. Compressed Air and Brake System Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION

END OF TESTING!

AIR-OPERATED ACCESSORIES
20. ALL AIR-OPERATED ACCESSORIES DO NOT OPERATE (HORN, WINDSHIELD WIPERS, WINDSHIELD WASHERS,
TRANSFER CASE CONTROLS), GAUGES AT NORMAL OPERATING PRESSURE
Check air pressure gauges on instrument panel.
a. If air gauges indicate normal operating pressure, defect is in air lines between the
governor and accessories or in accessories themselves.
b. If gauges indicate excessive air pressure, replace pressure protection valve
(para. 3-187).
END OF TESTING!
21. COOLING FAN DOES NOT OPERATE, ENGINE TEMPERATURE ABOVE 200°F (93°C) AS INDICATED BY
TEMPERATURE GAUGE
Test 1. Check availability of air as indicated on secondary air system pressure gauge.
If air pressure is below normal operating pressure, perform malfunction 14.
Test 2. Check temperature gauge for proper operation. See Electrical Troubleshooting, para. 2-22.
Test 3. Check fan drive clutch actuator for proper operation.
a. Remove and replace fan drive clutch actuator with one known to be good (para. 3-73
or 3-74).
b. If fan remains inoperative, notify DS maintenance.
END OF TESTING!

2-213

TM 9-2320-272-24-1
Table 2-4. Compressed Air and Brake System Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
22. COOLING FAN DOES NOT STOP RUNNING, ENGINE TEMPERATURE BELOW NORMAL OPERATING RANGE
(OVERRIDE BOLT NOT INSTALLED)
Replace fan drive clutch actuator (para. 3-73 or 3-74).
END OF TESTING!
23. FRONT WHEEL DRIVE DOES NOT ENGAGE (FRONT WHEEL DRIVE LOCK-IN SWITCH ENGAGED AND
TRANSFER CASE SHIFT LEVER IN HIGH POSITION)
Test 1. Isolate malfunction.
Shift transfer case shift lever in LOW position.
a. If front wheel drive continues to malfunction, perform test 2.
b. If front wheel drive operates, perform test 5 and 6.
Test 2. Inspect for air leakage in air system.
Step 1. Shift transfer case lever in HIGH position and engage front wheel drive lock-in switch.
Step 2. Start engine and allow air pressure to build to normal operating pressure.
Step 3. Stop engine.
Step 4. Observe secondary air pressure gauge.
a. If gauge indicates a steady loss of air, perform malfunction 14.
b. If gauge indicates no loss of air, proceed to step 5.
Step 5. Shift transfer case lever in LOW position and observe secondary air pressure gauge.
a. If gauge indicates a steady loss of air, perform tests 3 and 4.
b. If gauge indicates no loss of air, perform tests 7 and 8.
Test 3. Inspect air line (2) from actuator valve (1) to transfer case (transfer case shift lever in LOW
position, secondary air pressure gauge indicates steady loss of air).
a. If leakage is present, repair or replace air line (2) (TM 9-243).
b. If no leakage is present at air line (2), perform test 4.
Test 4. Inspect supply line (3) for leakage (transfer case shift lever in LOW position, secondary air
pressure gauge indicates steady loss of air).
a. If leakage is present, repair or replace air line (3) (TM 9-243).
b. If no leakage is present at air line (3), notify DS maintenance of defective actuator
valve (1).
Test 5. Check for air pressure at air line (4) from actuator valve (1) to front wheel drive lock-in
switch (front wheel drive functions with transfer case shift lever in LOW position, but does
not function with transfer case lever in HIGH position and front wheel drive lock-in switch
engaged ).
Step 1. Disconnect air line (4) from actuator valve (1) and connect test gauge to air line (4).
Step 2. Start engine, place transfer case shift lever in HIGH position, and engage front wheel
drive lock-in switch.
Step 3. Observe test gauge.
a. If air pressure is not indicated, perform test 6.
b. If air pressure is present, notify DS maintenance of defective actuator valve (1).
c. Stop engine, drain air, remove test gauge, and connect air line (4).

2-214

TM 9-2320-272-24-1
Table 2-4. Compressed Air and Brake System Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION

2-215

TM 9-2320-272-24-1
Table 2-4. Compressed Air and Brake System Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Test 6. Check for air pressure at front wheel drive lock-in switch (2).
Step 1. Disconnect air line (1) from front wheel drive lock-in switch (2) and connect test
gauge to front wheel drive lock-in switch (2).
Step 2. With engine at idle, ensure transfer case shift lever is in HIGH position, and engage
front wheel drive lock-in switch.
Step 3. Observe test gauge.
a. If air pressure is not indicated, replace front wheel drive lock-in switch (2)
(para. 3-101).
b. If air pressure is present, repair or replace air line (1).
Test 7. Check for air pressure from actuator valve air delivery line (4) at transfer case (supply
pressure normal).
Step 1. Disconnect air delivery line (4) and connect test gauge to air line (4).
Step 2. With engine at idle, place transfer case shift lever in LOW position.
Step 3. Observe test gauge.
a. If air delivery pressure is normal, notify DS maintenance that transfer case does not
engage front wheel drive.
b. If air delivery pressure is below normal, perform test 8.
c. Stop engine, drain air, remove test gauge, and connect delivery line (4).
Test 8. Check air pressure at actuator valve (3) (supply pressure normal).
Step 1. Disconnect air delivery line (4) at actuator valve (3) and connect test gauge to air
delivery port (5).
Step 2. With engine at idle, place transfer case shift lever in LOW position.
Step 3. Observe test gauge.
a. If air delivery pressure is normal, repair or replace blocked air delivery line (4).
(TM 9-243).
b. If air delivery pressure is below normal, actuator valve (3) is defective. Notify DS
maintenance.

2-216

TM 9-2320-272-24-1
Table 2-4. Compressed Air and Brake System Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION

END OF TESTING!
2-217

TM 9-2320-272-24-1
Table 2-4. Compressed Air and Brake System Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
24. HORN DOES NOT WORK (GAUGES AT NORMAL OPERATING PRESSURE, WARNING BUZZER NOT
SOUNDING)
Step 1. Check air supply at air electric valve (1).
Step 2. Loosen supply line (2) slowly.
a. If air is not heard escaping, repair or replace supply line (2) (TM 9-243).
b. If air is heard escaping, perform Electrical Troubleshooting, para. 2-22.

END OF TESTING!

2-218

TM 9-2320-272-24-1

2-24. STE/ICE TROUBLESHOOTING (SIMPLIFIED TEST EQUIPMENT FOR INTERNAL
COMBUSTION ENGINES)
a. General. This section is applicable only if STE/ICE is available. This section contains information
and tests which may be used with STE/ICE to locate malfunctions that may develop in the vehicle. The tests
can be used during troubleshooting, Preventive Maintenance Checks and Service (PMCS), or after replacing
parts to isolate malfunctions, anticipate failures, and ensure that proper repairs have been made.
STE/ICE is used primarily with the vehicle electrical system. These tests cannot cover all possible
troubles which may occur. If a particular malfunction is not covered, refer to Electrical Troubleshooting,
para. 2-22, and locate the troubleshooting procedure for the malfunction observed. To obtain the maximum
number of observed symptoms of the malfunction, question the operator.
b. STE/ICE Chain Index. PMCS (para. 2-12) contains a list of various troubles which may occur
during operation or inspection of the vehicle. When one of the malfunctions listed occurs, the mechanic
proceeds to the associated STE/ICE Chain Index.
c. Engine Chain Indexes. Tables 2-5 and 2-6 provide indexes for GO and NO-GO test chains for
M939/A1/A2 series vehicles. The test chains are presented on the pages which follow.
NOTE
Use vehicle entry 06 on test select switches for M939/A1 series
vehicles; 31 for M939A2 series vehicles.
Table 2-5. Go-Chain Test Index, Combined Mode Chain.
GO
TEST
NUMBER
GO1
GO2
GO3
GO4
GO5
GO6
GO7
GO8
—

MODE
DCA
TK
TK
DCA
DCA
DCA
DCA
DCA
—

TEST TITLE
VTM Connections and Checkout
First Peak Test - Starter Current
Engine Start - Lubrication Check
Charging Circuit and Battery Voltage Test
Engine Warmup/Coolant Check/Oil Pressure Test
Governor Check/Power Test
Idle Speed/Governor Check
Compression Unbalance Test
DC Voltage Test

PAGE
NUMBER
2-220
2-225
2-227
2-230
2-232
2-234
2-236
2-237
2-239

Table 2-6. No-Go-Chain Test Index, Combined Mode Chain.

NO-GO
TEST
NUMBER
NG05
NG20
NG30
NG31
NG50
NG80
NG81
NG90
NG130

MODE

TEST TITLE

PAGE
NUMBER

TK
DCA
DCA
DCA
DCA
DCA-TK
DCA
DCA
DCA

Low Oil Pressure Check
No Crank - No Start
Engine Crank - No Start
Gauge Test
Charging Circuit Tests
Starter Circuit Tests
Battery Tests
Governor/Power Test Fault Isolation
Engine Tightness Test

2-241
2-243
2-244
2-247
2-249
2-250
2-255
2-261
2-266

2-219

TM 9-2320-272-24-1

Table 2-5. STE

2-220

TM 9-2320-272-24-1

Table 2-5. STE

TM 9-4910-571-12&P

TM 9-4910-571-12&P

TM 9-4910-571-12&P

2-221

TM 9-2320-272-24-1

Table 2-5. STE

2-222

TM 9-2320-272-24-1

Table 2-5. STE

TM 9-4910-571-12&P

2-223

TM 9-2320-272-24-1

Table 2-5. STE

TM 9-4910-571-12&P

2-224

TM 9-2320-272-241-1

Table 2-5. STE

TM 9-4910-571-12&P

2-225

TM 9-2320-272-24-1

Table 2-5. STE

2-226

TM 9-2320-272-24-1

Table 2-5. STE

LO 9-2320-272-12
272-12

TM 9-2320-272-10

2-227

TM 9-2320-272-24-1

Table 2-5. STE

2-228

TM 9-2320-272-24-1

tABLE 2-5. STE

para. 2-22

2-229

TM 9-2320-272-24-1

tABLE 2-5. STE

para. 2.22

2-230

TM 9-2320-272-24-1

Table 2-5. STE

para. 3-79, 81.

para. 2-22

2-231

TM 9-2320-272-24-1

Table 2-5. STE

para. 2-21

2-232

TM 9-2320-272-24-1

Table 2-5. STE

para. 2-22

2-233

TM 9-2320-272-24-1

Table 2-5. STE

2-234

TM 9-2320-272-24-1

Table 2-5. STE

2-235

TM 9-2320-272-24-1

Table 2-5. STE

2-236

TM 9-2320-272-24-1

Table 2-5. STE

2-237

TM 9-2320-272-24-1

Table 2-5. STE

2-238

TM 9-2320-272-24-1
TM 9-2320-272-24-1

Table
Table2-5.
2-5.STE
STE

2-239
2-239

TM 9-2320-272-24-1

Table 2-5. STE

2-240

TM 9-2320-272-24-1

Table 2-6. STE

TM 9-4910-571-12&P

2-241

TM 9-2320-272-24-1

Table 2-6. STE

LO 9-2320-272-12

para. 2-21

2-242

TM 9-2320-272-24-1

Table 2-6. STE

para. 3-82

para. 3-82

2-243

TM 9-2320-272-24-1

Table 2-6. STE

TM 9-2320-272-10

2-244

TM 9-2320-272-24-1

Table 2-6. STE

TM 9-4910-571-12&P

TM 9-2320-272-10

para. 2-22

2-245

TM 9-2320-272-24-1

Table 2-6. STE

para 3-30
para. 2-21

2-246

TM 9-2320-272-24-1

Table 2-6. STE

2-247

TM 9-2320-272-24-1

Table 2-6. STE

para. 3-93

para 2-22

2-248

TM 9-2320-272-24-1

Table 2-6. STE

para. 2-21

para. 3-70 or 3-71

para. 3-131

para. 3-79 or 3-80

2-249

TM 9-2320-272-24-1

Table 2-6. STE

TM 9-4910-571-12&P
12&P

2-250

TM 9-2320-272-24-1

Table 2-6. STE

para.
3-82

2-251

TM 9-2320-272-24-1

Table 2-6. STE

2-252

TM 9-2320-272-24-1

Table 2-6. STE

2-253

TM 9-2320-272-24-1

Table 2-6. STE

para. 3-82

2-254

TM 9-2320-272-24-1

Table 2-6. STE

TM 9-4910-571-12&P

2-255

TM 9-2320-272-24-1

Table 2-6. STE

2-256

TM 9-2320-272-24-1

Table 2-6. STE

TM 9-4910-571-12&P

2-257

TM 9-2320-272-24-1

Table 2-6. STE

TM 9-4910-571-12&P

2-258

TM 9-2320-272-24-1

Table 2-6. STE

TM 9-4910-571-12&P
12&P

2-259

TM 9-2320-272-24-1

Table 2-6. STE

TM 9-6140-200-14

para. 3-125

2-260

TM 9-2320-272-24-1

Table 2-6. STE

para. 3-13 or 3-14

para. 3-15

2-261

TM 9-2320-272-24-1

Table 2-6. STE

para. 3-15

TM 9-4910-571-12&P
12&P

2-262

TM 9-2320-272-24-1

Table 2-6. STE

2-263

TM 9-2320-272-24-1

Table 2-6. STE

2-264

TM 9-2320-272-24-1

Table 2-6. STE

2-265

TM 9-2320-272-24-1

Table 2-6. STE

para. 3-82

2-266

TM 9-2320-272-24-1

2-25. CENTRAL

WARNING
Operation of a deadlined vehicle, without preliminary inspection,
may cause injury to personnel and/or damage to equipment.
NOTE
Prior to troubleshooting tests, vehicle air pressure must be at
operating level.
Notify DS maintenance if corrective action does not correct the
malfunction.
a. Troubleshooting procedures in this section are organized in a step-by-step format that directs tests
and inspections toward the source of a problem and a successful solution.
b. The Symptom Index, used in conjunction
with the Functional Troubleshooting Diagram (Figure 2-1), is designed to direct the technician to the
appropriate troubleshooting section where specific problems and solutions are listed.
NOTE
Repair of CTIS wiring harness is not recommended. However,
connectors are available for repair. Refer to para. 3-131 for wiring
harness repair procedures.
c. For most system components connected by wiring or pneumatic tubing, intermittent malfunctions
are the most difficult to correct. In many instances, erratic operation can be traced to faulty electrical or
pneumatic connections. If a symptom description of the malfunction cannot be found in the Symptom Index,
checking the continuity and integrity
of all connections is the first step to finding
the problem.
d. Before taking any action to correct a possible malfunction, the following rules should be followed:
(1) Question operator to obtain any information that might help determine the cause of the
problem.
(2) Never overlook the chance that the problem could be of simple origin and could be corrected
with minor adjustment.
(3) Use all senses to observe and locate troubles.
(4) Use test instruments or gages to help determine and isolate the problem.
(5) Always isolate the system where mal-function occurs and then locate the defective component.
e. This section cannot list all mechanical malfunctions that may occur. If a malfunction occurs that is
not listed in table Central Tire Inflation System (CTIS) Troubleshooting Symptom Index, notify direct
support maintenance.

2-267

TM 9-2320-272-24-1

CENTRAL TIRE INFLATION SYSTEM (CTIS) TROUBLESHOOTING SYMPTOM INDEX
MALFUNCTION
NO.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.

MALFUNCTION

TROUBLESHOOTING
PROCEDURE
PAGE

Two pressure modes indicated with steady mode lights. . . . . . . . . . . . . .
Four pressure mode lights flashing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Five indicator lights flashing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
System repeatedly resumes cycling 30 seconds after mode
light stops flashing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
System shuts off during inflation, single mode light continues to flash .
System fails to deflate, partially deflates, or tire pressures are
imbalanced . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Control panel lights work, system fails to inflate or deflate . . . . . . . . . .
Loss of amber warning light and/or overspeed pressure change . . . . . . .
System over-inflates tires . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Slow air recovery or occasional low air warning during braking . . . . . . .

2-269
2-270
2-271
2-273
2-273
2-273
2-274
2-275
2-276
2-276

Figure 2-1. Functional Troubleshooting Diagram - Central Tire Inflation System (CTIS).

2-268

TM 9-2320-272-24-1
Table 2-7. CTIS Troubleshooting.
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
WARNING
Release all air pressure before loosening or removing air system
component(s). Failure to do so may result in injury to personnel.
1. TWO PRESSURE MODES INDICATED WITH STEADY MODE LIGHTS
NOTE
The Electronic Control Unit (ECU) has five pressure mode
settings, with each setting having a mode light. If, during
programmed operation or after manually selecting a pressure
mode setting, two mode lights remain on, the CTIS will discontinue operation. Two steady mode lights indicate that a
particular inflate or deflate sequence has taken longer than the
programmed limits allow, and has shut the system off with air
pressure between the modes, indicated by lights.
If system was inflating when it stopped between modes, perform
tests 1 through 3.
If system was deflating when it stopped between modes,
perform tests 4 and 5.
Test 1. Check air supply to CTIS.
WARNING

Step

Step

Step
Test 2.
Step

Step

Compressed air source will not exceed 30 psi (207 kPa). When
cleaning with compressed air, eyeshields must be worn. Failure to
do so may result in injury to personnel.
1. Inspect air lines between wet tank and pneumatic controller for leaks, cracks, damage,
or restrictions.
a. Check for leaks at connections using soapy water. If leaks are present at connections,
tighten.
b. If leaks are result of cracked, split, damaged, or restricted tubing, replace tubing
(para. 3-452).
c. Disconnect air line at both ends. If air line is clogged, clear with compressed air or
sturdy wire.
d. Connect air line.
2. Determine adequacy of air supply from vehicle air compressor.
Repeat inflation sequence with engine running at 1000 rpm for three to five minutes. If
two steady mode lights persist, refer to Compressed Air and Brake Systems
Troubleshooting (para. 2-23).
3. Check water separator and filter element for clogs and damage. Replace filter element or
water separator if clogged or damaged (para. 3-465 or 3-466).
Check air supply to tires.
1. Inspect air lines between pneumatic controller and quick exhaust valves for leaks,
cracks, damage, or restrictions.
Refer to malfunction 1, test 1, step 1.
2. Inspect air lines between quick exhaust valves and wheels for leaks, cracks, damage, or
restrictions.
2-269

TM 9-2320-272-24-1
Table 2-7. CTIS Doubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Refer to malfunction 1, test 1, step 1.
Step 3. Perform leak test on hub air seals (para. 3-462). Replace faulty air seals
(para. 3-460 or 3-461).
Test 3. Check condition of pneumatic controller.
Listen for clicking noise when selecting mode change. If click is not heard, replace or
repair pneumatic controller (para. 3-454).
Test 4. Determine ability of system to maintain correct deflate control pressure.
WARNING
Compressed air source will not exceed 30 psi (207 kPa). When
cleaning with compressed air, eyeshields must be worn. Failure to
do so may result in injury to personnel.
Step 1. Check quick exhaust valves for obstructions. If clogged, clear with compressed air or
sturdy wire.
Step 2. Check for continuous and audible air flow from relief valve on pneumatic controller
during deflation. If air flow is continuous and audible, replace faulty relief safety
valve(s) (para. 3-455).
Test 5. Determine reason for false indication.
Step 1. Perform leak test on hub air seals (para. 3-462). Replace faulty air seals (para. 3-460 or
3-461).
CAUTION
Turn battery switch to “OFF” position before disconnecting or
connecting ECU wiring harness. Failure to do so may result in
damage to ECU.
Step 2. Disconnect CTIS wiring harness cannon at ECU and measure voltage between pins X
and V on cannon. Turn battery switch to “ON” position and check voltage.
a. If voltage is below 23 volts, replace CTIS wiring harness (para. 3-470).
b. Troubleshoot vehicle electrical system (para. 2-22).
Step 3. Check connection of electrical lead on pressure transducer at pneumatic controller.
Clean and tighten.
Step 4. Replace pressure transducer (para. 3-453).
Step 5. Replace pneumatic controller (para. 3-454).
Step 6. Replace ECU (para. 3-468).
END OF TESTING!
2. FOUR PRESSURE MODE LIGHTS FLASHING
Test 1. Determine which tire(s) is low.
Step 1. Measure and record pressure of each tire (TM 9-2320-272-10). If any tire(s) is
significantly outside limits, determine the cause.
Step 2. Inspect air lines between wheel valve and wheel rim for leaks, cracks, damage, and
restrictions.
Refer to malfunction 1, test 1, step 1.

2-270

TM 9-2320-272-24-1
Table 2-7. CTIS Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Step 3. With wheel valve still connected to tire, disconnect wheel valve and air manifold from
hub, and check for air loss from air manifold. Place air manifold in container of water
and look for air bubbles. Persistent air bubbles from air manifold indicates faulty wheel
valve.
a. If wheel valve does not leak, dry thoroughly and install.
b. If leaking, replace or repair wheel valve (para. 3-456 or 3-457).
Step 4. After correcting malfunction, start engine (TM 9-2320-272-10) and press RUN FLAT to
override ECU warning. System will then equalize all tires and inflate to selected tire
pressure mode.
Test 2. Determine any non-tire related cause of four mode light indication.
Step 1. Inspect air supply lines between pneumatic controller, quick exhaust valves, and each
wheel for leaks, cracks, damage, or restrictions.
Refer to malfunction 1, test 1, step 1.
Step 2. Perform leak test on hub air seals (para. 3-462). Replace faulty air seals
(para. 3-460 or 3-461).
Step 3. Check operation of pneumatic controller by listening for clicking noise when selecting
mode change. If click is not heard, replace or repair pneumatic controller (para. 3-454).
CAUTION
Turn battery switch to “OFF” position before disconnecting or
connecting ECU wiring harness. Failure to do so may result in
damage to ECU.
Step 4. Replace ECU with known good ECU and operate CTIS (para. 3-468).
END OF TESTING!
3. FIVE INDICATOR LIGHTS FLASHING
NOTE
The ECU has a self-diagnostic capability which prevents operation of the CTIS when key elements or components of the system
malfunction. When the ECU shuts down due to such system malfunction, the condition will be indicated by the flashing of all five
mode lights on ECU selector panel. Since it is unlikely that the
CTIS would operate properly, there is no option to override the
ECU until the problem is corrected. An indication of five flashing
lights can be caused by any of four conditions:
Test 1. Check air lines to tires.
Step 1. Inspect air lines between pneumatic controller and quick exhaust valves for leaks,
cracks, damage, and restrictions.
Refer to malfunction 1, test 1, step 1.
Step 2. Inspect air lines between quick exhaust valves and wheels for leaks, cracks, damage,
and restrictions.
Refer to malfunction 1, test 1, step 1.
Step 3. Perform leak test on hub air seals (para. 3-462). Replace faulty air seals
(para. 3-460 or 3-461).

2-271

TM 9-2320-272-24-1
Table 2-7. CTIS Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Test 2. Check for operation of pneumatic controller.
Select a different mode and listen for clicking noise. If click is not heard, repair or
replace pneumatic controller (para. 3-454).
Test 3. Determine if pressure switch circuit is functional.
Step 1. Check connection of electrical lead on pressure switch on wet tank. Clean and tighten.
CAUTION
Turn battery switch to “OFF position before disconnecting or
connecting ECU wiring harness. Failure to do so may result in
damage to ECU.
Step 2. Disconnect CTIS wiring harness cannon at ECU. Disconnect electrical lead at pressure
transducer and check for continuity to ECU cannon. If harness is faulty, repair
connections (para. 3-131) or replace CTIS wiring harness (para. 3-470).
Step 3. Connect multimeter to pressure switch at pin locations A and B. Start engine
(TM 9-2320-272-10) and operate until air pressure gauge, located on instrument
cluster, indicates more than 120 psi. Shut off engine and drain secondary tank
(TM 9-2320-272-10) until air pressure gauge indicates less than 80 psi. Pressure switch
should open (no continuity). If pressure switch remains closed (continuity) with
secondary tank less than 80 psi, replace pressure switch (para. 3-467).
Step 4. With engine running, drain secondary air tank (TM 9-2320-272-10) until air pressure
gage indicates less than 80 psi. If gauge does not reach 120 psi or greater, adjust air
governor (para. 3-207).
Step 5. Connect CTIS wiring harness cannon to ECU. With battery and CTIS switches in “ON”
position, check voltage from ECU to pressure switch. If voltage is less than 23 volts,
replace ECU (para. 3-468).
Step 6. Connect CTIS wiring harness electrical lead to pressure switch.
Test 4. Determine if pressure transducer circuit is functional.
Step 1. Check connection of electrical lead on pressure transducer, located on pneumatic
controller. Clean and tighten.
CAUTION

Step 2.

Step 8.
Step 4.
Step 5.
Step 6.
Step 7.

2-272

Turn battery switch to “OFF” position before disconnecting or
connecting ECU wiring harness. Failure to do so may result in
damage to ECU.
Disconnect CTIS wiring harness cannon at ECU. Disconnect electrical lead at pressure
gage and check for continuity to ECU cannon. If harness is faulty, repair connections
(para. 8-131) or replace CTIS wiring harness (para. 3-470).
Check voltage to ECU from vehicle’s electrical supply.
Refer to malfunction 1, test 5, step 2.
Disconnect CTIS wiring harness electrical lead from pressure transducer.
Check voltage from ECU to pressure transducer. Voltage should be 4.75-5.25 volts.
If voltage is within limits, replace pressure transducer (para. 3-453).
If voltage from ECU to pressure transducer is outside 4.75-5.25 volts, and voltage from
vehicle’s electrical supply to ECU is 23 volts or more, replace ECU (para. 3-468).
Connect CTIS wiring harness electrical lead to pressure transducer.
END OF TESTING!

TM 9-2320-272-24-1
Table 2-7. CTIS Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
4. SYSTEM REPEATEDLY RESUMES CYCLING 30 SECONDS AFTER MODE LIGHT STOPS FLASHING
NOTE
The ECU is programmed to check tire pressures 30 seconds after
completing a pressure changing sequence. The ECU does this to
verify that all wheel valves are properly closed before making
pressure checks at fifteen minute intervals. If the ECU repeatedly
checks pressure 30 seconds after a mode light stops flashing, it is
indicative of one or more tires losing air.
Test 1. Determine if tire(s) is losing air.
Shut off engine (TM 9-2320-272-10) and listen for air leaks.
Refer to malfunction 2, test 1, steps 1 and 2.
Test 2. Determine if wheel valve(s) is closing correctly.
Step 1. If individual tire(s) is low and leaks cannot be traced to faulty air lines, determine if
wheel valve(s) is leaking.
Refer to malfunction 2, test 1, steps 3 and 4.
Step 2. If both tires on same axle are low, check for restricted air line(s) to quick exhaust valve.
Refer to malfunction 1, test 1, step 1.
Step 3. Check quick exhaust valve for restriction.
Refer to malfunction 1, test 4, steps 1 and 2.
Step 4. Run engine at 1000 rpm and select HWY mode. Upon reaching air pressure indicated by
steady mode light reading, shut off engine. Wait for audible air flow from pneumatic
controller to stop.
Step 5. Disconnect and plug air line connected to top of each quick exhaust valve. Check shut-off
function of pneumatic controller by repeating step 4. If shut-off function does not occur,
replace or repair pneumatic controller (pare. 3-454).
Step 6. Connect air lines to top of each quick exhaust valve.
END OF TESTING!
5. SYSTEM SHUTS OFF WRING INFLATION, SINGLE MODE LIGHT CONTINUES TO FLASH
NOTE
If CTIS continuously shuts off air to wheel valves during air
compressor recovery, perform the following teat.
Check for air line leaks.
Inspect air lines from pneumatic controller and quick exhaust valves for leaks, cracks, damage, or
restrictions.
Refer to malfunction 1, test 1, step 1.
END OF TESTING!
6. SYSTEM FAILS TO DEFLATE, PARTIALLY DEFLATES, OR TIRE PRESSURES ARE IMBALANCED
NOTE
During deflation, all tires respond independently, Generally,
failure of the entire system to deflate indicates a control problem.
Failure of an individual tire to deflate indicates a problem at the
wheel.
Test 1. Determine control pressure during deflation.
2-273

TM 9-2320-272-24-1
Table 2-7. CTIS Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Step 1. Inspect relief valve on pneumatic controller. If poppet is stuck out, replace relief valve
(para. 3-455).
Step 2. Determine if quick exhaust valve(s) is malfunctioning.
Refer to malfunction 1, test 4, steps 1 and 2.
Step 8. With CTIS at Hwy air pressure, turn battery switch to “OFF” position. Check for air
leaks from pneumatic controller. If air is leaking, replace or repair pneumatic controller
(para. 3-454).
Step 4. Inspect air lines between pneumatic controller, quick exhaust valves, and wheels for
leaks, cracks, damage, and restrictions.
Refer to malfunction 1, test 1, step 1.
Step 5. Perform leak test on hub air seals (para. 3-462). Replace faulty air seals
(para. 3-460 or 3-461).
Step 6. While operating CTIS, select a mode to cause deflation. As tire deflation occurs, a
small amount of air should escape from relief valve. If no air escapes from relief valve,
pneumatic controller is not functioning properly Replace or repair pneumatic controller
(para. 3-454).
Test 2. Determine if wheel valve(s) is closing properly.
WARNING
Air pressure in tire is released during step 1. Eyeshields must be
worn. Failure to do so may result in injury to personnel.
CAUTION
Do not inflate any tire on the M939A2, including the spare, unless
external air source is known to be as clean and dry as air supplied
by vehicle. If in doubt, use vehicle’s air supply. Contaminated air
may disable the CTIS.
Step 1. Check for obstructed air flow between wheel valve and wheel.
a. Manually inflate any tire that does not deflate properly to 80 psi (552 kPa).
b. Disconnect hose assembly from wheel valve. Note consistency of air flow from hose
connected to wheel. If air flow varies, or is intermittent, sufficient water has collected
in tire to cause icing of air passage. (This can happen even at temperatures above
freezing.)
c. Repeatedly till tire with dry air and deflate until flow from hose connected to wheel
is consistent.
d. Connect hose assembly to wheel valve.
Step 2. Remove filter from wheel valve and replace filter if obstructed (refer to Chapter 2,
PMCS).
Step 3. Retest system by performing step 1. If not operational, replace wheel valve (para. 3-456
or 3-457).
END OF TESTING!
7. CONTROL PANEL LIGHTS WORK, SYSTEM FAILS TO INFLATE OR DEFLATE
Test 1. Determine adequacy of air supply to CTIS.
Refer to malfunction 1, test 1, steps 1 and 2.
2-274

TM 9-2320-272-24-1
Table 2-7. CTIS Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
CAUTION

Test 2.

Test 3.
Test 4.

8. LOSS OF

Test 1.
Step
Step

Step

Turn battery switch to “OFF” position before disconnecting or
connecting ECU wiring harness. Failure to do so may result in
damage to ECU.
Check connections to pneumatic controller solenoids.
Disconnect CTIS wiring harness cannon from ECU, and disconnect connector from
solenoid. Check for continuity. If harness is faulty, repair connections (para. 3-131) or
replace CTIS wiring harness (para. 3-470).
Check for operation of pneumatic controller.
Refer to malfunction 3, test 2.
Determine if pressure switch is functional.
Refer to malfunction 3, test 3, steps 1 through 3.
END OF TESTING!
AMBER WARNING LIGHT AND/OR OVERSPEED PRESSURE CHANGE
NOTE
The CTIS incorporates an overspeed warning and an automatic
pressure increase to prevent operation of the vehicle with
insufficient tire pressure. This system incorporates a sensor to
measure vehicle speed, a panel mounted flashing light, and a
connection to the vehicle blackout lights to prevent flashing of the
amber warning light when the vehicle is operating under blackout
conditions. The ECU periodically measures the speed of the
vehicle and compares the speed to programmed limits. If these
limits are exceeded, the warning light and automatic pressure
increase functions are actuated.
Determine condition of warning light.
1. Ensure vehicle blackout light switch is “OFF.” If warning light does not flash, replace
lamp with known good lamp.
2. Select EMERGENCY setting on ECU to cause CTIS to deflate. Amber warning light
should flash as soon as emergency pressure is obtained (steady emergency mode light).
Amber warning light should go out when blackout switch is turned on.
NOTE
The ECU limits time spent in the EMERGENCY mode to ten
minutes. Emergency mode must be re-selected to maintain correct
test conditions.
3. If warning light did not flash in step 2, disconnect blackout wire (wire #463) from CTIS
wiring harness. If this causes amber warning light to flash, check vehicle wiring harness
from source of blackout signal. Repair vehicle wiring harness connections as necessary
(para. 3-131).

2-275

TM 9-2320-272-24-1
Table 2-7. CTIS Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
CAUTION
Turn battery switch to “OFF” position before disconnecting or
connecting ECU wiring harness. Failure to do so may result in
damage to ECU.
Step 4. If disconnecting blackout wire in step 3 did not cause amber warning light to flash,
check CTIS wiring harness for shorts between blackout connection and ECU. If CTIS
wiring harness is faulty, repair connections (para. 3-131) or replace CTIS wiring harness
(para. 3-470).
Step 5. Replace ECU with known good ECU (para. 3-468).
Test 2. Determine condition of speed transducer.
Step 1. Check for continuity between ECU and speed signal generator connector. If CTIS wiring
harness is faulty, repair connections (para. 3-131) or replace CTIS wiring harness (para.
3-460).
Step 2. Replace speed signal generator (para. 3-471).
Step 3. Replace ECU with known good ECU (para. 3-468).
END OF TESTING!
9. SYSTEM OVER-INFLATES TIRES
CAUTION
When vehicle is connected to an external air source, ensure that
air is clean and dry. Dirty and wet air may result in CTIS
malfunctions.
Do not operate CTIS while vehicle is connected to an external
air source. This may result in over-inflation or damage to tires.
NOTE
The ECU is programmed in conjunction with vehicle air
compressor output. This procedure requires air source supplied
by vehicle for accurate diagnosis.
Determine accuracy of system pressure reading.
Manually balance tire pressures with external air source. Remove external air source
and run CTIS. Check operation of pressure transducer.
Refer to malfunction 3, test 4, steps 1 through 7.
END OF TESTING!
10. SLOW AIR RECOVERY OR OCCASIONAL LOW AIR WARNING DURING BRAKING
Determine if pressure switch has failed in closed position,
Step 1. Check CTIS wiring harness for continuity between pressure switch and ECU cannon.
Refer to malfunction 3, test 3, steps 1 and 2.
Step 2. Check pressure switch for continuity.
Refer to malfunction 3, test 3, steps 3 through 6.
END OF TESTING!

2-276

TM 9-2320-272-24-1

CHAPTER 3
UNIT MAINTENANCE
Section I.
Section II.
Section III.
Section IV.
Section V.
Section VI.
Section VII.
Section VIII.
Section IX.
Section X.
Section XI.
Section XII.
Section XIII.
Section XIV.
Section XV.
Section XVI.

Engine System Maintenance (3-1)
Air Intake System Maintenance (3-41)
Fuel System (3-55)
Exhaust System Maintenance (3-139)
Cooling System Maintenance (3-149)
Electrical System Maintenance (3-220)
Transmission Maintenance (3-353)
Propeller Shafts, Axles, and Suspension System Maintenance (3-403)
Compressed Air and Brake System Maintenance (3-476)
Wheels, Hubs, Drums, and Steering Maintenance (3-615)
Frame Maintenance (3-683)
Body, Cab, and Accessories Maintenance (3-730)
Winch and Power Takeoff Maintenance (3-823)
Special Purpose Bodies Maintenance (3-868)
Special Purpose Kits (3-968)
Central Tire Inflation System (CTIS) Maintenance (3-1231)

Section I. ENGINE SYSTEM MAINTENANCE
3-1. ENGINE

PARA.
NO.

TITLE

PAGE
NO.

3-2.
3-3.
3-4.
3-5.
3-6.
3-7.
3-8.
3-9.
3-10.

Crankcase Breather and Tube Maintenance
Oil Dipstick Tube Maintenance
Engine Oil Cooler (M939A2) Maintenance
Engine Oil Filter Maintenance
Valve Cover (M939A2) Maintenance
Oil Pump Pickup Hose Maintenance
Oil Pump Return Hose Maintenance
Front Sump Tube Maintenance
Engine AOAP Valve Maintenance

3-2
3-8
3-12
3-18
3-22
3-32
3-34
3-36
3-38

3-1

TM 9-2320-272-24-1

3-2. CRANKCASE

THIS TASK
a. Breather
b. Breather
c. Cleaning

COVERS:
and Tube Removal (M939/A1)
Tube Removal (M939A2)
and Inspection

d. Breather Tube Installation (M939A2)
e. Breather and Tube Installation (M939/A1)

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Locknut (M939/A1 early model engines)
(Appendix D, Item 272)
Lockwasher (M939/A1 early model engines)
(Appendix D, Item 354)
Drycleaning solvent (Appendix C, Item 71)
Rags (Appendix C, Item 58)
Adhesive sealant (M939/A1)
(Appendix C, Item 4)
Antiseize compound (Appendix C, Item 10)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Hood raised and secured (TM 9-2320-272-10).
Right splash shield removed (M939/A1)
(TM 9-2320-272-10).
Coolant drained (M939A2) (para. 3-53).
GENERAL SAFETY INSTRUCTIONS
Drycleaning solvent is flammable and toxic. Do not
use near an open flame.

NOTE
References to early model engines refer to engines with a serial
number before 11246664 used in M939/A1 series vehicles.

1.
2.
3.
4.
5.

6.

3-2

NOTE
Perform steps 1 and 2 on M939/A1 vehicles with late model
engines and steps 3 through 5 on M939/A1 vehicles early model
engines.
Remove four clamps (2), two breather hoses (3), and breather tube (4) from crankcase breather (1)
and elbow (5).
Remove elbow (5) from air connector (6).
Remove locknut (17), screw (13), and clamp (16) from mounting bracket (12) and breather tube (8).
Discard locknut (17).
Remove screw (15), lockwasher (14), and mounting bracket (12) from engine (11). Discard
lockwasher (14).
Remove two clamps (9), breather hose (10), and breather tube (8) from crankcase breather (1).
CAUTION
Perform step 6 only if crankcase breather requires replacement.
Removal will permanently damage breather, and it must be
replaced.
Mark position of crankcase breather (1) on valve cover (7) and remove breather (1).

TM 9-2320-272-24-1

3-2. CRANKCASE

3-3

TM 9-2320-272-24-1

3-2. CRANKCASE

1.
2.
3.
4.

Remove
Remove
Remove
Remove

four hose clamps (11) and two hoses (12) from aftercooler tubes (8) and aftercooler (13).
two screws (4), clamps (5), and breather tube (6) from valve cover (7).
two hose clamps (3) and hose (2) from vent connector (1) and breather tube (6).
hose clamp (9) and hose (10) from breather tube (6).

WARNING

1.

2.
3.
4.

1.
2.
3.
4.

Drycleaning solvent is flammable and toxic. Do not use near an
open flame and always have a fire extinguisher nearby when
solvents are used. Use only in well-ventilated places, wear
protective clothing, and dispose of cleaning rags in approved
container. Failure to do this may result in injury to personnel
and/or damage to equipment.
Clean breather tube (6) with drycleaning solvent and dry with clean rag.
NOTE
Perform step 2 for M939/A1 series vehicles and only if previously
removed.
Clean crankcase breather (14) and mating surface on valve cover (16).
Inspect breather tube (6) for obstructions and kinks that could cause restrictions. Remove
obstructions; replace if kinked.
Inspect hose (10) for obstructions, flat spots, or other deformities that could cause restrictions.
Remove obstructions; replace hose (10) if bent, deformed, or torn.

Install
Install
Install
Install

hose (10) on breather tube (6) with clamp (9).
hose (2) on breather tube (6) and vent connector (1) with two clamps (3).
two clamps (5) on valve cover (7) with two screws (4).
two hoses (12) on aftercooler (13) and aftercooler tubes (8) with four clamps (11).
CAUTION
For M939A2 series vehicles, ensure drainvalve on aftercooler is
open when filling cooling system. Failure to do so may result in
damage to equipment.

3-4

TM 9-2320-272-24-1

3-2. CRANKCASE

3-5

TM 9-2320-272-24-1

3-2. CRANKCASE

1.
2.

3.
4.
5.
6.
7.

NOTE
Perform steps 1 and 2 if breather was removed.
Apply adhesive sealant to mating surfaces of crankcase breather (1) and valve cover (7).
Install crankcase breather (1) on valve cover (7) and align with mark.
NOTE
Perform steps 3 and 4 on vehicles with late model engines and
steps 5 through 7 on vehicles with early model engines.
Apply antiseize compound to threads of elbow (5) and install on air connector (6).
Install two breather hoses (3) and breather tube (4) on elbow (5) and crankcase breather (1) with four
hose clamps (2).
Install breather hose (10) and breather tube (8) on crankcase breather (1) with two clamps (9).
Install mounting bracket (12) on engine (11) with new lockwasher (14) and screw (15).
Install clamp (16) on mounting bracket (12) and breather tube (8) with screw (13) and new locknut (17).

M939/A1 LATE MODEL ENGINE
3-6

TM 9-2320-272-24-1

3-2. CRANKCASE

M939/A1 EARLY MODEL ENGINE
FOLLOW-ON TASKS:

Fill coolant to proper level (M939A2) (para. 3-53).
Install right splash shield (M939/A1) (TM 9-2320-272-10).
3-7

TM 9-2320-272-24-1

3-3. OIL

THIS TASK COVERS:
a. Removal (M939/A1)
b. Removal (M939A2)
c. Inspection

d. Installation (M939/A1)
e. Installation (M939A2)

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Lockwasher (M939/A1) (Appendix D, Item 354)
Lockwasher (M939/A1) (Appendix D, Item 358)
Adhesive sealant (M939A2) (Appendix C. Item 5)

1.
2.

EQUIPMENT CONDITION
Hoed raised and secured (TM 9-2320-272-10).
Parking brake set (TM 9-2320-272-10).
Right splash shield removed (TM 9-2320-272-10).

3.
4.

Remove dipstick (1) from dipstick tube (9)
Remove nut (12), lockwasher (11), washer (10), screw (7), and clamp (8) from dipstick tube (9) and
bracket (4). Discard lockwasher (11).
Remove dipstick tube (9) from oil pan (6).
Remove screw (2), lockwasher (3), and bracket (4) from engine block (5). Discard lockwasher (3).

1.
2.

Remove dipstick (14) from dipstick tube (15).
Remove dipstick tube (15) from engine block (5).

1.

Inspect dipstick (1) or (14). Replace if cracked or broken.
NOTE
Perform step 2 for M939/A1 series vehicles.
Inspect rubber compression seal (13) on dipstick (1). Replace dipstick (1) if compression seal (13) is
damaged.

2.

3-8

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P

TM 9-2320-272-24-1
3-3. OIL

3-9

TM 9-2320-272-24-1

3-3. OIL

1.
2.
3.
5.

1.
2.
3.

3-10

Install bracket (8) on engine block (9) with new lockwasher (7) and screw (6).
Install dipstick tube (13) on oil pan (10).
Install clamp (12) on dipstick tube (13) and bracket (8) with screw (11), washer (14), new
lockwasher (15), and nut (16).
Install dipstick (5) in dipstick tube (13).

Apply adhesive sealant to mating surface of oil dipstick tube (2).
Align oil dipstick tube (2) with bore (3) and, using soft-headed hammer, drive oil dipstick tube (2)
until it seats in the bore (3) of engine block (4).
Install dipstick (1) in dipstick tube (2).

TM 9-2320-272-24-1

3-3. OIL

FOLLOW-ON TASKS:

Install right splash shield (TM 9-2320-272-10).
Start engine (TM 9-2320-272-10) and check for oil leaks.
3-11

TM 9-2320-272-24-1

3-4. ENGINE

THIS TASK COVERS:
a. Removal
b. Disassembly
c. Cleaning and Inspection

d. Assembly
e. Installation

INITIAL SETUP:
APPLICABLE MODELS
M939A2
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Torque wrench (Appendix E, Item 144)
Soft-jawed vise
MATERIALS/PARTS
Bypass valve (Appendix D, Item 31)
Gasket (Appendix D, Item 215)
Gasket (Appendix D, Item 230)
O-ring (early model engines only)
(Appendix D, Item 476)
Washer (Appendix D, Item 716)
Antiseize tape (Appendix C, Item 72)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Hood raised and secured (TM 9-2320-272-10).
Right splash shield removed (TM 9-2320-272-10).
Coolant drained (para. 3-53).
Engine oil drained and filter removed (para. 3-5).
Alternator removed (para. 3-80).
GENERAL SAFETY INSTRUCTIONS
Pressure regulator is under spring tension. Use care
when removing plug.

NOTE
References to early model engines refer to engines with a serial
number before 44487830 used in M939A2 series vehicles.

1.

2.
3.
4.

3-12

Loosen clamp (12) and remove hose (13) from nipple (11).
NOTE
Perform step 2 on vehicles with late model engines and step 3 on
early model engines.
Remove oil supply line (1), adapter (2), and O-ring (3) from oil filter head (4). Discard O-ring (3).
Remove oil supply line (1) and elbow (15) from oil filter head (4).
Remove eleven screws (6), clamp (5), wiring harness (7), oil filter head (4), gasket (8), oil cooler
core (9), and gasket (10) from engine block (14). Discard gaskets (8) and (10).

TM 9-2320-272-24-1

3-4. ENGINE

3-13

TM 9-2320-272-24-1

3-4. ENGINE

1.

Install oil filter head (3) in soft-jawed vise.
WARNING

2.
3.
4.

5.
6.

1.
2.
3.
4.

1.
2.
3.
4.
5.
6.

3-14

Pressure regulator is under spring tension. Use care when
removing plug. Failure to do so may result in injury to personnel,
Remove plug (7), washer (6), spring (8), and pressure regulator plunger (9) from port (10) and bore (11).
Discard washer (6).
Remove oil filter adapter (1) from oil filter head (3).
Remove plugs (2) and (4) from oil filter head (3).
CAUTION
When removing bypass valve, be careful not to score oil filter
head. Failure to do so may cause an improper seal resulting in
damage to engine.
Using screwdriver, position blade of screwdriver behind bypass valve (5) and pry bypass valve (5) out
of oil filter head (3). Discard bypass valve (5).
Remove oil filter head (3) from soft-jawed vise.

For general cleaning instructions, refer to para. 2-14.
For general inspection instructions, refer to para. 2-15.
Inspect pressure regulator plunger (9) for freedom of movement in bore (11). Replace plunger (9) if
sticking or binding in bore (11).
Inspect spring (8) for pits and cracks. Replace spring (8) if damaged.

NOTE
Ensure bypass valve is completely seated in oil filter head.
Install oil filter head (3) in soft-jawed vise. Install new bypass valve (5) on oil filter head (3).
Wrap male threads of oil filter adapter (1) and plugs (2), (4), and (7) with antiseize tape.
Install oil filter adapter (1) on oil filter head (3). Tighten oil filter adapter (1) 60 lb-ft (81 N•m).
Install pressure regulator plunger (9), spring (8), new washer (6), and plug (7) in bore (11) at port (10).
Tighten plug (7) 60 lb-ft (81 N•m).
Install plugs (2) and (4) on oil filter head (3).
Remove oil filter head (3) from soft-jawed vise.

TM 9-2320-272-24-1

3-4. ENGINE

3-15

TM 9-2320-272-24-1

3-4. ENGINE

1.
2.
3.
4.
5.

NOTE
If a late model engine oil filter head is to be installed on an
early model engine, the oil supply system must be replaced,
including oil pump, pressure regulator valve, oil supply line.
and elbow.
Perform step 1 if new oil cooler core is being installed.
Perform step 3 on vehicles with late model engines and step 4
on vehicles with early model engines.
Remove two shipping plugs (16) from new oil cooler core (8). Discard shipping plugs (16).
Install new gasket (9), oil cooler core (8), new gasket (7), oil filter head (3), wiring harness (6), and
clamp (4) on engine block (13) with eleven screws (5).
Install new O-ring (15) and adapter (14) on oil filter head (3) and connect oil supply line (1) to
adapter (14).
Install elbow (2) on oil filter head (3) and connect oil supply line (1) to elbow (2).
Install hose (12) on nipple (10) with clamp (11).
CAUTION
When filling cooling system on M939A2 series vehicles, ensure
drainvalve on aftercooler is open. Failure to do so may result in
damage to equipment.

3-16

TM 9-2320-272-24-1

3-4. ENGINE

FOLLOW-ON TASKS: Fill cooling system to proper level (para. 3-53).
Install alternator (para. 3-80).
Install filter and fill engine oil (para. 3-5).
Start engine (TM 9-2320-272-10) and check for leaks.
Install right splash shield (TM 9-2320-272-10).
3-17

TM 9-2320-272-24-1

3-5. ENGINE

THIS TASK COVERS:
a. Draining Oil
b. Oil Filter Removal
c. Filter Shell and Bolt Disassembly (M939/A1)

d. Cleaning and Inspection
e. Filter Shell and Bolt Assembly (M939/A1)
f. Oil Filter Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Torque wrench (Appendix E, Item 144)
MATERIALS/PARTS
Seal (Appendix D, Item 596)
Filter (M939A2) (Appendix D, Item 120)
Gasket (M939/A1) (Appendix D, Item 145)
Kit, filter (M939/A1) (Appendix D, Item 125)
Seal (M939/A1) (Appendix D, Item 594)
Drycleaning solvent (Appendix C, Item 71)
Oil, diesel (Appendix C, Item 41)
Rags (Appendix C, Item 58)

REFERENCES (TM)
LO 9-2320-272-12
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10)
Hood raised and secured (TM 9-2320-272-10).
Right splash shield removed (M939A2)
(TM 9-2320-272-10).
Left splash shield removed (M939/A1)
(TM 9-2320-272-10).
GENERAL SAFETY INSTRUCTIONS
Store and dispose of used oil properly.
Do not perform task when engine is hot or drain
oil when hot.
Drycleaning solvent is flammable and toxic.
When cleaning with compressed air, wear
eyeshield and ensure source pressure does not
exceed 30 psi (207 kPa).

WARNING
Accidental or intentional introduction of liquid contaminants
into the environment is in violation of state, federal, and
military regulations. Refer to Army POL (para. 1-8) for
information concerning storage, use, and disposal of these
liquids. Failure to do so may result in injury or death.
Do not drain oil from engine or remove lines containing oil when
engine is hot. Doing so may result in injury to personnel.
NOTE
References to early model engines refer to engines with a serial
number before 444487830 used in M939A2 series vehicles.

1.
2.
3.

3-18

NOTE
Have adequate drainage container ready to catch oil.
Perform steps 1 and 2 for M939/A1 series vehicles.
Remove drainplug (2) from filter shell (1) and drain oil completely from filter shell (1).
Install drainplug (2) in filter shell (1) and tighten drainplug (2) 25-35 lb-ft (34-47 N•m).
Remove drainplug (4) and seal (5) from oil pan (3) and drain oil. Discard seal (5).

TM 9-2320-272-24-1

3-5. ENGINE

WARNING

4.
5.

Drycleaning solvent is flammable and toxic. Do not use near an
open flame and always have a fire extinguisher nearby when
solvents are used. Use only in well-ventilated places, wear
protective clothing, and dispose of cleaning rags in approved
container. Failure to do this may result in injury to personnel
and/or damage to equipment.
Eyeshields must be worn when cleaning with compressed air.
Compressed air source will not exceed 30 psi (207 kPa). Failure
to do so may result in injury to personnel.
Clean drainplug (4) with drycleaning solvent and wipe area around drain hole (6).
Install new seal (5) and drainplug (4) on oil pan (3). Tighten drainplug (4) 100 lb-ft (136 N•m) on
M939/A1 series vehicles and 60 lb-ft (81 N•m) on M939A2 series vehicles.

3-19

TM 9-2320-272-24-1

3-5. ENGINE

1.
2.
3.

1.
2.

NOTE
Perform steps 1 and 2 for oil filter on M939/A1 series vehicles
and step 3 for oil filter on M939A2 series vehicles.
Support oil filter shell while loosening center bolt. Lightly tap
filter shell with palm of hand to loosen from filter base.
Loosen center bolt (9) until oil filter shell (11) can be removed from filter base (1), and remove oil
filter shell (11) from filter base (1).
Remove oil filter element (3) and seal (2) from oil filter shell (11). Discard oil filter element (3) and
seal (2).
Remove oil filter (13) from adapter (12). Discard oil filter (13).

Remove center bolt retaining pin (4), filter element support (5), gasket (6), washer (7), and
spring (8) from center bolt (9) and oil filter shell (11). Discard gasket (6).
Remove center bolt seal (10) and center bolt (9) from oil filter shell (11). Discard center bolt seal (10).

WARNING

1.
2.
3.
4.
5.

1.
2.

3-20

Drycleaning solvent is flammable and toxic. Do not use near an
open flame and always have a fire extinguisher nearby when
solvents are used. Use only in well-ventilated places, wear
protective clothing, and dispose of cleaning rags in approved
container. Failure to do this may result in injury to personnel
and/or damage to equipment.
Eyeshields must be worn when cleaning with compressed air.
Compressed air source will not exceed 30 psi (207 kPa). Failure
to do 80 may result in injury to personnel.
Clean center bolt (9) and oil filter shell (11) with drycleaning solvent and dry with compressed air.
Inspect center bolt (9). Replace if threads are stripped.
Inspect filter base (1). If cracked, nicked, or threads are stripped, notify DS maintenance.
Inspect filter element support (5). Replace if cracked or grooved.
Inspect spring (8). Replace if cracked or broken.

Install new center bolt seal (10) and center bolt (9) in oil filter shell (11).
Install spring (8), washer (7), new gasket (6), filter element support (5), and center bolt retaining
pin (4) on center bolt (9) and oil filter shell (11).

TM 9-2320-272-24-1

3-5. ENGINE

1.
2.
3.
4.
5.

NOTE
Perform steps 1 through 3 for oil filters on M939/A1 series
vehicles and steps 4 and 5 for oil filters on M939A2 series
vehicles.
Ensure correct filter is used during installation. Filter element
and oil filter shell seal used on the M939/A1 series vehicle
engines are supplied as a kit. Early and late model engines in
M939A2 series vehicles use different filters.
Install new oil filter element (3) in oil filter shell (11).
Install new seal (2) and oil filter shell (11) on filter base (1). Hand-tighten center bolt (9) until oil
filter shell (11) seats in filter base (1).
Tighten center bolt (9) 25-35 lb-ft (34-47 N•m).
Fill new oil filter (13) with clean engine oil and install on adapter (12). Hand-tighten.
Tighten oil filter (13) an additional 3/4 turn.

FOLLOW-ON TASKS:

Fill engine with oil to proper level (LO 9-2320-272-12).
Start engine (TM 9-2320-272-10) and check for leaks.
Check oil level and add oil as necessary (TM 9-2320-272-10).
Install right splash shield (M939A2 only) (TM 9-2320-272-10).
Install left splash shield (M939/A1 only) (TM 9-2320-272-10).
3-21

TM 9-2320-272-24-1

3-6. VALVE

THIS TASK COVERS:
a. Removal
b. Cleaning and Inspection

c. Installation

INITIAL SETUP:
APPLICABLE MODELS
M939A2
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Torque wrench (Appendix E, Item 144)
MATERIALS/PARTS
Gasket (Appendix D, Item 160)
Two locknuts (Appendix D, Item 280)
Six O-rings (Appendix D, Item 427)
Seal (Appendix D, Item 600)
O-ring (Appendix D, Item 431)
Cap and plug set (Appendix C, Item 14)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Hood raised and secured (TM 9-2320-272-10).
Reservoirs drained (TM 9-2320-272-10).
Coolant drained (para. 3-53).
Air cleaner hose removed (para. 3-13).
GENERAL SAFETY INSTRUCTIONS
Drycleaning solvent is flammable and toxic.
Ensure drainvalve on aftercooler is open when
filling cooling system.

CAUTION
Cover turbocharger ports immediately after removing attaching
parts to prevent foreign objects from lodging in blades of
turbocharger.
NOTE
l Tag all lines and connections for later installation.
l Plug all lines when removed to prevent dripping fluids and
contaminated lines.

3-22

TM 9-2320-272-24-1

3-6. VALVE

1.
2.
3.
4.
5.

Disconnect air lines (2) and (4) from elbows (3) and (1).
Remove four clamps (14) and two hoses (15) from aftercooler tubes (11) and aftercooler (16).
Remove two screws (8) and clamps (9) from breather tube (7) and valve cover (10).
Remove clamps (5) and hose (6) from vent connector (17) and breather tube (7).
Remove clamp (12) and hose (13) from breather tube (7).

3-23

TM 9-2320-272-24-1

3-6. VALVE COVER (M939A2) MAINTENANCE (Contd)
6.
7.
8.
9.

3-24

Remove clamps (1) from radiator inlet tube (2), hose (10), and cable (11).
Remove two locknuts (6), washers (5), screws (3), and washers (4) from bracket (9) and inlet tube (2).
Discard locknuts (6).
Loosen clamps (7) and (12) on elbow (8) and hose (13).
Remove radiator inlet tube (2) from elbow (8) and hose (13).

TM 9-2320-272-24-1

3-6. VALVE

10.
11.
12.
13.

Loosen clamps (19), (24), and (26) on hoses (18), (23), and (25).
Remove hoses (17), (18), (23), and (25) from surge tank assembly (15).
Remove nut (20) and screw (14) from surge tank assembly (15) and angle support bracket (21).
Remove two screws (16) and surge tank assembly (15) from exhaust manifold (22).

3-25

TM 9-2320-272-24-1

3-6. VALVE

14.
15.
16.
17.
18.

Loosen four clamps (8) on crossover tube (9) and two hoses (7).
Slide two hoses (7) over crossover tube (9) and remove crossover tube (9) from turbocharger (13) and
aftercooler (15).
Remove six screws (3), O-rings (2), and valve cover (1) from cylinder head (14). Discard O-rings (2).
Turn valve cover (1) upside down, depress locking tabs (6) on vent connector (5), and remove vent
connector (5) and O-ring (4) from valve cover (1). Discard O-ring (4).
Remove filler cap (11) and seal (12) from valve cover (1). Discard seal (12).

WARNING

1.
2.
3.
4.
5.
6.

1.

2.
3.
4.

5.

3-26

Drycleaning solvent is flammable and toxic. Do not use near an
open flame and always have a tire extinguisher nearby when
solvent is used. Use only in well-ventilated places, wear protective
clothing, and dispose of cleaning rags in approved container.
Failure to do this may result in injury to personnel and/or damage
to equipment.
Clean remains of valve cover gasket (16) and sealing compound from valve cover (1) and cylinder
head (14).
Clean breather tube (18) with drycleaning solvent and dry with clean rag.
Inspect breather tube (18) for obstructions or collapsed and bent sections that could cause
restrictions. Remove obstructions or replace breather tube (18) if bent.
Inspect hoses (19) and (20) for obstructions, tears, flat spots, or other deformities that could cause
restrictions. Remove obstructions or replace hoses (19) and (20) if torn or deformed.
Inspect vent connector (5). Replace if nicked, cracked, or damaged.
Inspect valve cover (1) for distortion, cracks, or nicks in casting that would prevent a tight seal.
Replace if damaged.

Install new seal (12) and filler cap (11) on valve cover (1).
CAUTION
Valve cover gasket must extend into overlap area. Trim excess
overlap, and do not stretch valve cover gasket. Damage to gasket
may result.
Turn valve cover (1) upside down and install new valve cover gasket (16) on valve cover (l),
overlapping ends in the overlap area (17). Apply gasket compound to overlap area (17).
Compress locking tabs (6) of vent connector (5), and install new O-ring (4) and vent connector (5) on
valve cover (1).
Install valve cover (1) on cylinder head (14) with six new O-rings (2) and screws (3). Tighten
screws (3) 18 lb-ft (24 N•m).
CAUTION
Ensure covers are removed from turbocharger intake output port
and aftercooler inlet port prior to installing crossover tube. Failure
to do so may cause damage to equipment.
Install crossover tube (9) by sliding two hoses (7) onto turbocharger (13) and aftercooler (15) and
tighten four clamps (8).

TM 9-2320-272-24-1

3-6. VALVE

3-27

TM 9-2320-272-24-1

3-6. VALVE

6.
7.
8.

3-28

Install surge tank assembly (2) on exhaust manifold (9) with two screws (3). Tighten screws (3)
50-55 lb-ft (68-75 N•m).
Install surge tank assembly (2) on angle support bracket (8) with screw (1) and nut (7). Tighten
screw (1) 35-40 lb-ft (47-54 N•m).
Install hoses (4), (5), (10), (12), and (12) on surge tank assembly (2) and tighen clamps (6), (11), and (13).

TM 9-2320-272-24-1

3-6. VALVE

9.
10.
11.

Install radiator inlet tube (14) on hose (26) and elbow (21) and tighten clamps (25) and (20).
Install radiator inlet tube (14) on bracket (22) with two washers (17), screws (16), washers (18), and
new locknuts (19).
Connect hose (23) and cable (24) to inlet tube (14) with tiedown straps (15), as required, to keep
hose (23) and cable (24) clear of moving parts.

3-29

TM 9-2320-272-24-1

3-6. VALVE

12.
13.
14.

15.

3-30

Install breather tube (3) and hose (2) on vent connector (13) with two clamps (1).
Install hose (9) on breather tube (3) with clamp (8).
Install two clamps (5) on breather tube (3) and valve cover (6) with two screws (4).
NOTE
Remove plugs from all lines before making connections. Be
prepared to catch any dripping of’ fluids when lines are uncapped.
Install two hoses (11) on aftercooler (12) and aftercooler tubes (7) with four clamps (10).

TM 9-2320-272-24-1

3-6. VALVE

16.

Connect air lines (17) and (19) to elbows (16) and (18). Secure air lines (17) and (19) to radiator inlet
tube (14) with tiedown straps (15), as required.
CAUTION
Ensure drainvalve on aftercooler is open when filling cooling
system. Failure to do so may result in damage to equipment.

FOLLOW-ON TASKS:

Install air cleaner hose (para. 3-13).
Fill coolant to proper level (para. 3-53).
Start engine (TM 9-2320-272-10) and check for leaks.
Check coolant level and add coolant as necessary (TM 9-2320-272-10).
3-31

TM 9-2320-272-24-1

3-7. OIL

THIS TASK COVERS:
a. Removal
b. Inspection

c. Installation

INITIAL SETUP:
APPLICABLE MODELS
M939/A1
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Torque wrench (Appendix E, Item 146)
MATERIALS/PARTS
Antiseize tape (Appendix C, Item 72)

1.
2.

REFERENCES (TM)
LO 9-2320-272-12
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Hood raised and secured (TM 9-2320-272-10).
Left splash shield removed (TM 9-2320-272-10).
Engine oil drained (para. 3-5).

NOTE
Engine oil pan is mounted with screw-assembled washers on
late model engines.
Have adequate drainage container ready to catch oil.
Remove two screws (6), washers (7), and clamps (5) from oil pump pickup and return hoses (2) and (8)
and engine oil pan (3).
Disconnect oil pump pickup hose (2) from adapter flange (4) and oil pump (1).

Inspect oil pump pickup hose (2). Replace if threads are stripped or hose (2) is cracked or frayed.

1.
2.
3.

3-32

Apply antiseize tape to male pipe threads of oil pump pickup hose (2) and adapter flange (4).
Connect oil pump pickup hose (2) to oil pump (1) and adapter flange (4).
Install two clamps (5) on oil pump pickup and return hoses (2) and (8) and engine oil pan (3) with
two washers (7) and screws (6). Tighten screws (6) 35-40 lb-ft (47-54 N•m).

TM 9-2320-272-24-1

3-7. OIL

FOLLOW-ON TASKS:

Fill engine with oil to proper level (LO 9-2320-272-12).
Start engine (TM 9-2320-272-10) and check for leaks.
Check oil level and add oil as necessary (TM 9-2320-272-10).
Install left splash shield (TM 9-2320-272-10).
3-33

TM 9-2320-272-24-1

3-8. OIL

THIS TASK COVERS:
a. Removal
b. Inspection

c. Installation

INITIAL SETUP:
APPLICABLE MODELS
M939/A1
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Torque wrench (Appendix E, Item 146)
MATERIALS/PARTS
Antiseize tape (Appendix C, Item 72)

1.
2.
3.

REFERENCES (TM)
LO 9-2320-272-12
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Hood raised and secured (TM 9-2320-272-10).
Left splash shield removed (TM 9-2320-272-10).
Engine oil drained (para. 3-5).

NOTE
Have adequate drainage container ready to catch oil.
Remove two screws (7), washers (8), and clamps (6) from oil pump pickup and return hoses (2)
and (3) and engine oil pan (5).
Disconnect oil pump return hose (3) from adapter (9) and oil pan aerator (4).
Remove adapter (9), elbow (10), and nipple (11) from oil pump (1).

1.
2.

Inspect oil pump return hose (3). Replace hose (3) if cracked, frayed, or split.
Inspect adapter (9), elbow (10), and nipple (11). Replace if adapter (9), elbow (10), or nipple (11)
have cracks or threads are stripped or crossed.

1.
2.
3.
4.

Apply antiseize tape to male pipe threads of oil pump return hose (3), adapter (9), and nipple (11).
Install nipple (11), elbow (10), and adapter (9) on oil pump (1).
Connect oil pump return hose (3) to oil pan aerator (4) and adapter (91.
Install two clamps (6) and oil pump pickup and return hoses (2) and (3) on engine oil pan (5) with
two washers (8) and screws (7). Tighten screws (7) 35-40 lb-ft (47-54 N•m).

3-34

TM 9-2320-272-24-1

3-8. OIL

FOLLOW-ON TASKS:

Fill engine with oil to proper level (LO 9-2320-272-12).
Start engine (TM 9-2320-272-10) and check for leaks.
Check oil level and add oil as necessary (TM 9-2320-272-10).
Install left splash shield (TM 9-2320-272-10).
3-35

TM 9-2320-272-24-1

3-9. FRONT

THIS TASK COVERS:
a. Removal
b. Inspection

c. Installation

INITIAL SETUP:
APPLICABLE MODELS
M939/A1
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Two bushings (Appendix D, Item 23)
Antiseize tape (Appendix C. Item 72)

1.
2.
3.

4.

1.
2.

1.

2.
3.
4.

5.

3-36

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Hood raised and secured (TM 9-2320-272-10).
Left splash shield removed (TM 9-2320-272-10).

NOTE
Have adequate drainage container ready to catch oil.
Loosen two nuts (4) on sump tube (5), and slide nuts (4) toward center of front sump tube (5).
Tighten elbow (3) 1/4 turn to free sump tube (5). Remove sump tube (5) from adapter (6) and
elbow (3).
Remove two bushings (7) from sump tube (5). Discard bushings (7).
NOTE
Mark position of elbow for installation.
Remove adapter (6) from oil pan (2), and elbow (3) from oil pump (1).

Inspect two nuts (4), elbow (3), and adapter (6). Replace nuts (4), elbow (3), or adapter (6) if threads
are damaged.
Inspect sump tube (5). Replace if cracked.

Apply antiseize tape to male pipe threads of adapter (6) and elbow (3).
NOTE
Ensure elbow is less than 1/8 turn from final position to allow
room for installation of front sump tube.
Install adapter (6) on oil pan (2), and elbow (3) on oil pump (1).
Install two nuts (4) and new bushings (7) on sump tube (5), and slide toward center of sump tube (5).
Position one end of sump tube (5) on adapter (6), and start elbow (3) in other end of sump tube (5).
Turn elbow (3) to tighten into final position, pressing front sump tube (5) into elbow (3) and aligning
front sump tube (5) with elbow (3).
Connect sump tube (5) to adapter (6) and elbow (3) by tightening two nuts (4).

TM 9-2320-272-24-1
3-9. FRONT

FOLLOW-ON TASKS:

Start engine (TM 9-2320-272-10) and check for leaks.
Check oil level and add oil as necessary (TM 9-2320-272-10).
Install left splash shield (TM 9-2320-272-10).
3-37

TM 9-2320-272-24-1

3-10. ENGINE

THIS TASK COVERS:
a Oil Sampling
b. Removal

c. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Bag, plastic (Appendix C, Item 11)
Bottle, oil sample (Appendix C, Item 12)
Hose (Appendix C, Item 34)
Sack, shipping (Appendix C, Item 60)
Gasket sealant (Appendix C, Item 30)

REFERENCES (TM)
LO 9-2320-272-12
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Hood raised and secured (TM 9-2320-272-10).
Parking brake set (TM 9-2320-272-10).
Right splash shield removed (TM 9-2320-272-10).
GENERAL SAFETY INSTRUCTIONS
Do not perform task when engine is hot, or drain
oil when hot.
Prevent spilling of oil. See Army POL (para. 1-8).

WARNING
Accidental or intentional introduction of liquid contaminants into
the environment is in violation of state, federal, and military
regulations. Refer to Army POL (para. 1-8) for information
concerning storage, use, and disposal of these liquids. Failure to do
so may result in injury or death.

1.
2.
3.

4.
5.
6.
7.
8.

3-38

NOTE
Sampling procedures are similar for M939/A1/A2 series
vehicles. This procedure is for M939A2 series vehicles.
Engine should be at operating temperature to ensure circulating oil
has reached a uniform consistency. Failure to allow engine to reach
operating temperature may result in inaccurate AOAP analysis.
Start engine (TM 9-2320-272-10) and run until operating temperature is reached.
Remove capnut (2) from oil sampling valve (1).
Install rubber hose (3) on sampling valve (1).
NOTE
Perform step 4 to flush engine oil from oil sampling valve.
Have clean drainage container ready to catch oil that is flushed
for return to the engine. Do not use sample bottle.
Open oil sampling valve (1) and drain 1 pt (0.473 L) of oil into clean drainage container.
Close oil sampling valve (1).
Return flushed oil to engine (LO 9-2320-272-12).
Place sample bottle (4) under oil sampling valve (1) and place rubber hose (3) in oil sample
bottle (4).
Open sampling valve (1) and fill oil sampling bottle (4) to within 0.5 in. (1.3 cm) from top of sample
bottle (4).

TM 9-2320-272-24-1

3-10. ENGINE

9.

10.
11.
12.
13.

Close sampling valve (1).
NOTE
Seal oil sample in plastic bag and shipping sack.
Remove rubber hose (3) from oil sample bottle (4) and oil sampling valve (1). Seal oil sample bottle (4).
Install capnut (2) on oil sampling valve (1).
Stop engine (TM 9-2320-272-10).
Notify supervisor for processing AOAP oil sample.

3-39

TM 9-2320-272-24-1

3-10. ENGINE

WARNING

1.
2.

1.

2.
3.

Do not perform this task when engine is hot. Doing so may result
in injury to personnel.
NOTE
Have adequate drainage container ready to catch oil.
Perform step 1 for M939/A1 series vehicles and step 2 for
M939A2 series vehicles.
Remove oil sampling valve (2) from engine oil cooler (1).
Remove oil sampling valve (2) from engine block (3).

Apply a thin coat of gasket sealant to male threads of oil sampling valve (2).
NOTE
Perform step 2 for M939/A1 series vehicles and step 3 for M939A2
series vehicles.
Install oil sampling valve (2) on engine oil cooler (1).
Install oil sampling valve (2) on engine block (3).

FOLLOW-ON TASKS: Start engine (TM 9-2320-272-10) and check for leaks.
Check oil level and add oil as necessary (TM 9-2320-272-10).
Install right splash shield (TM 9-2320-272-10).
3-40

TM 9-2320-272-24-1

Section II. AIR INTAKE SYSTEM MAINTENANCE INDEX
3-11. AIR INTAKE SYSTEM MAINTENANCE INDEX
PARA.
NO.
3-12.
3-13.
3-14.
3-15.

TITLE
Air
Air
Air
Air

Cleaner
Cleaner
Cleaner
Cleaner

Indicator and Tube Maintenance
Hose (M939A2) Maintenance
Intake Pipe (M939/A1) Maintenance
Assembly and Mounting Bracket Maintenance

PAGE
NO.
3-42
3-48
3-50
3-52

3-41

TM 9-2320-272-24-1

3-12. AIR CLEANER INDICATOR AND TUBE MAINTENANCE
THIS TASK COVERS:
a. Testing
b. Removal

c. Cleaning and Inspection
d. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Two locknuts (Appendix D, Item 313)
Antiseize tape (Appendix C, Item 72)

EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Hood raised and secured (TM 9-2320-272-10).
l Left splash shield removed (TM 9-2320-272-10).
GENERAL SAFETY INSTRUCTIONS
When cleaning with compressed air, wear eyeshields
and ensure source pressure does not exceed 30 psi
(207 kPa).

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P

1.
2.
3.
4.
5.

6.

3-42

NOTE
Perform step 1 for M939/A1 series vehicles.
Remove nut (3), screw (6), and extension tube cap (2) from extension tube (5).
Start engine (TM 9-2320-272-10) and run at 1,200 rpm.
Cover 90 percent of intake extension tube (5) opening with cardboard (4).
Observe filter indicator (1) to ensure red band is visible. If red band is visible, indicator (1) works
properly. If not, replace indicator (1).
Remove cardboard (4) and reset indicator (1) (TM 9-2320-272-10) if working properly.
NOTE
Perform step 6 for M939/A1 series vehicles.
Install extension tube cap (2) on extension tube (5) with screw (6) and nut (3).

TM 9-2320-272-24-1

3-12. AIR CLEANER INDICATOR AND TUBE MAINTENANCE (Contd)

3-43

TM 9-2320-272-24-1

3-12. AIR CLEANER INDICATOR AND TUBE MAINTENANCE (Contd)
b. Removal

1.
2.
3.
4.
5.
6.
7.

8.
9.
10.
11.
12.
13.
14.
15.

NOTE
Perform steps 1 through 7 for M939A2 series vehicles.
Remove clamp (14) and air cleaner indicator tube (1) from connector (13).
Remove connector (13) and filter (12) from air tube (11).
Remove four screws (5) and plate (4) from instrument panel (10).
Remove clamp (9) and indicator tube (1) from air cleaner indicator (6).
Remove two locknuts (8), screws (7), and air cleaner indicator (6) from plate (4). Discard locknuts (8).
Remove indicator tube (1) and grommet (2) from firewall (3).
Remove grommet (2) from indicator tube (1).
NOTE
Perform steps 8 through 15 for M939 and M939A1 series vehicles.
Remove four screws (26), plate (29), and air cleaner indicator (22) from instrument panel (25).
Disconnect indicator tube nut (20) from elbow (21).
Remove elbow (21) from adapter (30) and adapter (30) from air cleaner indicator (22).
Remove two locknuts (31), screws (27), plate (29), and gasket (28) from air cleaner indicator (22).
Discard locknuts (31).
Disconnect indicator tube nut (16) from elbow (15).
Remove grommet (18) and indicator tube (17) from firewall (19).
Remove grommet (18) from indicator tube (17).
Remove elbow (15) and filter (24) from intake manifold (23).

c. Cleaning and Inspection
WARNING

1.
2.
3.
4.

3-44

Eyeshields must be worn when cleaning with compressed air.
Compressed air source will not exceed 30 psi (207 kPa). Failure to
do so may result in injury to personnel.
NOTE
Cleaning and inspection of air cleaner indicator, indicator tube,
and filter are basically the same for M939, M939A1, and M939A2
series vehicles. This cleaning and inspection procedure covers
M939A2 series vehicles.
Clean air cleaner indicator tube (1) with compressed air.
For general inspection instructions, refer to para. 2-15.
Inspect indicator tube (1) and filter (12) for clogs, kinks, cracks, and breaks. Replace indicator tube (1)
and filter (12) if clogged, kinked, cracked, or broken.
Inspect air cleaner indicator (6) for cracks. Replace air cleaner indicator (6) if cracked.

TM 9-2320-272-24-1

3-12. AIR CLEANER INDICATOR AND TUBE MAINTENANCE (Contd)

M939/A1

M939/A1
3-45

TM 9-2320-272-24-1

3-12. AIR CLEANER INDICATOR AND TUBE MAINTENANCE (Contd)
d. Installation
NOTE
Perform steps 1 through 8 for M939A2 series vehicles.
l
Male pipe threads must be wrapped with antiseize tape before
installation.
Install filter (12) and connector (13) on air tube (11).
Install indicator tube (1) on connector (13) with clamp (14).
Insert indicator tube (1) through firewall (3).
Position grommet (2) on indicator tube (1) and install on firewall (3).
Insert indicator tube (1) through instrument panel (10).
Install air cleaner indicator (6) on plate (4) with two screws (7) and new locknuts (8).
Install indicator tube (1) on air cleaner indicator (6) with clamp (9).
Install plate (4) and air cleaner indicator (6) on instrument panel (10) with four screws (5).
NOTE
Perform steps 9 through 16 for M939 and M939A1 series vehicles.
Install filter (24) and elbow (15) on intake manifold (23).
Position grommet (18) on indicator tube (17), and install indicator tube (17) and grommet (18)
through firewall (19).
Connect indicator tube nut (20) to elbow (21).
Install adapter (30) on elbow (21).
Install plate (29) and gasket (28) over adapter (30).
Install air cleaner indicator (22) on adapter (30).
Install air cleaner indicator (22) on gasket (28) and plate (29) with two screws (27) and new
locknuts (31).
Connect indicator tube nut (16) to elbow (15) and install plate (29) on instrument panel (25) with
four screws (26).
l

1.
2.
3.
4.
5.
6.
7.
8.

9.
10.
11.
12.
13.
14.
15.
16.

3-46

TM 9-2320-272-24-1

3-12. AIR CLEANER INDICATOR AND TUBE MAINTENANCE (Contd)

M939/A1

M939/A1

FOLLOW-ON TASK: Install left splash shield (TM 9-2320-272-10).
3-47

TM 9-2320-272-24-1

3-13. AIR CLEANER HOSE (M939A2) MAINTENANCE
THIS TASK COVERS:
a. Removal
b. Disassembly
c. Inspection

d. Assembly
e. Installation

INITIAL SETUP:
APPLICABLE MODELS
M939A2
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Tiedown strap (Appendix D, Item 688)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Hood raised and secured (TM 9-2320-272-10).

a. Removal
1.
2.
3.
4.

5.
6.

Remove
Remove
Remove
tiedown
Remove

clamp (3) and air indicator tube (1) from connector (4).
connector (4) from nipple (2).
tiedown strap (17) and tachometer drive cable (18) from air intake ducting (7). Discard
strap (17).
two nuts (6), bracket (5), and U-bolt (14) from air intake ducting (7) and support bracket (13).
NOTE
Tag spacers for installation.
Remove two screws (15), washers (16), support bracket (13), and two spacers (12) from cylinder
head (10).
Remove two clamps (8) and air intake ducting (7) from turbocharger (9) and pipe (11).

b. Disassembly
1.
2.
3.
4.

Remove
Remove
Remove
Remove

1.
2.

Inspect tubes (21) and (25) for cracks and dents. Replace tube (21) or (25) if cracked or dented.
Inspect elbows (23) and (27) for cracks and dents. Replace elbow (23) or (27) if cracked or dented.

1.
2.
3.
4.

Install
Install
Install
Install

3-48

clamp
clamp
clamp
clamp

(20)
(22)
(24)
(26)

and
and
and
and

hose (19) from tube (21).
tube (21) from elbow (23).
elbow (23) from tube (25).
tube (25) from elbow (27).

tube (25) on elbow (27) with clamp (26). Do not tighten clamp (26).
elbow (23) on tube (25) with clamp (24). Do not tighten clamp (24).
tube (21) on elbow (23) with clamp (22). Do not tighten clamp (22).
hose (19) on tube (21) with clamp (20). Do not tighten clamp (20).

TM 9-2320-272-24-1

3-13. AIR CLEANER HOSE (M939A2) MAINTENANCE (Contd)
e. Installation
1.
2.
3.
4.
5.
6.
7.

Install air intake ducting (7) on turbocharger (9) and pipe (11) with two clamps (8).
Install two spacers (12) and support bracket (13) on cylinder head (10) with two washers (16) and
screws (15).
Install air intake ducting (7) on support bracket (13) with U-bolt (14), bracket (5), and two nuts (6).
Tighten clamps (20), (22), (24), and (26).
Install tachometer drive cable (18) on air intake ducting (7) with new tiedown strap (17).
Install connector (4) on nipple (2).
Install air indicator tube (1) on connector (4) with clamp (3).

3-49

TM 9-2320-272-24-1

3-14. AIR CLEANER INTAKE PIPE (M939/A1) MAINTENANCE
THIS TASK COVERS:
a. Removal
b. Inspection

c. Installation

INITIAL SETUP:
APPLICABLE MODELS
M939/A1
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Three locknuts (Appendix D, Item 288)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Hood raised and secured (TM 9-2320-272-10).
l Left splash shield removed (TM 9-2320-272-10).
l Ether valve and bracket removed (para. 3-35).

a. Removal
1.
2.
3.
4.
5.

6.
7.

Remove locknut (9), air intake clamp (15), screw (6), and harness cable clamp (7) from hanger
strap (8). Discard locknut (9).
Loosen hose clamps (13) and (5) and remove air intake pipe (14) and hose clamps (13) and (5) from
lower hump hose (12) and upper hump hose (4).
Loosen hose clamp (3) and remove upper hump hose (4) and hose clamp (3) from air intake
manifold (2).
Loosen hose clamp (11) and remove lower hump hose (12) and hose clamp (11) from air cleaner (10).
Remove locknut (22), washer (23), hanger strap (8), and screw (19) from mounting bracket (20).
Discard locknut (22).
NOTE
Assistant will help with step 6.
Pull back floor mat (17) in cab (1), and remove locknut (21), mounting bracket (20), and screw (16)
from floor (18). Discard locknut (21).
Remove intake clamp (15) from intake pipe (14).

b. Inspection
Inspect upper and lower hump hoses (4) and (12) and intake pipe (14) for cracks. Replace if cracked.
c. Installation
1.
2.

3.

3-50

Install hanger strap (8) on mounting bracket (20) with screw (19), washer (23), and new locknut (22).
Install mounting bracket (20) on floor (18) with screw (16) and new locknut (21). Install floor mat (17).
NOTE
Assistant will help with step 3.
Position hose clamp (11) on lower hump hose (12), install lower hump hose (12) on air cleaner (10),
and tighten hose clamp (11).

TM 9-2320-272-24-1

3-14. AIR CLEANER INTAKE PIPE (M939/A1) MAINTENANCE (Contd)
4.
5.

6.
7.

Position hose clamp (3) on upper hump hose (4), install upper hump hose (4) on air intake manifold (2),
and tighten hose clamp (3).
Position intake pipe clamp (15) over intake pipe (14).
NOTE
Assistant will help with step 6.
Install intake pipe (14) on lower hump hose (12) and upper hump hose (4) with hose clamps (13)
and (5).
Install intake pipe clamp (15) and harness cable clamp (7) on hanger strap (8) with screw (6) and
new locknut (9).

FOLLOW-ON TASKS:

l
l

Install ether valve and bracket (para. 3-35)
Start engine (TM 9-2320-272-10) and check for air leaks.
3-51

TM 9-2320-272-24-1

3-15. AIR CLEANER ASSEMBLY AND MOUNTING BRACKET MAINTENANCE
THIS TASK COVERS:
a. Removal
b. Inspection

c. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Three locknuts (Appendix D, Item 288)
Five lockwashers (Appendix D, Item 354)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
GENERAL SAFETY INSTRUCTIONS
If NBC exposure is suspected, all air filter media
should be handled by personnel wearing protective
equipment.

WARNING
If NBC exposure is suspected, all air filter media should be
handled by personnel wearing protective equipment. Consult your
unit NBC officer or NBC NCO for appropriate handling or disposal
instructions.
a. Removal
1.
2.
3.

4.
5.

6.
7.

Loosen hose clamps (6) and (12) on air cleaner tube hose (4) and cleaner-to-intake pipe hump hose (13).
Release support strap latch (8) from mounting bracket (5) and air cleaner assembly (9).
Remove two locknuts (1), mounting band (7), and two screws (2) from mounting bracket (3). Discard
locknuts (1).
NOTE
Assistant will help with step 4.
Remove air cleaner assembly (9) and hose clamps (6) and (12) from air cleaner tube hose (4) and
cleaner-to-intake pipe hump hose (13).
Remove locknut (10), screw (11), mounting band (7), and support strap (8) from air cleaner
assembly (9). Discard locknut (10).
NOTE
Floor mat must be pulled back to gain access to one screw.
Remove two screws (17), lockwashers (15), and mounting bracket (3) from mounting bracket (5) and
subfloor (18). Discard lockwashers (15).
Remove three screws (14), lockwashers (15), and mounting bracket (5) from cab floor (16). Discard
lockwashers (15).

b. Inspection
Inspect air cleaner assembly (9) for cracks and splits that would allow unfiltered air to enter.
Replace if cracked or split.

3-52

TM 9-2320-272-24-1

3-15. AIR CLEANER ASSEMBLY AND MOUNTING BRACKET MAINTENANCE (Contd)

3-53

TM 9-2320-272-24-1

3-15. AIR CLEANER ASSEMBLY AND MOUNTING BRACKET MAINTENANCE (Contd)
c. Installation

1.
2.
3.
4.

5.

6.
7.

NOTE
Floor mat must be pulled back to gain access to one screw hole in
steps 1 and 2.
Install mounting bracket (5) on cab floor (16) with three new lockwashers (15) and screws (14).
Install mounting bracket (3) on mounting bracket (5) and subfloor (18) with two new lockwashers (15)
and screws (17).
Install mounting band (7) on air cleaner assembly (9) with screw (11) and new locknut (10).
Position support strap (8) on air cleaner assembly (9).
NOTE
Assistant will help with step 5.
Position hose clamps (6) and (12) on air cleaner tube hose (4) and cleaner-to-intake pipe hump
hose (13), and install air cleaner assembly (9) on air cleaner tube hose (4) and cleaner-to-intake pipe
hump hose (13) with hose clamps (6) and (12).
Install air cleaner assembly (9) on mounting brackets (5) and (3) with support strap (8), two
screws (2), mounting band (7), and two new locknuts (1). Fasten support strap (8).
Tighten hose clamps (6) and (12).

FOLLOW-ON TASKS:

l
l

3-54

Start engine (TM 9-2320-272-10) and check for air leaks.
Ensure air filter indicator in cab indicates green (TM 9-2320-272-10).

TM 9-2320-272-24-1

Section III. FUEL SYSTEM MAINTENANCE
3-16. FUEL SYSTEM MAINTENANCE INDEX
PARA.
NO.
3-17.
3-18.
3-19.
3-20.
3-21.
3-22.
3-23.
3-24.
3-25.
3-26.
3-27.
3-28.
3-29.
3-30.
3-31.
3-32.
3-33.
3-34.
3-35.
3-36.
3-37.
3-38.
3-39.
3-40.
3-41.
3-42.
3-43.
3-44.
3-45.
3-46.

TITLE
Fuel Drain and Bypass Tubing (M939/A1) Replacement
Air Fuel Control (AFC) Tube (M939A2) Maintenance
Fuel Injector Tube (M939A2) Maintenance
Fuel Transfer Pump and Supply Lines (M939A2) Maintenance
Turbocharger and Coolant Lines (M939A2) Replacement
Priming Fuel System (M939A2)
Fuel Selector Valve Flex Hose Replacement
Fuel Selector Valve, Mounting Bracket, and Indicator Plate
Maintenance
Fuel Tank Filler Cap and Spout Replacement
Fuel Tank Maintenance
Fuel Tank (M936/A1/A2) Maintenance
Fuel Tank Hangers and Retaining Straps Maintenance
Fuel Tank Lines (M939A2) Replacement
Fuel Filter and Cover Maintenance
AFC Fuel Pump Filter Replacement
Fuel Pump with VS Governor Filter Replacement
Ether Start Switch Replacement
Ether Start Fuel Pressure Switch (M939/A1) Replacement
Ether Cylinder and Valve Replacement
Ether Thermal Close Valve and Bushing Replacement
Ether Atomizer (M939/A1) Replacement
Ether Atomizer and Temperature Sensor (M939A2) Replacement
Ether Tubing Replacement
Fuel Primer Pump (M939/A1) Replacement
Accelerator Pedal, Bracket, Rod, and Stopscrew Replacement
Accelerator Linkage (M939/A1) Maintenance
Accelerator Linkage (M939A2) Maintenance
Emergency Stop Control Cable Maintenance
Throttle Control Cable Maintenance
Throttle Control Solenoid (M939A2) Replacement

PAGE
NO.
3-56
3-61
3-62
3-66
3-68
3-72
3-74
3-76
3-78
3-80
3-84
3-92
3-96
3-104
3-108
3-110
3-112
3-113
3-114
3-116
3-117
3-118
3-120
3-122
3-123
3-124
3-126
3-130
3-134
3-138

3-55

TM 9-2320-272-24-1

3-17. FUEL DRAIN AND BYPASS TUBING (M939/A1) REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
M939/A1
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Torque wrench (Appendix E, Item 144)
MATERIALS/PARTS
Five lockwashers (Appendix D, Item 348)
Lockwasher (Appendix D, Item 349)
Antiseize tape (Appendix C, Item 72)

1.
2.
3.
4.

5.
6.
7.
8.

3-56

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Hood raised and secured (TM 9-2320-272-10).
l Water pump removed (para. 3-68).
l
Air compressor-to-engine coolant return tube
removed (para. 3-55).

NOTE
Have drainage container ready to catch fuel.
Disconnect fuel supply tube (7) from fuel pump shutoff valve (8).
Disconnect fuel return tube (10) from fuel pump elbow (23).
Remove screw (16), lockwasher (15), washer (14), clamp (13), and spacer (12) from left side of engine
block (1) and bracket (11). Discard lockwasher (15).
Remove screw (17), lockwasher (18), and bracket (11) from left side of engine block (1). Discard
lockwasher (18).
NOTE
Step 5 may not be required for all vehicles.
Remove screw (28), lockwasher (27), washer (26), two clamps (25), fuel supply tube (7), and fuel return
tube (6) from intake manifold (24). Discard lockwasher (27).
Remove nut (2), lockwasher (3), screw (5), and clamp (4) from left side of engine block (1). Discard
lockwasher (3).
Remove nut (21), lockwasher (22), screw (19), and clamp (20) from tubes (6) and (7) left side of
engine block (1). Discard lockwasher (22).
Disconnect fuel return tubes (6) and (10) from tee (9).

TM 9-2320-272-24-1

3-17. FUEL DRAIN AND BYPASS TUBING (M939/A1) REPLACEMENT (Contd)

3-57

TM 9-2320-272-24-1

3-17. FUEL DRAIN AND BYPASS TUBING (M939/A1) REPLACEMENT (Contd)
9.

10.

11.
12.
13.

14.
15.

Remove screw (10), lockwasher (11), washer (12), clamp (13) with fuel supply tube (4), support
bracket (14), and spacer (15) from front of cylinder head (2). Discard lockwasher (11).
NOTE
Perform step 10 for vehicles with early model engines.
Remove fuel supply tube (4) from adapter (5).
NOTE
Perform step 11 for vehicles equipped with late model engines.
Remove fuel supply tube (4) and fuel pressure transducer (6) from tee (7).
Remove fuel return tube (1) from adapter (3).
Remove two screws (8) and upper radiator support bracket (9) from front of cylinder head (2).
NOTE
Perform step 14 for early model engines or step 15 for late model
engines.
Remove two adapters (3) and (5) from front of cylinder head (2).
Remove tee (7) and adapter (3) from front of cylinder head (2).

b. Installation
NOTE
Wrap all male pipe threads with antiseize tape before
installation.
l Perform step 1 for early model engines or step 2 for late model
engines.
Install two adapters (3) and (5) on front of cylinder head (2).
Install tee (7) and adapter (3) on front of cylinder head (2).
Install upper radiator support bracket (9) on front of cylinder head (2) with two screws (8). Tighten
screws (8) 55-65 lb-ft (75-88 N.m).
Connect fuel return tube (1) to adapter (3).
NOTE
Perform step 5 for vehicles with early model engines.
Connect fuel supply tube (4) to adapter (5).
NOTE
Perform step 6 for vehicles with late model engines.
Connect fuel supply tube (4) and fuel pressure transducer (6) to tee (7).
Install spacer (15), support bracket (14), and clamp (13) with fuel supply tube (4) on front of
cylinder head (2) with washer (12), new lockwasher (11), and screw (10).
l

1.
2.
3.
4.

5.

6.
7.

3-58

TM 9-2320-272-24-1

3-17. FUEL DRAIN AND BYPASS TUBING (M939/A1) REPLACEMENT (Contd)

EARLY MODEL ENGINE

LATE MODEL ENGINE

3-59

TM 9-2320-272-24-1

3-17. FUEL DRAIN AND BYPASS TUBING (M939/A1) REPLACEMENT (Contd)
8.
9.

10.
11.
12.
13.
14.
15.

Install clamp (22) on fuel return tube (4) and fuel supply tube (9) with screw (21), new lockwasher (2),
and nut (1).
Install clamp (7) on fuel return tube (4) and fuel supply tube (9) with screw (8), new lockwasher (6),
and nut (5).
NOTE
Step 10 may not be required for all vehicles.
Install two clamps (25) and tubes (4) and (9) on manifold (24) with washer (26), new
lockwasher (27), and screw (28).
Install bracket (11) on engine block (3) with new lockwasher (19) and screw (18).
Install clamp (13) and tube (17) on bracket (11) with spacer (12), washer (14), new luckwasher (15),
and screw (16).
Connect fuel return tube (17) to fuel pump elbow (23).
Connect, fuel supply tube (9) to fuel pump shutoff valve (20).
Connect tubes (17) and (4) to tee (10).

FOLLOW-ON TASKS:

l
l

3-60

Install air compressor-to-engine coolant return tube (para. 3-55).
Install water pump (para. 3-68).

TM 9-2320-272-24-1

3-18. AIR FUEL CONTROL (AFC) TUBE (M939A2) MAINTENANCE
THIS TASK COVERS:
a. Removal
b. Inspection

c. Installation

INITIAL SETUP:
APPLICABLE MODELS
M939A2
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Two seal washers (Appendix D, Item 644)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Hood raised and secured (TM 9-2320-272-10).

a. Removal
1.
2.

Disconnect AFC tube (2) from adaptor (1).
Remove screw (3), two seal washers (4), and AFC tube (2) from fuel pump (5). Discard seal
washers (4).

b. Inspection
1.
2.

For general inspection instructions, refer to para. 2-15.
Replace all parts failing inspection.

c. Installation
1.
2.

Install AFC tube (2) on fuel pump (5) with new seal washers (4) and screw (3).
Connect AFC tube (2) to adapter (1).

FOLLOW-ON TASK: Start engine (TM 9-2320-272-10) and check for leaks.
3-61

TM 9-2320-272-24-1

3-19. FUEL INJECTOR TUBE (M939A2) MAINTENANCE
THIS TASK COVERS:
a. Removal
b. Cleaning and Inspection

c. Installation

INITIAL SETUP:
APPLICABLE MODELS
M939A2
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Seven banjo seals (Appendix D, Item 9)
Cap and plug set (Appendix C, Item 14)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10)
l Hood raised and secured (TM 9-2320-272-10)
GENERAL SAFETY INSTRUCTIONS
Diesel fuel is flammable. Do not perform this task
near open flames.

a. Removal
WARNING
Diesel fuel is highly flammable. Do not perform fuel system
procedures near open flame. Injury to personnel may result.
CAUTION

1.

2.
3.
4.

5.
6.
7.
8.

3-62

Cap or plug all openings immediately after disconnecting fuel lines
to prevent contamination. Failure to do so may result in damage
to fuel pump.
Remove seven screws (3), banjo seals (4), and fuel manifold (5) from six fuel injectors (6) and fuel
return tube (7). Discard banjo seals (4).
NOTE
Tag injector tubes for installation.
Loosen six fuel line nuts (10) and disconnect fuel injector tubes (11) from fuel injectors (6).
Loosen six fuel line nuts (10) and disconnect fuel injector tubes (11) from fuel injector pump (9).
Remove screw (1), washer (2), and fuel injector tubes (11) from cylinder head (8).
NOTE
Tag brace assemblies for installation.
Remove two screws (25), washers (28), tube braces (26), and isolators (27) from fuel injector tubes (11).
Remove screw (21), washer (24), two tube braces (22), and isolators (23) from fuel injector tubes (11).
Remove four screws (12), washers (15), two tubes braces (13), and isolators (14) from injector tubes (11).
Remove four screws (16), washers (17), two tube braces (18), brace (20), and four isolators (19) from
injector tubes (11).

TM 9-2320-272-24-1

3-19. FUEL INJECTOR TUBE (M939A2) MAINTENANCE (Contd)

3-63

TM 9-2320-272-24-1

3-19. FUEL INJECTOR TUBE (M939A2) MAINTENANCE (Contd)
b. Cleaning and Inspection
1.
2.
3.
4.
5.

For general
For general
Inspect fuel
tubes (11).
Inspect fuel
Replace all

cleaning instructions, refer to para. 2-14.
inspection instructions, refer to para. 2-15.
injection tubes (11) for cracks or dents. If cracked or dented, replace fuel injection
manifold (5) for cracks or dents. If cracked or dented, replace fuel manifold (5).
parts failing inspection.

c. Installation
CAUTION
Injector tubes deliver fuel at high pressure causing them to
expand and contract. Ensure injector tubes are securely
clamped and routed so they do not come in contact with each
other or any engine component. Failure to do so may result in
premature injector tube failure.
l
Injector tubes must be installed in correct positions as tagged.
Failure to do so may result in damage to tubes and engine
malfunction.
Install four isolators (19), brace (20), and two tube braces (18) on six fuel injector tubes (11) with
four washers (17) and screws (16). Finger tighten screws (16).
Install two isolators (14) and tube braces (13) on fuel injector tubes (11) with four washers (15) and
screws (12). Finger tighten screws (12).
Install two isolators (23) and tube braces (22) on fuel injector tubes (11) with washer (24) and screw
(21). Finger tighten screw (21).
Install two isolators (27) and tube braces (26) on injector tubes (11) with two washers (28) and
screws (25). Finger tighten screws (25).
Install six fuel injector tubes (11) on cylinder head (8) with washer (2) and screw (1).
Position six fuel injector tubes (11) on fuel injection pump (9) and fuel injectors (6).
Connect six fuel tube nuts (10) to fuel injection pump (9).
Connect six fuel tube nuts (10) to fuel injectors (6).
Tighten two screws (25), screw (21), four screws (12), and screws (16).
NOTE
Banjo seals must face toward fuel injectors to allow installation of
valve cover.
Install fuel manifold (5) and seven new banjo seals (4) on six fuel injectors (6) and fuel supply
tube (7) with seven screws (3).
l

1.
2.
3.
4.
5.
6.
7.
8.
9.

10.

3-64

TM 9-2320-272-24-1

3-19. FUEL INJECTOR TUBE (M939A2) MAINTENANCE (Contd)

FOLLOW-ON TASK: Prime fuel system (para. 3-22).
3-65

TM 9-2320-272-24-1

3-20. FUEL TRANSFER PUMP AND SUPPLY LINES (M939A2) MAINTENANCE
THIS TASK COVERS:
a. Removal
b. Cleaning and Inspection

c. Installation

INITIAL SETUP:
APPLICABLE MODELS
M939A2
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Banjo seal (Appendix D, Item 9)
Two seal washers (Appendix D, Item 645)
Two seal washers (Appendix D, Item 646)
Gasket (Appendix D, Item 139)
Antiseize tape (Appendix C, Item 72)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Hood raised and secured (TM 9-2320-272-10).
GENERAL SAFETY INSTRUCTIONS
Diesel fuel is flammable. Do not perform this task
near open flames.

a. Removal
WARNING

1.
2.
3.
4.
5.
6.

7.
8.

Diesel fuel is highly flammable. Do not perform fuel system
procedures near open flames. Injury to personnel may result.
Disconnect fuel pressure transducer (1) from wiring harness (2).
Remove fuel pressure transducer (1) from adapter (10).
Remove adapter (10), two seal washers (11), and fuel supply tube (5) from fuel transfer pump (13).
Discard seal washers (11).
Remove fuel supply line (16) from elbow (15) on fuel transfer pump (13).
Remove two screws (14), fuel transfer pump (13), and gasket (12) from engine block (17). Discard
gasket (12).
Remove elbow (15) from fuel transfer pump (13).
NOTE
Perform steps 7 and 8 if fuel supply tube is damaged.
Remove screw (8), banjo seal (9), and fuel drain manifold (7) from adapter (6). Discard banjo seal (9).
Remove adapter (6), two seal washers (4), and fuel supply tube (5) from fuel filter head (3). Discard
seal washers (4).

b. Cleaning and Inspection
1.
2.
3.

3-66

For general cleaning instructions, refer to para. 2-14.
For general inspection instructions, refer to para. 2-15.
Replace all parts failing inspection.

TM 9-2320-272-24-1

3-20. FUEL TRANSFER PUMP AND SUPPLY LINES (M939A2) MAINTENANCE (Contd)
c. Installation
1.
2.
3.
4.

5.
6.
7.
8.
9.

Apply antiseize tape to threads of elbow (15) and install elbow (15) on fuel transfer pump (13).
Install new gasket (12) and fuel transfer pump (13) on engine block (17) with two screws (14).
Connect fuel supply line (16) to elbow (15) on fuel transfer pump (13).
Install fuel supply tube (5) on fuel transfer pump (13) with two new seal washers (11) and adapter (10).
Finger tighten adapter (10).
NOTE
Perform steps 5 through 7 if fuel supply tube was removed.
Install fuel supply tube (5) on fuel filter head (3) with two new seal washers (4) and adapter (6).
Tighten adapter (10).
Place new banjo seal (9) around fuel drain manifold (7) and install on adapter (6) with screw (8).
Apply antiseize tape to threads on fuel pressure transducer (1) and install fuel pressure
transducer (1) on adapter (10).
Connect wiring harness (2) to fuel pressure transducer (1).

FOLLOW-ON TASK: Prime fuel system (para. 3-22).
3-67

TM 9-2320-272-24-1

3-21. TURBOCHARGER AND COOLANT LINES (M939A2) REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
M939A2
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Torque wrench (Appendix E, Item 146)
MATERIALS/PARTS
O-ring (Appendix D, Item 476)
Gasket (Appendix D, Item 141)
Gasket (Appendix D, Item 140)
Antiseize compound (Appendix C, Item 10)
Antiseize tape (Appendix C, Item 72)
Lubricating oil (Appendix C, Item 50)

REFERENCES (TM)
LO 9-2320-272-12
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Hood raised and secured (TM 9-2320-272-10).
l Coolant drained (para. 3-53).
GENERAL SAFETY INSTRUCTIONS
Do not perform this task when exhaust system is
hot.

WARNING
Do not touch hot exhaust system components with bare hands.
Injury to personnel may result.
a. Removal
1.
2.
3.

4.

5.
6.
7.
8.
9.
10.
11.

3-68

Remove four clamps (1), two hoses (2), and tube (3) from turbocharger (4) and aftercooler (5).
Remove two screws (7) from oil return tube (8) and turbocharger (4).
Remove two clamps (9), oil return tube (8), gasket (6), and hose (10) from tube (11). Discard
gasket (6).
NOTE
Perform step 4 if tube is damaged.
Remove tube (11) from engine block (12).
NOTE
l Perform steps 5 and 6 for early model engines.
l Perform steps 7 and 8 for late model engines.
Remove oil supply hose (13) from turbocharger (4) and connector (14).
Remove connector (14) from oil cooler (16).
Remove oil supply hose (13) from turbocharger (4) and connector (23).
Remove connector (23) and O-ring (24) from oil cooler (16). Discard O-ring (24).
Loosen clamp (15) and disconnect air intake tube (20) from turbocharger (4).
Loosen clamp (19) and disconnect exhaust pipe (18) from turbocharger (4).
Remove four nuts (22), turbocharger (4), and gasket (21) from exhaust manifold (17). Discard
gasket (21).

TM 9-2320-272-24-1

3-21. TURBOCHARGER AND COOLANT LINES (M939A2) REPLACEMENT (Contd)

3-69

TM 9-2320-272-24-1

3-21. TURBOCHARGER AND COOLANT LINES (M939A2) REPLACEMENT (Contd)
b. Installation
1.

2.
3.
4.
5.

6.
7.
8.
9.

10.
11.
12.
13.

Apply antiseize compound to four mounting studs (6) and install new gasket (12) and turbocharger (1)
on exhaust manifold (7) with four nuts (13). Tighten nuts (13) to 25 lb-ft (34 N.m).
CAUTION
Turbocharger must be lubricated with clean engine oil prior to
starting engine, or bearing damage may result.
With a small funnel positioned in turbocharger oil supply hole (2), pour 2-3 ounces (57-85 grams) of
clean engine oil into turbocharger (1) (LO 9-2320-272-12).
Spin impeller/turbine blades (14) by hand to coat bearings with oil (LO 9-2320-272-12).
Connect exhaust pipe (8) to turbocharger (1) and tighten clamp (9).
Connect air intake tube (11) to turbocharger (1) and tighten clamp (10).
NOTE
l Perform steps 6 and 7 for early model engines.
l Perform steps 8 and 9 for late model engines,
l
Wrap all male pipe threads with antiseize tape before
installation.
Install connector (4) on oil cooler (5).
Install oil supply hose (3) on turbocharger (1) and connector (4).
Install new O-ring (16) and connector (15) on oil cooler (5).
Install oil supply hose (3) on turbocharger (1) and connector (15).
NOTE
Perform step 10 if tube was removed.
Install tube (22) on engine block (23).
Install new gasket (17) and oil return tube (19) on turbocharger (1) with two screws (18).
Install hose (21) and oil return tube (19) on tube (22) with two clamps (20).
Install tube (26) and two hoses (25) on aftercooler (27) and turbocharger (1) with four clamps (24).
CAUTION
When filling cooling system, ensure drainvalve on aftercooler is
open. Failure to do so may result in damage to equipment.

3-70

TM 9-2320-272-24-1

3-21. TURBOCHARGER AND COOLANT LINES (M939A2) REPLACEMENT (Contd)

FOLLOW-ON TASK: Fill coolant system (para. 3-53).
3-71

TM 9-2320-272-24-1

3-22. PRIMING FUEL SYSTEM (M939A2)
THIS TASK COVERS:
Priming
INITIAL SETUP:
APPLICABLE MODELS
M939A2
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Cleaning cloth (Appendix C, Item 21)
REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P

EQUIPMENT CONDITION
l Parking brake set (TM 9-2302-272-10).
l Hood raised and secured (TM 9-2320-272-10).
l Air cleaner hose removed (para. 3-13).
GENERAL SAFETY INSTRUCTIONS
l
All personnel must stand clear during engine
cranking operations.
l Use eyeshields and gloves when loosening fuel
lines.

Priming
1.

2.
3.
4.

5.
6.

Loosen adapter (6) and vent screw (7) on fuel pump (5).
NOTE
Perform step 2 until all air is purged from fuel system.
Press plunger (3) on fuel transfer pump (4) until air is purged from fuel system.
Tighten vent screw (7) and adapter (6) on fuel pump (5).
Start engine (TM 9-2320-272-10).
NOTE
If engine fails to start, or runs rough, perform steps 5 through 10.
Loosen fuel line (2) from fuel injector (1).
Place cleaning cloth around fuel line (2) and fuel injector (1).
WARNING
All personnel must stand clear during engine cranking
operation. Failure to do so may result in injury to personnel.
l
Fuel pressure is sufficient to penetrate skin. Wear hand
protection and safety goggles at all times when removing
injector tubes. Failure to do so may result in injury to
personnel.
NOTE
Assistant will help with step 7.
Crank engine until all air is vented at fuel injector (1).
Tighten fuel line (2) at fuel injector (1).
Repeat steps 5 through 8 until all fuel injectors (1) are purged free of air.
Stop engine (TM 9-2320-272-10).
l

7.
8.
9.
10.

3-72

TM 9-2320-272-24-1

3-22. PRIMING FUEL SYSTEM (M939A2) (Contd)

FOLLOW-ON TASKS:

l
l

Install air cleaner hose (para. 3-13).
Start engine (TM 9-2320-272-10) and check for leaks.
3-73

TM 9-2320-272-24-1

3-23. FUEL SELECTOR VALVE FLEX HOSE REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
M929/A1/A2, M930/A1/A2, M931/A1/A2,
M932/A1/A2, M936/A1/A2

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P

TOOLS
General mechanic’s tool kit (Appendix E, Item 1)

EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Hood raised and secured (TM 9-2320-272-10).

MATERIALS/PARTS
Cap and plug set (Appendix C, Item 14)
Antiseize tape (Appendix C, Item 72)

GENERAL SAFETY INSTRUCTIONS
Diesel fuel is flammable. Do not perform this
procedure near flames.
WARNING

Diesel fuel is highly flammable. Do not perform fuel system
procedures near flames. Injury to personnel may result.
a. Removal

1.
2.

NOTE
l All hoses are disconnected the same.
l All hoses must be disconnected from fuel lines first.
l
Have drainage container ready to catch fuel.
l Plug all fuel lines using protective cap plugs.
l Tag lines and fittings for installation.
Disconnect six flex hoses (4) from four fuel lines (3) and two fuel line-to-hose adapters (5).
Disconnect six flex hoses (4) from two valve ports (6) and four elbows (2) on selector valve (1).

b. Installation
NOTE
Male pipe threads must be wrapped with antiseize tape before
installation.
l Remove protective cap plugs from fuel lines before installation.
Connect six flex hoses (4) to two valve ports (6) and four elbows (2) on selector valve (1).
Connect six flex hoses (4) to four fuel lines (3) and two fuel line-to-hose adapters (5).
l

1.
2.

3-74

TM 9-2320-272-24-1

3-23. FUEL SELECTOR VALVE FLEX HOSE REPLACEMENT (Contd)

FOLLOW-ON TASK: Start engine (TM 9-2320-272-10) and test selector valve for fuel leaks and proper
operation.
3-75

TM 9-2320-272-24-1

3-24. FUEL SELECTOR VALVE, MOUNTING BRACKET, AND INDICATOR PLATE
MAINTENANCE
THIS TASK COVERS:
a. Removal
b. Inspection

c. Installation

INITIAL SETUP:
APPLICABLE MODELS
M929/A1/A2, M930/A1/A2, M931/A1/A2,
M932/A1/A2, M936/A1/A2

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P

TOOLS
General mechanic’s tool kit (Appendix E, Item 1)

EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Selector valve flex hoses removed (para. 3-23).

MATERIALS/PARTS
One lockwashers (Appendix D, Item 352)
Two lockwashers (Appendix D, Item 354)
Two locknuts (Appendix D, Item 313)
Antiseize tape (Appendix C, Item 72)

GENERAL SAFETY INSTRUCTIONS
Diesel fuel is flammable. Do not perform this
procedure near flames.

WARNING
Diesel fuel is highly flammable. Do not perform fuel system
procedures near open flame. Injury to personnel may result.

1.
2.
3.

4.

1.
2.
3.
4.

3-76

Remove screw (1), lockwasher (2), and lever (3) from left rear cab floor (5). Discard
lockwasher (2).
Remove two screws (12), lockwashers (11), and selector valve (9) from mounting bracket (10).
Discard lockwashers (11).
Remove two locknuts (13), screws (15), washers (14), indicator plate (4), and mounting bracket (10)
from cab floor (5). Discard locknuts (13).
NOTE
l Use soft-nosed vise to hold selector valve.
l Tag fittings for installation.
Remove two elbows (7), pipe nipples (6), and elbows (8) from fuel selector valve (9).

Install lever (3) on selector valve (9) with screw (1).
Turn lever (3) left, then right, while checking inside of selector valve (9) for burrs and nicks. Replace
selector valve (9) if nicked or burred.
Remove screw (1) and lever (3) from selector valve (9).
Inspect two pipe nipples (6) and elbows (7) and (8) for stripped threads. Replace any part if threads
are stripped.

TM 9-2320-272-24-1

3-24. FUEL SELECTOR VALVE MOUNTING BRACKET, AND INDICATOR PLATE
MAINTENANCE (Contd)

1.

2.
3.
4.

NOTE
Locknuts are installed under cab floor.
Align indicator plate (4) and mounting bracket (10) with holes in cab floor (5) and install with two
washers (14), screws (15), and new locknuts (13).
NOTE
Male pipe threads must be wrapped with antiseize tape before
installation.
Install two elbows (8), pipe nipples (6), and elbows (7) on selector valve (9).
Install selector valve (9) on mounting bracket (10) with two new lockwashers (11) and screws (12).
Install lever (3) on selector valve (9) with new lockwasher (2) and screw (1). Ensure lever (3) pointer
is positioned opposite notch on stem of selector valve (9).

FOLLOW-ON TASKS: l Connect selector valve flex hoses (para. 3-23).
l
Start engine (TM 9-2320-272-10) and check for fuel leaks at valve when switching
selector valve to both tanks.
3-77

TM 9-2320-272-24-1

3-25. FUEL TANK FILLER CAP AND SPOUT REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Two gaskets (Appendix D, Item 142)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Filler cap removed (TM 9-2320-272-10).
GENERAL SAFETY INSTRUCTIONS
Diesel fuel is flammable. Do not perform this
procedure near flames.

WARNING
Diesel fuel is highly flammable. Do not perform fuel system
procedures near open flames. Injury to personnel may result.
a. Removal
1.
2.
3.
4.

Remove gasket (2) from filler cap (1). Discard gasket (2).
Remove filler cap retaining chain (6) from filler spout assembly (3).
Turn filler spout assembly (3) counterclockwise and remove it from fuel tank (5).
Remove gasket (4) from filler spout assembly (3). Discard gasket (4).

b. Installation

1.
2.
3.
4.

3-78

Install
Install
Install
Attach

NOTE
M939/A1 vehicles use same gaskets in steps 1 and 2. M939A2
vehicles use different gaskets for steps 1 and 2.
new gasket (2) on filler cap (1).
new gasket (4) on filler spout assembly (3).
filler spout assembly (3) in fuel tank (5).
filler cap retaining chain (6) to filler spout assembly (3).

TM 9-2320-272-24-1

3-25. FUEL TANK FILLER CAP AND SPOUT REPLACEMENT (Contd)

FOLLOW-ON TASK: Install filler cap (TM 9-2320-272-10).
3-79

TM 9-2320-272-24-1

3-26. FUEL TANK MAINTENANCE
THIS TASK COVERS:
a. Draining
b. Removal

c. Inspection
d. Installation

INITIAL SETUP:
APPLICABLE MODELS
All except M936/A1/A2
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Gasket (Appendix D, Item 144)
Gasket (Appendix D, Item 143)
Four locknuts (Appendix D, Item 288)
Antiseize tape (Appendix C, Item 72)

REFERENCES (TM)
FM 43-2
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Fuel tank filler cap and spout removed (para. 3-25).
GENERAL SAFETY INSTRUCTIONS
Diesel fuel is flammable. Do not perform this
procedure near flames.

WARNING
Diesel fuel is highly flammable. Do not perform fuel system
procedures near open flames. Injury to personnel may result.
NOTE
The replacement procedure for right and left single fuel tanks is
basically the same. This procedure covers the left fuel tank.
a. Draining

1.
2.

NOTE
Have drainage container ready to catch fuel.
Remove drainplug (10) and gasket (9) from bottom of fuel tank (16). Discard gasket (9).
After draining is complete, install new gasket (9) and drainplug (10) on bottom of fuel tank (16).

b. Removal

1.
2.
3.
4.
5.
6.
7.

3-80

NOTE
Tag lines for installation.
Disconnect two vent lines (6) from elbows (7).
Disconnect fuel return line (13) from elbow (12).
Disconnect fuel supply line (5) from elbow (14).
Disconnect fuel transmitter wire (2) from fuel transmitter unit (15).
Remove screw (3) and ground wire (4) from fuel tank (16).
Remove two locknuts (11) from hanger straps (8). Discard locknuts (11).
Remove two locknuts (22), screws (21), and hanger straps (8) from hangers (1). Discard locknuts (22).

TM 9-2320-272-24-1

3-26. FUEL TANK MAINTENANCE (Contd)

8.

9.

10.
11.
12.

NOTE
Perform step 8 for M934/A1/A2 model vehicles.
Disconnect personnel heater fuel supply line (18), adapter (19), and fitting (20) from top of fuel
tank (16).
NOTE
Assistant will help with step 9.
Remove fuel tank (16) from two hangers (1).
NOTE
Mark direction of elbows for installation before removing.
Remove fuel supply tube with elbow (14) from top of fuel tank (16).
Remove two vent line elbows (7) and return line elbow (12) from top of fuel tank (16).
Remove four screws (3), fuel transmitter unit (15), and gasket (17) from fuel tank (16). Discard
gasket (17).

M934/A1/A2

3-81

TM 9-2320-272-24-1

3-26. FUEL TANK MAINTENANCE (Contd)
c. Inspection
Inspect fuel tank (6) for cracks, holes, and stripped threads (FM 43-2.)
d. Installation

1.
2.
3.

4.
5.
6.

7.
8.
9.
10.
11.
12.

3-82

NOTE
l
Male pipe threads must be wrapped with antiseize tape before
installation.
l
When installing fuel transmitter unit, do not use screw hole
closest to vehicle frame. Ground wire will be installed at that
location.
Position new gasket (7) on fuel transmitter unit (2) and install unit (2) on fuel tank (6) with four
screws (1).
Install return line elbow (4) and two vent line elbows (5) on top of fuel tank (6).
Install fuel supply tube with elbow (3) on top of tank (6).
NOTE
Assistant will help with step 4.
Place fuel tank (6) on two hangers (8).
Install two hangers straps (14) on hangers (8) with two screws (18) and new locknuts (19).
Install outer ends of two hanger straps (14) on hangers (8) with two new locknuts (15).
NOTE
Perform step 7 for M934/A1/A2 model vehicles.
Install fitting (22), adapter (21), and personnel heater fuel supply line (20) on fuel tank (6).
Install ground wire (11) on fuel transmitter unit (2) with screw (10).
Connect fuel transmitter wire (9) to fuel transmitter unit (2).
Connect fuel supply line (12) to elbow (3).
Connect fuel return line (16) to elbow (4).
Connect vent lines (13) and (17) to elbows (5).

TM 9-2320-272-24-l

3-26. FUEL TANK MAINTENANCE (Contd)

FOLLOW-ON TASK: Install fuel tank filler cap and spout (para. 3-25).
3-83

TM 9-2320-272-24-1

3-27. FUEL TANK (M936/A1/A2) MAINTENANCE
THIS TASK COVERS:
a. Draining
b. Removal

c. Inspection
d. Installation

INITIAL SETUP:
APPLICABLE MODELS
M936/A1/A2
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Two lockwashers (Appendix D, Item 358)
Gasket (Appendix D, Item 144)
Gasket (Appendix D, Item 143)
Gasket (Appendix D, Item 142)
Locknut (Appendix D, Item 299)
Three locknuts (Appendix D, Item 288)
Lockwasher (Appendix D, Item 379)
Antiseize tape (Appendix C, Item 72)

REFERENCES (TM)
FM 43-2
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
GENERAL SAFETY INSTRUCTIONS
Diesel fuel is flammable. Do not perform this
procedure near flames.

WARNING
Diesel fuel is highly flammable. Do not perform fuel system
procedures near open flame. Injury to personnel may result.
NOTE
The replacement procedure for right and left fuel tanks is basically
the same. This procedure covers the left fuel tank.

1.

Loosen fuel filler cap (2) at top of tank (1).

2.
3.
4.

NOTE
Have drainage container ready to catch fuel.
Remove drainplug (4) and gasket (3) from bottom of fuel tank (1). Discard gasket (3).
After draining is complete, install new gasket (3) and drainplug (4) in fuel tank (1).
Tighten fuel filler cap (2) on fuel tank (1).

b. Removal
1.
2.
3.

3-84

Loosen two nuts on screws (6) on wrecker body (5), and slide stop plate (7) upward.
Remove outrigger (8) from body (5).
Remove locknut (14), screw (9), washer (10), ground wire (11), and lockwasher (12) from left side of
frame (13) and double check valve (15). Discard locknut (14) and lockwasher (12).

TM 9-2320-272-24-1

3-27. FUEL TANK (M936/A1/A2) MAINTENANCE (Contd)

3-85

TM 9-2320-272-24-1

3-27. FUEL TANK (M936/A1/A2) MAINTENANCE (Contd)
4.

5.
6.
7.

8.
9.
10.
11.
12.

13.
14.
15.

3-86

Disconnect fuel transmitter wire (6) from fuel transmitter unit (16).
NOTE
Perform steps 5, 6, and 7 for left fuel tank only.
Disconnect rubber hose adapter (4) from fuel supply line (3).
Disconnect rubber hose adapter (1) from fuel return line (2).
Remove locknut (24), screw (21), and clamps (22) and (23) from left side of frame (5). Discard
locknut (24).
NOTE
l Perform steps 8 and 9 for right side fuel tank only.
l
Tag lines and fittings for installation.
Disconnect fuel supply line (7) from elbow (15).
Disconnect fuel return line (14) from elbow (11).
Remove vent lines (9) and (19) from elbows (10) and (20).
Disconnect wire connector (25) from right side marker light (26).
Disconnect wire connector (29) from left side marker light (32).
NOTE
l Assistant will help with steps 13 through 15.
l
Screws for marker light are accessible through storage
compartment 1A (TM 9-2320-272-10).
Remove two nuts (31), lockwashers (30), screws (27), and left side marker light (32) from body (28).
Discard lockwashers (30).
Remove two locknuts (12) and hanger straps (8) and (17) from hangers (13). Discard locknuts (12).
Remove fuel tank (18) from hangers (13).

TM 9-2320-272-24-1

3-27. FUEL TANK (M936/A1/A2) MAINTENANCE (Contd)

LEFT SIDE

3-87

TM 9-2320-272-24-1

3-27. FUEL TANK (M936/A1/A2) MAINTENANCE (Contd)

16.
17.
18.
19.
20.
21.
22.

NOTE
Tag fittings and transmitter unit for direction during installation.
Remove fuel supply tube and elbow (5) from top of fuel tank (8).
Remove vent line elbows (7) and (9) from top of fuel tank (8).
Remove return line elbow (6) from top of fuel tank (8).
Remove screw (2) and ground wire (3) from fuel transmitter unit (4).
Remove four screws (2), fuel transmitter unit (4), and gasket (11) from fuel tank (8). Discard
gasket (11).
Remove filler cap (1) and disconnect S-chain (13) from fuel strainer (12).
Remove fuel strainer (12) and gasket (10) from fuel tank (8). Discard gasket (10).

c. Inspection
Inspect fuel tank (8) for cracks, holes, and stripped threads (FM 43-2).
d. Installation

1.
2.

3.
4.
5.

3-88

NOTE
Male pipe threads must be wrapped with antiseize tape before
installation.
Install new gasket (10) and fuel strainer (12) in fuel tank (8).
Connect S-chain (13) to fuel strainer (12) and install filler cap (1).
NOTE
Do not us screw hole nearest to vehicle frame.
Install new gasket (11) and fuel transmitter unit (4) on fuel tank (8) with four screws (2).
Install ground wire (3) on fuel transmitter unit (4) with screw (2).
Install return line elbow (6) and vent line elbows (7) and (9) on top of fuel tank (8).

TM 9-2320-272-24-1

3-27. FUEL TANK (M936/A1/A2) MAINTENANCE (Contd)

3-89

TM 9-2320-272-24-1

3-27. FUEL TANK (M936/A1/A2) MAINTENANCE (Contd)

6.
7.
8.
9.
10.

11.
12.
13.

14.
15.
16.
17.

3-90

NOTE
Assistant will help with steps 6 through 10.
Place fuel tank (18) on two hangers (13) far enough to support tank (18).
Connect vent lines (9) and (19) to elbows (10) and (20).
Connect fuel supply line (7) to elbow (15).
Connect fuel return line (14) to elbow (11).
Install hanger straps (8) and (17) on hangers (13) with two new locknuts (12).
NOTE
Slide fuel tank all the way in before performing steps 11 and 12.
Install left side marker light (30) on body (26) with two screws (25), new lockwashers (28), and
nuts (29).
Connect left side marker light (30) to harness connector (27).
Connect right side marker light (32) to harness connector (31).
NOTE
Perform steps 14, 15, and 16 for left side tank only
Connect fuel supply line (3) to rubber hose adapter (4).
Connect fuel return line (2) to rubber hose adapter (1).
Install clamps (22) and (23) on frame (5) with screw (21) and new locknut (24).
Connect fuel transmitter wire (6) to fuel transmitter unit (16).

TM 9-2320-272-24-1

3-27. FUEL TANK (M936/A1/A2) MAINTENANCE (Contd)
18.
19.
20.
21.

Install ground wire (37) on frame (5) and double check valve (34) with new lockwasher (38),
washer (36), screw (35), and new locknut (33).
Loosen two nuts on screws (40) and slide stop plate (41) upward.
Install outrigger (42) in wrecker body (39) and slide stop plate (41) down. Stop plate (41) must
contact back of slot in top of outrigger (42).
Tighten two nuts on screws (40).

LEFT SIDE

RIGHT SIDE

FOLLOW-ON TASKS: Start engine (TM 9-2320-272-10) and road test vehicle.
3-91

TM 9-2320-272-24-1

3-28. FUEL TANK HANGERS AND RETAINING STRAPS MAINTENANCE
THIS TASK COVERS:
a. Removal
b. Inspection

c. Installation

INITIAL SETUP:
APPLICABLE MODELS
All except M936/A1/A2
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Ten locknuts (Appendix D, Item 288)
Five locknuts (Appendix D, Item 291)
Two lockwashers (Appendix D, Item 379)
Eight locknuts (Appendix D, Item 309)
Adhesive sealant (Appendix C, Item 6)

l

l

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Fuel tank(s) removed (para. 3-26).
l Dual fuel tank wet air reservoir removed
(M929/A1/A2, M930/A1/A2, M931/A1/A2, and
M932/A1/A2 model vehicles (right side fuel tank
only) (para. 3-200).

NOTE
On models with dual fuel tanks (M929/A1/A2, M930/A1/A2,
M931/A1/A2, and M932/A1/A2), right side forward fuel tank
hanger must be removed and installed at direct support
maintenance.
The number of locknuts and lockwashers varies between
models. Refer to parts list for quantity for particular model.

a. Removal
1.
2.
3.
4.

6.
6.

3-92

Remove two locknuts (19), screws (8), retaining straps (22), and insulators (1) from two fuel tank
hangers (14). Discard locknuts (19).
Remove eight locknuts (13), screws (15), and two hanger stabilizing straps (12) from hangers (14).
Discard locknuts (13).
Remove four locknuts (9), screws (11), and two support brackets (10) from fuel tank hangers (14).
Discard locknuts (9).
Remove locknut (6), bracket (5), lockwasher (4), washer (3), screw (21), lockwasher (4), washer (3),
ground lead (20), and lockwasher (4) from hanger (14) and frame (7). Discard lockwashers (4) and
locknut (6).
NOTE
Assistant will help with step 5.
Remove eight locknuts (2), screws (18), and two fuel tank hangers (14) from frame (7). Discard
locknuts (2).
Remove two rubber sheets (16) and rubber sheets (17) from two fuel tank hangers (14).

TM 9-2320-272-24-1

3-28. FUEL TANK HANGERS AND RETAINING STRAPS MAINTENANCE (Contd)

3-93

TM 9-2320-272-24-1

3-28. FUEL TANK HANGERS AND RETAINING STRAPS MAINTENANCE (Contd)

1.
2.

Inspect two rubber sheets (16) and (17) for presence and damage. Replace if missing or damaged.
Inspect two insulators (1) for deterioration. Replace if missing or damaged.

c. Installation
1.
2.

3.
4.

5.
6.
7.

3-94

Apply adhesive sealant to two insulators (1) and install as needed, on retaining straps (22).
Apply adhesive sealant to two rubber sheets (16) and rubber sheets (17) and install, as needed, on
hangers (14).
NOTE
Assistant will help with step 2.
Install two fuel tank hangers (14) on frame (7) with eight screws (18) and new locknuts (2).
Place wiring harness bracket (5) over wiring harness and install new lockwasher (4), ground wire (20),
washer (3), screw (21), washer (3), new lockwasher (4), wiring harness bracket (5), and new locknut (6)
on frame (7).
Install two support brackets (10) on hangers (14) with four screws (11) and new locknuts (9).
Install two fuel hanger stabilizing straps (12) on hangers (14) with eight screws (15) and new
locknuts (13).
Install two retaining straps (22) and insulators (1) on hangers (14) with two screws (8) and new
locknuts (19).

TM 9-2320-272-24-1

3-28. FUEL TANK HANGERS AND RETAINING STRAPS MAINTENANCE (Contd)

FOLLOW-ON TASKS: • Install fuel tank(s) (para. 3-26).
l Install dual fuel tank wet air reservoir (M929/A1/A2, M930/A1/A2, M931/A1/A2,
and M932/A1/A2 model vehicles) (right side fuel tank only) (para. 3-200).
3-95

TM 9-2320-272-24-1

3-29. FUEL TANK LINES (M939A2) REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
M939A2
TOOLS
General mechanic’s tool kit (Appendix E, Item 11
MATERIALS/PARTS
Locknut (Appendix D, Item 300)
Tiedown straps (Appendix D, Item 690)
Cap and plug set (Appendix C, Item 14)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l
Parking brake set (TM 9-2320-272-10).
l Hood raised and secured (TM 9-2320-272-10).
GENERAL SAFETY INSTRUCTIONS
Diesel fuel is flammable. Do not perform this task
near open flames.

WARNING
Diesel fuel is highly flammable. Do not perform fuel system
procedures near open flame. Injury to personnel may result.

CAUTION

1.

2.
3.
4.

3-96

Cap or plug all openings immediately after disconnecting lines and
hoses to prevent contamination. Failure to do so may result in fuel
system damage.
NOTE
Remove and discard tiedown straps as required and note locations
for installation.
Disconnect two tubing nuts (3) and remove fuel supply hose (4) from elbow (2) and fuel supply line (7).
NOTE
l
Perform step 2 if fuel filter is damaged.
l
Note position and direction of arrow for installation.
Remove two clamps (5) and fuel filter (6) from fuel supply hose (4).
Remove locknut (12), screw (8), fuel return hose (14), and clamp (13) from bracket (11). Discard
locknut (12).
Loosen two hose clamps (10) and remove fuel return hose (14) from fitting (1) and fuel return line (9).

TM 9-2320-272-24-1

3-29. FUEL TANK LINES (M939A2) REPLACEMENT (Contd)

3-97

TM 9-2320-272-24-1

3-29. FUEL TANK LINES (M939A2) REPLACEMENT (Contd)
5.
6.
7.
8.
9.
10.
11.

3-98

Remove nut (4), screw (1), and clamp (3) from fuel return line (2).
Remove nut (8), screw (5), and clamp (7) from fuel supply line (6).
Remove nut (11) from screw (9).
Remove two clamps (10) from fuel supply line (6) and fuel return line (2).
Remove nut (17), screw (15), and two clamps (16) from fuel supply line (6) and fuel return line (2).
Disconnect two tubing nuts (18) and remove tee fitting (19) and front half of fuel supply line (6)
from rear half of fuel supply line (6).
Remove nut (14), screw (12), and clamp (13) from fuel return line (2).

TM 9-2320-272-24-1

3-29. FUEL TANK LINES (M939A2) REPLACEMENT (Contd)

VIEW B

VIEW C

VIEW D

3-99

TM 9-2320-272-24-1

3-29. FUEL TANK LINES (M939A2) REPLACEMENT (Contd)
12.
13.

14.
16.
16.

17.
18.
19.

Remove nut (5), screw (1), and two clamps (4) from fuel supply line (2) and fuel return line (3).
Remove nut (11), screw (8), and two clamps (10) from fuel supply line (2), fuel return line (3), and
bracket (7).
NOTE
Perform step 14 if bracket is damaged.
Remove nut (9), screw (6), and bracket (7) from frame rail (12).
Remove nut (15), screw (13), and two clamps (14) from fuel supply line (2) and fuel return line (3).
Disconnect two tubing nuts (17) from fittings (18), and remove fuel supply line (2) and fuel return
line (3) from fuel tank (16).
NOTE
Perform steps 17 through 19 for vehicles with dual tanks.
Remove nut (22) and screw (24) from two clamps (23).
Disconnect two tubing nuts (21) from adapter fittings (20) on selector valve (19).
Remove fuel supply line (2) and fuel return line (3) from adapter fittings (20).

b. Installation
1.
2.

3.
4.
5.

6.
7.

3-100

Connect rear half of fuel supply line (2) and fuel return line (3) to fittings (18) on fuel
tank (16) with tubing nuts (17).
Install two clamps (14) on fuel supply line (2) and fuel return line (3) with screw (13) and nut (15).
NOTE
Perform step 3 if bracket was removed.
Install bracket (7) on frame rail (12) with screw (6) and nut (9).
Install two clamps (10) on fuel supply line (2), fuel return line (3), and bracket (7) with screw (8)
and nut (11).
Install two clamps (4) on fuel supply line (2) and fuel return line (3) with screw (1) and nut (6).
NOTE
Perform steps 6 and 7 for vehicles with dual tanks.
Install fuel supply line (2) and fuel return line (3) on adapter fittings (20) of selector valve (19) with
tubing nuts (21).
Install two clamps (23) on fuel supply line (2) and fuel return line (3) with screw (24) and nut (22).

TM 9-2320-272-24-1

3-29. FUEL TANK LINES (M939A2) REPLACEMENT (Contd)

VIEW E
SINGLE TANK

VIEW H
SINGLE TANK

VIEW G
SINGLE TANK

VIEW F
SINGLE TANK
n

DUAL TANK
3-101

TM 9-2320-272-24-1

3-29. FUEL TANK LINES (M939A2) REPLACEMENT (Contd)
8.
9.
10.
11.
12.
13.
14.
15.

16.
17.
18.

3-102

Install clamp (2) on fuel return line (5) with screw (1) and nut (3).
Install front half of fuel supply line (6) and rear half of fuel supply line (6) on tee (10) with tubing
nuts (9).
Install two clamps (7) on fuel supply line (6) and fuel return line (5) with screw (4) and nut (8).
Install two clamps (12) on fuel supply line (6) and fuel return line (5) with screw (11) and nut (13).
Install clamp (15) on fuel supply line (6) with screw (14) and nut (16).
Install clamp (18) on fuel return line (5) with screw (17) and nut (19).
Install fuel return hose (28) on fitting (20) and fuel return line (5) with hose clamps (24).
Install fuel return hose (28) on bracket (25) with clamp (27), screw (23), and new locknut (26).
NOTE
Perform step 16 if fuel filter was removed.
Install fuel filter (25) on fuel supply hose (23) with two clamps (24).
Install fuel supply hose (23) on fuel supply line (6) and elbow (21) with with tubing nuts (22).
Install new tiedown straps as required.

TM 9-2320-272-24-1

3-29. FUEL TANK LINES (M939A2) REPLACEMENT (Contd)

FOLLOW-ON TASKS:

l
l

Prime fuel system (para. 3-22).
Start engine (TM 9-2320-272-10) and check for fuel leaks.
3-103

TM 9-2320-272-24-1

3-30. FUEL FILTER AND COVER MAINTENANCE
THIS TASK
a. Removal
b. Removal
c. Cleaning

COVERS:
(M939A2)
(M939/A1)
and Inspection

d. Installation (M939/A1)
e. Installation (M939A2)

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Torque wrench (Appendix E, Item 146)
MATERIALS/PARTS
Adapter (M939A2) (Appendix D, Item 1)
Fluid pressure parts kit (M939/A1)
(Appendix D, Item 129)
Fuel filter (M939A2) (Appendix D, Item 135)
Three locknuts (Appendix D, Item 288)
Lint-free cloth (Appendix C, Item 21)
Antiseize tape (Appendix C, Item 72)
Drycleaning solvent (Appendix C, Item 71)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Hood raised and secured (TM 9-2320-272-10).
GENERAL SAFETY INSTRUCTIONS
l Keep fire extinguisher nearby when using dry
cleaning solvent.
l Dry cleaning solvent is flammable and toxic. Do
not use near open flame.
l Diesel fuel is flammable. Do not perform this
procedure near flames.

WARNlNG
Diesel fuel is highly flammable. Do not perform fuel system
procedures near open flames. Injury to personnel may result.
a. Removal (M939A2)

1.

2.

3-104

NOTE
Have drainage container ready to catch fuel.
Remove fuel filter (3) from fuel filter head (1). Discard fuel filter (3).
NOTE
Perform step 2 if adapter threads are stripped.
Remove adapter (2) from fuel filter head (1). Discard adapter (2).

TM 9-2320-272-24-1

3-30. FUEL FILTER AND COVER MAINTENANCE (Contd)
b. Removal (M939/Al)

1.
2.
3.
4.
5.

NOTE
Have drainage container ready to catch fuel.
Open filter drainvalve (9) and inlet drainvalve (7) located at the left front underside of cab.
Close drainvalves (9) and (7) when fuel drainage is complete.
Holding filter case (8), remove center bolt (4), square washer (5), and small O-ring (6) from top of
filter cover (12). Discard O-ring (6).
Remove filter case (8), fuel filter element (10), and large gasket (11) from filter cover (12). Discard
gasket (11) and fuel filter element (10).
Remove drainvalve (9) from filter case (10).
NOTE
If only the filter is to be replaced, perform task c, steps 2 through 5.

3-105

TM 9-2320-272-24-1

3-30. FUEL FILTER AND COVER MAINTENANCE (Contd)

6.
7.

8.
9.
10.
11.

NOTE
Perform steps 6 through 11 to repair or replace filter cover or any
fittings.
Disconnect filter inlet line (8) from adapter (7).
Disconnect filter outlet line (1) from elbow (2).
NOTE
l Assistant will help with steps 8 through 10.
l Record the directions of elbow and tee before removal.
Remove three locknuts (5), screws (3), and filter cover (11) from mounting bracket (4). Discard
locknuts (5).
Remove elbow (2) from filter cover (11).
Remove adapter (7), tee (6), and elbow (10) from filter cover (11).
Remove drainvalve (9) from tee (6).

c . Cleaning and Inspection

1.

NOTE
Perform all steps of task c if fuel filter cover was removed from
vehicle.
Inspect elbows (2) and (10), tee (6), adapter (7), and drainvalve (9) for stripped threads. Replace any
damaged part(s).
WARNING

2.
3.
4.
5.

Drycleaning solvent is flammable and will not be used near open
flame. Use only in well-ventilated places. Failure to do this may
result in injury to personnel.
Clean filter cover (11) and filter case (15) with drycleaning solvent and dry with lint-free cloth.
Inspect fuel filter cover (11) for cracks or damage to gasket seating area. Replace if cracked or
seating area is damaged.
Inspect fuel filter case (15) for cracks, stripped threads, or damage to gasket seating area. Replace if
cracked, threads are stripped, or seating area is damaged.
Inspect drainvalve (16) for stripped threads. Replace if threads are stripped.

d. Installation (M939/A1)
NOTE
All male pipe threads must be wrapped with antiseize tape
before installation.
l If only the fuel filter element was changed, go to step 5.
Install adapter elbows (2) and (10) on filter cover (11) in directions noted during removal.
NOTE
Ensure drainvalve port on tee faces down.
Install tee (6) on elbow (10).
Install drainvalve (9) and adapter (7) on tee (6).
Connect filter outlet line (1) to elbow (2), and attach filter cover (11) to mounting bracket (4) with
three screws (3) and new locknuts (5).
l

1.

2.
3.
4.

3-106

TM 9-2320-272-24-1

3-30. FUEL FILTER AND COVER MAINTENANCE (Contd)
5.
6.
7.
8.

Install drainvalve (16) in fuel filter case (15).
Position new gasket (19) in fuel filter cover (11).
Place new filter element (17) in filter case (15), with handle (18) up.
Position filter case (15) against filter cover (11) and install filter case (15) on filter cover (11) with
new O-ring (14). washer (13), and screw (12). Tighten screw (12) 20-25 lb-ft (27-34 N•m).

e. Installation (M939A2)

1.
2.
3.

NOTE
Perform step 1 if adapter was removed.
Install new adapter (20) on fuel filter head (21).
Fill new fuel filter (23) with clean diesel fuel, Coat seal (22) with diesel fuel.
Install new fuel filter (23) on fuel filter head (21). Hand-tighten fuel filter (23), then tighten an
additional 3/4 turn.

FOLLOW-ON TASKS:

l
l

Prime fuel system (para. 3-22 for M939A2; TM 9-2320-272-10 for M939/A1).
Start engine (TM 9-2320-272-10) and check for fuel leaks.
3-107

TM 9-2320-272-24-1

3-31. AFC FUEL PUMP FILTER REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All except M936/A1/A2
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Torque wrench (Appendix E, Item 146)
MATERIALS/PARTS
Filter (Appendix D, Item 121)
Gasket (Appendix D, Item 146)
Rages (Appendix C, Item 58)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Left splash shield removed (TM 9-2320-272-10).
GENERAL SAFETY INSTRUCTIONS
Diesel fuel is flammable. Do not perform this
procedure near flames.

WARNING
Diesel fuel is highly flammable. Do not perform fuel system
procedures near open flame. Injury to personnel may result.

CAUTION

1.
2.
3.

Fuel pump exterior must be cleaned before filter cap is removed to
prevent foreign particles from entering fuel pump.
Using clean, dry cloth, clean exterior of fuel pump (5) located on left side of engine (6).
Remove filter cap (3) and gasket (4) from fuel pump (5). Discard gasket (4).
Remove filter spring (2) and filter (1) from fuel pump (5). Discard filter (1).

b. Installation
CAUTION

1.
2.
3.

3-108

Ensure small end of filter spring is against filter to assure proper
fuel flow. Failure to do this will result in fuel pump damage.
Install new filter (l), open end first, in fuel pump (5).
Install new gasket (4) and filter spring (2) on filter cap (3).
Install filter cap (3) on fuel pump (5). Tighten cap (3) to 8-12 lb-ft (11-16 N-m).

TM 9-2320-272-24-1

3-31. AFC FUEL PUMP FILTER REPLACEMENT (Contd)

FOLLOW-ON TASKS: • Prime fuel system (para. 3-22 for M939A2; TM 9-2320-272-10 for M939/A1).
l Install left splash shield (TM 9-2320-272-10)
l Start engine (TM 9-2320-272-10) and check for fuel leaks.
3-109

TM 9-2320-272-24-1

3-32. FUEL PUMP WITH VS GOVERNOR FILTER REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
M936/A1/A2
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
O-ring (Appendix D, Item 424)
Filter (Appendix D, Item 121)
Cleaning cloth (Appendix C, Item 21)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Left splash shield removed (TM 9-2320-272-10).
GENERAL SAFETY INSTRUCTIONS
Diesel fuel is flammable. Do not perform this
procedure near flames.

WARNING
Diesel fuel is highly flammable. Do not perform fuel system
procedures near open flame. Injury to personnel may result.

CAUTION

1.

2.
3.
4.

Fuel pump exterior must be cleaned before filter cap is removed to
prevent foreign particles from entering fuel pump.
Using a clean, dry cloth, clean fuel pump (7) located on left side of engine (6).
NOTE
Place hand under fuel filter to catch assembly when snapring is
removed.
Remove snapring (5), retainer (3), filter spring (2), and filter (1) from fuel pump (7).
Remove O-ring (4) from retainer (3). Discard O-ring (4).
Inspect filter (1) for holes or embedded metal particles. If holes or metal particles are found, discard
filter (1).

b. Installation
1.

Install new O-ring (4) on retainer (3).
CAUTION

2.

3-110

Small end of filter spring and hole in filter screen must be facing
up toward pump to allow fuel flow. Failure to do this will result in
fuel pump damage.
Install filter (1), filter spring (2), and retainer (3) in fuel pump (7) with snapring (5).

TM 9-2320-272-24-1

3-32. FUEL PUMP WITH VS GOVERNOR FILTER REPLACEMENT (Contd)

FOLLOW-ON TASKS: • Prime fuel system (para. 3-22 for M939A2; TM 9-2320-272-10 for M939/A1).
l Install left splash shield (TM 9-2320-272-10).
l Start engine (TM 9-2320-272-10) and check fuel pump for leaks and operation.
3-111

TM 9-2320-272-24-1

3-33. ETHER START SWITCH REPLACEMENT
THIS TASK COVERS:
a. Removal

APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)

1.
2.

b. Installation

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Battery ground cables disconnected (para. 3-126).

NOTE
Prior to removal, tag wires for installation.
Disconnect two ether start switch wires (3) from harness wires (2) under left side of dash (1).
Remove nut (5) and ether start switch (4) from left side of dash (1).

b. Installation
1.
2.

Install ether start switch (4) on left side of dash (1) with nut (5).
Connect two ether start switch wires (3) to wiring harness wires (2) under left side of dash (1).

FOLLOW-ON TASK: Connect battery ground cables (para. 3-126).
3-112

TM 9-2320-272-24-1

3-34. ETHER START FUEL PRESSURE SWITCH (M939/A1) REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
M9391/A1
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)

EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Left splash shield removed (TM 9-2320-272-10).
l Battery ground cables disconnected (para. 3-126).

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
a. Removal

1.
2.

NOTE
Have drainage container ready to catch fuel.
Disconnect two wires (2) from ether start pressure switch (3).
Remove ether start fuel pressure switch (3) from bottom of fuel pump (1).

b. Installation
1.
2.

Install ether start fuel pressure switch (3) on bottom of fuel pump (1).
Connect two wires (2) to ether start pressure switch (3).

FOLLOW-ON TASKS: • Connect battery ground cables (para. 3-126).
l Install left splash shield (TM 9-2320-272-10).
3-113

TM 9-2320-272-24-1

3-35. ETHER CYLINDER AND VALVE REPLACEMENT
THIS TASK COVERS:
a. Ether Cylinder Removal
b. Ether Valve Removal

c. Ether Valve Installation
d. Ether Cylinder Installation

APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Two locknuts (Appendix D, Item 299)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Hood raised and secured (TM 9-2320-272-10).
l Left splash shield removed (TM 9-2320-272-10).
l
Battery ground cables disconnected (para. 3-126).
GENERAL SAFETY INSTRUCTIONS
Ether is flammable. Do not perform this task near
open flames.

WARNING
Ether is extremely flammable. Do not perform ether system
procedures near open flames. Injury to personnel may result.
a. Ether Cylinder Removal
1.

2.

Loosen ether cylinder clamp (12) on ether cylinder bracket (11).
NOTE
Ether cylinder must be removed quickly to allow ether cylinder
check valve to close and prevent loss of ether.
Remove ether cylinder (1) from ether valve (10).

b. Ether Valve Removal
CAUTION

1.
2.
3.

3-114

When ether cylinder is removed, cover must be installed to
prevent dust or dirt from entering valve.
NOTE
Tag wires for installation.
Disconnect wire (7) from ether valve wire (6).
Disconnect ether supply tube (8) from ether valve adapter (9).
Remove two locknuts (5), screws (2), ground wire (3), ether valve bracket (4), and ether valve (10)
from ether cylinder bracket (11). Discard locknuts (5).

TM 9-2320-272-24-1

3-35. ETHER CYLINDER AND VALVE REPLACEMENT (Contd)
c. Ether Valve Installation
1.
2.
3.

Install ether valve bracket (4), ether valve (10), and ground wire (3) on ether cylinder bracket (11)
with two screws (2) and new locknuts (5).
Connect wire (7) to ether valve wire (6).
Connect ether supply tube (8) to ether valve fitting (9).

d. Ether Cylinder Installation
Install ether cylinder (1) on ether valve (10) and ether cylinder bracket (11) and tighten clamp (12).

FOLLOW-ON TASKS:

l
l

Connect battery ground cables (para. 3-126).
Install left splash shield (TM 9-2320-272-10).
3-115

TM 9-2320-272-24-1

3-36. ETHER THERMAL CLOSE VALVE AND BUSHING REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Antiseize tape (Appendix C, Item 72)

1.
2.
3.

1.
2.
3.

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Hood raised and secured (TM 9-2320-272-10).

NOTE
Tag tubes for installation.
Disconnect thermal close ether supply tube (3) and atomizer ether supply tube (1) from adapters (2)
on thermal close valve (6).
Remove thermal close valve (6) from adapter bushing (5).
Remove adapter bushing (5) from water manifold (4).

NOTE
Male pipe threads must be wrapped with antiseize tape before
installation.
Install adapter bushing (5) in water manifold (4).
Install thermal close valve (6) in bushing (5).
Connect atomizer ether supply tube (1) and thermal close ether supply tube (3) to adapters (2) on
thermal close valve (6).

FOLLOW-ON TASK: Start engine (TM 9-2320-272-10) and check for coolant leaks around thermal close
valve and adapter bushing.
3-116

TM 9-2320-272-24-1

3-37. ETHER ATOMIZER (M939/A1) REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
M939/A1
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Antiseize tape (Appendix C, Item 72)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Hood raised and secured (TM 9-2320-272-10).

1.
2.

Disconnect ether atomizer tube (2) from ether atomizer (1).
Remove ether atomizer (1) from intake manifold (3).

1.
2.

NOTE
Male pipe threads must be wrapped with antiseize tape before
installation.
Install atomizer (1) on intake manifold (3).
Connect ether atomizer supply tube (2) to atomizer (1).

3-117

TM 9-2320-272-24-1

3-38. ETHER ATOMIZER AND TEMPERATURE SENSOR (M939A2) REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
M939A2
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERlALS/PARTS
Lockwasher (Appendix D, Item 364)
Tiedown straps (Appendix D, Item 684)
Antiseize compound (Appendix C, Item 10)
Cap and plug set (Appendix C, Item 14)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Hood raised and secured (TM 9-2320-272-10).
GENERAL SAFETY INSTRUCTIONS
Ether is flammable. Do not perform this task near
open flames.

WARNING
Ether is extremely flammable. Do not perform ether system
procedures near open flame. Injury to personnel may result.

CAUTION

1.
2.
3.
4.
5.

1.
2.
3.
4.
5.
6.

3-118

Cap or plug all openings immediately after disconnecting lines and
hoses to prevent contamination. Failure to do so may result in
damage to engine.
NOTE
Record locations of tiedown straps.
Remove tiedown straps (3) as required. Discard tiedown straps (3).
Disconnect wire connector (5) from wiring harness (4).
Remove screw (11), washer (10), ground strap (9), lockwasher (8), and temperature sensor (7) from
engine block (6). Discard lockwasher (8).
Disconnect ether supply tube (1) from ether atomizer (2).
Remove ether atomizer (2) from adapter (12).

Coat threads of ether atomizer (2) with antiseize compound and install ether atomizer (2) in
adapter (12).
Tighten ether atomizer (2) until indicator mark is in three or nine o’clock position.
Connect ether supply tube (1) to ether atomizer (2).
Install temperature sensor (7) and ground strap (9) on engine block (6) with new lockwasher (8),
washer (10), and screw (11).
Connect wire (5) to wiring harness (4).
Install new tiedown straps (3) as required.

TM 9-2320-272-24-1

3-38. ETHER ATOMIZER AND TEMPERATURE SENSOR (M939A2) REPLACEMENT (Contd)

3-119

TM 9-2320-272-24-1

3-39. ETHER TUBING REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Three tiedown straps (Appendix D, Item 684)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Left splash shield removed (TM 9-2320-272-10).
GENERAL SAFETY INSTRUCTIONS
Ether is flammable. Keep a fire extinguisher nearby.

WARNING
Ether is extremely flammable. Do not perform this procedure near
open flame. Injury to personnel may result.

1.
2.

3.
4.

1.
2.
3.
4.

3-120

Remove three tiedown straps (5) from atomizer ether supply tube (1) and thermal close ether supply
tube (4). Discard tiedown straps (5).
Disconnect thermal close ether supply tube (4) from thermal close adapter (3) and ether valve
adapter (9).
NOTE
Tag tubes for installation.
Disconnect atomizer ether supply tube (1) from thermal close adapter (2) and atomizer (6).
Disconnect ether cylinder relief tube (8) from ether cylinder relief inlet adapter (7).

Connect ether cylinder relief tube (8) to ether cylinder relief inlet adapter (7).
Connect atomizer ether supply tube (1) to thermal close adapter (2) and atomizer (6).
Connect thermal close ether supply tube (4) to thermal close adapter (3) and ether valve adapter (9).
Secure atomizer ether supply tube (1) and thermal close ether supply tube (4) with three new
tiedown straps (5).

TM 9-2320-272-24-1

3-39. ETHER TUBING REPLACEMENT (Contd)

FOLLOW-ON TASK: Install left splash shield (TM 9-2320-272-10).
3-121

TM 9-2320-272-24-1

3-40. FUEL PRIMER PUMP (M939/A1) REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
M939/A1
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Hood raised and secured (TM 9-2320-272-10).

a. Removal
1.
2.
3.
4.
5.
6.
7.

Open drainvalve (7) on primer pump (8).
Disconnect fuel primer supply line (1) from fuel primer adapter (9).
Loosen plunger retainer locknut (6) from plunger retainer (5).
Loosen and remove plunger (4) and retainer (5) from primer pump (8).
Remove plunger retainer locknut (6) from primer pump (8).
Remove jamnut (3) and primer pump (8) from accelerator bracket (2).
Remove drainvalve (7) and fuel primer adapter (9) from primer pump (8).

b. Installation
1.
2.
3.
4.
5.
6.
7.

Install drainvalve (7) and fuel primer adapter (9) on primer pump (8).
Install primer pump (8) on accelerator bracket (2) with jamnut (3). Tighten jamnut (3) against
accelerator bracket (2).
Install plunger retainer locknut (6) on primer pump (8).
Install plunger (4) and plunger retainer (5) in primer pump (8).
Tighten plunger retainer (5) on pump (8).
Tighten locknut (6) against plunger retainer (5).
Connect fuel primer supply line (1) to fuel primer adapter (9).

FOLLOW-ON TASK: Prime fuel system (para. 3-22 for M939A2; TM 9-2320-272-10 for M939/A1).
3-122

TM 9-2320-272-24-1

3-41. ACCELERATOR PEDAL, BRACKET, ROD, AND STOPSCREW REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Two cotter pins (Appendix D, Item 66)

1.
2.
3.
4.
5.
6.

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Left splash shield removed (TM 9-2320-272-10).

Remove cotter pin (2) and washer (3) from accelerator pedal push rod (1). Discard cotter pin (2).
Remove hinge pin (8) and accelerator pedal (4) from accelerator pedal bracket (6).
Remove two screws (5) and bracket (6) from cab floor (7).
Remove cotter pin (13), washer (ll), and accelerator pedal rod (1) from link assembly (12). Discard
cotter pin (13).
Loosen jamnut (10) above cab floor (7) and remove accelerator pedal stopscrew (9).
Remove jamnut (10) from pedal stopscrew (9).

b. Installation
1.
2.
3.
4.
5.

Install jamnut (10) on pedal stopscrew (9) to limit of threads.
Install pedal stopscrew (9) on cab floor (7) and tighten jamnut (10) against cab floor (7).
Install accelerator pedal bracket (6) on cab floor (7) with two screws (5).
Install accelerator pedal (4) on bracket (6) with hinge pin (8).
Install accelerator pedal push rod (1) on accelerator pedal (4) and link assembly (12) with washers (3)
and (11) and new cotter pins (13) and (2). Spread ends of cotter pins (2) and (13) after adjustment.

FOLLOW-ON TASKS: • Adjust accelerator linkage (para. 3-42 or 3-43).
l Install left splash shield (TM 9-2320-272-10).
3-123

TM 9-2320-272-24-1

3-42. ACCELERATOR LINKAGE (M939/A1) MAINTENANCE
THIS TASK COVERS:
a. Removal
b. Installation

APPLICABLE MODELS
M939/A1
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERALS/PARTS
Locknut (Appendix D, Item 276)
Locknut (Appendix D, Item 277)
Screw (Appendix D, Item 569)
Spring pin (Appendix D, Item 674)

1.
2.
3.

4.
6.

1.
2.
3.
4.

c. Adjustment

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Hood raised and secured (TM 9-2329-272-10).
l Left splash shield removed (TM 9-2320-272-10).

Remove locknut (2), screw (6), and clevis rod (1) from throttle lever (7). Discard screw (6) and
locknut (2).
Disconnect return spring (8) from accelerator rod (5) and link assembly (12).
While holding nut (11), remove locknut (13) and accelerator rod (5) from link assembly (12). Discard
locknut (13).
NOTE
Record position of accelerator rod in ball joint for installation.
Loosen jamnut (9) and remove ball joint (10) from accelerator rod (5).
Remove spring pin (3), clevis rod (1), and spring (4) from accelerator rod (5). Discard spring
pin (3).

5.
6.

Install spring (4) and clevis rod (1) on accelerator rod (5) and secure with new spring pin (3).
Install ball joint (10) on accelerator rod (5).
Position accelerator rod (5) and ball joint (10) on link assembly (12).
While holding nut (11), install and tighten new locknut (13) on ball joint (10).
NOTE
If hole in clevis and throttle lever do not align, go to adjustment,
task c.
Connect clevis rod (1) to throttle lever (7) with new screw (6) and new locknut (2).
Connect return spring (8) to accelerator rod (5) and link assembly (12).

1.
2.

NOTE
Perform step 1 only if link assembly was removed.
Disconnect return spring (8) from link assembly (12) and accelerator rod (5).
Remove screw (6) and locknut (2). Discard locknut (2) and screw (6).

3-124

TM 9-2320-272-24-1

3-42. ACCELERATOR LINKAGE (M939/A1) MAINTENANCE (Contd)

3.
4.
6.
6.
7.
8.

NOTE
Assistant will help with steps 3 through 8.
Push throttle lever (7) forward to FULL THROTTLE position.
Pull clevis rod (1) forward as far as possible.
Loosen jamnut (9) and hand-turn accelerator rod (5) to shorten or lengthen as needed to align holes
in clevis rod (1) and throttle lever (7).
Install clevis (1) on throttle lever (7) with new screw (6) and new locknut (2).
Tighten jamnut (9) against ball joint (10).
Connect return spring (8) to accelerator rod (6) and link assembly (12).

FOLLOW-ON TASK: Install left splash shield (TM 9-2320-272-10).
3-125

TM 9-2320-272-24-1

3-43. ACCELERATOR LINKAGE (M939A2) MAINTENANCE
THIS TASK COVERS:
a. Removal
b. Disassembly
c. Cleaning and Inspection

d. Assembly
e. Installation
f. Adjustment

INITIAL SETUP:
APPLICABLE MODELS
M939A2
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERlALS/PARTS
Locknut (Appendix D, Item 277)
Two cotter pins (Appendix D. Item 46)

1.
2.
3.
4.
5.

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10.
l Hood raised and secured (TM 9-2320-272-10).

Compress spring-loaded sleeve (22) and remove quick-disconnect socket (21) from ball joint (1) on
control lever (2).
Remove throttle return spring (14) from accelerator rod (15) and throttle shaft (6).
Remove locknut (9) and ball joint (12) from bracket (8). Discard locknut (9).
Loosen screw (11) and remove connector (10) and cable (3) from bracket (8).
Remove two cotter pins (5), washers (7), throttle shaft (61, and bracket (8) from bracket (4). Discard
cotter pins (5).

b. Disassembly

1.
2.
3.
4.

5.

3-126

NOTE
Assistant will help with step 1.
Compress spring (17) and remove pin (16), spring (17), and yoke (18) from accelerator rod (15).
Loosen nut (19) and remove yoke (18) from rod (20).
Remove nut (19) from rod (20).
Remove rod (20) from quick-disconnect socket (211.
NOTE
Mark position of nut on accelerator rod for installation.
Loosen nut (13) and remove ball joint (12) from accelerator rod (15).

TM 9-2320-272-24-1

3-43. ACCELERATOR LINKAGE (M939A2) MAINTENANCE (Contd)

3-127

TM 9-2320-272-24-1

3-43. ACCELERATOR LINKAGE (M939A2) MAINTENANCE (Contd)

1.
2.
3.

For general cleaning instructions, refer to para. 2-14.
For general inspection instructions, refer to para. 2-15.
Replace all parts failing inspection.

1.
2.
3.
4.
5.
6.

7.

Position nut (13) to mark on accelerator rod (15).
Install ball joint (12) on accelerator rod (15).
Install rod (20) on quick-disconnect socket (21).
Install nut (19) on rod (20). Finger tighten nut (19).
Install yoke (18) on rod (20) so several threads are between yoke (18) and nut (19).
Install yoke (18) and spring (17) on accelerator rod (15).
NOTE
Assistant will help with step 7.
Compress spring (17) and install pin (16) in accelerator rod (15).

1.
2.
3.
4.

Install
Install
Install
Install

1.
2.
3.
4.
5.

6.
7.
8.
9.

3-128

bracket (8) on bracket (4) with throttle shaft (6), two washers (7), and new cotter pins (5).
connector (10) and cable (3) on bracket (8) and tighten screw (11).
ball joint (12) on bracket (8) with new locknut (9).
throttle return spring (14) on accelerator rod (15) and throttle shaft (6).

NOTE
Position control lever (2) to idle position.
Turn rod (20) until control lever (2) moves forward 0.125 in. (3.2 mm).
Tighten nut (19) securely.
Depress spring-loaded sleeve (22) and install quick-disconnect socket (21) on ball joint (1).
Check for engine idle at 550-650 rpm.
NOTE
Perform steps 6, 7, and 8 as necessary to obtain correct idle speed.
Compress spring-loaded sleeve (22) and disconnect socket (21) from ball joint (1).
Loosen jamnut (19) and lengthen or shorten rod (20) by turning rod (20) into or out of yoke (18) to
obtain correct movement for idle speed.
Depress spring-loaded sleeve (22) and install quick-disconnect socket (21) on ball joint (1).
Tighten jamnut (19) when correct idle speed is obtained.

TM 9-2320-272-24-1

3-43. ACCELERATOR LINKAGE (M939A2) MAINTENANCE (Contd)

FOLLOW-ON TASK: Start engine (TM 9-2320-272-10) and check engine idle.
3-129

TM 9-2320-272-24-1

3-44. EMERGENCY STOP CONTROL CABLE MAINTENANCE
THIS TASK COVERS:
a. Removal
b. Inspection

c. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Locknut (M939/A1) (Appendix D, Item 313)
Lockwasher (M939/A1) (Appendix D, Item 381)
Lockwasher (Appendix D, Item 354)
Lockpin (M939A2) (Appendix D, Item 271)
GAA grease (Appendix C, Item 28)

1.
2.
3.
4.

5.
6.
7.
8.
9.

10.
11.
12.

13.

3-130

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Hood raised and secured (TM 9-2320-272-10).
l Battery ground cables disconnected (para. 3-126).
l Left splash shield removed (TM 9-2320-272-10).

NOTE
Steps 1 through 4 are for M939A2 series vehicles.
Remove lockpin (10), washer (11), and cable pivot (4) from shutoff valve lever (1). Discard
lockpin (10).
Remove screw (2), connector (3), and cable pivot (4) from cable (5).
Remove screw (9), clamp (7), and cable conduit (6) from fuel bracket (8).
Remove clamp (7) from conduit (6).
NOTE
Steps 5 through 9 are for M939/A1 series vehicles.
Remove connector screw (18) and connector (19) from shutoff valve control lever (28) and cable (5).
Remove connector (19) from stop control cable (5).
Remove locknut (24), washer (25), and screw (21) from clamp (20) on conduit (6) and conduit clamp
bracket (26). Discard locknut (24).
Remove screw (23), lockwasher (22), and clamp bracket (26) from engine (27). Discard lockwasher (22).
Remove clamp (20) from conduit (6).
NOTE
Steps 10 through 13 applies to all vehicles.
From behind instrument panel (15), remove nut (12) and lockwasher (13) on emergency stop
control (14). Discard lockwasher (13).
Pull emergency stop control (14), conduit (6), and cable (5) through firewall (17), grommet (16), and
instrument panel (151.
Remove grommet (16) from tirewall (17).
NOTE
Perform step 13 only if replacing stop control cable.
Remove stop control cable (5) and handle of stop control (14) from conduit (6).

TM 9-2320-272-24-1

3-44. EMERGENCY STOP CONTROL CABLE MAINTENANCE (Contd)

3-131

TM 9-2320-272-24-1

3-44. EMERGENCY STOP CONTROL CABLE MAINTENANCE (Contd)

1.
2.

1.

2.
3.
4.
5.

6.
7.
8.
9.
10.
11.

12.
13.
14.
15.
16.

17.
18.
19.

3-132

Inspect stop control cable (8) for bends, breaks, or damage. Replace cable (8) if broken, bent, or
damaged.
Inspect conduit (5) for breaks on kinks that could cause cable (8) to bind. Replace conduit (5) if
broken or kinked.

Perform step 1 only if replacing cable in conduit.
Coat stop control cable (8) with light film of GM grease and thread through cable conduit (5)
NOTE
Steps 2 through 5 applies to all vehicles.
Thread stop control conduit (5) and cable (8) through instrument panel (4) and seat stop
control (3) in panel (4).
Place new lockwasher (2) and nut (1) over conduit (5) and install on stop control (3). Tighten nut (1)
on stop control (3).
Install grommet (6) in firewall (7).
Thread cable (8) and conduit (5) through grommet (6) and firewall (7).
NOTE
Steps 6 through 11 apply to M939/A1 series vehicles.
Thread cable (8) through hole in shutoff valve control lever (18).
Push shutoff lever (18) all the way forward and slide connector (10) over cable (8) and against
shutoff lever (18).
Install screw (9) in connector (10) and tighten screw (9) against cable (8).
Bend end of cable (8) projecting beyond connector (10) upward at a 90° angle.
Install clamp bracket (17) on engine (19) with screw (14) and new lockwasher (13).
Install stop control clamp (11) on conduit (5) and clamp bracket (17) with screw (12), washer (16), and
new locknut (15).
NOTE
Steps 12 through 16 apply to M939A2 series vehicles.
Position clamp (24) over cable conduit (5) and install clamp (24) on fuel bracket (25) with screw (26).
Position cable pivot (23) on cable (8), put pivot (23) into shutoff lever (20), and secure with
washer (28) and new lockpin (27).
Place connector (22) over cable (8) and snugged up to cable pivot (23).
Install screw (21) in connector (22) to secure connector (22) on cable (8).
Bend end of cable (8) projecting beyond connector (22) upward at 90° angle.
NOTE
Step 17 applies to all vehicles.
Start engine (TM 9-2320-272-10) and check for correct emergency stop operation.
For M939A2 series vehicles, loosen screw (21) in connector (22) and adjust as needed to achieve
engine cutoff.
For M939/A1 series vehicles, loosen screw (9) in connector (10) and adjust as needed to achieve
engine cutoff.

TM 9-2320-272-24-1

3-44.

FOLLOW-ON TASKS: • Connect battery ground cables (para. 3-126).
l Install left splash shield (TM 9-2320-272-10).
l Start engine (TM 9-2320-272-10) and test emergency stop control for proper
operation.
3-133

TM 9-2320-272-24-1

3-45. THROTTLE CONTROL CABLE MAINTENANCE
THIS TASK COVERS:
a. Removal
b. Inspection

c. Installation

APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Lockwasher (Appendix
Lockwasher (Appendix
Locknut (Appendix D,
GM grease (Appendix

D, Item 372)
D, Item 381)
Item 277)
C, Item 28)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Hood raised and secured (TM 9-2320-272-10).
l Left splash shield removed (TM 9-2320-272-10).

NOTE
Throttle control cable maintenance for all vehicles is basically the
same. This procedure covers M939/A1 series vehicles.

1.
2.

3.
4.
5.
6.
7.
8.
9.

10.

3-134

Throttle cable end may have to be straightened before performing
step 1.
Remove screw (18) and connector (17) from throttle cable (19).
Remove throttle cable (191 from throttle rod link (16).
NOTE
Perform step 3 if unmodified throttle routing (throttle cable on
bracket). Perform step 4 if throttle cable clamp is mounted on
firewall.
Remove locknut (12), washer (11), conduit clamp (14), and screw (15) from bracket (9) on firewall (10).
Discard locknut (12).
Remove screw (20), conduit (13) with clamp (21), wire harness (22) with clamp (23), washer (24),
ground strap (25), and lockwasher (26) from firewall (10). Discard lockwasher (26).
Pull conduit (13) and throttle cable (19) through grommet (1) in firewall (10) and into vehicle cab.
Remove grommet (1) from firewall (10).
Remove four screws (4) from throttle control plate (7) and instrument panel (2).
Remove nut (3), lockwasher (8), and plate (7) from throttle control (6). Discard lockwasher (8).
Remove throttle control (6), plate (7), and conduit (13) from instrument panel (2).
NOTE
Perform step 10 if throttle control cable is to be replaced.
Remove throttle control handle (5) and cable (19) from conduit (13).

TM 9-2320-272-24-1

3-45. THROTTLE CONTROL CABLE MAINTENANCE (Contd)

3-135

TM 9-2320-272-24-1

3-45. THROTTLE CONTROL CABLE MAINTENANCE (Contd)

1.
2.

Inspect throttle cable (14) for bends, breaks, and damage. Replace if bent, broken, or damaged,
Inspect conduit (10) for breaks and kinks that could bind on cable (14). Replace conduit (10) if
broken or kinked.

NOTE
If throttle control cable is being replaced, installed, or if throttle
sticks in the DOWN position, follow this installation procedure.
l Perform step 1 if throttle cable is new or has been removed from
conduit.
Coat throttle cable (14) with light film of GM grease and thread through cable conduit (10).
Install plate (7) over conduit (10) and secure to throttle control (6) with new lockwasher (8) and
nut (3).
Coat control cable (14) with light coat of GAA grease and feed throttle control cable (14) and
conduit (10) through instrument panel (2) and secure plate (7) to instrument panel (2) with four
screws (4).
Install grommet (1) in firewall (22).
Thread control cable (14) and conduit (10) through grommet (1) and into engine side of firewall (22).
Position conduit clamp (16) over conduit (10) and feed control cable (14) through hole in throttle rod
link (11).
NOTE
Throttle rod link and handle on end of control cable must be in
closed throttle position before performing step 7.
Ensuring handle (5) is fully seated on control (6), install connector (12) over control cable (14), slide
connector (12) up cable (14) into contact with link (11), and install screw (13). Bend projecting end of
cable (14) up at connector (12).
Install conduit clamp (16) and wiring harness (17) with clamp (18), washer (19), strap (20). and new
lockwasher (21) on firewall (22) with screw (15).
l

1.
2.
3.
4.
5.
6.

7.
8.

3-136

TM 9-2320-272-24-1

3-45. THROTTLE CONTROL CABLE MAINTENANCE (Contd)

FOLLOW-ON TASKS: • Install left splash shield (TM 9-2320-272-10).
l Start engine (TM 9-2320-272-10) and test throttle control for proper operation.
3-137

TM 9-2320-272-24-1

3-46. THROTTLE CONTROL SOLENOID (M939A2) REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
M939A2
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Hood raised and secured (TM 9-2320-272-10).
l Battery ground cables disconnected (para. 3-126).

1.
2.
3.
4.

Disconnect plug (6) from wiring harness (7).
Remove two screws (4) and throttle control solenoid (5) from bracket (3).
Remove boot (8) from throttle control solenoid (5).
Remove two screws (2) and bracket (3) from engine (1).

1.
2.
3.
4.

Install bracket (3) on engine (1) with two screws (2).
Install boot (8) on throttle control solenoid (5).
Install throttle control solenoid (5) on bracket (3) with two screws (4).
Connect plug (6) to wiring harness (7).

FOLLOW-ON TASK: Connect battery ground cables (para. 3-126).
3-138

TM 9-2320-272-24-1

Section IV. EXHAUST SYSTEM MAINTENANCE
3-47. EXHAUST SYSTEM MAINTENANCE INDEX
PARA.
NO.

TITLE

PAGE
NO.

3-48.

Exhaust Stack Replacement

3-140

3-49.

Rear Exhaust Pipe, Support Bracket, and Cab
Heat Shield Maintenance
Front Exhaust Pipe Replacement
Muffler and Shield Maintenance

3-142
3-144
3-146

3-50.
3-51.

3-139

TM 9-2320-272-24-1

3-48. EXHAUST STACK REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Gasket (Appendix D, Item 170)
Locknut (Appendix D, Item 317)
GM grease (Appendix C, Item 28)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
GENERAL SAFETY INSTRUCTIONS
Do not touch hot exhaust system components with
bare hands.

WARNING

1.

Remove

2.
3.

Remove
Remove
remains

Do not touch hot exhaust system components with bare hands.
Injury to personnel may result.
locknut (6) and screw (3) from clamp (2) at right rear of cab (7). Discard locknut (6).
NOTE
Assistant will help with step 2.
clamp (2) from exhaust stack (1) and muffler (4).
exhaust stack (1) and gasket (5) from muffler (4). Discard gasket (5) and clean gasket
from mating surfaces.

b. Installation
1.

2.

3-140

Apply small amount of GM grease on muffler mating surface, and position new gasket (5) and
exhaust stack (1) over muffler (4) so opening of exhaust stack (1) is directly away from cab (7).
NOTE
Assistant will help with step 2.
Secure exhaust stack (1) to muffler (4) with clamp (2), screw (3), and new locknut (6).

TM 9-2320-272-24-1

3-48. EXHAUST

FOLLOW-ON TASK: Start engine (TM 9-2320-272-10) and check for exhaust leaks.
3-141

TM 9-2320-272-24-1

3-49. REAR

THIS TASK COVERS:
a.
Removal
b.
Inspection

c. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Two gaskets (Appendix D, Item 170)
Two locknuts (Appendix D, Item 317)
Two locknuts (Appendix D, Item 291)
Two locknuts (Appendix D, Item 294)
GAA grease (Appendix C, Item 28)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
GENERAL SAFETY INSTRUCTIONS
Do not touch hot exhaust system components with
bare hands.

WARNING

1.
2.
3.
4.
5.
6.

Do not touch hot exhaust system components with bare hands.
Injury to personnel may result.
Remove two screws (14) and heat shield (13) from cab heat shield brackets (7).
Remove locknut (3), screw (20), exhaust pipe coupling clamp (4), and gasket (2) from muffler
flange (1). Discard locknut (3) and gasket (2).
Remove locknut (12), screw (8), exhaust pipe coupling clamp (9), and gasket (10) from front exhaust
pipe flange (11). Discard locknut (12) and gasket (10).
Remove two locknuts (15), screws (5), top support bracket (6), and rear exhaust pipe (19) from bottom
support bracket (6), muffler flange (11), and front exhaust pipe flange (11). Discard locknuts (15).
Remove two locknuts (17), screws (16), and bottom support bracket (6) from crossmember (18).
Discard locknuts (17).
Remove gasket remains from rear exhaust pipe (19) flange, front exhaust pipe flange (11), and
muffler flange (1).

Inspect rear exhaust pipe (19), front exhaust pipe flange (11), and muffler flange (1) for cracks. Replace if
cracked.

1.
2.
3.

3-142

Install bottom support bracket (6) on crossmember (18) with two screws (16) and new locknuts (17).
Apply small amount of GAA grease on new gaskets (2) and (10), and position gaskets (2) and (10) on
muffler flange (1) and front exhaust pipe flange (11).
Install rear exhaust pipe (19) on bottom support bracket (6) with top support bracket (6), two
screws (5), and new locknuts (15).

TM 9-2320-272-24-1

3-49. REAR

4.
5.

Install rear exhaust pipe (19) on muffler flange (1) and front exhaust pipe flange (11) with exhaust
pipe coupling clamps (4) and (9), screws (20) and (8), and new locknuts (3) and (12).
Install heat shield (13) on two cab heat shield brackets (7) with screws (14).

FOLLOW-ON TASK: Start engine (TM 9-2320-272-10) and check for exhaust leaks.
3-143

TM 9-2320-272-224-1

3-50. FRONT

THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE/MODELS
All

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P

TOOLS
General mechanic’s tool kit (Appendix E, Item 1) EQUIPMENT CONDITION
• Parking brake set (TM 9-2320-272-10).
MATERIALS/PARTS
• Hood raised and secured (TM 9-2320-272-10).
Locknut (Appendix D, Item 317)
• Right splash shield removed (TM 9-2320-272-10).
Gasket (Appendix D, Item 170)
GENERAL SAFETY INSTRUCTIONS
Gasket (Appendix D, Item 175)
GAA grease (Appendix C, Item 28)
Do not touch hot exhaust system components with
bare hands.

WARNING

1.
2.
3.
4.

1.
2.
3.
4.

3-144

Do not touch hot exhaust system components with bare hands.
Injury to personnel may result.
Remove two screws (12) and heat shield (13) from cab heat shield brackets (11).
Remove locknut (4) and manifold coupling clamp (1) from front exhaust pipe (5) and exhaust
manifold (2). Retain locknut (4).
Remove front exhaust pipe (5) and gasket (3) from exhaust manifold (2). Discard gasket (3).
Remove locknut (8), screw (10), coupling clamp (7), front exhaust pipe (5), and gasket (6) from rear
flex pipe (9). Discard locknut (8) and gasket (6).

Apply small amount of GAA grease on flange of front exhaust pipe (5), position new gasket (6) on front
exhaust pipe (5), and install pipe (5) on flex pipe (9) with coupling clamp (7), screw (10), and new
locknut (8).
Apply small amount of GM grease on flange of exhaust manifold (2), and position new gasket (3)
and front exhaust pipe (5) on exhaust manifold (2).
Install front exhaust pipe (5) on flange of exhaust manifold (2) with manifold coupling clamp (1) and
locknut (4).
Install heat shield (13) on two cab heat shield brackets (11) with screws (12).

TM 9-2320-272-24-1

3-50. FRONT

FOLLOW-ON TASKS:

• Start engine (TM 9-2320-272-10) and check for exhaust leaks.
• Install right splash shield (TM 9-2320-272-10).
3-145

TM 9-2320-272-24-1

3-51. MUFFLER

THIS TASK COVERS:
a. Removal
b. Inspection

c. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Gasket (Appendix D, Item 170)
Four locknuts (Appendix D, Item 291)
Locknut (Appendix D, Item 317)
GAA Grease (Appendix C, Item 28)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
• Parking brake set (TM 9-2320-272-10).
• Exhaust stack removed (para. 3-48).
GENERAL SAFETY INSTRUCTIONS
Do not touch hot exhaust system components with
bare hands.

WARNING

1.

2.
3.

Do not touch hot exhaust system components with bare hands.
Injury to personnel may result.
Remove four locknuts (8), screws (14), and muffler shield (1) from muffler shield support (5).
Discard locknuts (8).
NOTE
Assistant will help with steps 2 and 3.
Remove four nuts (7), lockwashers (6), two U-bolts (2), U-clamps (4), and muffler (3) from muffler
shield support (5). Retain lockwashers (6).
Remove locknut (13), screw (9), exhaust pipe coupling clamp (12), muffler (3), and exhaust pipe
gasket (11) from exhaust pipe (10). Discard locknut (13) and gasket (11).

Inspect muffler (3) for cracks. Replace if cracked.

1.

2.
3.

3-146

NOTE
Assistant will help with steps 1 and 2.
Apply small amount of GM grease on flange of exhaust pipe (10), position muffler (3) with narrow
side facing away from cab (15), and install new gasket (11) and muffler (3) on exhaust pipe (10) with
coupling clamp (12), screw (9), and new locknut (13).
Install muffler (3) on muffler shield support (5) with two U-clamps (4), U-bolts (2), four
lockwashers (6), and nuts (7).
Install muffler shield (1) on muffler shield support (5) with four screws (14) and new locknuts (8).

TM 9-2320-272-24-1

3-51. MUFFLER

FOLLOW-ON TASK: Install exhaust stack (para. 3-48).
3-147 (3-148 blank)

TM 9-2320-272-24-1

Section V. COOLING SYSTEM MAINTENANCE
3-52. COOLING

PARA.
NO.
3-53.
3-54.
3-55.
3-56.
3-57.
3-58.
3-59.
3-60.
3-61.
3-62.
3-63.
3-64.
3-65.
3-66.
3-67.
3-68.
3-69.
3-70.
3-71.
3-72.
3-73.
3-74.
3-75.
3-76.

TITLE
Cooling System Servicing
Coolant Hoses and Tubes (M939/A1) Replacement
Air Compressor Coolant Supply and Return
Tubes (M939/A1) Maintenance
Coolant Hoses and Lines (M939A2) Replacement
Air Compressor Coolant Lines (M939A2) Maintenance
Upper Radiator Hoses and Brackets (M939A2) Maintenance
Radiator (M939/A1) Replacement
Radiator (M939A2) Maintenance
Surge Tank, Radiator Vent Hose, and Manifold Return
Hose (M939/A1) Replacement
Surge Tank and Bracket (M939A2) Replacement
Radiator Fan Shroud (M939/A1) Replacement
Fan and Fan Shroud (M939A2) Maintenance
Thermostat (M939/A1) Maintenance
Thermostats and Housing (M939A2) Maintenance
Water Pump Drivebelt (M939/A1) Maintenance
Water Pump (M939/A1) Replacement
Water Pump (M939A2) Maintenance
Fan Drivebelts (M939/A1) Maintenance
Fan Drivebelt and Drivebelt Tensioner (M939A2) Replacement
Radiator Fan Blade (M939/A1)Replacement
Fan Drive Clutch Actuator (M939/A1) Maintenance
Fan Clutch and Fan Actuator (M939A2) Replacement
Fan Drive Clutch (M939/A1) Replacement
Aftercooler and Tubes (M939A2) Replacement

PAGE
NO.
3-150
3-154
3-160
3-164
3-168
3-170
3-172
3-176
3-180
3-184
3-186
3-188
3-190
3-192
3-196
3-200
3-202
3-204
3-206
3-208
3-210
3-212
3-214
3-216

3-149

TM 9-2320-272-24-1

THIS TASK COVERS:
a.
Depressurizing System
b. Draining System

c. Cleaning and Flushing System
d. Filling System

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Cleaning compound kit (Appendix C, Item 19)
Antifreeze (Appendix C, Item 8 or 9)

EQUIPMENT CINDITION
• Parking brake set (TM 9-2320-272-10).
• Hood raised and secured (TM 9-2320-272-10).
• Right splash shield removed (TM 9-2320-272-10).
GENERAL SAFETY INSTRUCTIONS
Cooling system must be depressurized to remove
surge tank cap when engine temperature is above
175°F (79°C).

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P

WARNING
Care should be taken when removing surge tank filler cap. Steam
or hot coolant under pressure may cause injury to personnel.
If engine is hot, place thick cloth over cap and turn cap to first stop. Wait until pressure has escaped then
remove cap from surge tank.

1.

2.
3.
4.

NOTE
Have drainage container ready to catch coolant.
Remove cap (1) from surge tank (2) and open drainvalve (4) on radiator (3) and allow system to
drain.
NOTE
Open drainvalve on aftercooler to permit cooling system to fully
drain.
Open aftercooler (6) drainvalve (5) on M939A2 series vehicles and allow cooling system to drain.
Inspect coolant for rust and foreign particles.
If drained coolant is heavily rusted, the partially clogged system must be cleaned and flushed.

c. Cleaning and Flushing System
Clean and flush radiator (3) and cooling system with cleaning compound kit. Follow instructions provided
with kit.

3-150

TM 9-2320-272-24-1

3-53. COOLING

3-151

TM 9-2320-272-24-1

3-53. COOLING

Table 3-1. Guide for Preparation of Antifreeze Solutions.
ETHYLENE-GLYCOL -60°F (-51 °C) INHIBITED ML-A-46153
LOWEST EXPECTED
AMBIENT
TEMPERATURE
F
C
-7
+20
+10
0
-10
-20
-30
-40
-50
-55
Below -60

-12
-18
-23
-29
-34
-40
-46
-48
Below -51

QUARTS OF
ANTIFREEZE
REQUIRED
9
11-3/4
16
19
20-1/2
23-1/2
25
22-6-1/2
28
Use arctic grade antifreeze
(-90°F)(-68°C)

ARCTIC GRADE ANTIFREEZE
-90°F (-68°C)
ML-A-11755
Freezing point of -90°F
(-68°C). Issued ready for
use and must not be mixed
with any other liquid.

CAUTION

1.
2.
3.
4.

3-152

When filling cooling system on M939A2 series vehicles, ensure
drainvalve on aftercooler is open. Failure to do so may result in
damage to equipment.
NOTE
The cooling system for the vehicles covered in this manual has a
47 qt (44.51) capacity.
Fill cooling system with required amount of antifreeze and add water to full mark. Close
aftercooler (6) drainvalve (5) when coolant starts running out of drainvalve (5) for on M939A2 series
vehicles.
Install filler cap (1) on surge tank (2).
Start engine (TM 9-2320-272-10) and run at fast idle (800-1,000 rpm) until engine temperature
reaches 185°F (85°C). At this temperature, thermostats should fully open.
Check antifreeze protection level using antifreeze tester. Follow surge tank filler cap (1) removal
procedure of task a.

TM 9-2320-272-24-1

3-53. COOLING

FOLLOW-ON TASKS: • Install right splash shield (TM 9-2320-272-10).
• Start engine (TM 9-2320-272-10) and check for coolant leaks.
3-153

TM 9-2320-272-24-1

3-54. COOLANT

THIS TASK COVERS:
a. Radiator Inlet Hoses and Tube Removal
b. Thermostat Housing Hose, Radiator
Bypass Tube, and Hose Removal
c. Surge Tank Hose Removal
d. Radiator Outlet Hoses and Tee Removal
e. Transmission Oil Cooler Hoses and
Tube Removal

f.
g.
h.
i.
j.

Transmission Oil Cooler Hoses and Tubes
Installation
Radiator Outlet Hoses and Tee Installation
Surge Tank Hose Installation
Thermostat Housing Hose, Radiator Bypass
Tube, and Hose Installation
Radiator Inlet Hoses and Tube Installation

INITIAL SETUP:
APPLICABLE MODELS
M939/A2
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Two locknuts (Appendix D, Item 313)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
• Parking brake set (TM 9-2320-272-10).
• Hood raised and secured TM 9-2320-272-10).
• Right splash shield removed (TM 9-2320-272-10).
• Coolant drained (para. 3-53).

1.
2.
3.

Loosen two clamps (2) and remove radiator inlet hose (1) from radiator (3) and inlet tube (18).
Loosen two clamps (17) and remove hose (8) from thermostat housing (16) and inlet tube (18).
Remove two locknuts (4), screws (7), clamps (6), and inlet tube (18) from upper radiator bracket (5).
Discard locknuts (4).

1.

Loosen two clamps (14) and remove thermostat hose (15) from thermostat housing (16) and bypass
tube (9).
Loosen clamp (10) and remove tube (9) from hose (11).
Loosen clamp (12) and remove hose (11) from tee (13).

2.
3.

3-154

TM 9-2320-272-24-1

3-54. COOLANT

3-155

TM 9-2320-272-24-1

3-54. COOLANT

Loosen two clamps (2) and remove surge tank hose (3) from surge tank (1) and engine oil cooler (4).

1.
2.
3.

Loosen two clamps (6) and remove hose (7) from outlet (5) and tee (8).
Loosen clamp (9) and remove tee (8) from hose (10).
Loosen clamp (11) and remove hose (10) from transmission oil cooler (12).

1.
2.
3.

Loosen two clamps (13) and remove hose (14) from transmission oil cooler (12) and tube (15).
Loosen clamp (16) and remove tube (15) from hose (17).
Loosen clamp (18) and remove hose (17) from engine oil cooler (4).

1.
2.
3.

Install hose (17) and clamp (18) on engine oil cooler (15) and tighten clamp (18).
Install tube (15) in hose (17) and tighten clamp (16).
Install two clamps (13) and hose (14) on transmission oil cooler (12) and tube (15) and tighten
clamps (13).

1.
2.
3.

Install clamp (11) and hose (10) on transmission oil cooler (12) and tighten clamp (11).
Install clamp (9) over hose (10) and install tee (8) and tighten clamp (9).
Install two clamps (6) and hose (7) on tee (8) and radiator outlet (5) and tighten clamps (6).

Install surge tank hose (3) on surge tank (1) and engine oil cooler (4) and tighten two clamps (2).

3-156

TM 9-2320-272-24-1

3-54. COOLANT

TM 9-2320-272-24-1

3-54. COOLANT

1.
2.
3.

Install bypass hose (10) and clamp (11) on tee (12) and tighten clamp (11).
Install tube (8) and clamp (9) on hose (10) and tighten clamp (9).
Install thermostat hose (14) on tube (8) and thermostat housing (15) and tighten two clamps (13).

1.
2.
3.
4.

Install
Install
Install
Install

3-158

two clamps (19) on upper radiator support (5) with two screws (6) and new locknuts (3).
clamp (16) and hose (7) on thermostat housing (15). Do not tighten clamp (16) at this time.
clamp (17) on tube (18) and install tube (18) in hose (7). Tighten clamps (16) and (17).
inlet hose (1) on radiator (4) and tube (18) with two clamps (2).

TM 9-2320-272-24-l

3-54. COOLANT

FOLLOW-ON TASKS: • Fill cooling system to proper level (para. 3-53).
• Install right splash shield (TM 9-2320-272-10).
• Start engine (TM 9-2320-272-10) and check for coolant leaks.
3-159

TM 9-2320-272-24-1

3-55. AIR

THIS TASK COVERS:
a. Supply Tube Removal
b. Return Tube Removal
c. Inspection

d. Supply Tube Installation
e. Return Tube Installation

INITIAL SETUP:
APPLICABLE MODELS
M939/A1
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Lockwasher (Appendix D, Item 349)
Four bushings (Appendix D, Item 21)
Antiseize tape (Appendix C, Item 72)

1.
2.
3.

3-160

REFERENCES (TM)
TM 9-243
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
• Parking brake set (TM 9-2320-272-10).
• Hood raised and secured (TM 9-2320-272-10).
• Cooling system drained (para. 3-63).

Loosen two flare nuts (4) and remove coolant supply tube (6) from water pump adapter (7) and air
compressor elbow (2), and slide nuts (4) to center of tube (6).
Remove and discard two bushings (3) from tube (6).
Remove water pump adapter (7) and air compressor elbow (2) from engine oil cooler (1) and air
compressor (5).

TM 9-2320-272-24-1

3-55. AIR

1.
2.
3.
4.
5.

1.
2.

Loosen flare nut (16) and disconnect coolant return tube (12) from engine oil cooler elbow (18).
Remove nut (13), lockwasher (14), washer (15), screw (8), washer (9), and coolant return tube
clamp (10) from bracket (11). Discard lockwasher (14).
Loosen flare nut (20) and remove coolant return tube (12) from elbow (22).
Remove bushings (21) and (17) from coolant return tube (12). Discard bushings (17) and (21).
Remove elbows (18) and (22) from engine oil cooler (19) and air compressor (23).

Inspect flare nuts (20) and (16), adapter (7), elbow (2), and coolant supply tube (6) for cracks and
stripped threads. Replace parts if cracked or are damaged threads. Refer to TM 9-243 for fabrication
of supply tube (6).
Inspect tubing (12) for cracks and severe bends. Discard tubing (12) if cracked or badly bent.
Refer to TM 9-243 for fabrication of tubing.

3-161

TM 9-2320-272-24-1

3-55. AIR

NOTE

1.
2.
3.
4.

3-162

Install
Install
Install
Install

Male pipe threads must be wrapped with antiseize tape before
installation.
water pump adapter adapter (7) in engine oil cooler (1).
air compressor elbow (2) on air compressor (3).
two new bushings (4) in coolant supply tube (6)
coolant supply tube (6) on air compressor elbow (2) and water pump adapter (7).

TM 9-2320-272-24-1

3-55. AIR

1.
2.
3.
4.
5.
6.

NOTE
Male pipe threads must be wrapped with antiseize tape before
installation.
Install air compressor elbow (22) on air compressor (23).
Install engine oil cooler elbow (18) on engine oil cooler (19).
Install return tube (12) on compressor elbow (22) with new bushing (21) and flare nut (20). Do not
tighten flare nut (20).
Connect return tube (12) on engine oil cooler elbow (18) with new bushing (17) and flare nut (16).
Do not tighten flare nut (16).
Install coolant return tube (12) on support bracket (11) with clamp (10), washers (9) and (15), new
lockwasher (14), and nut (13). Tighten nut (13).
Tighten flare nuts (16) and (20).

FOLLOW-ON TASKS: • Fill cooling system to proper level (para. 3-53).
• Start engine (TM 9-2320-272-10) and check for coolant leaks.
3-143

TM 9-2320-272-272-24-1

3-56. COOLANT

THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
M939A2
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Locknut (Appendix D, Item 306)
Antiseize tape (Appendix C, Item 72)

1.
2.
3.
4.
5.
6.
7.
8.
9.

10.
11.

12.
13.
14.
15.
16.

3-164

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
• Hood raised and secured (TM 9-2320-272-10).
• Right splash shield removed (TM 9-2320-272-10).
• Cooling system drained (para. 3-53).

NOTE
If removal of tiedown straps is necessary, note location for
installation.
Remove locknut (5), screw (2), clamp (3), and hose (1) from bracket (6). Discard locknut (5).
Disconnect hose (1) from adapter (4) and surge tank (18).
Remove two clamps (19) and hose (20) from surge tank (18) and thermostat housing (9).
Remove adapter (4) and two elbows (7) from radiator (8).
Remove two clamps (12) and remove hose (13) from heater valve (16) and fitting (10).
Remove two clamps (11) and remove hose (14) from heater valve (15) and fitting (17).
Remove nut (23), screw (28), clamp (27), and hose (26) from bracket (24).
Remove clamp (47) and hose (48) from surge tank fitting (21).
Remove clamp (29) and hose (26) from tube (40).
NOTE
Perform steps 10 and 11 for internal bypass systems.
Remove two clamps (36) and hose (37) from fitting (46) and thermostat canister (35).
Remove two clamps (38), hose (39), and thermostat canister (35) from tube (32).
NOTE
Perform step 12 for external bypass systems.
Remove two clamps (36) and hose (37) from fitting (49) and tube (32).
Remove two clamps (30) and hump hose (31) from outlet tube (25) and tube (32).
Remove two clamps (33) and tube (32) and hump hose (34) from transmission oil cooler (45).
Remove two clamps (41) and elbow hose (42) from outlet port (22) and tube (40).
Remove two clamps (43) and elbow hose (44) and tube (40) from transmission oil cooler (45).

TM 9-2320-272-24-1

3-56. COOLANT

3-165

TM 9-2320-272-24-1

3-56. COOLANT

1.
2.
3.
4.
5.
6.

Install
Install
Install
Install
Install
Install

7.

Install

8.
9.
10.
11.
12.
13.
14.
15.

Install
Install
Install
Install
Install
Install
Install
Install

16.
17.
18.
19.

Install
Install
Install
Install

elbow hose (24) on transmission oil cooler (25) with clamp (23).
tube (20) on elbow (24) with clamp (23).
elbow hose (22) on outlet port (2) and tube (20) with two clamps (21).
hump hose (16) on transmission oil cooler (25) with clamp (14).
tube (12) on hump hose (16) with clamp (14).
hump hose (11) on tube (12) and outlet tube (5) with two clamps (10).
NOTE
Perform step 7 for external bypass systems.
hose (19) on fitting (29) and tube (12) with two clamps (18).
NOTE
Perform steps 8, 9, and 10 for internal bypass systems.
hose (15) on tube (12) with clamp (13).
thermostat canister (17) on hose (15) with clamp (13).
hose (19) on fitting (26) and thermostat canister (17) with two clamps (18).
hose (6) on tube (20) with clamp (9).
hose (28) on surge tank fitting (1) with clamp (27).
hose (6) and clamp (7) on bracket (4) with screw (8) and nut (3).
hose (43) on heater valve (44) and fitting (46) with two clamps (42).
hose (41) on heater valve (45) and fitting (39) with two clamps (40).
NOTE
Wrap male pipe threads with antiseize tape before installation.
two elbows (36) and adapter (33) on radiator (37).
hose (49) on surge tank (47) and thermostat housing (38) with two clamps (48).
hose (30) on adapter (33) and surge tank (47).
clamp (32) and hose (30) on bracket (35) with screw (31) and new locknut (34).
CAUTION
When filling cooling system, ensure drainvalve on aftercooler is
open. Failure to do so may result in damage to equipment.

3-146

TM 9-2320-272-24-1

3-56. COOLANT

FOLLOW-ON TASKS: • Fill cooling system to proper level (para. 3-53).
• Install right splash shield (TM 9-2320-272-10).
• Start engine (TM 9-2320-272-10) and check for coolant leaks. Tighten fittings and
clamps as necessary.
3-167

TM 9-2320-272-24-1

3-57. AIR

THIS TASK COVERS:
a. Removal
b. Cleaning and Inspection

c. Installation

INITIAL SETUP:
APPLICABLE MODELS
M939A2
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Four seals (Appendix D, Item 625)
Cap and plug-set (Appendix C, Item 14)
Antiseize tape (Appendix C, Item 72)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
• Hood raised and secured (TM 9-2320-272-10).
• Right splash shield removed (TM 9-2320-272-10).
• Cooling system drained (para. 3-53).

3.

NOTE
When disconnecting water lines or hoses, plug ends and tag for
identification during installation.
Disconnect two tubing nuts (10) and remove water outlet tube (7) and two seals (5) from air
compressor (11) and elbow (2) in cylinder head (1). Discard seals (5).
Disconnect two tubing nuts (9) and remove water inlet tube (6) and two seals (4) from air
compressor (11) and elbow (3) in engine block (8). Discard seals (4).
Remove elbow (2) from cylinder head (1) and elbow (3) from engine block (8).

1.
2.
3.
4.

For general cleaning instructions, refer to para. 2-14.
For general inspection instructions, refer to para. 2-15.
Inspect tubes (6) and (7) for kinks, cracks, and bends.
Replace all parts failing inspection.

1.
2.

NOTE
Male pipe threads must be wrapped with antiseize tape before
installation.
Install elbow (3) on engine block (8) and elbow (2) on cylinder head (1).
Install water inlet tube (6) and two new seals (4) on air compressor (11) and elbow (3) on engine
block (8).
Install water outlet tube (7) and two new seals (5) on air compressor (11) and elbow (2) on cylinder
head (1).

1.
2.

3.

3-168

TM 9-2320-272-24-1

3-57. AIR

FOLLOW-ON TASKS:

• Fill cooling system to proper level (para. 3-53).
• Install right splash shield (TM 9-2320-272-10).
• Start engine (TM 9-2320-272-10) and check for coolant leaks.
3-169

TM 9-2320-272-24-1

3-58. UPPER

THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
M939A2
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Torque wrench (Appendix E, Item 144)
MATERIALS/PARTS
Locknut (Appendix D, Item 306)
Two locknuts (Appendix D, Item 280)
Two lockwashers (Appendix D, Item 360)
Two locknuts (Appendix D, Item 278)
Four isolators (Appendix D, Item 263)
Tiedown straps (Appendix D, Item 685)

1.
2.
3.
4.
5.
6.
7.
8.
9.

1.
2.
3.
4.
5.
6.
7.
8.
9.
3-170

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
• Hood raised and secured (TM 9-2320-272-10).
• Right splash shield removed (TM 9-2320-272-10).
• Coolant drained as necessary (para. 3-53).
• Fan actuator disconnected (para. 3-74)

Remove tiedown straps (4), tachometer drive cable (11), and cable (12) from radiator inlet tube (3).
Discard tiedown straps (4).
Remove two locknuts (8), washers (9), screws (5), and washers (6) from radiator inlet tube (3) and
bracket (14). Discard locknuts (8).
Remove four clamps (1), hose (2), elbow (7), and radiator inlet tube (3) from radiator (13) and
thermostat housing (10).
Remove two nuts (16), screws (19), washers (18), and hood stop cables (17) from bracket (40).
Straighten tabs of two lockwashers (41) and remove two screws (15) and lockwashers (41) from
bracket (40) and radiator (13). Discard lockwashers (41).
Remove two locknuts (37), washers (36), isolators (38), screws (33), washers (34), and isolators (35)
from bracket (14). Discard locknuts (37) and isolators (35) and (38).
Remove locknut (22), clamp (23), nut (20), washer (21), screws (24) and (26), and bracket (25) from
brackets (27) and (14). Discard locknut (22).
Remove screw (28), washer (29), and bracket (27) from engine (30).
Remove four screws (32), washers (31), and bracket (14) from engine (30).

Install bracket (14) on engine (30) with four washers (31) and screws (32). Finger tighten screws (32).
Install bracket (27) on engine (30) with washer (29) and screw (28). Finger tighten screw (28).
Install brackets (25) and (27) on bracket (14) with screw (26), washer (21), and nut (20).
Install clamp (23) on bracket (25) with screw (24) and new locknut (22).
Install two new isolators (38), new isolators (35), and bracket (40) on bracket (14) with two washers (34),
screws (33), washers (36), and new locknuts (37). Tighten screws (33) 30 lb-ft (41 N•m).
Install bracket (40) on radiator (13) with two washers (39), new lockwashers (41), and screws (15).
Tighten screws (15) 40 lb-ft (54 N•m). Tighten screws (32) 45 lb-ft (61 N•m). Tighten screw (28).
Bend tabs of two lockwashers (41) against flats of screws (15).
Install two hood stop cables (17) on bracket (40) with two washers (18), screws (19), and nuts (16).
Install hose (2), elbow (7), and radiator inlet tube (3) on radiator (13) and thermostat housing (10)
with four clamps (1).

TM 9-2320-272-24-1

3-58. UPPER

10.
11.

Install radiator inlet tube (3) on bracket (14) with two washers (6), screws (5), washers (9), and new locknuts (8).
Secure tachometer drive cable (11) and cable (12) to radiator inlet tube (3) with new tiedown straps (4).

FOLLOW-ON TASKS: •
•
•
•

Connect fan actuator (para. 3-74).
Fill cooling system (para. 3-53).
Install right splash shield (TM 9-2320-272-10).
Start engine (TM 9-2320-2272-10) and check for leaks.

3-171

TM 9-2320-272-272-1

3-59. RADIATOR

THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
M939/A1
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Locknut (Appendix D, Item 273)
Five locknuts (Appendix D, Item 291)
Two locknuts (Appendix D, Item 313)
Six locknuts (Appendix D, Item 294)
Two lockwashers (Appendix D, Item 360)
Two lockwashers (Appendix D, Item 382)
Six lockwashers (Appendix D, Item 350)
Three rubber mounts (Appendix D, Item 263)
Antiseize tape (Appendix C, Item 72)

1.
2.
3.
4.
5.

6.
7.
8.
9.
10.
11.

12.
13.

3-172

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272~24P
EQUIPMENT CONDITION
• Parking brake set (TM 9-2320-272-10).
• Hood raised and secured (TM 9-2320-272-10).
• Right and left splash shields removed
(TM 9-2320-272-1).
• Cooling system drained (para. 3-53).
• Fan shroud removed (para. 3-63).

Disconnect radiator vent hose (18) from radiator (19).
Remove two locknuts (6), washers (8), screws (9), and hood stop cables (7) from upper radiator
bracket (1). Discard locknuts (6).
Remove two screws (4), lockwashers (3), and washers (2) from upper radiator bracket (1). Discard
lockwashers (3).
Remove two locknuts (5), screws (15), and clamps (20) from upper radiator bracket (1). Discard
locknuts (5).
Remove two locknuts (11), washers (12), screws (14), and upper radiator bracket (1) from engine
bracket (10). Discard locknuts (11).
NOTE
Perform step 6 only if rubber mounts are damaged or new radiator
is being installed.
&move two rubber mounts (13) from engine bracket (10). Discard rubber mounts (13).
Loosen clamp (17) and disconnect radiator hose (16) from radiator (19).
Remove adapter (22) and two elbows (21) from radiator (19).
Remove two plugs (23) and drainvalve (24) from radiator (19).
Loosen clamp (25) and disconnect radiator outlet hose (26) from radiator (19).
Remove locknut (29), screw (37), and washer (36) from brackets (34) and (28). Discard locknut (29).
NOTE
Assistant will help with steps 12 and 13.
Remove four locknuts (30), two screws (33), and screws (38) from radiator support (34). Discard
locknuts (30).
Remove radiator (19) from vehicle.
NOTE
Perform step 14 only if rubber mount is damaged or a new
radiator is being installed.

TM 9-2320-272-24-1

3-59. RADIATOR

14.

15.
16.
17.
18.
19.

Remove and discard rubber mount (45).
NOTE
Perform step 15 only if bracket is damaged or being replaced.
Remove two screws (31), lockwashers (32), washers (27), and radiator support bracket (28) from
vehicle. Discard lockwashers (32).
Remove locknut (44), screw (48), and radiator support (34) from radiator (19). Discard locknut (44).
Remove two locknuts (40), screws (50), and control assembly (49) from mounting bracket (39).
Discard locknuts (40).
Remove four screws (43), lockwashers (42), washers (41), and mounting bracket (39) from radiator (19).
Discard lockwashers (42).
Remove two screws (46), lockwashers (47), and bracket (35) from radiator (19). Discard lockwashers (47).

3-173

TM 9-2320-272-24-1

3-59. RADIATOR

1.
2.
3.
4.
5.

6.

7.
8.
9.
10.
11.
12.
13.

14.
15.
16.
17.
18.
19.

3-174

NOTE
• If new radiator is being installed, use attaching parts and
fittings from old radiator.
• Fittings must be inspected for cracks or stripped threads.
• Male pipe threads must be wrapped with antiseize tape before
installation.
Install new rubber mount (9) in bracket (12).
Install bracket (12) on radiator (1) with two new lockwashers (11) and screws (10).
Install mounting bracket (2) on radiator (1) with four new lockwashers (5), washers (4), and
screws (6).
Install control assembly (14) on bracket (2) with two screws (15) and new locknuts (3).
Install radiator support (7) on control assembly (14) with screw (13) and new locknut (8).
NOTE
Perform step 6 only if bracket was removed.
Install radiator support bracket (23) with two washers (22), new lockwashers (28), and screws (27).
NOTE
Assistant is needed for steps 7, 8, and 9.
Install radiator (1) on frame (26).
Install radiator support (7) on support bracket (23) with two screws (29), screws (32), and four new
locknuts (25).
Install washer (30), screw (31), and new locknut (24) on brackets (12) and (23).
Connect radiator outlet hose (21) to radiator (1) and tighten clamp (20).
Install two plugs (18) and drainvalve (19) on radiator (1).
Install two elbows (16) and adapter (17) on radiator (1).
Connect radiator inlet hose (49) to radiator (1) and tighten clamp (50).
NOTE
Perform step 14 only if rubber mounts were removed.
Install two new rubber mounts (46) on engine bracket (43).
Install upper radiator bracket (34) on engine bracket (43) with two screws (47), washers (45), and
new locknuts (44).
Install upper radiator bracket (34) on radiator (1) with two screws (37), new lockwashers (36), and
washers (35).
Install two hood stop cables (39) on upper radiator bracket (34) with two screws (41), washers (40),
and new locknuts (42).
Install two clamps (33) on upper radiator bracket (34) with two screws (48) and new locknuts (38).
Connect radiator vent hose (51) on adapter (17).

TM 9-2320-272-24-1

3-59. RADIATOR

FOLLOW-ON TASKS: •
•
•
•

Install fan shroud (para. 3-63).
Fill cooling system to proper level (para. 3-53).
Install left and right splash shields (TM 9-2320-272-10).
Start engine (TM 9-2320-272-10) and check cooling system for leaks.
3-175

TM 9-2320-272-24-1

3-60. RADIATOR

THIS TASK COVERS:
a. Removal
b. Cleaning and Inspection

c. Installation

INITIAL SETUP:
APPLICABLE MODELS
M939A2
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Torque wrench (Appendix E, Item 146)
MATERIALS/PARTS
Two lockwashers (Appendix D, Item 360)
Two locknuts (Appendix D, Item 294)
Locknut (Appendix D, Item 273)
Four locknuts (Appendix D, Item 319)
Antiseize tape (Appendix C, Item 72)

1.
2.
3.
4.
5.
6.

7.
8.

9.
10.
11.

3-176

REFERENCES (TM)
TM 750-254
TM 9-2320-272-10
TM 9-2320-272-243?
EQUIPMENT CONDITION
• Parking brake set (TM 9-2320-272-10).
• Right and left splash shields removed
(TM 9-2320-272-10).
• Coolant drained (para. 3-53).
• Hood removed (para. 3-275).
• Oil cooler removed (para. 3-4).

Straighten tabs on two lockwashers (29) and remove screws (30), lockwashers (29), and washers (28)
from bracket (27) and radiator (1). Discard lockwashers (29).
Disconnect hose (5) from adapter (2).
Remove adaptor (2), elbow (3), and elbow (4) from radiator (1).
Loosen clamp (25) and disconnect hump hose (26) from inlet of radiator (1).
Loosen clamp (7) and disconnect lower hump hose (6) from outlet of radiator (1).
Remove screws (10) and (11) and washers (9) from radiator (1).
NOTE
Assistant will help with steps 7 and 8.
Remove four screws (21) and washers (20) from mounting bracket (19).
Remove radiator (1) from engine compartment (12).
NOTE
• Replace mounting bracket only if damaged.
• Retain attaching hardware, fan shroud, and fittings for
installation of new radiator.
Remove two locknuts (22), screws (18), washers (16), and radiator mounting bracket (19) from
control assembly (23). Discard locknuts (22).
Remove locknut (24), screw (15). and control assembly (23) from radiator support (13). Discard
locknut (24).
Remove four locknuts (8), screws (17), washers (14), and radiator support (13) from engine
compartment (12). Discard locknuts (8).

TM 9-2320-272-24-1

3-60. RADIATOR

1. Refer to TM 750-254 for radiator cleaning, inspection, and repair instructions.
2. Inspect mounting and fitting parts (para. 2-15).
3. Replace all parts failing inspection.

3-177

TM 9-2320-272-24-1

3-60. RADIATOR

1.
2.
3.

4.
5.
6.
7.
8.
9.
10.
11.

3-178

NOTE
• Refer to para. 3-64 for removing and installing fan and shroud.
• Perform steps 1 through 3 only if parts were removed.
Install radiator support (13) in engine compartment (12) with four washers (14), screws (17), and
new locknuts (8).
Install control assembly (23) on radiator support (12) with screw (15) and new locknut (24).
Install radiator mounting bracket (19) on control assembly (23) with two screws (18), washers (16),
and new locknuts (22).
NOTE
Assistant needed for steps 4 and 5.
Position radiator (1) in vehicle.
Attach radiator (1) to mounting bracket (19) with four screws (21) and washers (20). Hand tighten
screws (21).
Install two washers (9) and screws (10) and (11) through bracket (19) and into bottom of radiator (1).
Tighten screws (10), (11), and (21) to 40 lb-ft (55 N•m).
Connect lower hump hose (6) to outlet of radiator (1) and tighten clamp (7).
Connect upper hump hose (26) to inlet of radiator (1) and tighten clamp (25).
Wrap male threads of elbows (3) and (4) with antiseize tape and install in radiator (1).
Install adapter (2) in elbow (3) and connect hose (5) to adapter (2).
Install two washers (28), new lockwashers (29), and screws (30) through bracket (27) and into
radiator (1). Tighten screws (30) to 40 lb-ft (55 N•m). Bend tabs of lockwashers (29) over flats of
screws (30).

TM 9-2320-272-24-1

3-60. RADIATOR

FOLLOW-ON TASKS: • Install oil cooler (para. 3-4).
• Fill cooling system to proper level (para. 3-53).
• Start engine (TM 9-2320-272-10) and check cooling system for leaks. Tighten
fittings and clamps as necessary.
• Install right and left splash shields (TM 9-2320-272-10).
• Install hood (para. 3-275).
3-179

TM 9-2320-272-24-1

3-61. SURGE

THIS TASK COVERS:
a. Radiator Vent and Manifold Return
Hoses Removal
b. Surge Tank Removal

c. Surge Tank Installation
d. Radiator Vent and Manifold Return Hoses
Installation

INITIAL SETUP:
APPLICABLE MODELS
M939/A1
TOOLS

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P

General mechanic’s tool kit (Appendix E, Item 1)
Torque wrench (Appendix E, Item 144)

EQUIPMENT CONDITION

MATERIALS/PARTS
Four keywashers (Appendix D, Item 267)
Locknut (Appendix D, Item 288)
Antiseize tape (Appendix C, Item 72)

•
•
•
•

Hood raised and secured (TM 9-2320-272-10).
Parking brake set (para. 3-301).
Right splash shield removed (TM 9-2320-272-10).
Cooling system drained as required (para. 3-63).

1.
2.
3.
4.
5.
6.

Disconnect radiator vent hose (7) from adapter (13) on radiator (8).
Remove adapter (13) and elbows (12) and (11) from radiator (8).
Remove screw (5), washer (6), hose clamp (4), and spacer (10) from engine bracket (9).
Disconnect manifold return hose (2) from elbow (3) on water manifold (14).
Remove manifold return hose (2) and radiator vent hose (7) from surge tank (1).
Remove elbow (3) from water manifold (14).

1.
2.
3.
4.
5.
6.

Remove cap (15) from surge tank (1) and disconnect cap (15) from retaining pin (16).
Remove pin (19) and chain (17) from surge tank support (24).
Remove screw (18), washer (21), and surge tank support extension (28) from surge tank (1).
Remove locknut (23), screw (20), and surge tank support (24) from lifting eye (22). Discard locknut (23).
Loosen clamp (27) and disconnect engine oil cooler hose (26) from surge tank (1).
Unlock four keywashers (30) and remove four screws (29), keywashers (30), washers (31), and two
exhaust manifold clamps (32) from cylinder head (25). Discard keywashers (30).
Remove surge tank (1) from vehicle.

7.

3-180

TM 9-2320-272-24-1

3-61.SURGE

3-181

TM 9-2320-272-24-1

3-61. SURGE

1.
2.
3.
4.
5.
6.
7.

1.
2.
3.
4.
5.
6.

3-182

Install surge tank (3) on cylinder head (14) with two exhaust manifold clamps (21), four washers (20),
new keywashers (19), and screws (18). Ensure clamps (21) are parallel to surface of cylinder
head (14). Tighten screws (18) 15-20 lb-ft (20-27 N•m).
Retighten screws (18) 40-45 lb-ft (54-61 N-m) and bend tabs of keywashers (19) against flats of
screws (18).
Connect engine oil cooler hose (15) to surge tank (3) and tighten clamp (16).
Install surge tank support (13) on lifting eye (11) with screw (9) and new locknut (12).
Install surge tank support extension (17) on support (13) with washer (10) and screw (7).
Connect chain (6) to cap (4) and surge tank support (13) with pin (8).
Install cap (4) on surge tank (3) with retaining pin (5).

NOTE
• Fittings must be cleaned and inspected for cracks and crossed
or stripped threads.
• Male pipe threads must be wrapped with antiseize tape before
installation.
Install manifold return hose (22) and radiator vent hose (27) on surge tank (3).
Install elbow (23) on water manifold (1).
Install elbows (30) and (31) and adapter (32) on radiator (2).
Connect manifold return hose (22) to elbow (23) on water manifold (1).
Connect radiator vent hose (27) to adapter (32) on radiator (2).
Install spacer (29) and hose clamp (24) on engine bracket (28) with washer (26) and screw (25).
Tighten screw (25) 75-95 lb-in (8-10 N•m).

TM 9-2320-272-24-1

3-61. SURGE

FOLLOW-ON TASKS:

Install right splash shield (TM 9-2320-272-10).
Fill cooling system (para. 3-53).
Start engine (TM 9-2320-272-10) and check cooling system for leaks.
3-183

TM 9-2320-272-24-1

3-62. SURGE

THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
M939A2
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Two locknuts (Appendix D, Item 279)
Tiedown straps (Appendix D, Item 685)
Antiseize tape (Appendix C, Item 72)

1.
2.
3.
4.
5.
6.
7.
8.
9.

1.
2.
3.
4.
5.
6.
7.

3-184

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
• Parking brake set (TM 9-2320-272-10).
• Hood raised and secured (TM 9-2320-272-10).
• Cooling system drained as required (para. 3-53).
• Exhaust pipe removed (para. 3-50).

NOTE
Remove tiedown straps as necessary. Note location for installation.
Loosen clamp (18) and disconnect hose (17) from surge tank (3).
Loosen clamp (16) and disconnect hose (14) from surge tank (3).
Loosen clamp (12) and disconnect hose (13) from surge tank (3).
Remove fitting (4) from surge tank (3).
Disconnect hose (11) from surge tank (3).
Remove two locknuts (6), washers (5), screws (24), nuts (7), clamps (23), surge tank (3), and two
seats (22) from bracket (20). Discard locknuts (6).
Remove cap (2), chain (1), and S-hook (25) from surge tank (3).
Remove two screws (19), screw (10), and bracket (20) from engine (15).
Remove nut (9), screw (21), and bracket (8) from bracket (20).

Install S-hook (25), chain (1), and cap (2) on surge tank (3).
Install bracket (8) on bracket (20) with screw (21) and nut (9). Do not tighten nut (9).
Install bracket (8) and (20) on engine (15) with two screws (19) and screw (10).
Position two seats (22) on bracket (20).
Position two clamps (23) on surge tank (3) and install clamps (23) and surge tank (3) on bracket (20)
with two screws (24), nuts (7), washers (5), and new locknuts (6).
Connect hose (14) on surge tank (3) and tighten clamp (16).
Connect hose (17) to surge tank (3) and tighten clamp (18).
NOTE
Male pipe threads must be wrapped with antiseize tape before
installation.

TM 9-2320-272-24-1

3-62. SURGE

7.
8.
9.

Install fitting (4) on surge tank (3).
Connect hose (13) to fitting (4) and tighten clamp (12).
Connect hose (11) to surge tank (3).

FOLLOW-ON TASKS: • Install exhaust pipe (para. 3-50).
• Fill cooling system to proper level (para. 3-53).
• Start engine (TM 9-2320-272-10) and check for coolant leaks.
3-185

TM 9-2320-272-24-1

3-63. RADIATOR

THIS TASK COVERS
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
M939/A1
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Torque wrench (Appendix E, Item 146)
MATERIALS/PARTS
Six lockwashers (Appendix D, Item 364)
Four locknuts (Appendix D, Item 299)
Four locknuts (Appendix D, Item 313)
Eight locknuts (Appendix D, Item 304)

1.
2.
3.
4.
5.
6.
7.
8.

1.
2.
3.
4.
5.
6.

3-186

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
• Parking brake set (TM 9-2320-272-10).
• Hood raised and secured (TM 9-2320-272-10).
• Left and right splash shields removed
(TM 9-2320-272-10).
• Cooling system drained as needed (para. 3-53).

NOTE
Have drainage container ready to catch coolant.
Loosen hose clamp (2) and disconnect radiator inlet hose (1) from radiator pipe (3).
Remove screw (20), lockwasher (21), and washer (22) from comer shroud (23). Discard lockwasher (21).
Remove locknut (5), screw (18), and washers (6) and (19) from radiator (4) and comer
shroud (23). Discard locknut (5).
Remove four locknuts (10), eight washers (9), four screws (17), and comer shroud (23) from radiator (4).
Discard locknuts (10).
Remove three locknuts (7), washers (8), screws (13), and washers (12) from fan shroud (11) from
radiator (4). Discard locknuts (7).
Remove five screws (16), washers (14), and lockwashers (15) from radiator (4). Discard
lockwashers (15).
Remove fan shroud (11) from radiator (4).
Remove eight locknuts (27), sixteen washers (24), eight screws (25), and four brackets (26) from
radiator (4). Discard locknuts (27).

Install four brackets (26) on radiator (4) with sixteen washers (24), eight screws (25), and new
locknuts (27). Tighten screws (25) 10-14 lb-ft (14-19 N•m).
Install fan shroud (11) on radiator (4) with five washers (14), new lockwashers (15), and screws (16).
Tighten screws (16) to 110-14 lb-ft (14-19 N•m).
Install fan shroud (11) on radiator (4) with three washers (12), screws (13), washers (8), and new
locknuts (7).
Install corner shroud (23) on radiator (4) with four washers (9), screws (17), washers (9), and new
locknuts (10). Tighten screws (17) 66-86 lb-in. (7-10 N•m).
Install comer shroud (23) on radiator (4) with washer (19), screw (18), washer (6), and new locknut (5).
Tighten screw (18) 10-14 lb-ft (14-19 N•m).
Secure corner shroud (23) on radiator (4) with washer (22), new lockwasher (21), and screw (20).
Tighten screw (20) 110-14 lb-ft (14-19 N•m).

TM 9-2320-272-24-1

3-63. RADIATOR

7.

Connect radiator hose (1) to radiator inlet (3) and tighten clamp (2).

FOLLOW-ON TASKS: • Fill cooling system to proper level (para. 3-53).
• Start engine (TM 9-2320-272-10) and check for coolant leaks.
• Install left and right splash shields (TM 9-2320-272-10).
3-187

TM 9-2320-272-24-1

3-64. FAN

THIS TASK COVERS:
a. Removal
b. Inspection

c. Installation

INITIAL SETUP:
APPLICABLE MODELS
M939A2
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Torque wrench (Appendix E, Item 146)
MATERIALS/PARTS
Four locknuts (Appendix D, Item 299)
Four locknuts (Appendix D, Item 313)
Two locknuts (Appendix D, Item 278)
Two lockwashers (Appendix D, Item 360)
Two sets of isolators (Appendix D, Item 263)
Antiseize compound (Appendix C, Item 10)

1.
2.
3.

4.
6.
6.
7.
8.

1.
2.
3.
4.
5.

1.

3-188

REFERENCES (TM}
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
• Parking brake set (TM 9-2320-272-10).
• Hood raised and secured (TM 9-2320-272-10).

Remove two locknuts (24), snubbing washers (25), screws (13), and washers (14) from brackets (18)
and (23). Discard locknuts (24).
Remove two sets of isolators (12) from brackets (23) and (18). Discard isolators (12).
Straighten tabs on two lockwashers (20) and remove screws (21), lockwashers (20), bracket (23), and
spacer (19) from radiator (17). Let bracket (23) hang from attaching cables (22) on vehicle hood (1).
Discard lockwashers (20).
Remove four locknuts (5), eight washers (6), and four screws (7) securing top half of shroud (2) to
bottom half of shroud (8). Discard locknuts (5).
Remove five screws (4), six washers (3), two locknuts (16), and top half of shroud (2) from
radiator (17). Discard locknuts (16).
Remove two screws (27) from fan mounting bracket (26), position fan drive pulley (28) with fan
clutch (29) so fan clutch holes (34) are aligned, and install two screws (27) in fan clutch holes (34).
Remove six nuts (30), washers (31), and fan blade (32) from fan clutch (29).
Remove five screws (10), seven washers (11), two locknuts (15), clip (9), and bottom half of
shroud (8) from radiator (17). Discard locknuts (15).

Inspect fan (32) shrouds (2) and (8) for cracks and missing pieces.
Lay fan (32) on flat surface. Ensure all blades of fan (32) contact the flat surface the same way.
Inspect fan (32) for cracks, broken pieces, and loose anchorage and studs (33) for cracks or stripped
threads.
Inspect all other parts (para. 2-15).
Replace all parts failing inspection.

Install bottom half of shroud (8) on radiator (17) with clip (9), five screws (10), seven washers (11),
and two new locknuts (15). Ensure clip (9) is mounted under correct screw (10).

TM 9-2320-272-24-1

3-64. FAN

2.
3.
4.
5.
6.
7.
8.
9.
10.
11.

Align fan blade (32) with fan clutch holes (34) and install six washers (31) and nuts (30). Tighten
nuts (30) 36 lb-ft (47 N•m).
Remove two screws (27) from fan clutch (29).
Coat screw (27) threads with antiseize compound and install screws (27) on fan mounting bracket (26).
Install top half of shroud (2) on radiator (17) with five screws (4), six washers (3), and two new
locknuts (16). Finger tighten screws (4).
Secure halves of shroud (2) and (8) with eight washers (6), four screws (7), and new locknuts (6).
Tighten five screws (4) and two locknuts (16).
Install two new sets of isolators (12) in brackets (18) and (23).
Install spacer (19) and bracket (23) on bracket (18) and radiator (17) with two screws (13), washers (14),
snubbing washers (26), and new locknuts (24). Finger tighten locknuts (24).
Install two new lockwashers (20) and screws (21) on bracket (23) and radiator (17). Tighten screws (21)
40 lb-ft (55 N•m). Bend tabs on lockwashers (20) against flats of screws (21).
Tighten locknuts (24) 35 lb-ft (50 N•m).

FOLLOW-ON TASK: Start engine (TM 9-2320-272-10) and run until fan clutch locks up. Check fan for
alignment.
3-189

TM 9-2320-272-24-1

3-65. THERMOSTAT

THIS TASK COVERS:
a. Removal
b. Testing

c. Installation

INITIAL SETUP:
APPLICABLE MODELS
M939/A1
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Hot water thermometer
MATERIALS/PARTS
Four screw-assembled lockwashers (Appendix D,
Item 592)
Gasket (Appendix D, Item 147)
Thermostat seal (Appendix D, Item 597)
GAA grease (Appendix C, Item 28)

1.
2.
3.
4.
5.
6.

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
• Hood raised and secured (TM 9-2320-272-10).
• Parking brake set (TM 9-2320-272-10).
• Right splash shield removed (TM 9-2320-272-10).
• Cooling system drained as necessary (para. 3-53).
GENERAL SAFETY INSTRUCTIONS
Use caution when testing thermostat. Scalding hot
water may cause severe burns.

Loosen clamp (6) and disconnect radiator inlet hose (7) from thermostat housing (5).
Loosen two clamps (9) and remove radiator bypass hose (10) from thermostat housing (5) and
radiator bypass tube (8).
Remove four screw-assembled lockwashers (11) from thermostat housing (5) and water manifold
header (1). Discard screw-assembled lockwashers (11).
Remove thermostat housing (5) and gasket (2) from water manifold header (1). Discard gasket (2)
and clean gasket remains from mating surfaces.
Remove thermostat (3) from thermostat housing (5).
Remove seal (4) from thermostat housing (5). Discard seal (4).

WARNING

1.

2.

1.
2.
3.

3-190

Use caution when testing thermostat. Hot water may cause injury
to personnel.
Place thermostat (3) in a container of water at 197°F (92°C).
NOTE
Do not let thermostat touch container sides during testing.
Observe thermostat (3) to see if valve opens. Replace thermostat (3) if valve does not fully open.

Position new seal (4) in thermostat housing (5).
Install thermostat (3) in thermostat housing (5).
Coat one surface of gasket (2) with light coat of GAA grease and position new gasket (2) over four
holes on water manifold header (1).

TM 9-2320-272-24-l

3-65. THERMOSTAT

4.
5.
6.

Aligning holes in thermostat housing (5) and header (1), install housing (5) with four new screwassembled lockwashers (11).
Connect radiator bypass hose (10) to thermostat housing (5) and bypass tube (8) and tighten two
clamps (9).
Connect radiator inlet hose (7) to thermostat housing (5) and tighten clamp (6).

FOLLOW-ON TASKS:

Fill cooling system to proper level (para. 3-53).
Start engine (TM 9-2320-272-10), check for coolant leaks, and check temperature
gauge for normal reading of 175°F to 195°F (70°C to 97°C).
Install right splash shield (TM 9-2320-272-10).
3-191

TM 9-2320-272-24-1

THIS TASK COVERS:
a. Removal (Internal Bypass)
b. Cleaning and Inspection (Both Types)
c. Installation (Internal Bypass)

APPLICABLE MODELS
M939A2
TOOLS
General mechanic’s too kit (Appendix E, Item 1)
Torque wrench (Appendix E, Item 146)
MATERIALS/PARTS
Gasket (Appendix D, Item 148)
Gasket (Appendix D, Item 149)
Gasket (Appendix D, Item 150)
Gasket (Appendix D, Item 151)
Gasket (Appendix D, Item 152)
Seal (Appendix D, Item 598)
Antiseize tape (Appendix C, Item 72)

d. Removal (External Bypass)
e. Installation (External Bypass)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Hood raised and secured (TM 9-2320-272-10).
Drivebelt tensioner removed (para. 3-71)
GENERAL SAFETY INSTRUCTIONS
Do not drain coolant when engine is hot.

NOTE
There are two different bypass systems used for M939A2 engines.
An identifiable difference is the thermostat housing for external
bypass and internal bypass engines.

1.
2.
3.
4.
5.

6.
7.

8.

3-192

Do not drain coolant when engine is hot. Severe bums to
personnel may result.
Drain three quarts of coolant from oil cooler drainvalve (11) into container.
Loosen clamp (3) and remove hose (2) from adapter (4).
Loosen alternator link screw (12).
While supporting alternator (15), remove two screws (13) and washers (14) from bracket (16). Pivot
alternator (15) down and move bracket (16) aside.
Remove four screws (17) and bracket (18) from thermostat housing (7).
NOTE
Tag screws for identification in installation.
Remove two screws (1), adapter (4), and gasket (5) from thermostat housing (7). Discard
gasket (5)
Remove two screws (6), thermostat housing (7), and gasket (8) from engine block (10). Discard
gasket (8).
Cover coolant passages. Dirt in cooling system will cause
overheating and engine failure.
Remove two thermostats (9) from engine block (10).

TM 9-2320-272-24-1

3-66. THERMOSTATS

1.
2.
3.

Clean all parts and mating surfaces (para. 2-14).
Inspect all other parts (para. 2-15).
Replace all parts failing inspection.

1.
2.
3.
4.

Install two thermostats (9) in engine block (10).
Install new gasket (8) on engine block (10).
Install thermostat housing (7) on engine block (10) with two screws (6).
Install new gasket (5) and adapter (4) on thermostat housing (7) with two screws (1). Tighten
screws (1) and (6)
Install bracket (18) on thermostat housing (7) with four screws (17).
Move alternator (15) up with bracket (16), and install two washers (14) and screws (13). Tighten
screws (13) 35 lb-ft (45 N°m).
Tighten link screw (12).
Install hose (2) on adapter (4) with clamp (3).
NOTE
Go to follow-on tasks.

5.
6.
7.
8.

3-193

TM 9-2320-272-24-1

1.
2.
3.
4.
5.
6.
7.
8.
9.

10.
11.
12.
13.
14.
15.
16.

1.
2.
3.

4.
5.
6.
7.

Do not drain coolant when engine is hot. Severe bums may result.
Drain three quarts of coolant from oil cooler drain valve (17) into container.
Loosen clamp (5) and remove hose (4) from adapter (8).
Loosen alternator link screw (18).
While supporting alternator (21), remove two screws (19) and washers (20) from brackets (22) and (25)
and move alternator (21) aside.
Remove four screws (23) and bracket (25) from support (14).
Loosen clamp (33) and remove hose (1) from valve (32).
Loosen tube (29) and fittings (2) and (30) from tee (31).
Remove tee (31) from thermostat housing (10).
Remove valve (32) from tee (31).
NOTE
Note the location of long and short screws.
Remove short screw (6), long screw (3), adapter (8), and gasket (9) from thermostat housing (10).
Discard gasket (9).
Loosen clamp (28) and remove hose (26) from housing (10).
Remove two screws (7), housing (10), thermostat (12), and gasket (13) from support (14). Discard
gasket (13).
Remove seal (11) from housing (10). Discard seal (11).
Remove two screws (27), support (14), and gasket (15) from engine block (16). Discard gasket (15).
Remove plug (24) from support (14).
Go to task b for inspection procedures.

NOTE
If support was removed, perform steps 1 and 2.
Install plug (24) in support (14).
Install new gasket (15) and support (14) on engine block (16) with two screws (27).
With housing (10) upside down, install new seal (11), with cupped side down, until seal (11) is
seated.

Install
Install
Install
Install

If seal is damaged, engine failure may result.
thermostat (12) into seal (11) until thermostat (12) seats against housing (10).
new gasket (13) and housing (10) on support (14) with two screws (7).
hose (26) on housing (10) and tighten clamp (28).
new gasket (9) and adapter (8) on housing (10) with long screw (3) and short screw (6).
Ensure that drainvalve on aftercooler is open or cooling system
may overheat.

3-194

TM 9-2320-272-24-1

3-66. THERMOSTATS

8.
9.
10.
11.
12.
13.
14.

Wrap threads of valve (32) with antiseize tape and install in tee (31), and install tee (31) on
housing (10).
Install tube (29), fitting (2), and fitting (30) on tee (31).
Install hose (1) on valve (32) and tighten clamp (33).
Install bracket (25) on support (14) with four screws (23).
Move alternator (21) up and align bracket (22) to support (14) and install two washers (20) and
screws (19). Tighten screws (19) 35 lb-ft (45 N•m).
Tighten link screw (18).
Install hose (4) on adapter (8) and tighten clamp (5).

FOLLOW-ON TASKS:

Install drivebelt tensioner (3-71).
Fill cooling system to proper level (para. 3-53).
Start engine (TM 9-2320-272-10), check for leaks, and check temperature gauge
for indication of 180° F to 205° F (85’ C to 95° C).
3-195

TM 9-2320-272-24-1

THIS TASK COVERS:
a. Adjustment
b. Removal

APPLICABLE MODELS
M939/A1
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Belt tension gauge (Appendix E, Item 16)
MATERIALS/PARTS
Three lockwashers (Appendix D, Item 350)

1.

2.
3.
4.
5.
6.

3-196

c. Inspection
d. Installation

REFERENCES (TM)
TM 9-2320-2722-10
TM 9-2320-2722-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Hood raised and secured (TM 9-2320-272-10).
Bight splash shield removed (TM 9-2320-272-10).
Fan drivebelts removed (para. 3-70).
Power steering pump drivebelts removed
(para. 3-230).

Check for proper belt tension by positioning belt tension gauge on drivebelt (1) between pump
housing (6) and accessory drive pulley (2). New belt tension should be 95-105 lb-ft (423-467 N•m).
Used belt tension should be 90-95 lb-ft (378-422 N•m).
Loosen six screws (4) securing support bracket (3) to engine (7).
Place brass drift punch against stud (5) on water pump housing (6).
Referring to values in step 1, move stud (5) clockwise facing pump housing (6) to tighten drivebelt (1)
tension. Move stud (6) counterclockwise to loosen drivebelt (1) tension.
Tighten six screws (4) securing support bracket (3) to engine (7).
Recheck drivebelt (1) tension. If drivebelt (1) tension cannot be adjusted, replace drivebelt (1).

TM 9-2320-272-24-1

3-67. WATER

3-197

TM 9-2320-272-24-1

3-67. WATER

1.
2.
3.
4.
5.

NOTE
Assistant will help with step 1.
Remove screw (1), lockwasher (2), two screws (11), washers (12), screws (10), lockwashers (9), and
washers (8) from fan pulley bracket (3). Discard lockwashers (2) and (9).
Lower fan pulley bracket (3).
Loosen six screws (13) holding support bracket (4) to engine (16).
Place a brass drift punch against stud (14) on water pump housing (15) and turn
stud (14) counterclockwise to release drivebelt (7) tension.
Remove drivebelt (7) from pump pulley (6) and accessory drive pulley (5).

Inspect drivebelt for cracks, splits, and breaks. Replace drivebelt if cracked, split, or broken.

1.
2.
3.
4.

5.
6.
7.

3-198

Install drivebelt (7) over pump pulley (6) and accessory drive pulley (5).
Using brass drift punch, turn stud (14) clockwise for preliminary belt (7) tightening.
Check drivebelt (7) tension. Refer to task a.
Tighten six screws (13).
NOTE
Assistant will help with step 5.
Raise fan pulley bracket (3) and install new lockwasher (2), screw (1), two washers (8), new
lockwashers (9), screws (10), washers (12), and screws (11). Do not tighten screws (1), (11), and (10).
Recheck drivebelt tension. Refer to task a.
If drivebelt (7) tension is satisfactory, tighten screws (1), (11), and (10).

TM 9-2320-272-24-1

3-67. WATER

FOLLOW-ON TASKS:

Install power steering pump drivebelts (para. 3-230).
Install fan drivebelts (para. 3-70).
Start engine (TM 9-2320-272-10), idle engine for five minutes, and stop engine.
Install right splash shield (TM 9-2320-272-10).
3-199

TM 9-2320-272-24-1

THIS TASK COVERS:
a. Removal

APPLICABLE MODELS
M939/A1
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Torque wrench (Appendix E, Item 146)
MATERIALS/PARTS
Gasket (Appendix D, Item 153)
O-ring (Appendix D, Item 425)
Eight lockwashers (Appendix D, Item 349)
Two lockwashers (Appendix D, Item 350)
GAA grease (Appendix C, Item 28)

1.
2.
3.
4.
5.
6.

1.
2.
3.
4.
5.
6.
7.

3-200

b. Installation

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDlTlON
Parking brake set (TM 9-2320-272-10).
Hood raised and secured (TM 9-2320-272-10).
Cooling system drained (para. 3-53).
Fan drive clutch removed (para. 3-75).
Water pump drivebelt removed (para. 3-67).
Alternator adjusting link removed (para. 3-79).

Remove screw (4), lockwasher (5), hose clamp (6), and spacer (7) from engine bracket (8). Discard
lockwasher (5).
Remove screw (3), lockwasher (2), and washer (1) from engine bracket (8). Discard lockwasher (2).
Remove six screws (11), lockwashers (10), and support bracket (9) from engine (12). Discard
lockwashers (10).
Remove water pump body (16) and O-ring (15) from water pump support (14). Discard O-ring (15).
Remove two screws (17) and lockwashers (18) from water pump support (14) and engine (12).
Discard lockwasher (18).
Remove water pump support (14) and gasket (13) from engine (12). Discard gasket (13).

Coat both sides of new gasket (13) lightly with clean GAA grease and position on water pump
support (14).
Position water pump support (14) with gasket (13) on engine (12).
Install water pump support (14) on engine (12) with two new lockwashers (18) and
screws (17).
Put light coat of GAA grease on O-ring (15), mount O-ring (15) on water pump body (16), and install
water pump body (16) into support (14).
Install support bracket (9) on engine (12) with six new lockwashers (10) and screws (11). Tighten
screws (11) 30 lb-ft (41 N•m).
Install washer (1), new lockwasher (2), and screw (3) through engine bracket (8) and into support
bracket (9).
Install hose clamp (6) and spacer (7) on engine bracket (8) with new lockwasher (5) and screw (4).

TM 9-2320-272-24-l

3-68. WATER

FOLLOW-ON TASKS:

Install and adjust water pump drivebelt (para. 3-67).
Install fan drive clutch (para. 3-75).
Fill cooling system to proper level (para. 3-53).
Install alternator adjusting link (para. 3-79).
Start engine (TM 9-2320-272-10) and check for coolant leaks.
3-201

TM 9-2320-272-24-1

THIS TASK COVERS:
a. Removal
b. Cleaning and Inspection

APPLICABLE MODELS
M939A2
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
O-ring (Appendix D, Item 462)

1.

c. Installation

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-16).
Hood raised and secured (TM 9-2320-272-10).
Engine coolant drained (para. 3-53).
Fan drivebelt removed (para. 3-71).

Loosen alternator link screw (10) and remove long screw (8) and two short screws (2) from water
pump (3). Note locations of long and short screws.

2.
3.

Do not strike or pry on water pump pulley or shaft. Coolant leaks
may result.
Tap edge of water pump flange (4) to release water pump (3) from engine block (1).
Remove water pump (3) and O-ring (7) from engine block (1). Discard O-ring (7).

1.
2.
3.
4.
5.
6.

Clean mating surfaces of water pump (3) and engine block (1).
Inspect water pump flange (4) for cracks and nicks.
Check for smooth shaft rotation.
Inspect impeller blades (6) for corrosion or wear.
Inspect weep hole (5) for evidence of leakage.
Replace pump (3) if any parts fail inspection.

1.
2.
3.

Do not pinch, cut, or crimp O-ring while performing steps 1 and 2.
Damaged O-ring may result in coolant leak.
Install new O-ring (7) on water pump (3).
Install water pump (3) engine block (1) with two short screws (2). Hand tighten screws (2).
Align alternator link (9) with water pump flange (4) and install long screw (8). Hand tighten
screw (8).
Tighten alternator link screw (10) and short and long screws (2) and (8).

4.

3-202

TM 9-2320-272-24-1

3-69. WATER

FOLLOW-ON TASKS:

Install fan drivebelt (para. 3-71).
Fill cooling system to proper level (para. 3-53).
Start engine (TM 9-2320-272-10), idle engine for five minutes, and check for
coolant leaks when temperature gauge reads 180°-205° F (85°-95°C).
3-203

TM 9-2320-272-24-1

3-70. FAN

THIS TASK COVERS:
a. Adjustment
b. Removal

APPLICABLE MODELS
M939/A1
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Belt tension gauge (Appendix E, Item 16)
Torque wrench (Appendix E, Item 146)
MATERIALS/PARTS
Cap and plug set (Appendix C, Item 14)
Antiseize tape (Appendix C, Item 72)

1.
2.
3.
4.
5.

6.

7.
8.

9.
10.

1.
2.
3.
3-204

c. Inspection
d. Installation

REFERENCES (TM
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Hood raised and secured (TM 9-2320-272-10).
Air reservoirs drained (TM 9-2320-272-10).
Right splash shield removed (TM 9-2320-272-10).
GENERAL SAFETY INSTRUCTIONS
Do not disconnect air lines or hoses before draining
air reservoirs.

Do not disconnect air lines or hoses before draining air reservoirs.
Small parts under pressure may shoot out with high velocity,
causing injury to personnel.
Disconnect air line (7) from elbow (8).
Remove elbow (8) and adapter (9) from union (10).
Loosen three screws (1) on fan pulley bracket (6).
Loosen jamnut (2) on adjusting screw (3) on water pump clamp ring (4).
Using belt tension gauge on inner belt midway between pulleys, adjust tension of inner belt (5) by
turning screw (3). Tension should be 95-105 lb-ft (423-467 N•m) for a new belt (5) and 85-95 lb-ft
(378-422 N•m) for a used belt (5).
Repeat tension check of step 5 for outer belt (5). Recheck inner belt (5).
NOTE
Belts must be replaced as a matched set.
If either inner or outer belts (5) cannot be adjusted in proper range, replace both belts (5).
Tighten top screw (1) 25-35 lb-ft (34-47 N•m). Tighten two side screws (1) 25-35 lb-ft (34-47 N•m).
NOTE
Male pipe threads must be wrapped with antiseize tape before
installation.
Install adapter (9) and elbow (8) on union (10).
Connect air line (7) to elbow (8).

Disconnect air line (7) from elbow (8).
Remove elbow (8) and adapter (9) from union (10).
Loosen three screws (1) on bracket (6).

TM 9-2320-272-24-1

3-70. FAN

4.
5.

Loosen jamnut (2) on adjusting screw (3).
Push fan pulley bracket (6) toward accessory drive pulley (12) and remove two fan drivebelts (5).

Inspect two fan drivebelts (6) for cracks, splits, and breaks. Replace both belts (5) if either one fails
inspection.

1.
2.

Fan drivebelts must be replaced in matched sets. Failure to do so
will result in premature belt wear or failure.
Position two fan drivebelts (5) over fan clutch pulley (11) and in first and second grooves of
accessory drive pulley (12).
Complete installation with correct tensioning of drivebelts (5). Refer to task a.

FOLLOW-ON TASKS:

Start engine (TM 9-2320-272-10) and idle for five minutes.
Install right splash shield (TM 9-2320-272-10).
3-205

TM 9-2320-272-24-1

3-71. FAN

THIS TASK COVERS:
a. Removal

APPLICABLE MODELS
M939A2
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Torque wrench (Appendix E, Item 146)

1.

2.
3.
4.
5.

1.
2.
3.
4.

5.

3-206

b. Installation

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-2722-10).
Hood raised and secured (TM 9-2320-272-10).
Right splash shield removed (TM 9-2320-272-10).

Using a breaker bar in square drive hole (7) of belt tensioner (4), move belt tensioner (4) up.
NOTE
Assistant will help with step 2.
Remove drivebelt (8) from alternator pulley (11), and release belt tensioner (4).
Remove drivebelt (8) from vibration damper pulley (9), water pump pulley (10), and fan pulley (1).
Remove two screws (6) and belt tensioner bracket (2) from thermostat housing (12).
Remove screw (5) and belt tensioner (4) from bracket (2).

Install belt tensioner bracket (2) on thermostat housing (12) with two screws (6).
Align locating pin (3) on belt tensioner (4) with belt tensioner bracket (2) and install screw (5).
Tighten screw (5) 30 lb-ft (45 N•m).
Install drivebelt (8) over fan pulley (1) and under vibration damper pulley (9).
Install drivebelt (8) between water pump pulley (10) and belt tensioner (4).
NOTE
Assistant will help with step 5.
Using breaker bar in square drive hole (7) of belt tensioner (4), move belt tensioner (4) up and
install drivebelt (8) on alternator pulley (11). Release belt tensioner (4).

TM 9-2320-272-24-1

FOLLOW-ON TASKS:

Start engine (TM 9-2320-272-10) and check drivebelt.
Install right splash shield (TM 9-2320-272-10).
3-207

TM 9-2320-272-24-1

THIS TASK COVERS:
a. Removal

APPLICABLE MODELS
M939/A1
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Torque wrench (Appendix E, Item 146)
MATERIALS/PARTS
Four locknuts (Appendix D, Item 313)
Locknut (Appendix D, Item 299)
Six lockwashers (Appendix D, Item 354)

1.
2.
3.
4.

1.
2.
3.
4.

3-208

b. Installation

REFERENCES (TM)
TM 9-2320-272- 10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Hood raised and secured (TM 9-3220-272-10).
Right splash shield removed (TM 9-2320-272-10).

Remove four locknuts (1), eight washers (2), and four screws (3) from corner shroud (4). Discard
locknuts (1).
Remove screw (5) and washer (6) from corner shroud (4) and radiator (7).
Remove locknut (11), washers (12) and (9), screw (8), and comer shroud (4) from bracket (10).
Discard locknut (11).
Remove six screws (13), lockwashers (14), and fan (16) from fan hub (15). Discard lockwashers (14).

NOTE
Ensure fan installation does not block fan drive clutch lockup
holes.
Install fan blade (16) on fan hub (15) with six new lockwashers (14) and screws (13). Tighten
screws (13) 25-31 lb-ft (34-42 N•m).
Install comer shroud (4) on bracket (10) with washer (9), screw (8), washer (12), and new locknut (11).
Install comer shroud (4) on radiator (7) with washer (6) and screw (5).
Secure comer shroud (4) on radiator (7) with four washers (2), screws (3), washers (2), and new
locknuts (1).

TM 9-2320-272-24-1

3-72. RADIATOR

FOLLOW-ON TASK: Install right splash shield (TM 9-2320-272-10).
3-209

TM 9-2320-272-24-1

3-73. FAN

THIS TASK COVERS:
a. Removal
b. Inspection

APPLICABLE MODELS
M939/A1
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Cap and plug set (Appendix C, Item 14)
Antiseize tape (Appendix C, Item 72)
REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P

1.
2.
3.
4.
5.

c. Installation

EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Primary and secondary air tanks drained
(TM 9-2320-272-10).
Hood raised and secured (TM 9-2320-272-10).
Coolant drained below water manifold level
(para. 3-53).
GENERAL SAFETY INSTRUCTIONS
Do not disconnect air lines or hoses before draining
air reservoirs.

Do not disconnect air lines or hoses before draining air reservoirs.
Small parts under pressure may shoot out with high velocity,
causing injury to personnel.
Disconnect air hose (3) from adapter (4) on fan drive clutch actuator (5).
Remove adapter (4) from fan drive actuator (5).
Remove actuator-to-fan hose (2) from adapter (6).
Remove adapter (6) from actuator (5).
Remove actuator (5) from water manifold (1).

Inspect all connections for cracks and stripped threads. Replace any parts with cracks, or stripped or
damage threads.

1.
2.
3.
4.
5.

3-210

NOTE
Male pipe threads must be wrapped with antiseize tape before
installation.
Install actuator (5) on water manifold (1).
Install adapter (6) on actuator (5).
Connect actuator-to-fan hose (2) on adapter (6).
Install adapter (4) in actuator (5).
Connect air hose (3) to adapter (4).

TM 9-2320-272-24-l

FOLLOW-ON TASKS:

Fill cooling system to proper level (para. 3-53).
Start engine (TM 9-2320-272-10) and check for air and coolant leaks.
Check for proper operation of actuator (TM 9-2320-272-10).
3-211

TM

9-2320-272-24-1

THIS TASK COVERS:
a. Removal
b. Cleaning and Inspection

APPLICABLE MODELS
M939A2
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Cap and plug set (Appendix C, Item 14)
Antiseize tape (Appendix C, Item 72)

1.
2.

c. Installation

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Hood raised and secured (TM 9-2320-272-10).
Coolant drained below water manifold level
(para. 3-53).
Fan and fan shroud removed (para. 3-64).
Drivebelt removed (para. 3-71).

5.
6.

Disconnect air line (6) and elbow (2) from actuator (3).
Disconnect air line (5) and elbow (4) from actuator (3).
NOTE
Note position of actuator for installation.
Remove actuator (3) from radiator inlet tube (1).
Disconnect air line (5) from elbow (7).
NOTE
Assistant will support fan clutch while removing screws.
Remove four screws (10), washers (9), and fan clutch (11) from engine (8).
Remove elbow (7) from fan clutch (11).

1.
2.
3.
4.

Clean all parts (para. 2-14).
Inspect air lines (5) and (6) for cracks, kinks, and wear.
Inspect other parts (para. 2-15).
Replace all parts failing inspection.

3.
4.

3-212

TM 9-2320-272-24-1

1.
2.
3.
4.
5.
6.

NOTE
All male threads must be wrapped with antiseize tape before
installation.
Assistant will support fan clutch during installation.
Install fan clutch (11) on engine (8) with four washers (9) and screws (10).
Install elbow (7) on fan clutch (11).
Connect air line (5) to elbow (7).
Wrap male pipe threads of actuator (3) with antiseize tape and install in radiator inlet tube (1).
Install air line (6) and elbow (2) on actuator (3).
Install air line (5) and elbow (4) on actuator (3).

FOLLOW-ON TASKS:

Fill cooling system to proper level (para. 3-53).
Install drivebelt (para. 3-71).
Install fan and fan shroud (para. 3-64).
Start engine (TM 9-2320-272-10), check for leaks, and tighten any loose fittings.
3-213

TM 9-2320-272-24-l

THIS TASK COVERS:
a. Removal

APPLICABLE MODELS
M939/A1
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Three lockwashers (Appendix D, Item 350)
Loctite (Appendix C, Item 63)
Cap and plug set (Appendix C, Item 14)
Antiseize tape (Appendix C, Item 72)

1.
2.
3.
4.

1.
2.

3.
4.

3-214

b. Installation

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Hood raised and secured (TM 9-2320-272-10).
Fan drivebelts removed (para. 3-70).
Fan removed (para. 3-72).

Disconnect hose (2) from fan drive actuator (1) and elbow (4) on fan pulley bracket (3).
Remove elbow (4) and adapter (6) from union (5).
Remove two fan clutch override screws (7) and washers (8) from fan bracket (3) or fan drive
clutch (13) holes (12).
Remove two screws (16), lockwashers (15), washers (14), screw (9), lockwasher (10), fan drive
clutch (13), and fan pulley bracket (3) from support bracket (11). Discard lockwashers (15) and (10).

Install fan drive clutch (13) and fan pulley bracket (3) on support bracket (11) with new
lockwasher (10), two new lockwashers (15), two washers (14), screws (16), and screw (9). Do not
tighten screws (16) and (9) until drivebelts are installed.
Apply Loctite on threads of screws (7). Install two fan clutch override washers (8) and screws (7) in
fan pulley bracket (3).
NOTE
Male pipe threads must be wrapped with antiseize tape before
installation.
Install adapter (6) and elbow (4) on union (5).
Connect hose (2) to elbow (4) and fan drive actuator (1).

TM 9-2320-272-24-1

3-75. FAN

FOLLOW-ON TASKS:

Install drivebelts (para. 3-70).
Install fan (para. 3-72).
Start engine (TM 9-2320-272-10), check for leaks, and check for proper fan
operation.
3-215

TM 9-2320-272-24-1

THIS TASK COVERS:
a. Removal

APPLICABLE MODELS
M939A2
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Torque wrench (Appendix E, Item 146)
MATERIALS/PARTS
Gasket (Appendix D, Item 154)
Two seals (Appendix D, Item 599)
Antiseize tape (Appendix C, Item 72)
Cleaning cloth (Appendix C, Item 21)

1.
2.

b. Installation

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITlON
Parking brake set (TM 9-2320-272-10).
Hood raised and secured (TM 9-2320-272-10).
Coolant drained from block (para. 3-53).
Air cleaner hose removed (para. 3-13).
Surge tank and bracket removed (para. 3-62).

10.

Remove screw (5) and tube brace (12) from aftercooler (6).
Remove screws (4) and (7) from aftercooler (6) and clamps (8) and rotate clamps (8) away from
aftercooler (6).
Disconnect plug (1) from wiring harness plug (13).
Remove two screws (3) and throttle control solenoid bracket (2) from aftercooler (6). Move clamp (10)
clear of aftercooler (6).
Remove two screws (9) and clamps (11) from aftercooler (6).
Loosen two clamps (16) and disconnect crossover tube (15) from aftercooler (6) and turbocharger (28).
Remove screw (24) and clamping plate (25) from engine block (26).
NOTE
Tag tubes for installation.
Loosen four hose clamps (16) and remove two hoses (18) and water return tube (20) from
aftercooler (6) and elbow (23).
Loosen four hose clamps (19) and remove two hoses (17) and water supply tube (27) from
aftercooler (6) and elbow (21).
Remove elbows (23) and (21) and two seals (22) from engine block (26). Discard seals (22).

11.

Cover intake manifold with lint-free cloth to prevent
contamination from entering engine. Failure to do so may result in
damage to engine.
Remove thirteen screws (14), aftercooler (6), and gasket (29) from engine block (26). Discard gasket (29).

3.
4.
5.
6.
7.

8.
9.

3-216

TM 9-2320-272-24-1

3-217

TM 9-2320-272-24-1

1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.

3-218

NOTE
Male pipe threads must be wrapped with antiseize tape before
installation.
Install new gasket (29) and aftercooler (6) on engine block (26) with thirteen screws (14). Tighten
screws (14) 28 lb-ft (24 N•m).
Install two new seals (22) and elbows (21) and (23) on engine block (26).
Install two hoses (17) and water supply tube (27) on aftercooler (6) and elbow (21) with four hose
clamps (19).
Install two hoses (18) and water return tube (20) on aftercooler (6) and elbow (23) with four hose
clamps (16).
Install clamping plate (25) on engine block (26) with screw (24).
Install crossover tube (15) on aftercooler (6) and turbocharger (28) with two clamps (16).
Install two clamps (11) on aftercooler (6) with two screws (9).
Install clamp (10) and throttle control solenoid bracket (2) on aftercooler (6) with two screws (3).
Connect plug (1) to wiring harness plug (13).
Rotate two clamps (8) into position on aftercooler (6) and install with screws (7) and (4).
Install tube brace (12) on aftercooler (6) with screw (5).

TM 9-2320-272-24-1

3-76. AFTERCOOLER

FOLLOW-ON TASKS:

Install surge tank and bracket (para. 3-62).
Install air cleaner hose (para. 3-13).
3-219

TM 9-2320-272-24-1

3-77. ELECTRICAL

3-78.
3-79.
3-80.
3-81.
3-82.
3-83.
3-84.
3-85.
3-86.
3-87.
3-88.
3-89.
3-90.
3-91.
3-92.
3-93.
3-94.
3-95.
3-96.
3-97.
3-98.
3-99.
3-100.
3-101.
3-102.
3-103.
3-104.
3-105.
3-106.
3-107.
3-108.
3-109.
3-110.
3-111.
3-112.
3-113.
3-114.
3-220

Alternator Drivebelts (M939/A1) Maintenance
Alternator and Mounting Bracket (M939/A1) Replacement
Alternator, Mounting Bracket, and Pulley (M939A2) Maintenance
Alternator Pulley (M939/A1) Replacement
Starter Replacement
Instrument Cluster Maintenance
Indicator Panel Light and Lamp Replacement
Instrument Panel Replacement
Electrical Gauges Replacement
Air Gauge Replacement
Speedometer and Tachometer Replacement
Tachometer Driveshaft (M939/A1) Replacement
Speedometer Driveshaft Maintenance
Oil Pressure Sending Unit Replacement
Fuel Level Sending Unit Replacement
Water Temperature Sending Unit Replacement
Tachometer Pulse Sensor (M939/A1) Replacement
Tachometer Pulse Sensor (M939A2) Replacement
Fuel Pressure Transducer (M939/A1) Replacement
Transmission Temperature Transmitter Replacement
Transmission Neutral Start Switch Replacement
Primary and Secondary Low Air Pressure Switch Replacement
Spring Brake Pressure Switch Replacement
Front Wheel Drive Lock-in Switch Replacement
Horn Contact Brush Replacement
Horn, Solenoid, and Bracket Replacement
Horn Switch Replacement
Circuit Breaker Replacement
Failsafe Warning Module Replacement
Electrical Switches Replacement
Main Light Switch Replacement
Fuel Selector Valve Switch Replacement
Auxiliary Outlet Socket and Receptacle (M936/A1/A2) Replacement
Stoplight Switch Replacement
High Beam Selector Switch Replacement
Turn Signal Control and Indicator Lamp Replacement
Turn Signal Flasher Replacement

3-222
3-224
3-228
3-232
3-234
3-238
3-246
3-248
3-250
3-252
3-254
3-256
3-258
3-262
3-264
3-266
3-268
3-270
3-271
3-272
3-273
3-274
3-278
3-280
3-282
3-284
3-286
3-288
3-290
3-292
3-294
3-296
3-298
3-300
3-301
3-302
3-303

TM 9-2320-272-24-1

3-77. ELECTRICAL

3-115.
3-116.
3-117.
3- 118.
3-119.
3-120.
3-121.
3-122.
3-123.
3-124.
3-125.
3-126.
3-127.
3-128.
3-129.
3-130.
3-131.

Protective Control Box Replacement
Headlight Maintenance
Blackout Light Maintenance
Front and Rear Composite Light and Bracket Replacement
Floodlight Sealed Beam Lamp and Door (M936/A1/A2) Replacement
Floodlight Control Switch (M936/A1A2) Maintenance
Floodlight Maintenance
Side Marker Lights and Bracket Replacement
Battery Box Cover Replacement
Battery Cable and Terminal Adapter Replacement
Battery Maintenance
Battery Ground Cable Maintenance
Slave Receptacle Replacement
Battery Box Replacement
Ground Strap Replacement
Instrument Cluster Harness Replacement
Wiring Harness Repair

3-304
3-306
3-308
3-310
3-322
3-324
3-326
3-330
3-332
3-334
3-336
3-338
3-340
3-342
3-344
3-348
3-349

3-221

TM 9-2320-272-24-1

3-78. ALTERNATOR

THIS TASK COVERS:
a. Removal
b. Inspection

APPLICABLE MODELS
M939/A1
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Belt tension gauge (Appendix E, Item 16)
Torque wrench (Appendix E, Item 144)
Prybar

c. Installation and Adjustment

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Right splash shield removed (TM 9-2320-272-10).
Hood raised and secured (TM 9-2320-272-10).

NOTE
For replacement of alternator/fan drivebelt on M939A2 series
vehicles, refer to paragraph 3-71.

1.
2.
3.

Loosen screws (3) and (6) at adjusting link (2). Do not remove screws (3) and (6).
Loosen two screws (9) at alternator mounting bracket (10). Do not remove screws (9).
Push alternator (1) toward engine (5) until slack exists in two alternator belts (8). Remove two
alternator belts (8) from alternator pulley (4) and vibration damper (7).

Inspect two alternator belts (8) for breaks, cracks, or splits. Replace if broken, cracked, or split.

1.
2.
3.
4.
5.
6.

3-222

NOTE
Alternator belts must be replaced as matched sets.
Position two alternator belts (8) over vibration damper (7) and alternator pulley (4).
Insert prybar between engine (5) and alternator (1) and pull prybar down until alternator belts (8)
appear tight.
Tighten screw (3) on adjusting link (2) 15-20 lb-ft (20-27 N•m).
Tighten screw (6) on adjusting link (2125-31 lb-ft (34-42 N•m).
Using belt tension gauge, check for proper belt tension. Tension of new belts (8) should be 95-105 lb
(423-467 N). Tension of used belts (8) should be 85-95 lb (378-422 N). Replace belts (8) if they cannot
be adjusted.
Tighten two screws (9) on mounting bracket (10) 39-49 lb-ft (53-66 N•m).

TM 9-2320-272-24-l

3-78. ALTERNATOR

FOLLOW-ON TASKS:

Start engine (TM 9-2320-272-10) and check alternator operation.
Install right splash shield (TM 9-2320-272-10).
3-223

TM 9-2320-272-24-1

3-79. ALTERNATOR

THIS TASK COVERS:
a. Removal

APPLICABLE MODELS
M939/A1
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Torque wrench (Appendix E, Item 144)
MATERIALS/PARTS
Two screw-assembled lockwashers
(Appendix D, Item 587)
Five lockwashers (Appendix D, Item 354)
Two lockwashers (Appendix D, Item 376)
Two locknuts (Appendix D, Item 281)
Lockwasher (Appendix D, Item 401)
Lockwasher (Appendix D, Item 403)
Tiedown strap (Appendix D, Item 684)
Lockwasher (Appendix D, Item 364)
Gasket sealant (Appendix C, Item 30)

b. Installation

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT DESCRIPTION
Parking brake set (TM 9-2320-272-10).
Battery ground cables disconnected (para. 3-126).
Alternator drivebelts removed (para. 3-78).
GENERAL SAFETY INSTRUCTIONS
Alternator is heavy. Use assistance when replacing
alternator.

1. Remove two screw-assembled lockwashers (5) and terminal cover (4) from alternator (10). Discard
screw-assembled lockwashers (5).
2. Remove two screws (3), lockwashers (2), and wire retaining strap (1) from alternator (10). Discard
lockwashers (2).
NOTE
Sealant must be removed before removing wires.
Tag all wires for installation.
3. Remove screw (15), lockwasher (14), and wire (13) from alternator (10). Discard lockwasher (14).
4. Remove nut (19), lockwasher (18), washer (17), and wire (16) from alternator (10). Discard
lockwasher (18).
5. Remove nut (6), lockwasher (7), washer (8), and wire (9) from alternator (10). Discard lockwasher (7).
6. Disconnect connector (11) from alternator (10).
7. Remove and discard tiedown strap (12).

8.
9.
10.

3-224

Alternator is heavy. Assistant will help with alternator removal.
Failure to do so may result in injury to personnel.
Remove screw (32), lockwasher (20), washers (21) and (22), screw-assembled washer (23), and
adjusting link (31) from alternator (10). Discard lockwasher (20).
Remove two locknuts (24), washers (25), screws (30), and alternator (10) from mounting bracket (26).
Discard locknuts (24).
Remove four screws (29), lockwashers (28), and mounting bracket (26) from engine (27). Discard
lockwashers (28).

TM 9-2320-272-24-1

3-79. ALTERNATOR

3-225

TM 9-2320-272-24-1

Alternator is heavy. Assistant will help with alternator
installation. Failure to do so may result in injury to personnel.

1.
2.

3.
4.
5.
6.

7.
8.
9.
10.
11.

3-226

Install mounting bracket (7) on engine (8) with four new lockwashers (9) and screws (10).
Install alternator (12) on mounting bracket (7) with two screws (11), washers (6), and new locknuts (5).
Finger tighten locknuts (5).
NOTE
Ensure wire connecting points are thoroughly cleaned before
connections are made.
Install wire (29) on alternator (12) with washer (30), new lockwasher (31), and nut (32). Tighten nut (32)
45-55 bin. (5-6 N•m).
Install wire (23) on alternator (12) with washer (22), new lockwasher (21), and nut (20). Tighten nut (20)
20-25 lb-in. (2-3 N•m).
Connect connector (24) to alternator (12).
Install wire (26) on alternator (12) with new lockwasher (27) and screw (28). Tighten screw (28)
82-102 lb-in. (9-12 N•m).
NOTE
Wires are held in place with strap.
Install wire retaining strap (15) on alternator (12) with two new lockwashers (16) and screws (17).
Install washer (3) and adjusting link (13) on alternator (12) with screw-assembled washer (4),
washer (2), new lockwasher (1), and screw (14).
Seal wires (29) and (23) and connectors with gasket sealant.
Install terminal cover (18) on alternator (12) with two new screw-assembled lockwashers (19).
Install new tiedown strap (25) on alternator wires.

TM 9-2320-272-24-l

3-79. ALTERNATOR

FOLLOW-ON TASKS:

Install alternator belts (para. 3-78).
Connect battery ground cable (para. 3-126).
Start engine (TM 9-2320-272-10) and check alternator operation.
3-227

TM 9-2320-272-24-1

THIS TASK COVERS:
a. Alternator and Mounting Bracket
Removal
b. Pulley Removal
c. Pulley Installation

APPLICABLE MODELS
M939A2
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Torque wrench (Appendix E, Item 146)
Universal puller (Appendix E, Item 103)
Multimeter (Appendix E, Item 86)
Vise
MATERIALS/PARTS
Two screw-aesembled lockwashers
(Appendix D, Item 587)
Lockwasher (Appendix D, Item 364)
Locknut (Appendix D, Item 282
Woodruff Key (Appendix D, Item 726)
Lockwasher (Appendix D, Item 403)
Lockwasher (Appendix D, Item 401)
Gasket sealant (Appendix C, Item 30)

1.
2.
3.

4.
5.
6.
7.

8.
9.
10.

3-228

d. Alternator and Mounting Bracket
Installation
e. Adjustment

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Hood raised and secured (TM 9-2320-272-10).
Right splash shield removed (TM 9-2320-272-10).
Battery ground cables disconnected (para. 3-126).
Fan drivebelt removed (para. 3-71).
GENERAL SAFETY INSTRUCTIONS
Alternator is heavy. Use assistant when replacing
alternator.

Remove screw (16) and washer (15) from alternator link (14).
Loosen two screws (2) and pivot alternator (1) upward to access terminal cover (23).
Remove two screw-assembled lockwashers (24) and terminal cover (23) from alternator (1). Discard
screw-assembled lockwashers (24).
NOTE
Sealant must be removed before removing wires.
Tag all leads for installation.
Remove screw (22), lockwasher (21), and wire (27) from alternator (1). Discard lockwasher (21).
Remove nut (20), lockwasher (19), and wire (26) from alternator (1). Discard lockwasher (19).
Remove nut (18), lockwasher (17), and wire (25) from alternator (1). Discard lockwasher (17).
Disconnect wire (28) from connector (29).
Alternator is heavy. Assistant will help with alternator removal.
Failure to do so may result in injury to personnel.
Remove two screws (2), washers (3), and alternator (1) from brackets (4) and (6). Move bracket (4) to
one side.
Remove four screws (7) and bracket (6) from engine (5).
Remove screw (12), washer (13), and alternator link (14) from engine (5).

TM 9-2320-272-24-1

3-80. ALTERNATOR

1.
2.
3.
4.

Place alternator pulley (11) in vise.
Remove locknut (10) and washer (9) from alternator (1). Diecard locknut (10).
Remove alternator pulley (11) from vise.
Using universal puller, remove alternator pulley (11) and woodruff key (8) from alternator (1).
Discard woodruff key (8).

3-229

TM 9-2320-272-24-1

1.
2.
3.
4.

1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.

1.
2.
3.
4.
5.
6.

3-230

Install new woodruff key (8) and alternator pulley (9) on alternator (1).
Place alternator pulley (9) in vise.
Install washer (11) and new locknut (10) on alternator (1). Tighten locknut (10) 90-100 lb-ft
(122-136 N•m).
Remove alternator pulley (9) from vise.

Alternator is heavy. Assistant will help with alternator
installation. Failure to do so may result in injury to personnel.
NOTE
Ensure wire connecting points are thoroughly cleaned before
connections are made.
Install alternator link (14) on engine (5) with washer (13) and screw (12).
Install mounting bracket (6) on engine (5) with four screws (7).
Install alternator (1) on mounting bracket (6) and bracket (4) with two washers (3) and screws (2).
Finger-tighten screws (2).
Connect wire (28) to connector (29).
Install wire (25) on alternator (1) with new lockwasher (17) and nut (18). Tighten nut (18)
45-55 lb-in (5-6 N•m).
Install wire (26) on alternator (1) with new lockwasher (19) and nut (20). Tighten nut (20) 20-25 lb-in
(2-3 N•m).
Install wire (27) on alternator (1) with new lockwasher (21) and screw (22). Tighten screw (22)
82-102 lb-in (9-12 N•m).
Pivot alternator (1) to align with alternator link (14).
Install alternator link (14) on alternator (1) with washer (15) and screw (16).
Install fan drivebelt (para. 3-71).
Connect battery ground cables (para. 3-126).
Adjust alternator (1) (task e.).

Start engine (TM 9-2320-272-10).
Set engine speed to 1200 rpm (TM 9-2320-272-10)
Turn on headlights (TM 9-2320-272-10) to place load on alternator (1).
Using multimeter, check alternator (1) output voltage. Connect black lead to ground cable (27) and
touch red lead to wire (28). Output voltage should be 27.8-28.2 VDC. If adjustment is required,
continue with next step. If no adjustment is required, proceed to step 8.
Using hex-head driver, remove pipe plug (30) from alternator (1).
Turn adjusting screw counterclockwise to increase or clockwise to decrease voltage.

TM 9-2320-272-24-1

3-80. ALTERNATOR

7.
8.
9.
10.
11.

Apply gasket sealant to pipe plug (30) threads. Using hex-head driver, install pipe plug (30) and
tighten 24-36 lb-in. (3-4 N•m).
Turn off headlights (TM 9-2320-272-10).
Stop engine (TM 9-2320-272-10).
Seal wires (28), (27), (26), and (25) and connector (29) completely with gasket sealant.
Install terminal cover (23) on alternator (1) with two new screw-assembled lockwashers (24).

FOLLOW-ON TASK: Install right splash shield (TM 9-2320-272-10).
3-231

TM 9-2320-272-24-1

3-81. ALTERNATOR

THIS TASK COVERS
a. Removal

APPLICABLE MODELS
M939/A1
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Torque wrench (Appendix E, Item 144)
Universal puller (Appendix E, Item 103)
Vise

b. Installation

MATERIALS/PARTS
Locknut (Appendix D, Item 282)
Woodruff key (Appendix D, Item 726)
REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Hood raised and secured (TM 9-2320-272-10).
Alternator removed (para. 3-79).

1.
2.
3.
4.

Position alternator pulley (1) in vise.
Remove locknut (3) and washer (2) from pulley shaft (5). Discard locknut (3).
Remove alternator pulley (1) from vise.
Using universal puller, remove alternator pulley (1) and woodruff key (4) from pulley shaft (5). Discard
woodruff key (4).

1.
2.
3.
4.

Install new woodruff key (4) in groove of pulley shaft (5) with flat edge up.
Install pulley (1) on pulley shaft (5) with keyway (6) on woodruff key (4).
Place alternator pulley (2) in vise.
Install washer (2) and new locknut (3) on pulley shaft (5). Tighten locknut (3) 90-95 lb-ft
(122- 128 N•m).

3-232

TM 9-2320-272-24-l

3-81. ALTERNATOR

FOLLOW-ON TASK: Install alternator (para. 3-79).
3-233

TM 9-2320-272-24-1

3-82. STARTER

THIS TASK COVERS:
a. Removal

APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)

b. Installation

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-20P

EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
MATERIALS/PARTS
Hood raised and secured (TM 9-2320-272-10).
Battery ground cables disconnected (para. 3-126).
Two lockwashers (M939/A1) (Appendix D,Item 416)
Four lockwashers (M939A2) (Appendix D, Item 416)
Gasket (M939/A1) (Appendix D, Item 155)
Gasket (M939/A1) (Appendix D, Item 156)
Gasket (M939A2) (Appendix D, Item 157)
Gasket (M939A2) (Appendix D, Item 158)

1.
2.

3.

Tag wires for installation.
Step 1 is for M939A2 vehicles only.
Remove nut (24), lockwasher (23), and wire (22) from solenoid (2). Discard lockwasher (23).
Remove nut (16), lockwasher (17), and wires (18) and (15) from solenoid (2). Discard lockwasher (17).
Ground strap will be present on M939/A1 vehicles only.
Remove nut (12), lockwasher (13), wires (14) and (11), and ground strap (10) from starter (9).
Discard lockwasher (13).

4.

Step 4 is for M939A2 vehicles only.
Remove nut (25), lockwasher (26), and wire (27) from starter (9). Discard lockwasher (26).

5.

Step 5 is for M939/A1 vehicles only.
Remove screw (21), clip (20), and wire (19) from solenoid (2).

7.

Steps 6 and 7 are for M939A2 vehicles only.
Assistant will help with step 6.
Remove three screws (8), washers (7), starter (9), gasket (6), spacer (5), and gasket (4) from flywheel
housing (3). Discard gaskets (6) and (4).
Remove three sleeves (28) from starter (9).

8.

Steps 8 and 9 are for M939/A1 only.
Assistant will help with step 9.
Remove screw-assembled washer (1) from starter (9).

6.

3-234

TM 9-2320-272-24-1

3-82. STARTER

9.

Remove two screws (8), washers (7), starter (9), gasket (6), spacer (5), and gasket (4) from flywheel
housing (3). Discard gaskets (6) and (4).

3-235

TM 9-2320-272-24-l

3-82. STARTER

1.
2.

3.
4.

Steps 1 and 2 are for M939/A1 vehicles only.
Assistant will help with step 1.
Install new gasket (4), spacer (5), new gasket (6), and starter (9) on flywheel housing (3) with two
washers (7) and screws (8). Tighten screws (8) 55 lb-ft (76 N•m).
Install screw-assembled washer (1) in starter (9).
Steps 3 and 4 are for M939A2 vehicles only.
Assistant will help with step 4.
Install three sleeves (28) on starter (9).
Install new gasket (4), spacer (6), new gasket (6), and starter (9) on flywheel housing (3) with three
washers (7) and screws (8). Tighten screws (8) 55 lb-ft (75 N•m).

5.

Step 5 is for M939/A1 vehicles only.
Install wire (19) on solenoid (2) with clip (20) and screw (21).

6.

Step 6 is for M939A2 vehicles only.
Install wire (27) on starter (9) with new lockwasher (26) and nut (25).

8.

Ground strap will be present on M939/A1 vehicles only.
Install ground strap (10) and wires (11) and (14) on starter (9) with new lockwasher (13) and
nut (12).
Install wires (15) and (18) on solenoid (2) with new lockwasher (17) and nut (16).

9.

Step 6 is for M939A2 vehicles only.
Install wire (22) on solenoid (2) with new lockwasher (23) and nut (24).

7.

3-236

TM 9-2320-272-24-1

3-82. STARTER

FOLLOW-ON TASK: Connect battery ground cables (para. 3-126).
3-237

TM

9-2320-272-24-1

3-83. INSTRUMENT

THIS TASK COVERS:
a. Removal
b. Disassembly

c. Assembly
d. Installation

APPLICABLE MODELS
All

EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Air reservoirs drained (TM 9-2320-272-10).
TOOLS
Hood raised and secured (TM 9-2320-272-10).
General mechanic’s tool kit (Appendix E, Item 1) Battery ground cables disconnected (para. 3-126).
Disconnect CTIS electrical components (M939A2)
MATERIALS/PARTS
(para. 3-470).
Three spring nuts (Appendix D, Item 673)
GENERAL SAFETY INSTRUCTIONS
Three cotter pins (Appendix D, Item 53)
Do not disconnect air lines before draining air
REFERENCES (TM)
reservoirs. Small parts under pressure may shoot
TM 9-2320-272-10
out with high velocity, causing injury to personnel.
TM 9-2320-272-20P

1.
2.

3.
4.
5.
6.
7.
8.
9.
10.
11.

3-238

Remove screw (15), clamp (3), cable (1), and retaining clip (4) from diverter bracket (6).
Remove cotter pin (16) from control rod (5). Discard cotter pin (16).

Remove
Remove
Remove
Remove
Remove
Remove
Remove

Tag cables for installation.
cable (1) and spring nut (2) from control rod (5). Discard spring nut (2).
screw (14), clamp (10), cable (13), and retaining clip (8) from diverter bracket (7).
cotter pin (12) from control rod (9). Discard cotter pin (12).
heat control cable (13) and spring nut (11) from control rod (9). Discard spring nut (11).
screw (20), retaining nut (22), and clamp (21) from heater assembly (17).
cotter pin (23) from heater assembly (17). Discard cotter pin (23).
fresh air control cable (19) and spring nut (18) from heater assembly (17). Discard spring

Remove eight screws (26) from instrument cluster (25).
Separate instrument cluster (25) from instrument panel (24).

TM 9-2320-272-24-1

3-83. INSTRUMENT

3-239

TM 9-2320-272-24-1

3-83. INSTRUMENT

12.
13.

14.
15.
16.
17.

18.
19.
20.
21.
22.
23.
24.
25.

3-240

Tag wires and drive shaft for installation.
Disconnect tachometer driveshaft (9) from instrument cluster (4).
Disconnect speedometer driveshaft (14) from instrument cluster (4).

Disconnect
Disconnect
Disconnect
Disconnect

Do not disconnect air lines before draining air reservoirs. Small
parts under pressure may shoot out with high velocity, causing
injury to personnel.
air lines (5), (19), and (21) from instrument cluster (4).
four wires (10) from instrument cluster (4).
three wires (11) from instrument cluster (4).
wire (15) from wire (17).

Disconnect
Disconnect
Disconnect
Disconnect
Disconnect
Disconnect
Disconnect
Disconnect

Wires in steps 20 through 28 are located behind instrument
cluster.
five wires (8) from instrument cluster (4).
wires (12) and (13) from instrument cluster (4).
wires (16) and (18) from instrument cluster (4).
wires (24) and (23) from instrument cluster (4).
wires (6) and (7) from instrument cluster (4).
wire (20) from instrument cluster (4).
two wires (22) from instrument cluster (4).
cables (1), (2), and (3) from instrument cluster (4).

TM 9-2320-272-24-1

3-83. INSTRUMENT

3-241

TM 9-2320-272-24-1

3-83. INSTRUMENT

1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.

Remove
Remove
Remove
Remove
Remove
Remove
Remove
Remove
Remove
Remove
Remove
Remove

1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.

Install
Install
Install
Install
Install
Install
Install
Install
Install
Install
Install
Install

3-242

battery switch lever (1) from instrument cluster (13) (para. 3-107).
starter switch lever (12) from instrument cluster (13) (para. 3-107).
five indicator panel lights (10) from instrument cluster (13) (para. 3-84).
tachometer (2) from instrument cluster (13) (para. 3-88).
speedometer (3) from instrument cluster (13) (para. 3-88).
five electrical gauges (4) from instrument cluster (13) (para. 3-86).
primary air gauge (5) from instrument cluster (13) (para. 3-87).
secondary air gauge (11) from instrument cluster (13) (para. 3-87).
fresh air vent control (8) from instrument cluster (13) (para. 3-293).
defroster control (6) from instrument cluster (13) (para. 3-294).
heater control (7) from instrument cluster (13) (para. 3-294).
spring brake pressure switch (9) from instrument cluster (13) (para. 3-100).

spring brake pressure switch (9) on instrument cluster (13) (para. 3-100).
heater control (7) on instrument cluster (13) (para. 3-294).
defroster control (6) on instrument cluster (13) (para. 3-294).
fresh air vent control (8) on instrument cluster (13) (para. 3-293).
secondary air gauge (11) on instrument cluster (13) (para. 3-87).
primary air gauge (5) on instrument cluster (13) (para. 3-87).
five electrical gauges (4) on instrument cluster (13) (para. 3-86).
speedometer (3) on instrument cluster (13) (para. 3-88).
tachometer (2) on instrument cluster (13) (para. 3-88).
five indicator panel lights (10) on instrument cluster (13) (para. 3-84).
starter switch lever (12) on instrument cluster (13) (para. 3-107).
battery switch lever (1) on instrument cluster (13) (para. 3-107).

TM 9-2320-272-24-1

3-83. INSTRUMENT

3-243

TM 9-2320-272-24-1

3-83. INSTRUMENT

1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.

3-244

Connect cables (3), (2), and (1) to instrument cluster (4).
Connect two wires (22) to instrument cluster (4).
Connect wire (20) to instrument cluster (4).
Connect wires (7) and (6) to instrument cluster (4).
Connect wires (23) and (24) to battery instrument cluster (4).
Connect wires (18) and (16) to instrument cluster (4).
Connect wires (13) and (12) to instrument cluster (4).
Connect five wires (8) to instrument cluster (4).
Connect wire (15) to wire (17).
Connect three wires (11) to instrument cluster (4).
Connect four wires (10) to instrument cluster (4).
Connect air lines (21), (19), and (5) to instrument cluster (4).
Connect speedometer driveshaft (14) to instrument cluster (4).
Connect tachometer driveshaft (9) to instrument cluster (4).
Install fresh air control cable (27) and new spring nut (26) on heater assembly (25).
Install new cotter pin (31) on heater assembly (25).
Install clamp (29), retaining nut (30), and screw (28) on heater assembly (25).

TM 9-2320-272-24-1

3-83. INSTRUMENT

18.
19.
20.
21.
22.

Route heat control cable (43) and defroster control cable (32) through diverter brackets (37) and (38).
Install heat control cable (43), defroster control cable (32), and new spring nuts (33) and (41) on
control panel rods (40) and (36).
Install new cotter pins (42) and (47) on control rods (40) and (36).
Install retaining clips (35) and (39), cables (32) and (43), and clamps (34) and (44) on diverter
brackets (37) and (38) with screws (46) and (45).
Install instrument cluster (4) on instrument panel (48) with eight screws (49).

FOLLOW-ON TASKS:

Connect CTIS electrical components (M939A2) (para. 3-470).
Connect battery ground cables (para. 3-126).
Start engine (TM 9-2320-272-10) and check gauges for proper operation. Check
for air leaks at air gauges.
3-245

TM 9-2320-272-24-1

3-84. INDICATOR

THIS TASK COVERS:
a. Light Assembly Removal
b. Light Assembly Installation

c. Lamp Removal
d. Lamp Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Two lockwashers (Appendix D. Item 351)

1.
2.
3.

4.
5.

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2326-272-10).
Battery ground cables disconnected (para. 3-126).

Remove four screws (7) from warning light panel (1) and pull warning light panel (1) away from
instrument panel (2).
Remove lamp lens (10) from lamp holder (5).
Remove two screws (9) and lockwashers (8) from warning light panel assembly (1) and lamp holder
bracket (6). Discard lockwashers (8).
NOTE
Tag wire for installation.
Disconnect wire (3) from lamp holder connector (4).
Remove lamp holder (5) and bracket (6) from warning light panel assembly (1).

2.
3.
4.

Install lamp holder (5) and bracket (6) on warning light panel assembly (1) with two new
lockwashers (8) and screws (9).
Connect wire (3) to lamp holder connector (4).
Install lamp lens (10) on lamp holder (5).
Install warning light panel (1) on instrument panel (2) with four screws (7).

1.
2.

NOTE
All panel light lamps are removed and installed the same.
Remove lamp lens (10) from lamp holder (5).
Push lamp (11) inward and turn counterclockwise to remove.

1.
2.

Push lamp (11) inward and turn clockwise to install.
Install lamp lens (10) on lamp holder (5).

1.

3-246

TM 9-2320-272-24-1

3-84. INDICATOR

FOLLOW-ON TASK: Connect battery ground cables (para. 3-126).
3-247

TM 9-2320-272-24-1

3-85. INSTRUMENT

THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Battery ground cables disconnected
(para. 3-126).
Instrument cluster removed (para. 3-83).
Electrical switches removed (para. 3-107).
Fuel selector valve switch removed
(para. 3-109).

EQUIPMENT CONDITION (Contd)
Floodlight control switch removed (para. 3-120).
Pressure gauge removed (para. 3-86).
Steering wheel removed (para. 3-226).
Cold-start indicator and lamp removed
(para. 3-84).
Engine stop and throttle control cable removed
(para. 3-45).
Turn signal flasher removed (para. 3-114).
Instrument panel circuit breaker removed
(para. 3-105).
Windshield wiper pump removed (para. 3-281).
Windshield wiper hoses removed (para. 3-282).
Heater control box removed (para. 3-295).
Personnel heater control cables removed
(para. 3-294).

NOTE
It may be necessary to remove the upper steering column. If so,
notify DS maintenance.

1.
2.
3.
4.
5.

6.

two screws (5) from instrument panel (4) and bracket (7).
five screws (3) from instrument panel (4).
four screws (2) from instrument panel (4).
two screw-assembled washers (1) from instrument panel (4).
screw (6) from instrument panel (4).
NOTE
Assistant will help with step 5.
Remove instrument panel (4) from cab (8) and brackets (7) and (9).

1.
2.
3.
4.
5.
6.

NOTE
Assistant will help with step 1.
Position instrument panel (4) on cab (8) and brackets (7) and (9).
Install screw (6) on instrument panel (4).
Install two screw-assembled washers (1) on instrument panel (4).
Install four screws (2) on instrument panel (4).
Install five screws (3) on instrument panel (4).
Install two screws (5) on instrument panel (4) and bracket (7).

3-248

Remove
Remove
Remove
Remove
Remove

TM 9-2320-272-24-1

3-85. INSTRUMENT

FOLLOW-ON TASKS:

Install turn signal flasher (para. 3-114).
Install instrument cluster (para. 3-83).
Install electrical switches (para. 3-107).
Install fuel selector valve switch (para. 3-109).
Install floodlight control switch (para. 3-120).
Install pressure gauge switch (para. 3-86).
Install steering wheel (para. 3-226).
Install cold-start indicator and lamp (para. 3-84).
Install engine stop and throttle control cables (para. 3-45).
Install instrument panel circuit breaker (para. 3-105).
Install personnel heater control cables (para. 3-294).
Install heater control box (para. 3-295).
Install windshield wiper hoses (para. 3-282).
Install windshield wiper pump (para. 3-281).
Connect battery ground cables (para. 3-126).
3-249

TM 9-2320-272-24-1

3-86. ELECTRICAL

THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Two lockwashers (Appendix D, Item 352)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Battery ground cables disconnected (para. 3-126).

NOTE
Engine coolant temperature, transmission oil temperature, engine
oil pressure, battery/alternator, and fuel level gauges are removed
and installed the same.

1.
2.

3.
4.
5.

1.
2.
3.
4.

3-250

Remove eight screws (7) from instrument panel (4).
Pull instrument cluster (5) away from instrument panel (4).
NOTE
Battery indicator gauge has only one wire to disconnect.
Tag wires for installation.
Disconnect wires (3) and (9) from fuel level gauge (6).
Remove two nuts (1), lockwashers (2), and gauge mounting bracket (8) from fuel level gauge (6).
Discard lockwashers (2).
Remove fuel level gauge (6) from instrument cluster (5).

Install fuel level gauge (6) on instrument cluster (5).
Install gauge mounting bracket (8) on fuel level gauge (6) with two new lockwashers (2) and
nuts (1).
Connect wires (3) and (9) to fuel level gauge (6).
Install instrument cluster (5) on instrument panel (4) with eight screws (7).

TM 9-2320-272-24-1

3-86. ELECTRICAL

FOLLOW-ON TASKS:

Connect battery ground cables (para. 3-126).
Start engine (TM 9-2320-272-10) and check gauge for proper operation.
3-251

TM 9-2320-272-24-1

3-87. AIR

THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Two lockwashers (Appendix D, Item 352)
Antiseize tape (Appendix C. Item 72)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Air reservoirs drained (TM 9-2320-272-10).
Battery ground cables disconnected (para. 3-126).

NOTE
The primary and secondary air pressure gauges are removed and
installed in the same manner.

1.
2.

3.
4.
5.

1.
2.

3.
4.

3-252

Remove eight screws (7) from instrument cluster (6).
Pull instrument cluster (6) away from instrument panel (8).
NOTE
Tag air line for installation.
Disconnect air line (1) from primary air gauge (5).
Remove two nuts (2), lockwashers (3), and gauge mounting bracket (4) from primary air gauge (5).
Discard lockwashers (3).
Remove primary air gauge (5) from instrument cluster (6).

Install primary air gauge (5) on instrument cluster (6).
Install gauge mounting bracket (4) on primary air gauge (5) with two new lockwashers (3) and
nuts (2).
NOTE
Male pipe threads must be wrapped with antiseize tape before
installation.
Connect air line (1) to primary air gauge (5).
Install instrument cluster (6) on instrument panel (8) with eight screws (7).

TM 9-2320-272-24-1

3-87. AIR

FOLLOW-ON TASKS:

Connect battery ground cables (para. 3-126).
Start engine (TM 9-2320-272-10), allow air pressure to build up to normal
operating range, and check for air leaks at gauge.
Check if gauge is indicating air pressure (TM 9-2320-272-10).
3-253

TM 9-2320-272-24-1

3-88. SPEEDOMETER

THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Two lockwashers (Appendix D, Item 352)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Battery ground cables disconnected (para. 3-126).

NOTE
Speedometer and tachometer are replaced the same. This
procedure covers speedometer.

1.
2.
3.
4.
5.

1.
2.
3.
4.

3-254

Remove eight screws (7) from instrument cluster (8).
Pull instrument cluster (8) away from instrument panel (9).
Loosen nut (2) and disconnect speedometer driveshaft (1) from speedometer (6).
Remove two nuts (3), cable assembly (11), extension stud (10), washer (12), and two lockwashers (4)
from speedometer mounting bracket (5). Discard lockwashers (4).
Remove mounting bracket (5) and speedometer (6) from instrument cluster (8).

Install speedometer (6) and mounting bracket (5) on instrument cluster (8) with two new
lockwashers (4), extension stud (10), and nut (3).
Install cable assembly (11) on extension stud (10) with washer (12) and nut (3).
Install speedometer driveshaft (1) on speedometer (6) and tighten nut. (2).
Install instrument cluster (8) on instrument panel (9) with eight screws (7).

TM 9-2320-272-24-1

3-88. SPEEDOMETER

FOLLOW-ON TASKS:

Connect battery ground cables (para. 3-126).
Start engine (TM 9-2320-272-10) and road test to check speedometer and
tachometer for proper operation.
3-255

TM 9-2320-272-24-1

3-89. TACHOMETER

THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
M939/A1
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Rubber grommet (Appendix D, Item 565)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-27224P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Left splash shield removed (TM 9-2320-272-10).

1.
2.
3.
4.
5.
6.
7.

Disconnect tachometer driveshaft (5) from tachometer pulse sender unit (12).
Remove screw (1), washer (2), and loop clamp (3) from intake manifold (11).
Remove rubber grommet (4) from firewall (6). Discard grommet (4).
Remove eight screws (9) from instrument cluster (8).
Pull instrument cluster (8) away from instrument panel (10).
Disconnect tachometer driveshaft (5) from tachometer (7) on instrument cluster (8).
Remove tachometer driveshaft (5) from engine side of firewall (6). Replace if bent or cracked.

1.
2.
3.
4.
5.
6.

Push tachometer driveshaft (5) through hole in firewall (6) to tachometer (7).
Install tachometer driveshaft (5) on tachometer (7).
Install instrument cluster (8) on instrument panel (10) with eight screws (9).
Slide new rubber grommet (4) over disconnected end of driveshaft (5) and install in firewall (6).
Install driveshaft (5) on tachometer pulse sender unit (12).
Position loop clamp (3) over driveshaft (5) and install on intake manifold (11) with washer (2) and
screw (1).

3-256

TM 9-2320-272-24-1

3-89. TACHOMETER

FOLLOW-ON TASKS:

Install left splash shield (TM 9-2320-272-10).
Start engine (TM 9-2320-272-10) and check tachometer for proper operation.
3-257

TM 9-2320-272-24-1

3-90. SPEEDOMETER

THIS TASK COVERS:
a. Removal
b. Inspection

c. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Torque wrench (Appendix E, Item 144)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).

MATERIALS/PARTS
Five tiedown straps (Appendix D, Item 690)
GAA grease (Appendix C, Item 28)

1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.

3-258

Remove screw (5), washer (4), two clamps (2), speedometer driveshaft (6), and clamp (3) from air
intake manifold (1).
Remove eight screws (11) from instrument cluster (10) and pull away from instrument panel (9).
Loosen shaft nut (7) and disconnect speedometer driveshaft (6) from speedometer (8).
Remove nut (15), screw (20), and clamps (19) and (14) from bracket (16) on engine bell
housing (18).
Remove screw (17) and bracket (16) from engine bell housing (18).
Remove clamp (19) from speedometer driveshaft (6).
Remove screw (23) and clamp (22) from transfer case (21).
Remove clamp (22) from speedometer driveshaft (6).
Disconnect shaft nut (24) from transfer case input gear cover (25).
Remove five tiedown straps (26) from speedometer driveshaft (6). Discard tiedown straps (26).
Remove speedometer driveshaft (6) and grommet (13) from firewall (12).
Remove grommet (13) from speedometer driveshaft (6).

TM 9-2320-272-24-1

3-90. SPEEDOMETER

3-259

TM 9-2320-272-24-1

3-90. SPEEDOMETER

13.

1.
2.

1.
2.
3.
4.
5.
6.
7.
8.
9.
10.

3-260

NOTE
Pull driveshaft core out from driveshaft conduit 1-1/2 in. (38 mm)
to gain access to retaining washer.
Remove retaining washer (3) and driveshaft core (1) from driveshaft (2).

Inspect driveshaft (2) for cracks. Replace if cracked.
Inspect driveshaft core (1) for breaks. Replace if broken.

NOTE
Apply thin coat of GM grease to driveshaft core.
Install driveshaft core (1) and retaining washer (3) on driveshaft (2).
Install grommet (10) with speedometer driveshaft (2) on firewall (9).
Connect shaft nut (21) to transfer case input gear cover (22).
Install speedometer driveshaft (2) and clamp (19) on transfer case (18) with screw (20). Tighten
screw (20) 40-65 lb-ft (54-88 N•m).
Install bracket (13) on engine bell housing (15) with screw (14). Tighten screw (14) 25-31 lb-ft
(34-42 N•m).
Install speedometer driveshaft (2), clamps (11) and (16) on bracket (13) with screw (17) and nut (12).
Install five new tiedown straps (23) on speedometer driveshaft (2).
Connect shaft nut (24) to speedometer (25).
Install instrument cluster (27) on instrument panel (26) with eight screws (28).
Install two clamps (5), speedometer driveshaft (2), clamp (6), washer (7), and screw (8) on air intake
manifold (4).

TM 9-2320-272-24-1

3-90. SPEEDOMETER

FOLLOW-ON TASK: Start engine (TM 9-2320-272-10) and road test for proper speedometer operation.
3-261

TM 9-2320-272-24-1

3-91. OIL

THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Antiseize tape (Appendix C, Item 72)

1.
2.

3.

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Left splash shield removed (TM 9-2320-272-10).
Battery ground cables disconnected (para. 3-126).

Disconnect wire (1) from oil pressure sending unit (2).
Remove oil sending unit (2) from adapter fitting (5).
NOTE
Step 3 is for M939/A1 models only
Remove adapter fitting (5) and elbow (4) from left side of engine (3).

b. Installation

1.
2.
3.
4.

3-262

NOTE
Male pipe threads must be wrapped with antiseize tape before
installation.
Steps 1 and 2 are for M939/A1 models only.
Install elbow (4) on left side of engine (3).
Install adapter fitting (5) on elbow (4).
Install oil sending unit (2) on adapter fitting (5).
Connect wire (1) to oil pressure sending unit (2).

TM 9-2320-272-24-1

3-91. OIL

FOLLOW-ON TASKS:

Install left splash shield (TM 9-2320-272-10).
Connect battery ground cables (para. 3-126).
Start engine (TM 9-2320-272-10) and check oil pressure sending unit operation.
3-263

TM 9-2320-272-24-1

3-92. FUEL

THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:

TOOLS
General mechanic’s tool kit (Appendix E, Item 1)

EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Spare tire carrier access step removed (M931/A1/A2
and M932/A1/A2) (para. 3-260).
Battery ground cables disconnected (para. 3-126).

MATERIALS/PARTS
Casket (Appendix D, Item 143)

GENERAL SAFETY INSTRUCTIONS
Do not perform this task near open flame.

APPLICABLE MODELS
All

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
WARNING
Diesel fuel is highly flammable. Do not perform this procedure
near open flame. Injury to personnel may result.

1.
2.
3.

Disconnect wire (2) from sending unit (3).
Remove five screws (1) and ground wire (6) from sending unit (3) and fuel tank (5).
Remove sending unit (3) and gasket (4) from fuel tank (5). Discard gasket (4).

1.
2.

Install new gasket (4), sending unit (3), and ground wire (6) on fuel tank (5) with five screws (1).
Connect wire (2) to sending unit (3).

3-264

TM 9-2320-272-24-1

3-92. FUEL

FOLLOW-ON TASKS:

Install spare tire carrier access step (M931/A1/A2 and M932/A1/A2) (para. 3-260).
Connect battery ground cables (para. 3-126).
Start engine (TM 9-2320-272-10) and check fuel gauge.
3-265

TM 9-2320-272-24-1

3-93. WATER

THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Antiseize tape (Appendix C, Item 72)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Battery ground cables disconnected (para. 3-126).
Right splash shield removed (TM 9-2320-272-10).
Surge tank cap removed (TM 9-2320-272-10).
Engine coolant drained (para. 3-53).

1.
2.

Disconnect wire (3) from water temperature sending unit (2).
Remove water temperature sending unit (2) from water manifold (1).

1.
2.

NOTE
Male pipe thread must be wrapped with antiseize tape before
installation.
Install water temperature sending unit (2) on water manifold (1).
Connect wire (3) to water temperature sending unit (2).

3-266

TM 9-2320-272-24-1

3-93. WATER

FOLLOW-ON TASKS:

Connect battery ground cables (para. 3-126).
Fill coolant (para. 3-53).
Install surge tank cap (TM 9-2320-272-10).
Start engine (TM 9-2320-272-10) and check for leaks at water manifold. Check
temperature gauge for proper operation.
Install right splash shield (TM 9-2320-272-10).
3-267

TM 9-2320-272-24-1

3-94. TACHOMETER

THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
M939/A1
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Battery ground cables disconnected (para. 3-126).

1.
2.
3.
4.

Disconnect tachometer pulse sender connector (1) from pulse sender receptacle (6).
Remove tachometer cable (2) from tachometer pulse sender (3).
Remove tachometer pulse sender (3) from adapter fitting (5).
Remove drive tip (4) from adapter fitting (5).

1.
2.
3.
4.

Install drive tip (4) on adapter fitting (5).
Install tachometer pulse sender (3) on adapter fitting (5).
Install tachometer cable (2) on tachometer pulse sender (3).
Connect tachometer pulse sender connector (1) to pulse sender receptacle (6).

3-268

TM 9-2320-272-24-1

3-94. TACHOMETER

FOLLOW-ON TASKS:

Connect battery ground cables (para. 3-126).
Start engine (TM 9-2320-272-10) and test tachometer for proper operation.
3-269

TM 9-2320-272-24-1

3-95. TACHOMETER

THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
M939A2
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Hood raised and secured (TM 9-2320-272-10).
Battery ground cables disconnected (para. 3-126).

1.
2.
3.
4.

Remove eight screws (3) and pull instrument cluster (2) from instrument panel (1).
Disconnect tachometer drive cable (8) from tachometer pulse sensor (7).
Disconnect plug (4) from connector (5).
Remove tachometer pulse sensor (7) from tachometer gauge (6).

1.
2.
3.
4.

Install tachometer pulse sensor (7) on tachometer gauge (6).
Connect plug (4) to connector (5).
Connect tachometer drive cable (8) to tachometer pulse sensor (7).
Install instrument cluster (2) on instrument panel (1) with eight screws (3).

FOLLOW-ON TASKS:

3-270

Connect battery ground cables (para. 3-126).
Start engine (TM 9-2320-272-10) and test tachometer for proper operation.

TM 9-2320-272-24-1

3-96. FUEL

THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Antiseize tape (Appendix D, Item 72)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Left splash shield removed (TM 9-2320-272-10).
Battery ground cables disconnected (para. 3-126).

1.
2.

Disconnect fuel pressure transducer connector (4) from harness wire (1).
Remove fuel pressure transducer (2) from fuel pump (3).

1.
2.

NOTE
Male pipe threads must be wrapped with antiseize tape before
installation.
Install fuel pressure transducer (2) on fuel pump (3).
Connect fuel pressure transducer connector (4) to harness wire (1).

FOLLOW-ON TASKS:

Connect battery ground cables (para. 3-126).
Start engine (TM 9-2320-272-10) and check fuel pressure gauge for proper operation.
Install left splash shield (TM 9-2320-272-10).
3-271

TM 9-2320-272-24-1

3-97. TRANSMISSION

THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Battery ground cables disconnected (para. 3-126).

NOTE
Access to transmitter can be gained through access plate on cab
floor.

1.
2.

Disconnect wire (1) from temperature transmitter (2).
Remove temperature transmitter (2) from transmission adapter fitting (3).

1.
2.

Install temperature transmitter (2) on transmission adapter fitting (3).
Connect wire (1) to temperature transmitter (2).

FOLLOW-ON TASKS: Connect battery ground cables (para. 3-126).
Start engine (TM 9-2320-272-10) and check transmission temperature gauge for
operation.
3-272

TM 9-2320-272-24-1

3-98. TRANSMISSION

THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P

APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)

1.

EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Battery ground cables disconnected (para. 3-126).

2.
3.

Remove nut (2) and retainer shift linkage (3) from left side of transmission (1).
NOTE
Tag wires for installation.
Disconnect wires (5) and (6) from neutral start switch (4).
Remove neutral start switch (4) from left side of transmission (1).

1.
2.
3.

Install neutral start switch (4) on left side of transmission (1). Do not overtighten.
Connect wires (6) and (5) to neutral start switch (4).
Install retainer shift linkage (3) on left side of transmission (1) with nut (2).

FOLLOW-ON TASKS:

Connect battery ground cables (para. 3-126).
Check operation of neutral start switch (TM 9-2320-272-10).
3-273

TM 9-2320-272-24-1

3-99. PRIMARY

THIS TASK COVERS:
a. Primary Switch Removal
b. Primary Switch Installation

c. Secondary Switch Removal
d. Secondary Switch Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Antiseize tape (Appendix C, Item 72)
REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P

EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Air reservoirs drained (TM 9-2320-272-10).
Battery ground cables disconnected (para. 3-126).
GENERAL SAFETY INSTRUCTIONS
Do not disconnect air lines before draining
reservoirs.
Exhaust system components are hot.

WARNING
Do not disconnect air lines before draining air reservoirs. Small
parts under pressure may shoot out with high velocity, causing
injury to personnel.
Do not touch hot exhaust system components with bare hands.
Injury to personnel may result.

1.
2.

NOTE
Tag wires for installation.
Disconnect wires (1) and (2) from primary low air pressure switch (5).
Remove low air pressure switch (5) and adapter fitting (4) from adapter elbow (3).

1.
2.

NOTE
Male pipe threads must be wrapped with antiseize tape before
installation
Install adapter fitting (4) and low air pressure switch (5) on adapter elbow (3).
Connect wires (2) and (1) to primary low air pressure switch (5).

3-274

TM 9-2320-272-24-1

3-99. PRIMARY

3-275

TM 9-2320-272-24-1

3-99. PRIMARY

1.

2.
3.
4.

1.

2.
3.

3-276

NOTE
Tag wires for installation.
Disconnect wire (8) and ground wire (1) from secondary low air pressure switch (7).
NOTE
Assistant will help with steps 2 and 3.
Remove two nuts (4) and screws (3) from secondary air reservoir (6).
Push and rotate secondary air reservoir (5) toward rear of vehicle.
Remove low air pressure switch (7) and adapter fitting (6) from adapter elbow (2).

NOTE
Male pipe threads must be wrapped with antiseize tape before installation.
Install adapter fitting (6) and secondary low air pressure switch (7) on adapter elbow (2).
NOTE
Assistant will help with step 2.
Install two screws (3) and nuts (4) on secondary air reservoir (6).
Connect wire (8) and ground wire (1) to secondary low air pressure switch (7).

TM 9-2320-272-24-1

3-99. PRIMARY

FOLLOW-ON TASKS: Connect battery ground cables (para. 3-126).
Start engine (TM 9-2320-272-10) and allow air pressure to build to normal
operating range, Check for air leaks at switch. Check if air pressure warning light
and buzzer stop operating when air pressure has built to 60 psi (413 kPa).
3-277

TM 9-2320-272-24-1

3-100. SPRING

THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s too1 kit (Appendix E, Item 1)
MATERIALS/PARTS
Antiseize tape (Appendix C, Item 72)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Air reservoirs drained (TM 9-2320-272-10).
Battery ground cables disconnected (para. 3-126).
GENERAL SAFETY INSTRUCTIONS
Do not disconnect air lines before draining air
reservoirs.

WARNING
Do not disconnect air lines before draining air reservoirs. Small
parts under pressure may shoot out with high velocity, causing
injury to personnel.

1.
2.
3.
4.

1.
2.
3.

3-278

Remove eight screws (3) from instrument cluster (2).
Pull instrument cluster (2) away from instrument panel (1).
Disconnect two wires (8) from spring brake pressure switch (7).
Remove spring brake pressure switch (7), fitting (6), and elbow (5) from spring brake release control
valve (4).

NOTE
Male pipe threads must be wrapped with antiseize tape before
installation.
Install elbow (5), fitting (6), and spring brake pressure switch (7) on spring brake release control
valve (4).
Connect two wires (8) to spring brake pressure switch (7).
Install instrument cluster (2) on instrument panel (1) with eight screws (3).

TM 9-2320-272-24-1

3-100. SPRING

FOLLOW-ON TASKS:

Connect battery ground cables (para. 3-126).
Start engine (TM 9-2320-272-10) and allow air pressure to build up to normal
operating range. Check for air leaks at point switch is attached to valve. Stop
engine and engage spring brakes. Spring brake warning light should glow.
3-279

TM 9-2320-272-24-1

3-101. FRONT

THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Antiseize tape (Appendix C, Item 72)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Air reservoirs drained (TM 9-2320-272-10).
Battery ground cables disconnected (para. 3-126).
GENERAL SAFETY INSTRUCTIONS
Do not disconnect air lines before draining air
reservoirs.

WARNING
Do not disconnect air lines before draining air reservoirs. Small
parts under pressure may shoot out with high velocity, causing
injury to personnel.

1.
2.

Disconnect wire connector (3) from front wheel drive lock-in switch (2).
Remove lock-in switch (2) from front wheel drive lock-in valve elbow (1).

1.
2.

NOTE
Male pipe threads must be wrapped with antiseize tape before
installation.
Install lock-in switch (2) on front wheel drive lock-in valve elbow (1).
Connect wire connector (3) to front wheel drive lock-in switch (2).

3-280

TM 9-2320-272-24-1

3-101. FRONT

FOLLOW-ON TASKS:

Connect battery ground cables (para. 3-126).
Start engine (TM 9-2320-272-10) and allow air pressure to build up to normal
operating range. Check for leaks at switch.
Engage front wheel drive and check if axle lock-in indicator light is illuminated.
3-281

TM 9-2320-272-24-1

3-102. HORN

THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)

1.

2.
3.
4.
5.
6.
7.
8.
9.
10.

1.
2.
3.
4.
5.
6.
7.
8.

9.
10.

3-282

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Left splash shield removed (TM 9-2320-272-10).
Battery ground cables disconnected (para. 3-126).

Loosen two screws (26) and nuts (28) on outer cab firewall (27).
NOTE
Step 2 applies to M931 and M932 models only.
Loosen two screws (22) on trailer brake control valve bracket (25).
Loosen two screws (23) on steering column bracket (24).
Turn steering column (14) until contact brush cover (20) is free from firewall (13).
Separate floormat (11) from steering column (14) and cab floor (12).
Disconnect connector (1) and boot (21) from brush cover (20).
Remove four screws (4), wire (5), contact brush cover (20), and gasket (8) from steering column (14).
Remove screw (19) and locktab (18) from contact brush (9). Disconnect wire (17) and capacitor (16).
Remove two screws (15), capacitor (16), contact brush (9), and pad (10) from steering column (14).
Remove nut (2), two washers (3), washer (6), wire (17), screw (7), and boot (21) from contact brush
cover (20).

Install pad (10), contact brush (9). and capacitor (16) on steering column (14) with two screws (15).
Install boot (21) and wire (17) on contact brush cover (20) with screw (7), two washers (3), washer (6),
and nut (2).
Install wire (17) and capacitor (16) on contact brush (9) with locktab (18) and screw (19).
Install gasket (8), contact brush cover (20), and ground wire (5) on steering column (14) with
four screws (4).
Connect connector (1) and boot (21) to brush cover (20).
Turn steering column (14) until contact brush cover (20) is toward firewall (13).
Position floormat (11) against steering column (14) on cab floor (12).
Tighten two screws (23) on steering column bracket (24).
NOTE
Step 9 applies to M931 and M932 vehicles only
Tighten two screws (22) on trailer brake control valve bracket (25).
Tighten two screws (26) and nuts (28) on outer cab firewall (27).

TM 9-2320-272-24-1

3-102. HORN

FOLLOW-ON TASKS:

Connect battery ground cables (para. 3-126).
Check horn for proper operation (TM 9-2320-272-10).
Install left splash shield (TM 9-2320-272-10).
3-283

TM 9-2320-272-24-1

3-103. HORN,

THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic's tool kit (Appendix E, Item 1)

EQUIPMENT CONDITION
Parking brake ret (TM 9-2320-272-10).
Air reservoirs drained (TM 9-2320-272-10).
Hood raised and secured (TM 9-2320-272-10).
Battery ground cables disconnected (para. 3-126).

MATERIALS/PARTS
Two lockwashers (Appendix D, Item 371)
Antiseize tape (Appendix C, Item 72)

GENERAL SAFETY INSTRUCTIONS
Do not disconnect air lines before draining air
reservoirs.

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P

1.

Disconnect wires (6) and (7) from horn solenoid (6).
WARNING

2.
3.

4.
5.

6.

3-284

Do not disconnect air lines before draining air reservoirs. Small
parts under pressure may shoot out with high velocity, causing
injury to personnel.
Disconnect air line (4) from elbow (3).
Remove elbow (3) from horn solenoid (6).
NOTE
Horn solenoid fitting may become disconnected from horn solenoid
during removal. Horn solenoid and fitting are replaced as an
assembly.
Remove horn solenoid (6) from horn (2).
Remove two nuts (10), wire (9), two lockwashers (11), screws (1), and horn (2) from
bracket (13). Discard lockwashers (11).
NOTE
Assistant will help with step 6.
Pull insulation away from inside cab firewall to allow access to
nut.
Remove screw-assembled washer (8), nut (15), washer (14), screw (12), and bracket (13) from
firewall (16).

TM 9-2320-272-24-1

3-103. HORN,

1.
2.
3.
4.
5.
6.

When new solenoid is installed, fitting from old solenoid may
be used. Fitting must be cleaned and inspected for cracks or
stripped threads.
Male pipe threads must be wrapped with antiseize tape before
installation.
Assistant will help with step 1.
Install bracket (13) on firewall (16) with washer (14), screw (12), nut (15), and screw-assembled
washer (8).
Install horn (2) on bracket (13) with two screws (1), new lockwashers (11), wire (9), end two nuts (10).
Install horn solenoid (6) on horn (2).
Install elbow (3) on horn solenoid (6).
Connect air line (4) to elbow (3).
Connect wires (6) and (7) to horn solenoid (5).

FOLLOW-ON TASKS: Connect battery ground cables (para. 3-126).
Start engine (TM 9-2320-272-10) and allow air pressure to build up to normal
operating range. Check for air leaks at horn solenoid.
Check horn for proper operation (TM 9-2320-272-10).
3-285

TM 9-2320-272-24-1

3-104. HORN

THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATRIALS/PARTS
O-ring (Appendix D, Item 428)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Battery ground cables disconnect (para. 3-126).

1.
2.
3.
4.

Remove three screws (6) and horn switch assembly (2) from steering column (1).
Disconnect horn switch connector (9) from diode lead (3).
Remove spring (11) and seat (4) from diode lead (3).
Remove retaining ring (8), horn switch (7), and O-ring (10) from adapter (5). Discard O-ring (10).

1.
2.
3.
4.

Install new O-ring (10), horn switch (7), and retaining ring (8) on adapter (5).
Install seat (4) and spring (11) over diode lead (3).
Connect horn switch connector (9) to diode lead (3).
Install horn switch assembly (2) on steering column (1) with three screws (6).

3-286

TM 9-2320-272-24-1

3-104. HORN

FOLLOW-ON TASKS:

Connect battery ground cables (para. 3-126).
Check horn for proper operation (TM 9-2320-272-10).
3-287

TM 9-2320-272-24-1

3-105. CIRCUIT

THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Hood raised and secured (TM 9-2320-272-10).
Battery ground cables disconnected (para. 3-126).

1.
2.
3.
4.

NOTE
Perform steps 1 and 2 to remove circuit breakers located on
engine firewall.
Perform steps 3 and 4 to remove circuit breakers located behind
instrument panel and above steering column.
Tag wires for installation
Disconnect wires (4) and (5) from circuit breaker (2).
Remove two screws (3) and circuit breaker (2) from firewall (1).
Disconnect wires (6) and (7) from circuit breaker (9).
Remove two screws (10) and circuit breaker (9) from instrument panel brace (8).

1.
2.
3.
4.

NOTE
Perform steps 1 and 2 to install circuit breakers on engine
firewall.
Perform steps 3 and 4 to install circuit breakers behind
instrument panel.
Install circuit breaker (2) on firewall (1) with two screws (3).
Connect wires (5) and (4) to circuit breaker (2).
Install circuit breaker (9) on instrument panel brace (8) with two screws (10).
Connect wires (7) and (6) to circuit breaker (9).

3-288

TM 9-2320-272-24-1

3-105. CIRCUIT

FOLLOW-ON TASKS: Connect battery ground cables (para. 3-126).
3-289

TM 9-2320-272-24-1

3-106. FAILSAFE

THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Battery ground cables disconnected (para. 3-126).

1.
2.
3.

Disconnect harness connector (2) from failsafe warning module (6).
Remove screw (5), ground wire (4), and washer (3) from failsafe warning module (6).
Remove screw (7), washer (8), and failsafe warning module (6) from cowl (1).

1.
2.
3.

Install failsafe warning module (6) on cowl (1) with washer (8) and screw (7).
Install washer (3) and ground wire (4) on failsafe warning module (6) with screw (5).
Connect harness connector (2) to failsafe warning module (6).

3-290

TM 9-2320-272-24-1

3-106. FAILSAFE WARNING MODULE REPLACEMENT (Contd)

FOLLOW-ON TASKS: • Connect battery ground cables (para. 3-126).
l Start engine (TM 9-2320-272-10) and check failsafe warning module for proper
operation.
3-291

TM 9-2320-272-24-1

3-107. ELECTRICAL SWITCHES REPLACEMENT
THIS TASK COVERS:
a. Accessory Switcher Removal
b. Accessory Switcher Installation

c. Battery and Starter Switch Removal
d. Battery and Starter Switch Installation

INITIAL SETUP:
APPLICABLE MODELS
All
Tools
General mechanic's tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Three lockwashers (Appendix D, Item 355)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Blower motor in OFF position (TM 9-2320-272-10).
l Battery ground cables disconnected (para. 9-126).

NOTE
Heater switch, floodlight switch, and warning switches are all
replaced the same way, Tasks a. and b. covers heater switch.

1.
2.

3.
4.

Remove screw (1) and lever (2) from blower motor switch (9).
Remove nut (3), lockwasher (4), and blower motor switch (9) from instrument panel (10). Discard
lockwasher (4).
NOTE
Tag all connectors for installation.
Disconnect connectors (6), (7), and (8) from blower motor switch (9).
Remove plug (16) from blower motor switch (9).

CAUTION
1.
2.
3.
4.
6.
6.

Ensure each connector is inserted into proper terminal end.
Install plug (16) into terminal (13).
Install connector (7) into terminal (11).
Install connector (8) into terminal (12).
Install connector (6) into terminal (14).
Install blower motor switch (9) on instrument panel (10), with key (6) into keyway behind
instrument panel (10), with new lockwasher (4) and nut (3).
Position lever (2) on blower motor switch (9) with pointing edge placed in OFF position and install
with screw (1).
NOTE
Battery and starter switches are replaced basically the same.
Tasks c. and d. cover battery switch.

c. Battery and Starter Switch Removal
1.

3-292

Remove screw (24), lockwasher (23), switch lever (16), felt washer (17), and washer (18) from
battery switch (20). Discard lockwasher (23).

TM 9-2320-272-24-1

3-107. ELECTRICAL SWITCHES REPLACEMENT (Contd)
2.

3.

1.
2.
3.

Remove nut (22) and lockwasher (19) from instrument cluster (21) and pull switch (20) from behind
instrument cluster (21).
NOTE
Tag wires for installation.
Disconnect wires (25), (26), (27), and (28) and remove battery switch (20) from instrument
cluster (21).

NOTE
If new switch is being installed, use mounting hardware supplied
with switch, Starter switch has only three wires.
Connect wires (28),(27), (26), and (25) to battery switch (20).
Position battery switch (20) through instrument cluster (21) from the rear and install with new
lockwasher (19) and nut (22).
Position washer (18), felt washer (17), and switch lever (16) on battery switch (20) and install with
new lockwasher (23) and screw (24).

FOLLOW-ON TASK: Connect battery ground cables (para. 3-126).
3-293

TM 9-2320-272-24-1

3-108. MAIN LIGHT SWITCH REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

APPLICABLE MODELS
All

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P

General mechanic’s tool kit (Appendix E, Item 1)

EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Battery ground cables disconnected (para. 3-126).

NOTE
Two different types of light switches are used.
a. Removal
1.

2.
3.

1.
2.
3.

3-294

Remove three screws (8), washers (7), switch levers (6), and washers (5) from main light switch (1).
NOTE
Switch is removed from behind instrument panel.
Remove four screws (4) and light switch (1) from instrument panel (3).
Disconnect harness connector (2) from main light switch (1).

Connect harness connector (2) to main light switch (1).
Install main light switch (1) on instrument panel (3) with four screws (4).
Install three washers (5) and switch levers (6) on main light switch (1) with three washers (7) and
screws (8).

TM 9-2320-272-24-1

3-108. MAIN LIGHT SWITCH REPLACEMENT (Contd)

FOLLOW-ON TASKS: • Connect battery ground cables (para. 3-126).
l Check lights for proper operation (TM 9-2320-272-10).
3-295

TM 9-2320-272-24-1

3-109. FUEL SELECTOR VALVE SWITCH REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Two locknuts (Appendix D. Item 283)

1.
2.
3.
4.
6.

1.
2.
3.
4.

3-296

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Battery ground cables disconnected (para. 3-126).

NOTE
Tag wires for installation.
Disconnect two wires (2) and wire (14) from fuel selector valve switch (3).
Remove screw (9), washer (10), lever (8), felt washer (11), and washer (7) from fuel selector valve
switch (3).
Remove nut (12), washer (6), and plate (5) from fuel selector valve switch (3).
Remove fuel selector valve switch (3) from bracket (4).
Remove two locknuts (1), screws (13), and bracket (4) from instrument panel (15). Discard locknuts (1).

Install bracket (4) on instrument panel (15) with two screws (13) and new locknuts (1).
Position fuel selector valve switch (3) on bracket (4) and install plate (5), washer (6), and nut (12).
Install lever (8) on fuel selector valve switch (3) with washer (7), felt washer (11), washer (10), and
screw (9).
Connect two wires (2) and wire (14) to fuel selector valve switch (3).

TM 9-2320-272-24-1

FOLLOW-ON TASKS:

l
l

Connect battery ground cables (para. 3-126).
Check fuel selector valve switch for proper operation (TM 9-2320-272-10).
3-297

TM 9-2320-272-24-1

3-110. AUXILIARY OUTLET SOCKET AND RECEPTACLE (M936/A1/A2) REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
M936/A1/A2
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)

1.
2.
3.
4.
5.

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Battery ground cables disconnected (para. 3-126).

Remove screw (13) and outlet cable (11) from auxiliary outlet socket (14).
Remove screw (10), clamp (2), and auxiliary outlet socket (14) from instrument panel (1).
Remove clip (12) from instrument panel (1).
Disconnect wire (5) from wire (4).
Remove four nuts (3), screws (9), cover (8), and auxiliary outlet receptacle (7) from instrument
panel (1).

b. Installation
1.
2.
3.
4.
5.
6.

3-298

Insert wire (4) through hole (6) on instrument panel (1) and connect to wire (5).
Install auxiliary outlet receptacle (7) and cover (8) on instrument panel (1) with four screws (9) and
nuts (3).
Install clip (12) on instrument panel (1).
Install auxiliary outlet socket (14) on instrument panel (1) with clamp (2) and screw (10).
Install outlet cable (11) on auxiliary outlet socket (14) with screw (13).
Install outlet cable (11) on clip (12).

TM 9-2320-272-24-1

3-110. AUXILIARY OUTLET SOCKET AND RECEPTACLE (M936/A1/A2) REPLACEMENT (Contd)

FOLLOW-ON TASK: Connect battery ground cables (para. 3-126).
3-299

TM 9-2320-272-24-1

3-111. STOPLIGHT SWITCH REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Antiseize tape (Appendix C, Item 72)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Air reservoirs drained (TM 9-2320-272-10).
l Battery ground cables disconnected (para. 3-126).

1.
2.

Tag wires for installation.
Disconnect two wires (1) from stoplight switch (2).
Remove stoplight switch (2) from double check valve (3).

1.
2.

NOTE
Male pipe threads must be wrapped with antiseize tape before
installation.
Install stoplight switch (2) on double check valve (3).
Connect two wires (1) to stoplight switch (2).

FOLLOW-ON TASKS: • Connect battery ground cables (para. 3-126).
l Start engine (TM 9-2320-272-10) and allow air pressure to build up to normal
operating range. Check for air leaks at switch.
l Check stoplights for proper operation (TM 9-2320-272-10).
3-300

TM 9-2320-272-24-1

3-112. HIGH BEAM SELECTOR SWITCH REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
ALL
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)

1.

2.

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Battery ground cables disconnected (para. 3-126).

NOTE
Tag all wires for installation.
Disconnect electrical wires (3), (4), and (5) from selector switch (6) under cab floor (2).
NOTE
Assistant will help with step 2.
Remove two screws (1) and selector switch (6) from cab floor (2).

b. Installation

1.
2.

NOTE
Assistant will help with step 1.
Install selector switch (6) on cab floor (2) with two screws (1).
Connect electrical wires (5), (4), and (3) to selector switch (6).

FOLLOW-ON TASKS: • Connect battery ground cables (para. 3-126).
l Check headlight beam selector for proper operation (TM 9-2320-272-10).
3-301

TM 9-2320-272-24-1

3-113. TURN SIGNAL CONTROL AND INDICATOR LAMP REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Battery ground cables disconnected (para. 3-126).

a. Removal
1.
2.
3.

Disconnect connector (9) from turn signal control (1).
Remove clamp (7), signal self-canceller (8), and turn signal control (1) from steering column (6).
Remove lamp lens (3) and lamp (2) from lamp socket (4).

b. Installation
1.
2.
3.
4.

Install lamp (2) on lamp socket (4).
Install lamp lens (3) on turn signal control (1).
Align signal self-canceller (8) with cancelling pin (5), and install turn signal control (1) on steering
column (6) with clamp (7).
Connect connector (9) to turn signal control (1).

FOLLOW-ON TASKS:

l
l

3-302

Connect battery ground cables (para. 3-126).
Check turn signal control for proper operation (TM 9-2320-272-10).

TM 9-2320-272-24-1

3-114. TURN SIGNAL FLASHER REPLACEMENT
THIS TASK COVERS:
a. Removal

APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)

1.
2.

1.
2.

b. Installation

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Battery ground cables disconnected (para. 3-126).

Remove screws (7) and (8), washers (6) and (9), wire (5), horn ground wire (4), and flasher (3) from
firewall (1).
Remove harness connector (2) from flasher (3)

Install harness connector (2) on flasher (3).
Install flasher (3), horn ground wire (4), and wire (5) on firewall (1) with washers (6) and (9) and
screws (7) and (8).

FOLLOW-ON TASKS: • Connect battery ground cables (para. 3-126).
l Check turn signal flasher for proper operation (TM 9-2320-272-10).
3-303

TM 9-2320-272-24-1

3-115. PROTECTIVE CONTROL BOX REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Torque wrench (Appendix E, Item 146)
MATERIALS/PARTS
Six lockwashers (Appendix D, Item 355)

1.
2.
3.

1.
2.
3.

3-304

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Battery ground cables disconnected (para. 3-126).
l Ether cylinder and valve removed (para. 3-35).

Remove windshield washer bottle lid (2) and washer bottle (3) from windshield washer bottle
bracket (4). Do not disconnect windshield washer hoses (1).
Disconnect harness connector (12) from protective control box (13).
Remove four screws (11), lockwashers (10), ground wire (9), protective control box (13), two
lockwashers (8), spacers (7), spacers (5), and washer bottle bracket (4) from firewall (6). Discard
lockwashers (10) and (8).

Install washer bottle bracket (4) on firewall (6) with two spacers (5), new lockwashers (8),
spacers (7). protective control box (13). ground wire (9), four new lockwashers (10), and screws (11).
Connect harness connector (12) on protective control box (13). Tighten connector (12) 10 lb-ft (14 N•m).
Install washer bottle (3) and windshield washer bottle lid (2) on windshield washer bottle bracket (4).

TM 9-2320-272-24-1

3-115. PROTECTIVE CONTROL BOX REPLACEMENT (Contd)

FOLLOW-ON TASKS: • Install ether cylinder and valve (para. 3-35).
l Connect battery ground cables (para. 3-126).
3-305

TM 9-2320-272-24-1

3-116. HEADLIGHT MAINTENANCE
THIS TASK COVERS:
a. Removal
b. Installation

APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Three lockwashers (Appendix D, Item 345)

c. Alignment

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Hood raised and secured (TM 9-2320-272-10).
l Battery ground cables disconnected (para. 3-126).

a. Removal

1.
2.
3.
4.
5.
6.

1.
2.
3.
4.
5.
6.
7.

NOTE
Tag all connectors for installation.
Remove three screws (3) and retaining ring (2) from headlamp housing (1).
Pull headlamp (4) out from headlamp housing (1).
Disconnect three connectors (5) from headlamp housing (1).
Remove three nuts (10), lockwashers (8), and headlamp housing (1) from hood (9). Discard
lockwashers (8).
Disconnect three connectors (11) from headlamp housing (1).
Remove three headlamp connectors (7) and grommets (6) from headlamp housing (1).

Install three grommets (6) and headlamp connectors (7) on headlamp housing (1).
Connect three connectors (11) to headlamp housing (1).
Install headlamp housing (1) on hood (9) with three new lockwashers (8) and nuts (10).
Connect three connectors (5) to headlamp housing (1).
Position headlamp (4) in headlamp housing (1) with the words SEALED BEAM positioned at
bottom of headlamp (4).
Install retaining ring (2) on headlamp housing (1) with three screws (3).
Connect battery ground cables (para. 3-126).

c. Alignment
1.
2.
3.
4.
5.
6.
7.

3-306

Draw a horizontal line (12) on a wall the height of center of headlights (15).
Park truck facing wall so headlights (15) are 25 ft (7.6 m) from wall.
Draw a vertical line (14) through horizontal line (12) so it is in line with center of headlight (15).
Turn headlights on low beam (TM 9-2320-260-102
Adjust headlight horizontal direction with adjusting screw (16) until left edge of bright light
area (13) on wall is 2-6 in. (5.08-15.24 cm) right of vertical line (14).
Adjust headlight vertical direction with adjusting screw (17) until top edge of bright light area (13)
on wall is touching lower side of horizontal line (12).
Adjust other headlight using same procedure.

TM 9-2320-272-24-1

3-116. HEADLIGHT MAINTENANCE (Contd)

FOLLOW-ON TASK: Check headlamps for proper operation (TM 9-2320-272-10).
3-307

TM 9-2320-272-24-1

3-117. BLACKOUT LIGHT MAINTENANCE
THIS TASK COVERS:
a. Removal
b. Disassembly

c. Assembly
d. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Lockwasher (Appendix D, Item 354)
Four locknuts (Appendix D, Item 313)

1.
2.

3.
4.

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Hood raised and secured (TM 9-2320-272-10).
l Battery ground cables disconnected (para. 3-126).

Disconnect wire (8) from blackout light connector (12).
Remove nut (7), lockwasher (9), and adjustment washer (10) from mounting bracket (3). Discard
lockwasher (9).
NOTE
Assistant will help with step 3.
Remove four locknuts (2), screws (5) and (6), and mounting bracket (3) from hood (4). Discard
locknuts (2).
Remove blackout light (1) and spacer (11) from mounting bracket (3).

b. Disassembly
1.
2.
3.
4.

Loosen three screws (17) on door (13).
Remove door (13) from light housing (14).
Remove gasket (16) from door (13).
Remove lamp (15) from light housing (14).

1.
2.
3.

Install lamp (15) on lamp housing (14).
Install gasket (16) on door (13).
Install door (13) on light housing (14) and tighten three screws (17).

d. Installation
1.

2.
3.
4.

3-308

Install blackout light (I) and spacer (11) on mounting bracket (3).
NOTE
Assistant will help with step 2.
Install mounting bracket (3) on hood (4) with two screws (5) and (6), and four new locknuts (2).
Install adjustment washer (10), new lockwasher (9), and nut (7) on mounting bracket (3).
Connect wire (8) to blackout light connector (12).

TM 9-2320-272-24-1

3-117. BLACKOUT LIGHT MAINTENANCE (Contd)

FOLLOW-ON TASKS: • Connect battery ground cables (para. 3-126).
l Check blackout light for proper operation (TM 9-2320-272-10).
3-309

TM 9-2320-272-24-1

3-118. FRONT AND REAR COMPOSITE LIGHT AND BRACKET REPLACEMENT
THIS TASK COVERS:
a. Front Composite Light Removal
b. Front Composite Light Installation
c. Removal (M923/A1/A2)
d. Installation (M923/A1/A2)
e. Removal (M936/A1/A2)
f. Installation (M936/A1/A2)
g. Removal (M929/A1/A2)

APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Two lockwashers (Appendix D, Item 356)
Four locknuts (Appendix D, Item 299)
Four lockwashers (M936/A1/A2)
(Appendix D, Item 345)
Two locknuts (M936/A1/A2) (Appendix D,
Item 291)
Three locknuts (M929/A1/A2) (Appendix D,
Item 313)
Two locknuts (M931/A1/A2) (Appendix D,
Item 322)
Locknut (M931/A1/A2) (Appendix D, Item 288)
Four locknuts (M931/A1/A2)
(Appendix D, Item 313)
Two locknuts (M934/A1/A2) (Appendix D,
Item 288)
Two screw-assembled lockwashers
(Appendix D, Item 583)

h. Installation (M929/A1/A2)
i. Removal (M931/A1/A2)
j. Installation (M931/A1/A2)
k. Removal (M934/A1/A2)
L. Installation (M934/A1/A2)
m. Composite Light Lamp Removal
n. Composite Light Lamp Installation

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Battery ground cables disconnected (para. 3-126).

a. Front Composite Light Removal
1.

2.
3.
4.
5.
6.

3-310

Remove four locknuts (13) and screws (5) from fender (3). Discard locknuts (13).
NOTE
Tag wires for installation.
Disconnect wires (7), (8), (9), and (10).
Remove wiring cover (11) from cable (12).
Remove grommet (14) from fender (3).
Remove two screws (1), lockwasher (2), and front composite light (6) from fender (3). Discard
lockwasher (2).
Remove locknut (19), two washers (17) and lockwashers (15), screw (16), and mounting bracket (4)
from fender (3). Discard lockwashers (15) and locknut (19).

TM 9-2320-272-24-1

3-118. FRONT AND REAR COMPOSITE LIGHT AND BRACKET REPLACEMENT (Contd)
b. Front Composite Light Installation
1.
2.
3.
4.
5.
6.

Install mounting bracket (4) on fender (3) with screw (16), two washers (17), new lockwashers (15),
and new locknut (19).
Insert wires (7), (8), (9), and (10) through hole in fender (3).
Install grommet (14) on fender (3).
Install composite light (6) on fender (3) with new lockwasher (2) and two screws (1).
Insert wires (7), (8), (9), and (10) through hole in wiring cover (11) and connect.
Install wiring cover (11) with four screws (5) and new locknuts (13).

3-311

TM 9-2320-272-24-1

3-118. FRONT AND REAR COMPOSITE LIGHT AND BRACKET REPLACEMENT (Contd)

1.

2.

NOTE
Left and right composite lights are replaced the same way.
Remove two screw-assembled lockwashers (2), clamp (3), and rear composite light (6) from
bracket (1). Discard screw-assembled lockwashers (2).
NOTE
Tag connectors for installation.
Disconnect four connectors (4) from wires (5).

d. Installation (M923/A1/A2
1.
2.

3-312

Connect four connectors (4) to wires (5).
Install rear composite light (6) and clamp (3) on bracket (1) with two new screw-assembled
lockwashers (2).

TM 9-2320-272-24-1

3-118. FRONT AND REAR COMPOSITE LIGHT AND BRACKET REPLACEMENT (Contd)
e. Removal (M936/A1/A2)

1.
2.

3.
4.
5.

NOTE
Left and right composite lights and brackets are replaced the same
way.
Remove two locknuts (14), screws (16), and reflector (15) from taillight guard (11). Discard
locknuts (14).
Remove four screws (13), lockwashers (12), and taillight guard (11) from bracket (20). Discard
lockwasher (12).
NOTE
Tag wires for installation.
Disconnect four connectors (17) from wires (18).
Remove two screw-assembled lockwashers (10) and rear composite light (19) from bracket (20).
Discard screw-assembled lockwashers (10).
Remove two locknuts (9), screws (8), and bracket (20) from ladder bracket (7). Discard locknuts (9).

f. Installation (M936/A1/A2)
1.
2.
3.
4.
5.

Install bracket (20) on ladder bracket (7) with two screws (8) and new locknuts (9).
Install rear composite light (19) on bracket (20) with two new screw-assembled lockwashers (10).
Connect four connectors (17) to wires (18).
Install taillight guard (11) on bracket (20) with four new lockwashers (12) and screws (13).
Install reflector (15) on taillight guard (12) with two screws (16) and new locknuts (14).

3-313

TM 9-2320-272-24-1

3-118. FRONT AND REAR COMPOSITE LIGHT AND BRACKET REPLACEMENT (Contd)
g. Removal (M929/A1/A2)

1.

2.
3.

NOTE
Left and right composite lights and covers are replaced the same
way.
Remove three locknuts (4), screws (5), and cover (3) from dump bed (1). Discard locknuts (4).
NOTE
Tag wires for installation.
Disconnect four connectors (6) from wires (7).
Remove two screw-assembled lockwashers (2) and rear composite light (8) from dump bed (1).
Discard screw-assembled lockwashers (2).

h. Installation (M929/A1/A2)
1.
2.
3.

3-314

Install rear composite light (8) on dump bed (1) with two new screw-assembled lockwashers (2).
Connect four connectors (6) to wires (7).
Install cover (3) on dump bed (1) with three screws (5) and new locknuts (4).

TM 9-2320-272-24-1

3-118. FRONT AND REAR COMPOSITE LIGHT AND BRACKET REPLACEMENT (Contd)

3-315

TM 9-2320-272-24-1

3-118. FRONT AND REAR COMPOSITE LIGHT AND BRACKET REPLACEMENT (Contd)

1.
2.

3.
4.
5.

NOTE
Left and right composite lights, covers, and brackets are replaced
the same way.
Remove two locknuts (6), screws (12), and reflector (11) from bracket (5). Discard locknuts (6).
Remove four locknuts (9), screws (13), and cover (8) from bracket (5). Discard locknuts (9).
NOTE
Tag wires for installation.
Disconnect four connectors (10) from wires (14).
Remove two screw-assembled lockwashers (7) and rear composite light (15) from bracket (5).
Dircard screw-assembled lockwashers (7).
Remove nut (2), locknut (3), two screws (4), and bracket (5) from frame (1). Discard locknut (3).

j. Installation (M931/A1/A2)
1.
2.
3.
4.
5.

3-316

Install bracket (5) on frame (1) with two screws (4), new locknut (3), and nut (2).
Install rear composite light (15) on bracket (5) with two new screw-assembled lockwashers (7).
Connect four connectors (10) to wires (14).
Install cover (8) on bracket (5) with four screws (13) and new locknuts (9).
Install reflector (11) on bracket (5) with two screws (12) and new locknuts (6).

TM 9-2320-272-24-1

3-118. FRONT AND REAR COMPOSITE LIGHT AND BRACKET REPLACEMENT (Contd)

3-317

TM 9-2320-272-24-1

3-118. FRONT AND REAR COMPOSITE LIGHT AND BRACKET REPLACEMENT (Contd)

5.

NOTE
l Left and right composite lights, brackets, covers, and braces are
replaced the same way.
l Tag wires for installation.
Remove four screws (6) and cover (5) from bracket (9)
Disconnect four connectors (8) from wires (10).
Remove two screw-assembled lockwashers (4) and rear composite light (11) from bracket (9).
Discard screw-assembled lockwashers (4).
Remove locknuts (14) and (7), two screws (3), and bracket (9) from brace (2). Discard locknuts (14)
and (7).
Remove two nuts (12), screws (13), and brace (2) from frame rail (1).

1.
2.
3.
4.
5.

Install brace (2) on frame rail (1) with two screws (13) and nuts (12).
Install bracket (9) on brace (2) with two screws (3) and new locknuts (14) and (7).
Install rear composite light (11) on bracket (9) with two new screw-assembled lockwashers (4).
Connect four connectors (8) to wires (10).
Install cover (5) on bracket (9) with four screws (6).

1.
2.
3.
4.

3-318

TM 9-2320-272-24-1

3-118. FRONT AND REAR COMPOSITE LIGHT AND BRACKET REPLACEMENT (Contd)

3-319

TM 9-2320-272-24-1

3-118. FRONT AND REAR COMPOSITE LIGHT AND BRACKET REPLACEMENT (Contd)

1.
2.
3.

4.

1.

2.
3.

3-320

NOTE
Composite light is off vehicle for this task.
Loosen six screws (8) on composite light body (4).
Remove composite light door (1) and seal (7) from composite light body (4).
Remove stoplight lamp (5), blackout marker lamp (6), turn signal lamp (2), and parking lamp (3)
from composite light body (4).
NOTE
Perform step 4 for diode configured rear composite lights only.
Remove stoplight lamp (5). blackout marker diode (6), turn signal lamp (2), and parking lamp (3)
from composite light body (4).

NOTE
Composite light is off vehicle for this task.
Install stoplight lamp (5), blackout marker lamp (6), turn signal lamp (2), and parking lamp (3) on
composite light body (4).
NOTE
Perform step 2 for diode configured rear composite lights only.
Install stoplight lamp (5), blackout marker diode (6), turn signal lamp (2), and parking lamp (3) on
composite light body (4).
Install seal (7) and composite light door (1) on composite light body (4) and tighten six screws (8).

TM 9-2320-272-24-l

3-118. FRONT AND REAR COMPOSITE LIGHT AND BRACKET REPLACEMENT (Contd)

FOLLOW-ON TASKS: • Connect battery ground cables (para. 3-126).
l Check rear composite light for proper operation (TM 9-2320-272-10).
3-321

TM 9-2320-272-24-1

3-119. FLOODLIGHT SEALED BEAM LAMP AND DOOR (M936/A1/A2) REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
M936/A1/A2
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P

EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Battery ground cables disconnected (para. 3-126).
GENERAL SAFETY INSTRUCTIONS
Lamp door retaining clips are under tension.

NOTE
All floodlight sealed beam lamps and doors are replaced the
same way.
a. Removal
1.
2.
3.

Remove three screws (1) and retaining rings (2) from lamp door (10).
Separate lamp door (10) from lamp housing (6).
Remove two screws (5) and wires (8) from sealed beam lamp (4).
WARNING

4.
5.

Lamp door retaining clips are under tension and must be removed
with firm grip or injury to personnel may result.
NOTE
Note position of clips for installation.
Remove four retaining clips (3) from lamp door (10).
Remove sealed beam lamp (4) from lamp door (10).

b. Installation
1.
2.
3.
4.

3-322

Install sealed beam lamp (4) on lamp door (10). Align lamp (4) with notch (11) on lamp door (10).
Install four retaining clips (3) on lamp door (10).
Install two wires (8) on lamp (4) with two screws (5).
Align drain hole (9) in door (10) with notch (7) in lamp housing (6) and install lamp door (10) on
lamp housing (6) with three screws (1) and retaining rings (2).

TM 9-2320-272-24-1

3-119. FLOODLIGHT SEALED BEAM LAMP AND DOOR (M936/A1/A2) REPLACEMENT
(Contd)

FOLLOW-ON TASKS: • Connect battery ground cables (para. 3-126).
l Check floodlight for proper operation (TM 9-2320-272-10).
3-323

TM 9-2320-272-1

3-120. FLOODLIGHT CONTROL SWITCH MAINTENANCE
THIS TASK COVERS:
a. Removal
b. Disassembly
c. Inspection

d. Assembly
e. Installation

INITIAL SETUP:
APPLICABLE MODELS
M936/A1/A2
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Two locknuts (Appendix D, Item 283)
Lockwasher (Appendix D, Item 355)
Lockwasher (Appendix D, Item 351)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Battery ground cables disconnected (para. 3-126).

a. Removal
1.
2.

3.

Remove two locknuts (1) and mounting screws (11) from angle bracket (2) and instrument panel (16).
Discard locknuts (1).
Lower floodlight control switch (12).
NOTE
Tag connectors for installation.
Disconnect four connectors (15) from floodlight control switch (12).

b. Disassembly
1.
2.

1.
2.

1.
2.

3-324

Remove screw (7), lockwasher (6), switch lever (8), washer (5), and felt washer (9) from floodlight
control switch (12). Discard lockwasher (6).
Remove nut (4), lockwasher (10), identification plate (3), angle bracket (21, plug (14), and shell (13)
from floodlight control switch (12). Discard lockwasher (10).

Inspect floodlight control switch (12) for breaks and cracks in housing. Replace if housing is broken
or cracked.
Inspect switch lever (8) for breaks and cracks. Replace if broken or cracked.

Install shell (13), plug (14), angle bracket (2), and identification plate (3) on floodlight control
switch (12) with new lockwasher (10) and nut (4).
Install felt washer (9), washer (5), and switch lever (8) on floodlight control switch (12) with new
lockwasher (6) and screw (7).

TM 9-2320-272-24-1

3-120. FLOODLIGHT CONTROL SWITCH MAINTENANCE (Contd)

1.
2.

Install floodlight control switch (12) and angle bracket (2) on instrument panel (16) with two
screws (11) and new locknuts (1).
Connect four connectors (15) to floodlight control switch (12).

FOLLOW-ON TASKS: • Connect battery ground cables (para. 3-126).
l Check operation of floodlight control switch (TM 9-2320-272-10).
3-325

TM 9-2320-272-24-1

3-121. FLOODLIGHT MAINTENANCE
THIS TASK COVERS:
a. Removal
b. Disassembly

c. Assembly
d. Installation

APPLICABLE MODELS
M936/A1/A2
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Two lockwashers (Appendix D, Item 351)
Two lockwashers (Appendix D, Item 354)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Floodlight sealed beam lamp and door removed
(para. 3-119).

NOTE
All floodlights are maintained the same way.

1.
2.

NOTE
Tag wires for installation.
Disconnect two wires (6) from connectors (4).
Remove two nuts (9), washer (7), floodlight housing (2), and washer (7), from floodlight bracket (8).

b. Disassembly

1.
2.
3.
4.

3-326

NOTE
Tag wires for installation.
Disconnect switch wire (3) and lamp wire (1) from floodlight housing (2).
Remove two connectors (4) and grommets (5) from floodlight housing (2).
Remove two screws (10), retainer (11), and pressure switch (12) from floodlight housing (2).
Remove two screws (15), lockwashers (14), and switch housing (13) from floodlight housing (2).
Discard lockwashers (14).

TM 9-2320-272-24-1

3-121. FLOODLIGHT MAINTENANCE (Contd)

3-327

TM 9-2320-272-24-1

3-121. FLOODLIGHT MAINTENANCE (Contd)
5.
6.
7.
8.

Remove two nuts (1), lockwashers (10), and washers (2) from floodlight housing (3) and screws (5).
Discard lockwashers (10).
Remove two screws (5), washers (4), four spring washers (6), two washers (4), floodlight housing (3),
and two washers (4) from mounting bracket (9).
Remove pin (8) and stud (7) from mounting bracket (9).
Remove two spacers (18) and grommets (17) from floodlight assembly (3).

c. Assembly
1.
2.
3.

6.
7.
8.

Install two grommets (17) and spacers (18) on floodlight housing (3).
Install stud (7) on mounting bracket (9) with pin (8).
Install floodlight housing (3) and two washers (4) on mounting bracket (9) with four spring
washers (6), two washers (4), and screws (5).
Install two washers (2), new lockwashers (10), and nuts (1) on floodlight housing (3) and screws (5).
Install switch housing (14) on floodlight housing (3) with two new lockwashers (15) and
screws (16).
Install pressure switch (13) on floodlight housing (3) with retainer (12) and two screws (11).
Install two grommets (20) and connectors (19) on floodlight housing (3).
Connect lamp wire (21) and switch wire (22) to floodlight housing (3).

1
2.

Install washer (24) and floodlight housing (3) on floodlight bracket (25) with washer (24) and two nuts (26).
Connect two wires (23) to connectors (19).

4.
5.

3-328

TM 9-2320-272-24-1

3-121. FLOODLIGHT MAINTENANCE (Contd)

FOLLOW-ON TASKS: • Install floodlight sealed beam lamp and door (para. 3-119).
l Check floodlight for proper operation (TM 9-2320-272-10).
3-329

TM 9-2320-272-24-1

3-122. SIDE MARKER LIGHTS AND BRACKET REPLACEMENT
THIS TASK COVERS:
a. Lamp Removal
b. Light Removal

c. Light Installation
d. Lamp Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Four lockwashers (Appendix D, Item 356)
Four lockwashers (Appendix D, Item 357)
Two locknuts (Appendix D, Item 288)

l

l

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10)
l Battery ground cables disconnected (para. 3-126).

NOTE
Clearance lights have the same design as side marker lights.
Only their location on the vehicle is different.
Front and rear side markers are replaced basically the same.
This procedure is for rear side marker light.

1.
2.

Remove two screws (4), cover (3), and lens cover (2) from side marker light (5).
Remove lamp (1) from side marker light (5).

1.
2.

Disconnect side marker light plug (15) from wiring harness lead (16).
Remove four nuts (14), lockwashers (13), screws (12), and side marker light (5) from bracket (9).
Discard lockwashers (13).
Remove two locknuts (6), screws (11), four lockwashers (7), clamp (8), and bracket (9) from rail (10).
Discard locknuts (6) and lockwashers (7).
Remove clamp (8) from wiring harness lead (16).

3.
4.

c. Light Installation
1.
2.
3.
4.

Position clamp (8) on wiring harness lead (16).
Install bracket (9) and clamp (8) on rail (10) with four new lockwashers (7). two screws (11), and
new locknuts (6).
Install side marker light (5) on bracket (9) with four screws (12), new lockwashers (13), and
nuts (14).
Connect side marker light plug (15) to wiring harness lead (16).

d. Lamp Installation
1.
2.

3-330

Install lamp (1) on side marker light (5).
Install lens cover (2) and cover (3) on side marker light (5) with two screws (4).

TM 9-2320-272-24-1

3-122. SIDE MARKER LIGHTS AND BRACKET REPLACEMENT (Contd)

FOLLOW-ON TASKS • Connect battery ground cables (para. 3-126).
l Check operation of clearance and side marker lights (TM 9-2320-272-10).
3-331

TM 9-2320-272-24-1

3-123. BATTERY BOX COVER REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Six locknuts (Appendix D, Item 283)
REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P

EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Companion seat cushion removed (para. 3-286).
GENERAL SAFETY INSTRUCTIONS
l Remove all jewelry before beginning procedure.
l Ensure batteries are clamped down, rubber boots
are installed, clamps are well down on battery
posts, and all batery cables lie flat against top of
batteries.

WARNING
l

l

1.
2.

1.
2.

3-332

When performing battery maintenance, ensure batteries are
seated and clamped down, all rubber boots are installed, clamps
are well down on battery posts, and all battery cables lie flat
against top of batteries. Failure to do so may result in injury to
personnel or damage to equipment.
Remove all jewelry. If jewelry or disconnecter battery ground
cable contacts battery terminal, a direct short will result and
may cause injury to personnel.

NOTE
Assistant will hold battery box cover open while mechanic removes
support rod.
Release two latches (2) and raise battery box cover (1).
Remove six locknuts (5), screws (3), and battery box cover (1) from battery box cover hinge (4).
Discard locknuts (5).

Install battery box cover (1) on battery box cover hinge (4) with six screws (3) and new locknuts (5).
Lower battery box cover (1) and secure with two latches (2).

TM 9-2320-272-24-1

3-123. BATTERY BOX COVER REPLACEMENT (Contd)

FOLLOW-ON TASK: Install companion seat cushion (para. 3-286).
3-333

TM 9-2320-272-24-1

3-124. BATTERY CABLE AND TERMINAL ADAPTER REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
TM 9-6140-200-14

EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Battery ground cables disconnected (para. 3-126).
GENERAL SAFETY INSTRUCTIONS
l Remove all jewelry before performing procedure.
l Ensure batteries are clamped down, rubber boots
are installed, clamps are well down on battery
posts, and all battery cables lie flat against top of
batteries.

Remove all jewelry. If jewelry or disconnected battery ground cable
contacts battery terminal, a direct short will result and may cause
injury to personnel.
NOTE
l All battery cables and terminal adapters are replaced the same
way.
l Tag cables for installation.

1.
2.
3.

Remove nut (1) and screw (6) from terminal adapter (4).
Remove terminal adapter (4) and rubber boot (8) from battery post (7).
Remove nut (2), screw (5), and two battery cables (3) from terminal adapter (4).
NOTE
Refer to TM 9-6140-200-14 for inspection and service of battery
cables and adapters.

b. Installation
WARNING
When performing battery maintenance, ensure batteries are
seated and clamped down, all rubber boots are installed, clamps
are well down on battery posts, and all battery cables lie flat
against top of batteries. Failure to do so may result in injury to
personnel or damage to equipment.
NOTE
When installing one cable to an adapter, place the cable under bolt
head. When installing two cables, place one cable on each side of
adapter.

3-334

TM 9-2320-272-24-1

3-124. BATTERY CABLE AND TERMINAL ADAPTER REPLACEMENT (Contd)
1.
2.
3.

Install rubber boot (8) on battery post (7).
Install two cables (3) on terminal adapter (4) with screw (5) and nut (2).
Install terminal adapter (4) on battery post (7) and with screw (6) and nut (1).

FOLLOW-ON TASK: Connect battery ground cables (para. 3-126).
3-335

TM 9-2320-272-24-1

3-125. BATTERY MAINTENANCE
THIS TASK COVERS:
a. Removal
b. Inspection and Cleaning

c. Installation

APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Ten lockwashers (Appendix D, Item 354)
Rags (Appendix C, Item 58)
Sodium bicarbonate (Appendix C, Item 69)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
TM 9-6140-200-14
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Battery ground cables disconnected (para. 3-126).
GENERAL SAFETY INSTRUCTIONS
Remove all jewelry before performing procedure.

WARNING
Remove all jewelry when working on electrical circuits. Jewelry
coming in contact with electrical circuits may produce a short
circuit, causing extreme heat, explosions, and fling particles of
metal. Failure to comply may result in injury to personnel.

1.

2.
3.
4.

5.
6.

Loosen six nuts (4) and screws (5) on terminal adapters (2).
NOTE
Tag cables for installation.
Remove six terminal adapters (2) and eight rubber boots (3) from four batteries (1).
Remove ten nuts (6), lockwashers (7), and washers (8) from battery tiedown bolts (10). Discard
lockwashers (7).
Remove two battery tiedowns (11) from battery box (9).
NOTE
Assistant will help with step 5.
Remove four batteries (1) from battery box (9).
Remove ten battery tiedown bolts (10) from battery box (9).

NOTE
Refer to TM 9-6140-200-14 for battery inspection and service.
Inspect battery box (9) for corrosion and acid deposits. If found:
a. Apply sodium bicarbonate and water solution to inside of battery box.
b. Let solution set for five minutes.
c. Rinse with clean water.
d. Wipe dry with clean rag.

3-336

TM 9-2320-272-24-1

3-125. BATTERY MAINTENANCE (Contd)
c. Installation
1.

Install ten battery tiedown bolts (10) in battery box (9).
NOTE
Assistant will help with step 2.

2.
3.
4.
5.

Lower four batteries (1) into battery box (9).
Install two battery tiedowns (11) over ten bolts (10) with washers (8), new lockwashers (7), and nuts (6).
Install eight rubber boots (3) on batteries (1).
Install six terminal adapters (2) on batteries (1) and tighten screws (5) and nuts (4).

FOLLOW-ON TASK: Connect battery ground cables (para. 3-126).
3-337

TM 9-2320-272-24-1

3-126. BATTERY GROUND CABLE MAINTENANCE
THIS TASK COVERS:
a. Disconnection

b. Connection

APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P

EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Battery box cover raised and secured
(TM 9-2320-272-10).
GENERAL SAFETY INSTRUCTIONS
l Remove all jewelry before performing procedure.
l Ensure batteries are seated and clamped down,
rubber boots are installed, clamps are well down
on battery posts and all battery cables be flat on
top of batteries.

WARNING
l

l

1.

Remove all jewelry. If jewelry or disconnected battery ground
cable contacts battery terminal, a direct short will result and
may cause injury to personnel.
When performing battery maintenance, ensure batteries are
seated and clamped down, all rubber boots are installed, clamps
are well down on battery posts, and all battery cables lie flat
against top of batteries. Failure to do so may result in injury to
personnel or damage to equipment.

2.
3.
4.

Loosen nut (5) and screw (3) on terminal adapter (6).
NOTE
Tag all terminal adapters and rubber boots for installation.
Remove terminal adapter (6) and rubber boot (4) from battery (7).
Loosen nut (10) and screw (2) on terminal adapter (1).
Remove terminal adapter (1) and rubber boot (9) from battery (8).

1.
2.
3.

Install rubber boots (4) and (9) on batteries (7) and (8).
Install terminal adapter (1) on battery (8) and tighten screw (2) and nut (10).
Install terminal adapter (6) on battery (7) and tighten screw (3) and nut (5).

3-338

TM 9-2320-272-24-1

3-126. BATTERY GROUND CABLE MAINTENANCE (Contd)

FOLLOW-ON TASK: Lower battery box cover and secure (TM 9-2320-272-10).
3-339

TM 9-2320-272-24-1

3-127. SLAVE RECEPTACLE REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Two lockwashers (Appendix D, Item 354)

REFERENCES (TM)
TM 9-23201272-10
TM 9-2320-272-24P
l

l

Parking brake set (TM 9-2320-272-10).
Battery ground cables disconnected (para. 3-126).

GENERAL SAFETY INSTRUCTIONS
l Remove all jewelry before performing procedure.
l Disconnect battery cables before removing slave
receptacles.
WARNING

l

l

1.

2.
3.
4.
5.

1.
2.
3.
4.
5.
6.

3-340

Remove all jewelry. If jewelry or disconnected battery ground
cable contacts battery terminal, a direct short will result and
may cause injury to personnel.
Do not remove slave receptacle before disconnecting battery
ground cables. If energized battery cable contacts cab, a direct
short will result and may cause injury to personnel.

Remove four nuts (7), screws (10), rope (9), and cover (11) from cab (6).
NOTE
Insulating hose remains inside cab.
Pull slave receptacle (12) until battery cables (3) and (8) are exposed.
Remove two screws (1), lockwashers (2), and battery cables (3) and (8) from slave receptacle (12).
Discard lockwashers (2).
Remove insulator (5) and gasket (4) from slave receptacle (12).
Pull cables (3) and (8) clear of insulating hose (13) and remove from battery box (14).

Route cables (3) and (8) through insulating hose (13) and battery box (14).
Pull cables (3) and (8) through insulating hose (13) until exposed outside cab (6).
Install gasket (4) and insulator (5) on slave receptacle (12).
Install battery cables (3) and (8) on slave receptacle (12) with two new lockwashers (2) and screws (1).
Insert slave receptacle (12) in cab (6) and position insulating hose (13) over screws (1). Install slave
receptacle (12) with three screws (10) and nuts (7).
Install cover (11) and rope (9) on slave receptacle (12) with screw (10) and nut (7).

TM 9-2320-272-24-1

3-127. SLAVE RECEPTACLE REPLACEMENT (Contd)

FOLLOW-ON TASK: Install battery ground cables (para. 3-126).
3-341

TM 9-2320-272-24-1

3-128. BATTERY BOX REPLACEMENT
THIS TASK COVER:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Torque wrench (Appendix D, Item 146)
MATERIALS/PARTS
Four lockwashers (Appendix D, Item 358)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Battery box cover removed (para. 3-123).
l
Battery cable terminal adapters removed
(para. 3-124).
l
Batteries removed (para. 3-125).

a. Removal
1.
2.
3.
4.
5.
6.
7.

Pull slave receptacle cables (12) and (13) through grommets (14) and cab (11).
Loosen two clamps (5) on hose (2).
Remove hose (2) from battery box (6) and cab (11).
Remove wood battery support blocks (1) from battery box (6).
Remove four screws (3) and lockwashers (4) from battery box (6). Discard lockwashers (4).
Push battery cables (7) through grommets (8). Remove battery box (6) from cab (11).
Remove four grommets (14) and two grommets (8) from battery box (6).

b. Installation
1.
2.
3.
4.
5.
6.
7.

3-342

Install four grommets (14) and two grommets (8) on battery box (6).
Align vent tube (9) with hole in cab floor (10) and install battery box (6) on cab (11) with cable
grommets (8) aligned with cables (7).
Pull battery cables (7) through grommets (8).
Secure battery box (6) to cab (11) with four screws (3) and new lockwashers (4). Tighten screws (3)
to 25 lb-ft (34 N•m).
Place wood battery support blocks (1) in battery box (6).
Install hose (2) on battery box (6) and cab (11) with two clamps (5).
Pull slave receptacle cables (13) and (12) through grommets (14).

TM 9-2320-272-24-1

3-128. BATTERY BOX REPLACEMENT (Contd)

FOLLOW-ON TASKS:

l
l
l

Install batteries (para. 3-125).
Install battery cable terminal adapters (para. 3-124).
Install battery box cover (para. 3-123).
3-343

TM 9-2320-272-24-1

3-129. GROUND STRAP REPLACEMENT
THIS TASK COVERS:
a. Ground Strap (M939/A1) Removal
b. Ground Strap (M939/A1) Installation

c. Ground Strap (M939A2) Removal
d. Ground Strap (M939A2) Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Three lockwashers (M939/A1)
(Appendix D, Item 379)
Lockwasher (M939/A1) (Appendix D, Item 372)
Lockwasher (M939/A1) (Appendix D, Item 382)
Locknut (M939/A1) (Appendix D, Item 291)
Three lockwashers (M939A2)
(Appendix D, Item 356)
Four lockwashers (M939A2)
(Appendix D, Item 372)
Two lockwashers (M939A2)
(Appendix D, Item 360)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Hood raised and secured (TM 9-2320-272-10).

a . Ground Strap (M939/A1) Removal
1.
2.
3.
4.
5.
6.

Remove screw (1), washer (2), ground strap (6), lockwasher (4), and clamp (3) from firewall (5).
Discard lockwasher (4).
Remove screw (7), wire (8), ground strap (6), and lockwasher (9) from engine (10). Discard
lockwasher (9).
Remove screw (11), two washers (12), ground strap (15), and lockwasher (14) from air compressor (13).
Discard lockwasher (14).
Remove locknut (18), clamp (19), screw (16), lockwasher (20), and ground strap (15) from frame rail (17).
Discard locknut (18) and lockwasher (20).
Remove screw (24), washer (23), ground strap (22), and lockwasher (21) from engine (10). Discard
lockwasher (21).
Remove nut (28), washer (27), wires (29) and (26), and ground strap (22) from engine starter (25).

b. Ground Strap (M939/A1) Installation
1.
2.
3.
4.
5.
6.

3-344

Install ground strap (22) on engine starter (25) with wires (26) and (29), washer (27), and nut (28).
Install new lockwasher (21), ground strap (22), washer (23), and screw (24) on engine (10).
Install screw (16), new lockwasher (20), ground strap (15), clamp (19), and new locknut (18) on
frame rail (17).
Install new lockwasher (14), ground strap (15), two washers (12), and screw (11) on air compressor (13).
Install new lockwasher (9), ground strap (6), wire (8), and screw (7) on engine (10).
Install new lockwasher (4), ground strap (6), clamp (3), washer (2), and screw (1) on firewall (5).

TM 9-2320-272-24-1

3-129. GROUND STRAP REPLACEMENT (Contd)

3-345

TM 9-2320-272-24-1

3-129. GROUND STRAP REPLACEMENT (Contd)
c. Ground Strap (M939A2) Removal
1.
2.
3.
4.
5.
6.

Remove nut (1), washer (2), lockwasher (12), ground strap (5), lockwasher (11), and screw (9) from
frame rail (10). Discard lockwashers (12) and (11).
Remove screw (6), washer (7), ground strap (5), three wires (8), and lockwasher (4) from engine
block (3). Discard lockwasher (4).
Remove nut (20), lockwasher (21), screw (25), washer (24), ground strap (17), and lockwasher (23)
from frame rail (22). Discard lockwashers (21) and (23).
Remove nut (14), lockwasher (15), screw (19), washer (18), ground strap (17), and lockwasher (16)
from hood (13) Discard lockwashers (15) and (16).
Remove screw (35), lockwasher (33), clamp (36), ground strap (29), and bracket (34) from firewall (32).
Discard lockwasher (33).
Remove screw (31), washer (30), ground strap (29), lockwasher (28), temperature sensor (27), and
washer (26) from engine block (3). Discard lockwasher (28).

d. Ground Strap (M939A2) Installation
1.
2.
3.
4.
5.
6.

3-346

Install washer (26), temperature sensor (27), new lockwasher (28), ground strap (29), washer (30),
and screw (31) on engine block (3).
Install bracket (34), ground strap (29), clamp (36), new lockwasher (33), and screw (35) on firewall (32).
Install new lockwasher (16), ground strap (17), washer (18), screw (19), new lockwasher (15), and
nut (14) on hood (13).
Install new lockwasher (23), ground strap (17), washer (24), screw (25), lockwasher (21), and nut (20)
on frame rail (22).
Install new lockwasher (4), three wires (8), ground strap (5), washer (7), and screw (6) on engine
block (3).
Install new lockwasher (11), ground strap (5), new lockwasher (12), screw (9), washer (2), and nut (1)
on frame rail (10).

TM 9-2320-272-24-1

3-129. GROUND STRAP REPLACEMENT (Contd)

3-347

TM 9-2320-272-24-1

3-130. INSTRUMENT CLUSTER HARNESS REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
Tools
General mechanic’s tool kit (Appendix E, Item 1)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l
Parking brake set (TM 9-2320-272-10).
l
Battery ground cables disconnected (para. 3-126).

a. Removal
Disconnect five leads (5), nut (3), washer (2), cable assembly (4), and washer (1) from speedometer stud (6).
b. Installation
Install cable assembly (4) on speedometer stud (6) with washer (1), washer (2), and nut (3) and connect five
leads (5).

FOLLOW-ON TASK: Connect battery ground cables (para. 3-126).
3-348

TM 9-2320-272-24-1

3-131. WIRING HARNESS REPAIR
THIS TASK COVERS:
a. Terminal-Type Cable Connector
b. Male Cable Connector
c. Female Connector (With Sleeve)

d. Plug Assembly
e. Receptacle Assembly

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Electrical tool kit (Appendix E, Item 40)
Heat gun (Appendix E, Item 62)
Soldering torch kit (Appendix E, Item 126)
MATERIALS/PARTS
Solder (Appendix C, Item 70)

REFERENCES (TM)
TB SIG-222
TM 9-2320-272-10
TM 9-232-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l
Battery ground cables disconnected (para. 3-126).
GENERAL SAFETY INSTRUCTIONS
Do not wear jewelry when repairing harnesses.

Do not wear jewelry when repairing harnesses. Injury to personnel
may result if circuit is suddenly energized.
NOTE
If a wiring harness is damaged beyond repair, notify Direct
Support maintenance for replacement.
a. Terminal-Type Cable Connector
1.
2.
3.
4.

Strip cable insulation (1) from cable (2) equal to depth of terminal well (4).
Slide insulator (3) over cable (2).
Insert cable (2) into terminal well (4) and crimp.
Slide insulator (3) over crimped end of terminal (5).

3-349

TM 9-2320-272-24-1

3-131. WIRING HARNESS REPAIR (Contd)
b. Male Cable Connector
1.
2.
3.
4.
6.

Strip cable insulation (1) from cable (2) equal to depth of ferrule well (5).
Slide shell (3) over cable (2).
Insert cable (2) into ferrule well (5) and crimp.
Place C-washer (4) over crimped junction at terminal (6).
Slide shell (3) over C-washer (4) and terminal (6).

c. Female Cable Connector (With Sleeve)
1.
2.
3.
4.

Strip cable insulation (7) from cable (8) equal to depth of terminal well (11).
Slide shell (9) and sleeve (10) over cable (8).
Insert cable (8) into terminal well (11) and crimp.
Slide shell (9) and sleeve (10) over terminal (12).

d. Plug Assembly

1.
2.
3.
4.
5.

NOTE
Refer to TB SIG-222 for soldering instructions.
Strip cable insulation (13) from cable (15) equal to depth of solder wells (16) of inserts (17).
Pass cable ends (15) through grommet retaining nut (14), grommet (18), and coupling nut (20).
Insert cable ends (15) into solder wells (16) of inserts (17) and solder.
Slide grommet (18) over inserts (17) and press into shell assembly (19) until seated.
Slide retaining nut (14) up cable (15) and install on shell assembly ( 19).

e. Receptacle Assembly

1.
2.
3.
4.
5.

3-350

NOTE
Refer to TB SIG-222 for soldering instructions.
Strip cable insulation (21) from cable (23) equal to depth of solder wells (24) of inserts (25).
Pass cable ends (23) through grommet retaining nut (22) and grommet (26).
Insert cable ends (23) into solder wells (24) of insert (25) and solder.
Slide grommet (26) over inserts (25) and press into receptacle assembly (27) until seated.
Thread grommet retaining nut (22) into receptacle (27) until seated.

TM 9-2320-272-24-1

3-131. WIRING HARNESS REPAIR (Contd)

FOLLOW-ON TASK: Connect battery ground cables (para. 3-126).
3-351 (3-352 blank)

TM 9-2320-272-24-1

Section VII. TRANSMISSION AND TRANSFER CASE MAINTENANCE
3-132. TRANSMISSION MAINTENANCE INDEX
PARA.
NO.
3-133.
3-134.
3-135.
3-136.
3-137.
3-138.
3-139.
3-140.
3-141.
3-142.
3-143.
3-144.
3-145.

TITLE
Transmission Oil Service Instructions
Transmission Dipstick Tube and Dipstick Maintenance
Governor Piping and Capacitor Maintenance
Transmission Breather Replacement
Transmission Mounting Bracket and Isolator (M939A2) Replacement
Transmission 5th Gear Lock-up Pressure Switch Replacement
Transmission Oil Cooler Filter and Head Replacement
Transmission Oil Cooler and Mount (M939/A1) Replacement
Transmission Oil Cooler and Mount (M939A2) Replacement
Transmission Oil Cooler Hoses Replacement
Transfer Case Interlock Valve Replacement
Transfer Case Front Axle Engagement Control Valve Replacement
Transmission Modulator and Cable Maintenance

PAGE
NO.
3-354
3-362
3-364
3-372
3-373
3-374
3-376
3-373
3-380
3-384
3-392
3-396
3-398

3-353

TM 9-2320-272-24-1

3-133. TRANSMISSION OIL SERVICE INSTRUCTIONS
THIS TASK COVERS:
a. Draining Oil
b. Oil Filter Removal
c. Oil Filter Installation

d. Governor Filter Removal
e. Governor Filter Installation
f. Replenishing Oil

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Torque wrench Appendix E, Item 144)
MATERIALS/PARTS
Governor filter (Appendix D, Item 249)
Governor filter O-ring (Appendix D, Item 250)
Rubber O-ring (Appendix D, Item 429)
Transmission oil filter (Appendix D, Item 699)
Transmission oil pan gasket (Appendix D, Item
159)
Tiedown strap (Appendix D, Item 690)
Fiber washer (Appendix D, Item 119)
Lubricating oil (Appendix C, Item 49)
Drycleaning solvent (Appendix C, Item 71)

REFERENCES (TM)
LO 9-2320-272-12
TM 9-2320-272-10
TM 9-2320-27224P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
GENERAL SAFETY INSTRUCTIONS
l
Exhaust gases can kill. Operate vehicle only in
well-ventilated area.
l Store or dispose of used oil properly.
l
Keep fire extinguisher nearby when using
drycleaning solvent.

WARNING
l

l

Exhaust gases can kill. Operate vehicle only in a well-ventilated
area. Failure to do this may result in injury to personnel.
Accidental or intentional introduction of liquid contaminants
into the environment is in violation of state, federal, and
military regulations. Refer to Army POL (para. 1-8) for
information concerning storage, use, and disposal of these
liquids. Failure to do so may result in injury or death.

a. Draining Oil

1.

2.

3.

3-354

NOTE
Do not shift transmission through driving gear ranges when
warming transmission oil. This is a procedure used only when
replenishing transmission oil.
Start engine (TM 9-2320-272-10), operate at 700-750 rpm until transmission oil reaches normal
operating temperature of 120°-220°F (49°-105°C), then shut off engine.
NOTE
Have drainage container ready to catch oil.
Remove drainplug (3) and fiber washer (2) from right rear of transmission oil pan (1) and drain oil.
Discard fiber washer (2).
NOTE
Inspect oil for grit, foaminess, and/or milkiness. If present, notify
your supervisor.
Install new fiber washer (2) and drainplug (3) in transmission oil pan (1).

TM 9-2320-272-24-1

3-133. TRANSMISSION OIL SERVICE INSTRUCTIONS (Contd)

3-355

TM 9-2320-272-24-1

3-133. TRANSMISSION OIL SERVICE INSTRUCTIONS (Contd)
b. Oil Filter Removal

1.

2.
3.
4.
5.
6.
7.
8.

NOTE
Removal of transmission oil filter is basically the same for M939,
M939A1, and M939A2 series vehicles. This procedure covers M939
and M939A1 series vehicles only.
Open access door (1) in cab floor.
CAUTION
Wipe area around dipstick tube before removal to prevent entry of
dirt Damage may occur if dirt or dust enters transmission.
Remove screw (5) and washer (4) from transmission (2).
Remove tiedown strap (7) from dipstick tube (3) and tube (6). Discard tiedown strap (7).
Loosen flare nut (8) and remove dipstick tube (3) from transmission oil pan (14).
Remove twenty-one screws (15) from transmission oil pan (14).
Remove oil pan (14) and oil pan gasket (13) from transmission (2). Discard gasket (13).
Remove screw (16) and oil filter assembly (17) from transmission (2).
Remove oil filter assembly (17) from suction tube (12). Discard oil filter assembly (17).
WARNING

9.
10.
11.

12.
13.
14.

Drycleaning solvent is flammable and will not be used near open
flame. Use only in well-ventilated areas. Failure to do so may
result in injury to personnel.
Remove suction tube (12) and rubber O-ring (11) from transmission (2). Discard O-ring (11) and
clean suction tube (12) thoroughly with drycleaning solvent.
Remove transmission oil cooler filter (para. 3-139).
Disconnect transmission oil cooler hoses (18) and (20) from transmission oil filter base (19).
CAUTION
Compressed air source will not exceed 60 psi (41 kPa). Doing so
may cause damage to internal components of the transmission.
Using compressed air, drain remaining oil from transmission oil cooler hoses (18) and (20).
Connect transmission oil cooler hoses (18) and (20) to transmission oil filter base (19).
Install transmission oil cooler filter (para. 3-139).

c. Oil Filter Installation

1.
2.
3.
4.

3-356

NOTE
Installation of transmission oil filter is basically the same for
M939, M939A1, and M939A2 series vehicles. This procedure
covers M939 and M939A1 series vehicles only.
Position new rubber O-ring (11) on suction tube (12) and slide downward until O-ring (11) contacts
suction tube lip (21).
Install suction tube (12) in transmission oil input port (10), pressing until O-ring (11) seats on oil
input port (10).
Install new oil filter assembly (17) on suction tube (12), pressing until oil filter assembly intake
grommet (22) contacts suction tube lip (23).
Install oil filter assembly (17) on transmission mounting boss (9) with screw (16). Tighten screw (16)
10-15 lb-ft (14-20 N•m).

TM 9-2320-272-24-1

3-133. TRANSMISSION OIL SERVICE INSTRUCTIONS (Contd)

3-357

TM 9-2320-272-24-1

3-133. TRANSMISSION OIL SERVICE INSTRUCTIONS (Contd)
CAUTION

5.
6.

7.
8.
9.
10.

Do not use gasket sealing compound when installing oil pan
gasket; oil leakage will result. If necessary, oil or light grease
coating may be used to hold oil pan gasket in position during
installation.
Install new oil pan gasket (2) and oil pan (4) on transmission (1) with twenty-one screws (3).
Tighten twenty-one screws (3) 10-15 lb-ft (14-20 N•m) in sequence shown.
NOTE
Due to gasket compression, torque values will be lost and screws
must be retightened.
After oil pan gasket (2) is seated, loosen and retighten screws (3) 5 lb-ft (7 N-m) in sequence shown.
Install dipstick tube (5) on transmission (1) with washer (8), clamp (6), and screw (7).
Install dipstick tube (5) in oil pan port (12) with flare nut (11). Tighten flare nut (11) 10-25 1b-ft (1434 N•m).
Install new tiedown strap (9) on dipstick tube (5) and tube (10).

d. Governor Filter Removal
WARNING
Drycleaning solvent is flammable and will not be used near open
flame. Use only in well-ventilated areas. Failure to do so may
result in injury to personnel.
Remove governor filter plug (13) and O-ring (14) from transmission (1). Discard O-ring (14) and
clean plug (13) thoroughly with drycleaning solvent.
CAUTION

2.

Do not pry governor tilter from governor filter housing. Use thin,
pliable wire as a hook to reach into the housing to slide out
filter. Failure to do this will result in governor filter housing
damage.
Remove governor filter (16) from governor fiber housing (15). Discard filter (16).

e. Governor Filter Installation

NOTE
1.
2.
3.

3-358

Failure to properly install governor filter into governor filter
housing will greatly reduce its effectiveness.
Install governor filter (16), with open end inserted first, into governor filter housing (16).
Install O-ring (14) on governor filter plug (13).
Install governor filter plug (13) in filter housing (15). Tighten governor filter plug (13)
15 lb-ft (20 N•m).

TM 9-2320-272-24-1

3-133. TRANSMISSION OIL SERVICE INSTRUCTIONS (Contd)

TIGHTENING SEQUENCE

3-359

TM 9-2320-272-24-1

3-133. TRANSMISSION OIL SERVICE INSTRUCTIONS (Contd)
f. Replenishing Oil

1.
2.
3.

NOTE
Refer to LO 9-2320-272-12 for drain and refill capacity and
recommended grade of transmission oil.
Open access door (2) inside vehicle cab and remove transmission oil dipstick (1) from transmission
oil dipstick tube (3).
Add recommended quantity of transmission oil in transmission oil dipstick tube (3).
Install transmission oil dipstick (1) in dipstick tube (3).
WARNING

4.

5.
6.

3-360

Exhaust gases can kill. Operate vehicle only in a well-ventilated
area. Failure to do so may result in injury to personnel.
Start engine (TM 9-2320-272-10), operate engine at 700-750 rpm until transmission oil reaches
normal operating temperature of 120°-220°F (49°-105°C), then shut off engine.
NOTE
Begin shifting transmission through driving ranges only after
transmission oil has reached normal operating temperature.
Perform shifting procedure for approximately two minutes before
returning transmission to neutral and shutting off engine.
Shift transmission (4) through driving ranges to allow oil to circulate throughout transmission (4).
Check transmission oil and fill to proper level (LO 9-2320-272-12).

TM 9-2320-272-24-1

3-133. TRANSMISSION OIL SERVICE INSTRUCTIONS (Contd)

FOLLOW-ON TASK: Start engine (TM 9-2320-272-10), check for leaks, and road test vehicle.
3-361

TM 9-2320-272-24-1

3-134. TRANSMISSION DIPSTICK TUBE AND DIPSTICK MAINTENANCE
THIS TASK COVERS:
a. Removal
b. Inspection

c. Installation

INITIAL SETUP:
APPLICABLE MODELS:
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Torque wrench (Appendix E, Item 144)
MATERIALS/PARTS
Tiedown strap (Appendix D, Item 690)
Rags (Appendix C, Item 58)

REFERENCES (TM)
LO 9-2320-272-12
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Hood raised and secured (TM 9-2320-272-10).
l
Transmission oil drained (para. 3-133).

a. Removal
CAUTION

1.
2.
3.

4.
5.
6.

Wipe area around dipstick tube before removal to prevent entry of
dirt. Damage may occur if dirt or dust enters transmission.
NOTE
Perform steps 1 through 3 for M939/A1 model vehicles only.
Open access door (3) in cab floor and remove transmission oil dipstick (1) from transmission oil
dipstick tube (2).
Remove screw (7), washer (6), clip (5), and dipstick tube (2) from flywheel housing (4).
Remove tiedown strap (9) from dipstick tube (2) and tube (8). Discard tiedown strap (9).
NOTE
Perform steps 4 and 5 for M939A2 model vehicles only.
Remove transmission oil dipstick (1) from transmission oil dipstick tube (2).
Remove screw (7), clip (5), and dipstick tube (2) from flywheel housing (4).
Loosen flare nut (10) and remove dipstick tube (2) from transmission oil pan (12).

b. Inspection
1.
2.
3.

Inspect dipstick tube (2) for cracks, blockage, weld damage at clip (5), and damage to flared end, If
blocked, remove obstruction. If damaged, replace.
Inspect flare nut (10) for cross-threading and burrs. If cross-threaded or burred, replace dipstick
tube (2).
Inspect oil pan dipstick tube port (11) for cracked or broken welds, burrs, and cross-threading. If
cracked or broken, replace oil pan (12). If burred or cross-threaded, repair threads.

c. Intstallation
1.

2.
3-362

Install dipstick tube (2) on transmission oil pan (12) with flare nut (10). Tighten flare nut (10)
10-25 lb-ft (14-34 N•m).
NOTE
Perform steps 2 and 3 for M939A2 model vehicles only.
Install dipstick tube (2) on flywheel housing (4) with clip (5) and screw (7).

TM 2320-272-24-1

3-134. TRANSMISSION DIPSTICK TUBE AND DIPSTICK MAINTENANCE (Contd)
3.

Install dipstick (1) in dipstick tube (2).

4.
5.
6.

NOTE
Perform steps 4 through 6 for M939/A1 model vehicles only.
Install dipstick tube (2) and clip (5) on flywheel housing (4) with washer (6) and screw (7).
Install dipstick tube (2) on tube (8) with new tiedown strap (9).
Install dipstick (1) in dipstick tube (2).

FOLLOW-ON TASK: Fill transmission (LO 9-2320-272-12).
3-363

TM 9-2320-272-24-1

3-135. GOVERNOR PIPING AND CAPACITOR MAINTENANCE
THIS TASK COVERS:
a. Removal
b. Inspection

c. Installation

INITIAL SETUP:
APPLICABLE MODELS
M936/A1/A2
TOOLS
a. General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Two locknuts (Appendix D, Item 313)
Lockwasher (Appendix D, Item 350)
Two cotter pins (Appendix D, Item 66)
Three tiedown straps (Appendix D, Item 684)
Antiseize tape (Appendix C, Item 72)

REFERENCES (TM)
TM 9-2320-272-24-1
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).

a. Removal

1.
2.
3.
4.
5.
6.

7.
8.
9.
10.
11.

3-364

NOTE
l Perform steps 1 and 2 for M936/A1 model vehicles only.
l
Have drainage container ready to catch oil.
Remove hose (13) from elbow (14) and tee (2).
Remove elbow (14) from governor (15).
Remove cap (1) from tee (2).
Remove hose (10) from tee (2).
Remove tee (2) from nipple (3).
Remove nipple (3) from adapter (4).
NOTE
Note location of tiedown strap for installation.
Remove tiedown strap (12) from hoses (10) and (11). Discard tiedown strap (12).
Remove hose (10) from adapter (9).
Remove adapter (9) from tee (5).
Remove hose (7) from elbows (8) and (6).
Remove elbow (8) from tee (5).

TM 9-2320-272-24-1

3-135. GOVERNOR PIPING AND CAPACITOR MAINTENANCE (Contd)

3-365

TM 9-2320-272-24-1

3-135. GOVERNOR PIPING AND CAPACITOR MAINTENANCE (Contd)
NOTE
12.
13.
14.
15.
16.

17.
18.
19.
20.
21.
22.
23.
24.
25.

26.
27.

Tag all leads for installation.
Disconnect capacitor leads (8) and (9) from transmission 5th gear lock-up pressure switch (7).
Remove pressure switch (7) from tee (6).
Disconnect capacitor leads (2), (12), and (15) from leads (1), (13), and (14).
Remove screw (10), lockwasher (11), tee (6), and capacitor (5) from body (3). Discard lockwasher (11).
Remove clamp (4) from capacitor (5).
NOTE
Note location of tiedown straps for installation.
Remove two tiedown straps (31) from hoses (32) and (35). Discard tiedown straps (31).
Remove hose (32) from adapters (30) and (37).
Remove adapters (30) and (37) from valves (19) and (38).
Remove cotter pin (33), washer (34), and rod (17) from lever (16). Discard cotter pin (33).
Remove cotter pin (27), washer (26), pin (24), and clevis (25) from valve (19). Discard cotter pin (27).
Remove clevis (25) from rod (17).
Remove breather (22) from adapter (23).
Remove elbow (21) and adapter (23) from valve (19).
Remove two locknuts (28), screws (20), and valve (19) From bracket (18). Discard locknuts (28).
NOTE
Perform step 26 for M936/Al series vehicles only
Remove two screws (36) and bracket (18) from body (3).
Remove two screws (29) and bracket (18) from body (3).

b. Inspection
Inspect hoses (39), (32), and (40). Replace hoses (39), (32), or (40) if damaged.

3-364

TM 9-2320-272-24-1

3-135. GOVERNOR PIPING AND CAPACITOR MAINTENANCE (Contd)

3-367

TM 9-2320-272-24-1

3-135. GOVERNOR PIPING AND CAPACITOR MAINTENANCE (Contd)
c. Installation
1.

2.
3.

4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.

3-368

Install bracket (18) on body (3) with two screws (29).
NOTE
Perform step 2 for M936/A1 series vehicles only.
Install bracket (18) on body (3) with two screws (36).
Install valve (19) on bracket (18) with two screws (20) and new locknuts (28).
NOTE
Male pipe threads must be wrapped with antiseize tape before
installation.
Install elbow (21) and adapter (23) on valve (19).
Install breather (22) on adapter (23).
Install clevis (25) on rod (17).
Install clevis (25) on valve (19) with pin (24), washer (26), and new cotter pin (27).
Install rod (17) on lever (16) with washer (34) and new cotter pin (33).
Install adapters (30) and (38) on valves (19) and (37).
Install hose (32) on adapters (30) and (38).
Install two new tiedown straps (31) on hoses (32) and (35).
Install clamp (4) on capacitor (5).
Install capacitor (5) and tee (6) on body (3) with new lockwasher (11) and screw (10).
Connect capacitor leads (2), (12), and (15) to leads (1), (13), and (14).
Install transmission 5th gear lock-up pressure switch (7) on tee (6).
Connect capacitor leads (8) and (9) to pressure switch (7).

TM 9-2320-272-24-1

3-135. GOVERNOR PIPING AND CAPACITOR MAINTENANCE (Contd)

3-369

TM 9-2320-272-24-1

3-135. GOVERNOR PIPING AND CAPACITOR MAINTENANCE (Contd)
17.
18.
19.
20.
21.
22.
23.
24.

25.
26.
27.

3-370

Install
Install
Install
Install
Install
Install
Install
Install

elbow (11) on tee (8).
hose (10) on elbows (11) and (9).
adapter (12) on tee (8).
hose (13) on adapter (12).
new tiedown strap (15) on hoses (13) and (14).
nipple (6) on adapter (7).
tee (2) on nipple (6).
hose (13) on tee (2).
NOTE
Perform steps 25 and 26 for M936/A1 series vehicles only.
Install elbow (3) on governor (4).
Install hose (1) on elbow (3) and tee (2).
Install cap (5) on tee (2).

TM 9-2320-272-24-1

3-135. GOVERNOR PIPING AND CAPACITOR MAINTENANCE (Contd)

3-371

TM 9-2320-272-24-1

3-136. TRANSMISSION BREATHER REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Antiseize tape (Appendix C, Item 72)
Rag (Appendix C, Item 58)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).

a. Removal
CAUTION

1.
2.

Clean area around breather before removal to prevent entry of
dirt. Damage may occur if dirt or dust enters the transmission.
Disconnect vent line (2) from transmission breather (1).
Remove breather (1) and adapter (4) from transmission (3). Discard breather (1) and adapter (4) if
threads are stripped.

b. Installation

1.
2.

3-372

NOTE
Male pipe threads must be wrapped with antiseize tape before
installation.
Install adapter (4) and breather (1) on transmission (3).
Connect vent line (2) to transmission breather (1).

TM 9-2320-272-24-1

3-137. TRANSMISSION MOUNTING BRACKET AND ISOLATOR (M939A2) REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
M939A2
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Transmission jack (Appendix E, Item 147)
MATERIALS/PARTS
Two lockwashers (Appendix D, Item 350)
Two lockwashers (Appendix D, Item 392)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
GENERAL SAFETY INSTRUCTIONS
Keep hands clear of transmission during bracket
and isolator replacement.

a. Removal
WARNING

1.
2.

Keep hands clear of transmission when removing bracket and
isolator. A slipped jack may result in injury to personnel.
Using a transmission jack, raise transmission (7) and remove two screws (5) and lockwashers (6)
from transmission mounting bracket (8). Discard lockwashers (6).
Remove two screws (2), lockwashers (3), isolator (4), and transmission mounting bracket (8) from
bracket (1). Discard lockwashers (3).

b. Installation

1.
2.

NOTE
It will be necessary to raise and lower transmission slightly to
obtain proper alignment of screws.
Install transmission mounting bracket (8) on bracket (1) with isolator (4), two new lockwashers (3),
and screws (2).
Using jack, position transmission (7) on transmission mounting bracket (8) and install with two new
lockwashers (6) and screws (5).

3-373

TM 9-2320-272-24-1

3-138. TRANSMISSION 5TH GEAR LOCK-UP PRESSURE SWITCH REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)

EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Wheels chocked (TM 9-2320-272-10).
l
Battery ground cable disconnected (para. 3-126).

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
a. Removal
1.
2.

Disconnect two capacitor leads (3) from pressure switch (2).
Remove pressure switch (2) from tee (1).

b. Installation
1.
2.

3-374

Install pressure switch (2) on tee (1).
Connect two capacitor leads (3) to pressure switch (2).

TM 9-2320-272-24-1

3-138. TRANSMISSION 5TH GEAR LOCK-UP PRESSURE SWITCH REPLACEMENT
(Contd)

FOLLOW-ON TASK: Connect battery ground cable (para. 3-126).
3-375

TM 9-2320-272-24-1

3-139. TRANSMISSION OIL COOLER FILTER AND HEAD REPLACEMENT
THIS TASK COVERS:
a. Oil Cooler Filter Removal
b. Oil Cooler Filter Head Removal

c. Oil Cooler Filter Head Installation
d. Oil Cooler Filter Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Oil filter (Appendix D, Item 491)
Three locknuts (Appendix D, Item 299)
Lubricating oil (Appendix C, Item 48)
Rag (Appendix C, Item 58)
Cap and plug set (Appendix C, Item 14)

REFERENCES (TM)
LO 9-2320-272-12
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Hood raised and secured (TM 9-2320-272-10).

a. Oil Cooler Filter Removal
NOTE
Have drainage container ready to catch oil.
Remove oil filter (3) and oil filter seal (2) from oil filter head (1). Drain oil and discard oil filter (3) and
oil filter seal (2).
b. Oil Cooler Filter Head Removal
CAUTION
Clean area around hoses before removal to prevent entry of dirt.
Damage may occur if dirt or dust enters the transmission.
l
Cover or plug all open hoses and connections immediately after
disconnection to prevent contamination. Failure to do this may
result in transmission damage.
NOTE
l
Have drainage container ready to catch oil.
l Tag hoses for installation.
oil filter (3) as shown in task a.
oil filter supply hose (8) from adapter elbow (7).
supply hose (9) from adapter elbow (10).
three locknuts (4), screws (6), and oil filter head (1) from oil filter bracket (5). Discard
(4).
l

1.
2.
3.
4.

3-376

Remove
Remove
Remove
Remove
locknuts

TM 9-2320-272-24-1

3-139. TRANSMISSION OIL COOLER FILTER AND HEAD REPLACEMENT (Contd)
c. Oil Cooler Filter Head Installation
CAUTION

1.
2.
3.
4.

Install
Install
Install
Install

Ensure plugs or covers are completely removed from all hoses and
connections. Failure to do this may result in transmission damage.
NOTE
If new filter head is to be installed, use fittings from old filter
head.
oil filter head (1) on oil filter bracket (5) with three screws (6) and new locknuts (4).
supply hose (9) on adapter elbow (10).
oil filter supply hose (8) on adapter elbow (7).
oil filter (3) as shown in task d.

d. Oil Cooler Filter Installation
1.
2.

Lightly coat new oil filter seal (2) with lubricating oil and position on oil filter head (1).
Install new oil filter (3).

FOLLOW-ON TASKS:

l
l

Fill transmission oil to proper level (LO 9-2320-272-12).
Start engine (TM 9-2320-272-10), check for leaks, and road test vehicle.
3-377

TM 9-2320-272-24-1

3-140. TRANSMISSION OIL COOLER AND MOUNT (M939/A1) REPLACEMENT
THIS TASK COVERS:
a. Oil Cooler Removal
b. Oil Cooler Mount Removal

c. Oil Cooler Mount Installation
d. Oil Cooler Installation

INITIAL SETUP:
APPLICABLE MODELS
M939, M939A1
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Four locknuts (Appendix D, Item 291)
Four locknuts (Appendix D, Item 309)
Cap and plug set (Appendix C, Item 14)
Rag (Appendix C, Item 58)

REFERENCES (TM)
LO 9-2320-272-12
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Right splash shield removed (TM 9-2320-272-10).
l
Cooling system drained (para. 3-53).

a. Oil Cooler Removal
CAUTION
Clean area around hoses before removal to prevent entry of dirt.
Damage may occur if dirt or dust enters the transmission.
l
Cover or plug all open hoses and connections immediately after
disconnection to prevent contamination. Failure to do this may
result in transmission damage.
NOTE
l
Have drainage container ready to catch oil and coolant.
l
Tag hoses for installation.
Loosen hose clamp (7) and remove coolant supply hose (8) from coolant inlet flange (6) and clamp (7)
from hose (8).
Loosen hose clamp (15) and remove coolant return hose (1) from coolant outlet flange (14) and
clamp (15) from hose (1).
Disconnect oil cooler-to-cooler filter supply hose (4) from elbow (5).
Disconnect transmission-to-oil cooler supply hose (3) from elbow (2).
Remove four locknuts (11), screws (13), washers (12), and oil cooler (10) from two mounts (9).
Discard locknuts (11) and empty coolant from oil cooler (10).
l

1.
2.
3.
4.
5.

b. Oil Cooler Mount Removal
Remove four locknuts (16), screws (18), and two mounts (9) from frame rail (17). Discard locknuts (16).
c. Oil Cooler Mount Installation
Install two mounts (9) on frame rail (17) with four screws (18) and new locknuts (16).

3-378

TM 9-2320-272-24-1

3-140. TRANSMISSION OIL COOLER AND MOUNT (M939/A1) REPLACEMENT (Contd)
d. Oil Cooler Installation
CAUTION

1.
2.
3.
4.
5.

Ensure plugs or covers are completely removed from all hoses and
connections. Failure to do this may result in transmission and oil
cooler damage.
NOTE
If new oil cooler is to be installed, use fittings from old oil cooler.
Install transmission oil cooler (10) on two mounts (9) with four washers (12), screws (13), and new
locknuts (11).
Connect transmission-to-oil cooler supply hose (3) on elbow (2).
Connect oil cooler-to-cooler filter supply hose (4) on elbow (5).
Position hose clamp (15) on hose (1) and install hose (1) on flange (14) and tighten clamp (15).
Position clamp (7) on hose (8) and install hose (8) on flange (6) and tighten clamp (7).

FOLLOW-ON TASKS:

l
l
l
l

Fill vehicle cooling system to proper operating level (para. 3-53).
Install right splash shield (TM 9-2320-272-10).
Fill transmission oil reservoir to proper level (LO 9-2320-272-12).
Start engine (TM 9-2320-272-10), check for leaks, and road test vehicle.
3-379

TM 9-2320-272-24-1

3-141. TRANSMISSION OIL COOLER AND MOUNT (M939A2) REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
M939A2

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P

TOOLS
General mechanic's tool kit (Appendix E, Item 1) EQUIPMENT CONDITION
l Parking brake ret (TM 9-2320-272-10).
MATERIALS/PARTS
l
Cooling system drained (para. 3-63).
Four locknuts (Appendix D, Item 291)
Four lockwashers (Appendix D, Item 354)
Two O-rings (Appendix D, Item 430)
Antiseize tape (Appendix C, Item 72)
Cap and plug ret (Appendix C, Item 14)
a. Removal
CAUTION
Clean area around hoses before removal to prevent entry of dirt
Damage may occur if dirt or dust enters the transmission.
l
Cover or plug all open hoses and connections immediately after
disconnection to prevent contamination. Failure to do this may
result in transmission damage.
NOTE
Have drainage container ready to catch oil.
Disconnect transmission oil lines (4) and (18) from oil sampling valve (5) and elbow (15).
Loosen clamps (1) and (17) and disconnect hoses (2) and (16) from oil cooler (11).
Remove four locknuts (20), washers (10), screws (9), washers (10), and oil cooler (11) from
bracket (3) and splash panel extension (22). Discard locknuts (20).
Remove oil sampling valve (5), nut (6), washer (7), and O-ring (8) from oil cooler (11). Discard O-ring (8).
Remove elbow (16), nut (14), washer (13), and O-ring (12) from oil cooler (11). Discard O-ring (12).
Remove four locknuts (23), lockwashers (24), screws (21), and splash panel extension (22) from
bracket (25) and frame rail (19). Discard locknuts (23) and lockwashers (24).
l

1.
2.
3.
4.
5.
6.

3-380

TM 9-2320-272-24-1

3-141. TRANSMISSION OIL COOLER AND MOUNT (M939A2) REPLACEMENT (Contd)

3-381

TM 9-2320-272-24-1

3-141. TRANSMISSION OIL COOLER AND MOUNT (M939A2) REPLACEMENT (Contd)
b. Installation
1.

2.
3.
4.
5.
6.

Install splash panel extension (22) on bracket (25) and frame rail (19) with four screws (21), new
lockwashers (24), and new locknuts (23).
NOTE
Male pipe threads must be wrapped with antiseize tape before
installation.
Install new O-ring (12), washer (13), nut (14), and elbow (15) on oil cooler (11).
Install new O-ring (8), washer (7), nut (6), and oil sampling valve (5) on oil cooler (11).
Install oil cooler (11) on bracket (3) and splash panel extension (22) with four washers (10), screws (9),
washers (10), and new locknuts (20).
Connect hoses (2) and (16) to oil cooler (11) and tighten clamps (1) and (17).
Connect transmission oil lines (4) and (18) to oil sampling valve (5) and elbow (15).
CAUTION
When filling cooling system, ensure drain valve on aftercooler is
open. Failure to do so may result in damage to equipment.

3-382

TM 9-2320-272-24-1

3-141. TRANSMISSION OIL COOLER AND MOUNT (M939A2) REPLACEMENT (Contd)

FOLLOW-ON TASKS:

l
l
l

Fill cooling system (para. 3-53).
Check transmission oil level (TM 9-2320-272-10).
Start engine (TM 9-2320-272-10) and check for leaks.
3-383

TM 9-2320-272-24-1

3-142. TRANSMISSION OIL COOLER HOSES REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Two O-rings (Appendix D, Item 430)
Two O-rings (Appendix D, Item 470)
Two lockwashers (Appendix D, Item 416)
Locknut (Appendix D, Item 306)
Two tiedown straps (Appendix D, Item 697)
Cap and plug set (Appendix C, Item 14)
Antiseize tape (Appendix C, Item 72)

REFERENCES (TM)
LO 9-2320-272-12
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake Bet (TM 9-2320-272-10).
l Eight splash shield removed (TM 9-2320-272-10).
l
Transmission temperature transmitter unit
removed (para. 3-97).

CAUTION
l

l

Clean area around hoses before removal to prevent entry of dirt.
Damage may occur if dirt or dust enters the transmission.
Cover or plug all open hoses and connections immediately after
disconnect to prevent contamination. Failure to do this may
result in transmission damage.

a. Removal
NOTE
Have drainage container ready to catch oil.
l
Access to hose connection in step 1 is gained through access
door in cab floor.
l
Tag hoses for installation.
Disconnect supply hose (1) from adapter (6).
Remove adapter (6) and adapter (5) from elbow (4).
Remove elbow (4) and O-ring (3) from transmission (2). Discard O-ring (3).
NOTE
Perform step 4 for vehicles equipped with front winch.
Remove locknut (7) and screw (11) from hanger strap (8), and move winch hydraulic hoses (9)
and (10) and two clamps (12) aside. Discard locknut (7).
l

1.
2.
3.

4.

3-384

TM 9-2320-272-24-1

3-142. TRANSMISSION OIL COOLER HOSES REPLACEMENT (Contd)

3-385

TM 9-2320-272-34-1

3-142. TRANSMISSION OIL COOLER HOSES REPLACEMENT (Contd)

5.
6.
7.
8.
9.
10.
11.
12.
13.
14.

NOTE
Perform steps 5 through 10 for vehicles equipped with
transmission Power Takeoff (PTO).
Disconnect hose (11) from hose adapter (1).
Remove adapter (1) from adapter (2).
Remove adapter (2) from adapter (3).
Disconnect hose (11) from hose adapter (10).
Remove adapter (10) from adapter (9).
Remove adapter (9) from PTO (6).
Disconnect hose (4) from adapter (3).
Remove adapter (3) and O-ring (8) from valve housing (7). Discard O-ring (8).
Remove two tiedown straps (5) from hoses (4) and (17). Discard tiedown straps (5).
Remove two screws (13), washers (14), lockwashers (15), clamps (16), and hoses (4) and (17) from
engine access cover (12). Discard lockwashers (15).

WITH PTO

3-386

WITHOUT PTO

TM 9-2320-272-24-1

3-142. TRANSMISSION OIL COOLER HOSES REPLACEMENT (Contd)

3-387

TM 9-2320-272-24-1

3-142. TRANSMISSION OIL COOLER HOSES REPLACEMENT (Contd)
16.
16.
17.
18.
19.
20.
21.
22.

Disconnect oil cooler supply hose (8) from elbow (11).
Remove elbow (11) and O-ring (10) from oil cooler (9). Discard O-ring (10).
Disconnect supply hose (6) from adapter elbow (6).
Remove elbow (6) and O-ring (7) from oil cooler (9). Discard O-ring (7).
Remove supply hose (6) from adapter elbow (4).
Remove adapter elbow (4) from oil filter housing (3).
Disconnect return hose (1) from elbow (2).
Remove elbow (2) from oil filter housing (3).

b. Installation
CAUTION

1.
2.
3.
4.
6.
6.
7.
8.

3-388

Ensure plugs or covers are completely removed from all hoses and
connections. Failure to do this may result in transmission and oil
cooler damage.
NOTE
Male pipe threads must he wrapped with antiseize tape before
installation.
Install elbow (2) on housing (3).
Connect return hose (1) to elbow (2).
Install elbow (4) on housing (3).
Connect supply hose (6) to elbow (4).
Install new O-ring (7) and elbow (6) in oil cooler (9).
Connect supply hose (5) to elbow (6).
Install new O-ring (10) and elbow (11) in oil cooler (9).
Connect oil cooler supply hose (8) to elbow (11).

TM 9-2320-272-24-1

3-142. TRANSMISSION OIL COOLER HOSES REPLACEMENT (Contd)

3-389

TM 9-2320-272-24-1

3-142. TRANSMISSION OIL COOLER HOSES REPLACEMENT (Contd)
9.
10.
11.
12.

13.
14.
16.
16.
17.
18.

19.
20.
21.
22.
23.

Install two clamps (17) and hoses (4) and (18) on engine access cover (13) with two washers (15),
new lockwashers (16), and screws (14).
Install two new tiedown straps (5) on hoses (4) and (18).
Install new O-ring (8) and adapter (3) in valve housing (7).
Connect hose (4) to adapter (3).
NOTE
Perform step 13 through 18 for vehicles equipped with
transmission PTO.
Install adapter (9) on PTO (6).
Install adapter (10) on adapter (9).
Connect hose (11) to adapter (10).
Install adapter (2) on adapter (3).
Install adapter (1) on adapter (2).
Connect hose (11) to adapter (1).
NOTE
Perform step 19 for vehicles equipped with front winch.
Install hydraulic hoses (21) and (22) on hanger strap (20) with two clamps (24), screw (23), and new
locknut (19).
Install new O-ring (26) and elbow (27) on transmission (12).
Install adapter (28) on elbow (27).
Install adapter (29) on adapter (28).
Connect supply hose (25) to adapter (29).

WITH PTO

3-390

WITHOUT PTO

TM 9-2320-272-24-1

3-142. TRANSMISSION OIL COOLER HOSES REPLACEMENT (Contd)

FOLLOW-ON TASKS:

l
l
l
l

Install transmission temperature transmitter unit (para. 3-97).
Fill transmission oil reservoir to proper level (LO 9-2320-272-12).
Install right splash shield (TM 9-2320-272-10).
Start engine (TM 9-2320-272-10), check for leaks, and road test vehicle.
3-391

TM 9-2320-272-24-1

3-143. TRANSFER CASE INTERLOCK VALVE REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All (Except M936/A1/A2)
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Lockwasher (Appendix D, Item 404)
Two locknuts (Appendix D, Item 306)
Antiseize tape (Appendix C, Item 72)

EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Air reservoirs drained (TM 9-2320-272-10).
l Dump spare tire carrier removed (M929/A1/A2,
M930/A1/A2) (para. 3-257).
GENERAL SAFETY INSTRUCTIONS
Do not disconnect air lines before draining air
reservoirs.

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P

WARNING

1.
2.
3.
4.

5.

6.
7.

3-392

Do not disconnect air lines before draining air reservoirs. Small
parts under pressure may shoot out with high velocity, causing
injury to personnel.
NOTE
l Replacement of the interlock valve on M936/A1/A2 series
vehicles is not performed at unit level because the transfer
case must be removed. Notify DS maintenance.
l Tag air lines and wires for installation.
Disconnect interlock valve supply line (6) from elbow (5).
Disconnect air cylinder supply line (1) from elbow (2).
Disconnect vent line (12) from elbow (11).
Disconnect wire (8) from connector (9).
NOTE
Assistant will help with step 5.
Remove locknut (17), washer (18), diode ground wire (19), locknut (20), interlock valve ground
wire (16), lockwasher (21), cable clamp (15), and screw (10) from frame (7). Discard lockwasher (21)
and locknuts (17) and (20).
Remove two screws (14) and interlock valve (3) from bracket (13).
Remove elbows (2), (5), and (11) and adapter (4) from interlock valve (3).

TM 9-2320-272-24-1

3-143. TRANSFER CASE INTERLOCK VALVE REPLACEMENT (Contd)

3-393

TM 9-2320-272-24-1

3-143. TRANSFER CASE INTERLOCK VALVE REPLACEMENT (Contd)
b. Installation

1.
2.

3.
4.
5.
6.
7.

3-394

NOTE
Male pipe threads must be wrapped with antiseize tape before
installation.
Install elbow (2), adapter (4), and two elbows (5) and (11) on interlock valve (3).
Install interlock valve (3) on bracket (13) with two screws (14).
NOTE
Assistant will help with step 3.
Install screw (10) and cable clamp (15) on Frame (7) with new lockwasher (21), interlock valve
ground wire (16), new locknut (20), diode ground wire (19), washer (18), and new locknut (17).
Connect wire (8) to connector (9).
Connect vent line (12) to elbow (11).
Connect air cylinder supply line (1) to elbow (2).
Connect interlock valve supply line (6) to elbow (5).

TM 9-2320-272-24-1

3-143. TRANSFER CASE INTERLOCK VALVE REPLACEMENT (Contd)

FOLLOW-ON TASKS:

l
l

Install dump spare tire carrier (M929/A1/A2, M930/A1/A2) (para. 3-257).
Start engine (TM 9-2320-272-10), allow air pressure to build to normal operating
range, and check interlock valve for leaks. Road test vehicle.
3-395

TM 9-2320-272-24-1

3-144. TRANSFER CASE FRONT AXLE ENGAGEMENT CONTROL VALVE
REPLACEMENT
THIS TASK COVERS:
a Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, 1)
MATERIALS/PARTS
Antiseize tape (Appendix D, Item 72)

EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Air reservoirs drained (TM 9-2320-272-10).
GENERAL SAFETY INSTRUCTIONS
Do not disconnect air lines before draining air
reservoirs.

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
a. Removal
WARNING

1.
2.
3.
4.

Do not disconnect air lines before draining air reservoirs. Small
parts under pressure may shoot out with high velocity, causing
injury to personnel.
NOTE
Tag air lines for installation.
Disconnect three air lines (4) from elbows (3), (6), and (7).
Remove elbows (6) and (7) and pipes (5) and (8) from control valve (1).
Remove elbow (3) from control valve (1).
Remove two nuts (10), screws (2), and control valve (1) from front transfer case bracket (9).

b. Installation

1.
2.
3.
4.

3-396

NOTE
Wrap all male pipe threads with antiseize tape before installation.
Install central valve (1) on front transfer case bracket (9) with two screws (2) and nuts (10).
Install elbow (3) on control valve (1).
Install pipes (8) and (5) and elbows (7) and (6) on control valve (1).
Connect three air lines (4) to elbows (7), (6), and (3).

TM 9-2320-272-24-1

3-144. TRANSFER CASE FRONT AXLE ENGAGEMENT CONTROL VALVE
REPLACEMENT (Contd)

FOLLOW-ON TASK: Start engine (TM 9-2320-272-10), allow air pressure to build to normal operating
range, and check for air leaks and proper front axle engagement. Road test vehicle.
3-397

TM 9-2320-272-24-1

3-145. TRANSMISSION MODULATOR AND CABLE MAINTENANCE
THIS TASK COVERS:
a Removal
b. Installation

c. Adjustment

INITIAL SETUP:
APPLICABLE MODELS
All

REFERENCES (TM)
LO 9-2320-272-12
TM 9-2320-272-10
TM 9-2320-272-24P

TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
EQUIPMENT CONDITION
Torque wrench (Appendix E, Item 144)
l Parking brake set (TM 9-2320-272-10).
MATERIALS/PARTS
l Left splash shield removed (TM 9-2320-272-10).
O-ring (Appendix D, Item 454)
Locknut (Appendix D, Item 276)
Two locknuts (Appendix D, Item 283)
Locknut (Appendix D, Item 284)
a. Removal
NOTE
1.
2.
3.
4.
5.
6.

3-398

Have drainage container ready to catch oil.
Remove screw (15), retaining bracket (14), modulator (17), and O-ring (16) from transmission (13).
Discard O-ring (16).
Remove locknut (22), screw (19), speedometer cable clamp (18), and modulator cable clamp (20) from
transmission bracket (21). Discard locknut (22).
Remove modulator return spring (8) from modulator link (9) and bracket (2).
Remove two locknuts (3), screws (7), clamp (6), and shim (5) from bracket (2). Discard locknuts (3).
Remove locknut (1), screw (10), modulator link (9), and modulator cable (4) from throttle lever (11)
on fuel pump (12). Discard locknut (1).
Remove modulator link (9) from modulator cable (4).

TM 9-2320-272-24-1

3-145. TRANSMISSION MODULATOR AND CABLE MAINTENANCE (Contd)

3-399

TM 9-2320-272-24-1

3-145. TRANSMISSION MODULATOR AND CABLE MAINTENANCE (Contd)
b. Installation
1.

2.

3.

Install new O-ring (22) and modulator (23) on transmission (19) with retaining
bracket (20) and screw (21). Tighten screw (21) 16-20 lb-ft (22-27 N.m).
NOTE
Clamp and shim must align on modulator cable.
Install shim (13) and modulator cable (14) on bracket (11) with clamp (15), two screws (16), and new
locknuts (12).
NOTE
Locate modulator cable away from sharp edges and avoid sharp bends.
Install modulator cable (14) on transmission bracket (27) with modulator cable clamp (26),
speedometer cable clamp (24), screw (25), and new locknut (28).

c. Adjustment

1.
2.
3.

4.
5.

6.
7.
8.
9.

3-400

NOTE
Assistant will help with steps 1 through 4.
Move throttle lever (8) on fuel pump (6) to FULLY OPEN position and hold.
Pull threaded end of modulator cable (14) out to STOP position.
Loosen jamnut (10) and thread modulator link (18) onto modulator cable (14) until front of slot
aligns with hole in throttle lever (8). Continue to loosen jamnut (10) as needed to position modulator
link (18).
Back off modulator link (18) two turns to provide free pin clearance and tighten jamnut (10).
Install modulator link (18) on throttle lever (8) with screw (7) and new locknut (9).
NOTE
l Assistant will help with steps 6 and 7.
l Ensure throttle lever is still in FULLY OPEN position.
Loosen throttle stopscrew (3) and jamnut (4) on cab floor (1). Loosen nut (5) as needed.
Adjust stop screw (3) to barely touch cab floor (1) side of accelerator pedal (2). Tighten jamnut (4)
and nut (5).
Release throttle lever (8) on fuel pump (6).
Install modulator return spring (17) on modulator link (18) and bracket (11).

TM 9-2320-272-24-1

3-145. TRANSMISSION MODULATOR AND CABLE MAINTENANCE (Contd)

FOLLOW-ON TASKS:

l
l
l

Fill transmission to proper level (LO 9-2320-272-12).
Install left splash shield (TM 9-2320-272-10).
Start engine (TM 9-2320-272-10) and road test vehicle.
3-401 (3-402 blank)

TM 9-2320-272-24-1

Section VIII. PROPELLER SHAFTS, AXLES, AND
SUSPENSION SYSTEM MAINTENANCE
3-146. PROPELLER SHAFTS, AXLES, AND SUSPENSION SYSTEM MAINTENANCE INDEX
PARA.
NO.
3-147.
3-148.
3-149.
3-150.
3-151.
3-152.
3-153.
3-154.
3-155.
3-156.
3-157.
3-158.
3-159.
3-160.
3-161.
3-162.
3-163.
3-164.
3-165.
3-166.
3-167.
3-168.
3-169.
3-170.

TITLE
Transfer Case Front Axle Lock-in Control Valve Replacement
Transmission to Transfer Case Propeller Shaft Maintenance
Transfer Case to Front Axle Propeller Shaft Replacement
Transfer Case to Forward-Rear Axle Propeller Maintenance
Forward-Rear to Rear-Rear Propeller Shaft Replacement
Toe-in Check and Adjustment
Tie Rod Maintenance
Front Axle Shaft and Universal Joint Maintenance
Steering Knuckle Boot Maintenance
Front Axle Drive Flange Maintenance
Rear Axle Shaft Maintenance
Carrier Differential Top Cover Gasket and Side Cover Gasket Replacement
Front and Rear Axle Breather Replacement
Front Axle Seal Replacement
Front Spring and Main Leaf Replacement
Front Spring Shackle Replacement
Front Spring Bushing Maintenance
Front Spring Bumper Replacement
Rear Spring Bumper Replacement
Shock Absorber and Mounting Pins Replacement
Rear Spring Replacement
Rear Axles Spring Seat Wear Pads and Upper Bracket Maintenance
Rear Spring Seat Maintenance
Upper and Lower Torque Rod Maintenance

PAGE
NO.
3-404
3-406
3-410
3-412
3-420
3-422
3-424
3-426
3-430
3-432
3-433
3-434
3-438
3-439
3-440
3-446
3-448
3-450
3-451
3-452
3-454
3-460
3-464
3-468

3-403

TM 9-2320-272-24-1

3-147. TRANSFER CASE FRONT AXLE LOCK-IN CONTROL VALVE REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Antiseize tape (Appendix C, Item 72)
REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P

EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Air reservoirs drained (TM 9-2320-272-10).
l Front axle lock-in switch removed (para 3-101).
l Fuel selector valve removed (if equipped)
(para. 3-24).
GENERAL SAFETY INSTRUCTIONS
Do not disconnect air lines before draining air
reservoirs.

WARNING
Do not disconnect air lines before draining air reservoirs. Small
parts under pressure may shoot out with high velocity, causing
injury to personnel.
a. Removal

1.
2.
3.

NOTE
Tag air lines for installation.
Disconnect control line (8) from front axle control valve elbow (7).
Disconnect manifold tee supply line (1) from adapter fitting (2).
Remove two screws (4), instruction plate (5), and control valve (3) from instrument panel (6).

b. Installation

1.
2.
3.

3-404

NOTE
If new control valve is being installed, use fitting from old valve.
Clean all male pipe threads and wrap with antiseize tape before
installation.
Install control valve (3) and instruction plate (5) on instrument panel (6) with two screws (4).
Connect manifold tee supply line (1) to adapter fitting (2).
Connect control line (8) to front axle control valve elbow (7).

TM 9-2320-272-24-1

3-147. TRANSFER CASE FRONT AXLE LOCK-IN CONTROL VALVE REPLACEMENT
(Contd)

FOLLOW-ON TASKS:

l
l
l

l

Install front axle lock-in switch (para. 3-101).
Install fuel selector (para. 3-24).
Start engine (TM 9-2320-272-10) and allow air pressure to build up to normal
operating pressure. Check for air leaks at axle lock-in valve. Road test vehicle.
Check front axle lock-in valve for proper operation.
3-405

TM 9-2320-272-24-1

3-148. TRANSMISSION TO TRANSFER CASE PROPELLER SHAFT MAINTENANCE
THIS TASK COVERS:
a. Removal
b. Disassembly

c. Assembly
d. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Torque wrench (Appendix E, Item 144)
MATERIALS/PARTS
Twelve lockwashers (Appendix D, Item 361)
Universal joint kit (Appendix D, Item 702)

REFERENCES (TM)
LO 9-2320-272-12
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Wheels chocked (TM 9-2320-272-10).

a. Removal
1.
2.
3.
4.
5.
6.

3-406

Place transfer case lever (1) in high position.
Remove four screws (5) and lockwashers (4) from transmission yoke (2) and transfer case yoke (3).
Discard lockwashers (4).
Place transfer case lever (1) in neutral position.
Turn propeller shaft (6) until remaining screws (5) can be seen.
Place transfer case lever (1) to high position.
Remove four remaining screws (5), lockwashers (4), and propeller shaft (6) from transmission
yoke (2) and transfer case yoke (3). Discard lockwashers (4).

TM 9-2320-272-24-1

3-148. TRANSMISSION TO TRANSFER CASE PROPELLER SHAFT MAINTENANCE (Contd)

3-407

TM 9-2320-272-24-1

3-148. TRANSMISSION TO TRANSFER CASE PROPELLER SHAFT MAINTENANCE (Cod)
b. Disassembly
1.
2.
3.

Remove grease fitting (5) from input yoke (4).
Remove four screws (1), lockwashers (2), and cross assembly (3) from input yoke (4). Discard
lockwashers (2).
Separate input yoke (4) from output yoke (7). Replace oil seal (6) if damaged.

c. Assembly

1.
2.
3.
4.

Install
Install
Install
Install

NOTE
Perform step 1 only if seal was removed.
seal assembly (6) over splined output yoke (7).
output yoke (7) into input yoke (4).
cross assembly (3) on input yoke (4) with four new lockwashers (2) and screws (1).
grease fitting (5) on input yoke (4).

d. Installation
1.
2.
3.
4.
5.

3-408

Install propeller shaft (13) between transmission yoke (9) and transfer case yoke (12) with four new
lockwashers (10) and screws (11). Tighten screws (11) 90-110 lb-ft (122-149 N.m).
Place transfer case lever (8) in neutral position.
Turn propeller shaft (13) until remaining screws (11) can be installed.
Place transfer case lever (8) in high position.
Install propeller shaft (13) between transmission yoke (9) and transfer case yoke (12) with four
remaining new lockwashers (10) and screws (11). Tighten screws (11) 90-110 lb-ft (122-149 N.m).

TM 9-2320-272-24-1

3-148. TRANSMISSION TO TRANSFER CASE PROPELLER SHAFT MAINTENANCE (Contd)

FOLLOW-ON TASK: Lubricate propeller shaft universal joints (LO 9-2320-272-12).
3-409

TM 9-2320-272-24-1

3-149. TRANSFER CASE TO FRONT AXLE PROPELLER SHAFT REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Torque wrench (Appendix E, Item 146)
MATERIALS/PARTS
Sixteen locknuts (Appendix D, Item 291)
Two lockwashers (Appendix D, Item 382)

REFERENCES (TM)
LO 9-2320-272-12
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Wheels chocked (TM 9-2320-272-10).

a. Removal

1.
2.
3.
4.

NOTE
Step 1 refers to M939/A1 vehicles only
Remove two screws (4), lockwashers (5), and center bearing bracket (6) from bracket (7). Discard
lockwashers (5).
Remove eight locknuts (10) and screws (8) from propeller shaft flange (11) and differential
flange (9). Discard locknuts (10).
Remove eight locknuts (1) and screws (2) from propeller shaft flange (12) and transfer case
flange (13). Discard locknuts (1).
Remove transfer case to front propeller shaft assembly (3).

b. Installation
1.
2.

3.

3-410

Install transfer
screws (2) and
Install transfer
screws (8) and

case
new
case
new

to front
locknuts
to front
locknuts

axle propeller shaft assembly (3) on transfer case flange (13) with eight
(1). Tighten locknuts (1) 32-40 lb-ft (43-54 N.m).
axle propeller shaft assembly (3) on differential flange (9) with eight
(10). Tighten locknuts (10) 32-40 lb-ft (43-54 N.m).
NOTE
Step 4 refers to M939/A1 vehicles only.
Install center bearing bracket (6) on bracket (7) with two new lockwashers (5) and screws (4).

TM 9-2320-272-24-1

3-149. TRANSFER CASE TO FRONT AXLE PROPELLER SHAFT REPLACEMENT (Contd)

FOLLOW-ON TASK: Lubricate propeller shaft universal joints (LO 9-2320-272-12).
3-411

TM 9-2320-272-24-1

3-150. TRANSFER CASE TO FORWARD-REAR AXLE PROPELLER SHAFT MAINTENANCE
THIS TASK COVERS:
a. Removal
b. Disassembly
c. Cleaning and Inspection

d. Assembly
e. Installation

INITIAL SETUP:
APPLICABLE MODELS
M927/A1/A2, M928/A1/A2, M934/A1/A2,
M935/A1/A2
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Torque wrench (Appendix E, Item 146)
MATERIALS/PARTS
Twenty-two locknuts (M939A2 old
configuration) (Appendix D, Item 291)
Sixteen locknuts (Appendix D, Item 291)
Two universal plates (Appendix D, Item 704)
Cotter pin (M939/A1 old configuration)
(Appendix D, Item 80)
Twelve locknuts (M939/A1 old configuration)
(Appendix D, Item 291)
Drycleaning solvent (Appendix C, Item 71)
GAA Grease (Appendix C, Item 28)

REFERENCES (TM)
LO 9-2320-272-12
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Wheels chocked (TM 9-2320-272-10).
GENERAL SAFETY INSTRUCTIONS
l
Drycleaning solvent is hazardous and flammable.
Do not use near open flame.
l
Keep fire extinguisher nearby when drycleaning
solvent is used.

a. Removal
1.
2.
3.
4.

5.
6.
7.
8.
9.

3-412

Remove eight locknuts (3) from transfer case brake drum (1) and transfer case shaft yoke
flange (2). Discard locknuts (3).
Remove eight screws (13), locknuts (12), and rear propeller shaft yoke flange (14) from forward-rear
axle yoke flange (11). Discard locknuts (12).
Remove forward propeller shaft front section (4) from forward propeller shaft aft section (24).
Remove dustcover (5) and spacer (6) from forward propeller shaft front section (4).
NOTE
l Perform steps 5 through 14 only for vehicles equipped with old
forward-rear axle propeller shaft.
l Perform steps 5 through 9 for models M927/A1, M928/A1,
M934/A1, and M935/A1 models only.
Remove eight screws (17) and locknuts (21) from rear propeller shaft companion flange (16) and
center bearing companion flange (20). Discard locknuts (21).
Remove forward-rear axle propeller shaft (15) and center bearing flange (20) from center bearing
bracket (10).
Remove four screws (8) and locknuts (7) from center bearing mounting bracket (10) and crossmember (9). Discard locknuts (7).
Remove cotter pin (18) and nut (19) from forward propeller shaft (4). Discard cotter pin (18).
Remove center bearing companion flange (20), dustcover (22), spacer (23), center bearing mounting
bracket (l0), spacer (6), and dustcover (5) from forward propeller shaft (4).

TM 9-2320-272-24-1

3-150. TRANSFER CASE TO FORWARD-REAR AXLE PROPELLER SHAFT MAINTENANCE
(Contd)

3-413

TM 9-2320-272-24-1

3-150. TRANSFER CASE TO FORWARD-REAR AXLE PROPELLER SHAFT MAINTENANCE
(Contd)

10.
11.
12.
13.
14.
15.
16.

NOTE
Perform steps 10 through 14 for M927A2, M928A2, M934A2, and
M935A2 models only.
Remove eight locknuts (9), screws (7), and rear axle flange (8) from center bearing flange (6).
Discard locknuts (9).
Remove eight locknuts (13) and flange (14) from transfer case brakedrum studs (1). Discard
locknuts (13).
Remove two locknuts (12), screws (4), washers (3), center bearing (11), forward-rear axle propeller
shaft (10), and vibration damper (5) from bracket (2). Discard locknuts (12).
Remove locknut (15), washer (16), clamp (17), spacer (18), screw (20), and clamp (19) from bracket (2)
and crossmember (22). Discard locknut (15).
Remove three locknuts (24), washers (23), screws (21), and bracket (2) from crossmember (22). Discard
locknuts (24).
Straighten tabs on two universal plates (26).
Remove four screws (25), two universal plates (26), bearing caps (34), and universal joint (28) from
center bearing propeller shaft (27). Discard universal plates (26).

b. Disassembly

1.
2.
3.
4.

NOTE
Perform disassembly for M927A2, M928A2, M934A2, and M935A2
models only.
Loosen dust seal (31) on shaft (30).
Remove shaft (30) from shaft (32).
Remove dust seal (31) from shaft (32).
Remove grease fitting (33) from yoke (29).

c. Cleaning and Inspection
WARNING

1.
2.

3-414

Drycleaning solvent is flammable and toxic. Do not use near open
flame and always have fire extinguisher nearby when solvents are
used. Use only in well-ventilated places, wear protective clothing,
and dispose of cleaning rags in approved container. Failure to do
this may result in injury or death to personnel and/or damage to
equipment.
Clean all parts in drycleaning solvent and allow to dry.
Inspect all parts for cracks, fitting, or scoring. Replace parts as necessary if cracked, pitted, or
scored.

TM 9-2320-272-24-1

3-150. TRANSFER CASE TO FORWARD-REAR AXLE PROPELLER SHAFT MAINTENANCE
(Contd)

3-415

TM 9-2320-272-24-1

3-150. TRANSFER CASE TO FORWARD-REAR AXLE PROPELLER SHAFT MAINTENANCE
(Contd)
d. Assembly

1.

2.
3.
4.

NOTE
Perform assembly for M927A2, M928A2, M934A2, and M935A2
models only.
Install grease fitting (10) in yoke (6).
NOTE
Apply light coat of GAA grease to dust seal and splines of shaft
before installation.
Install dust seal (8) on splines of shaft (9).
Install shaft (7) on shaft (9).
Tighten dust seal (8) on shaft (7).

e. Installation
1.
2.

3.
4.

5.
6.
7.

3-416

Install universal joint (5) on center bearing propeller shaft (4) with two bearing caps (1), new
universal plates (3), and four screws (2). Tighten screw (2) 32-40 lb-ft (43-54 N.m).
Bend tabs on universal plates (3) against screws (2).
NOTE
Perform steps 3 through 7 for M927A2, M928A2, M934A2, and
M935A2 models only.
Install bracket (19) on crossmember (18) with three screws (17), washers (20), and new
locknuts (21).
Install clamps (15) and (13) on bracket (19) and crossmember (18) with screw (16), spacer (14),
washer (121, and new locknut (11).
NOTE
Assistant will help with steps 5 through 7.
Holding forward-rear axle propeller shaft (27) on brakedrum studs (32) and forward-rear axle
flange (24), install center bearing (28) on bracket (19) with two washers (33), screws (34), and new
locknuts (29).
Install flange (31) on eight transfer case brakedrum studs (32) with new locknuts (30). Tighten
locknuts (30) 32-40 lb-ft (43-54 N.m) in alternate sequence.
Install vibration dampener (22) and flange (25) on forward-rear flange (24) with eight screws (23)
and new locknuts (26). Tighten locknuts (26) 30-40 lb-ft. (43-54 N.m).

TM 9-2320-272-24-1

3-150. TRANSFER CASE TO FORWARD-REAR AXLE PROPELLER SHAFT MAINTENANCE
(Contd)

3-417

TM 9-2320-272-24-1

3-150. TRANSFER CASE TO FORWARD-REAR AXLE PROPELLER SHAFT MAINTENANCE
(Contd)

8.

9.

10.

11.
12.
13.
14.
15.

3-418

NOTE
Perform steps 8 through 12 only for vehicles equipped with old
propeller shaft.
Install dustcover (5), spacer (6), center bearing mounting bracket (10), spacer (23), dustcover (22),
and center bearing companion flange (20) on forward propeller shaft (4) with nut (19). Tighten
nut (19) 100-115 lb-ft (136-156 N.m). If needed, turn nut (19) clockwise to align nearest slot with
hole in shaft (4) to install new cotter pin (18).
Install new cotter pin (18) on nut (19) and forward propeller shaft (4).
NOTE
Assistant will help with steps 10 through 14.
Install center bearing mounting bracket (10) on crossmember (9) with four screws (8) and new
locknuts (7).
NOTE
Position rear-rear propeller shaft so that grease fitting on U-joint
faces downward. Refer to new configuration for steps 13 and 14.
Install rear propeller shaft (15) companion flange (16) on center bearing companion flange (20) with
eight screws (17) and new locknuts (21). Tighten locknuts (21) 30-40 lb-ft (41-54 N.m).
Install spacer (6) and dustcover (5) on forward propeller shaft front section (4).
Install forward propeller shaft front section (4) on forward propeller shaft aft section (24).
Install rear propeller shaft yoke flange (14) on forward-rear axle yoke flange (11) with eight
screws (13) and new locknuts (12).
Install transfer case shaft yoke flange (2) on transfer case brake drum (1) with eight new locknuts (3).

TM 9-2320-272-24-1

3-150. TRANSFER CASE TO FORWARD-REAR AXLE PROPELLER SHAFT MAINTENANCE
(Contd)

FOLLOW-ON TASK: Lubricate propeller shaft universal joints (LO 9-2320-272-12).
3-419

TM 9-2320-272-24-1

3-151. FORWARD-REAR TO REAR-REAR PROPELLER SHAFT REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All except M927/A1, M928/A1/A2, M934/A1/A2,
M935/A1/A2

REFERENCES (TM)
TM 9-2320-272-12
TM 9-2320-272-10

TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Torque wrench (Appendix E, Item 148)

EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Wheels chocked (TM 9-2320-272-10).

MATERIALS/PARTS
Sixteen locknuts (Appendix D, Item 291)
PERSONNEL REQUIRED
Two
a. Removal
1.
2.

Remove eight locknuts (4), screws (3), and forward-rear to rear-rear axle propeller shaft (2) from
transfer case input flange (5). Discard locknuts (4).
Remove eight locknuts (7), screws (1), and forward-rear to rear-rear axle propeller shaft (2) from
transmission output flange (6). Discard locknuts (7).

b. Installation
1.
2.

3-420

Install forward-rear
screws (1) and new
Install forward-rear
screws (3) and new

to rear-rear axle propeller shaft (2) on transmission output flange (6) with eight
locknuts (7). Tighten locknuts (7) 32-40 lb-ft. (43-54 N.m).
to rear-rear axle propeller shaft (2) on transfer case input flange (5) with eight
locknuts (4). Tighten locknuts (4) 32-40 lb-ft (43-54 N.m).

TM 9-2320-272-24-1

3-151. FORWARD-REAR TO REAR-REAR PROPELLER SHAFT REPLACEMENT (Contd)

3-421

TM 9-2320-272-24-1

3-152. TOE-IN CHECK AND ADJUSTMENT
THIS TASK COVERS:
a. Toe-in Check

b. Toe-in Adjustment

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Toe-in gauge (Appendix E, Item 56)
Torque wrench (Appendix E, Item 144)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Vehicle parked on level ground (TM 9-2320-272-10).
l Engine off (TM 9-2320-272-10).
l Parking brake set (TM 9-2320-272-10).
l Tires properly inflated (TM 9-2320-272-10).
l Wheel bearings adjusted (para. 3-225).

a. Toe-in Check
1.
2.
3.
4.

5.
6.
7.

Place front wheels (1) in straight-ahead position.
Place toe-in gauge between front wheels (1) at middle of tires (3) as far in front of axle (2) as
possible.
Move toe-in gauge until chains just touch the ground.
Move scale so pointer reads 0.
NOTE
Assistant will help with steps 5 through 7.
Start engine (TM 9-2320-272-10).
With toe-in gauge in place, move vehicle forward until toe-in gauge is in back of axle (2) and chains
just touch ground.
Stop engine (TM 9-2320-272-10).

b. Toe-in Adjustment
1.
2.
3.
4.
5.
6.

3-422

Read position of pointer on scale. Pointer should read 1/16-3/16-inch toe-in.
If reading is not within limits given, leave toe-in gauge in place and proceed to step 3.
Loosen two nuts (5) on tie rod (4).
Turn tie rod (4) until pointer reads 1/16-3/16-inch toe-in on scale.
Tighten nuts (5) 60-80 lb-ft (81-109 N.m).
Remove toe-in gauge.

TM 9-2320-272-24-1

3-152. TOE-IN CHECK AND ADJUSTMENT (Contd)

3-423

TM 9-2320-272-24-1

3-153. TIE ROD MAINTENANCE
THIS TASK COVERS:
a. Removal
b. Inspection

c. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Torque wrench (Appendix E, Item 145)
MATERIALS/PARTS
Two cotter pins (Appendix D, Item 85)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Wheels chocked (TM 9-2320-272-10).

a. Removal
1.
2.
3.
4.

5.
6.

Remove two cotter pins (3) from tie rod ends (5) and nuts (1). Discard cotter pins (3).
Remove two nuts (1) from tie rod ends (5). Mark tie rod ends left and right.
Remove tie rod (10) from 1eft and right steering knuckle arms (2).
Loosen two screws (8), nuts (6), and clamps (7) on tie rod (10).
NOTE
Record number of turns required to remove tie rod ends.
Remove two tie rod ends (5) from tie rod (10).
Remove two tie rod boots (4) and grease fittings (9) from tie rod ends (5).

b. Inspection
Inspect tie rod (10) and tie rod ends (5) for cracks, bends, and stripped threads. Replace tie rod (10)
and/or tie rod ends (5) if bent, cracked, or stripped.
c. Installation
1.

2.
3.
4.
5.

3-424

Install two tie rod boots (4) and grease fittings (9) on tie rod ends (5).
NOTE
Use same number of turns recorded during removal of tie rod ends.
Install two tie rod ends (5) on tie rod (10).
Tighten two screws (8) and nuts (6) on clamps (7). Tighten nuts (6) 60-80 lb-ft (81-109 N.m).
Install tie rod ends (5) on left and right steering knuckle arms (2) with two nuts (1). Tighten two
nuts (1) to 160-180 lb-ft (217-244 N.m).
Install two new cotter pins (3) on tie rod ends (5) and nuts (1).

TM 9-2320-272-24-1

3-153. TIE ROD MAINTENANCE (Contd)

FOLLOW-ON TASK: Check and adjust toe-in (para. 3-152).
3-425

TM 9-2320-272-24-1

3-154. FRONT AXLE SHAFT AND UNIVERSAL JOINT MAINTENANCE
THIS TASK COVERS:
a. Removal
b. Cleaning and Inspection
c . Universal Joint Disassembly

d. Universal Joint Assembly
e . Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Vise
MATERIALS/PARTS
Cap and plug set (Appendix C, Item 14)
GAA grease (Appendix C, Item 28)
Sealing compound (Appendix C, Item 62)
Drycleaning solvent (Appendix C, Item 71)
Antiseize tape (Appendix C, Item 72)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Air reservoir drained (TM 9-2320-272-10).
l Front hub and drum removed (para. 3-223).
l Front hub and drum removed (M939A2)
(para. 3-460).
GENERAL SAFETY INSTRUCTIONS
l Do not disconnect air lines before draining air
reservoirs.
l
Keep fire extinguisher nearby when drycleaning
solvent is used.
l Drycleaning solvent is flammable and toxic. Do not
use near open flame.

WARNING
Do not disconnect air lines before draining air reservoirs. Small parts under
pressure may shoot out with high velocity, causing injury to personnel.
a. Removal

1.
2.
3.
4.
5.
6.

CAUTION
Cap or plug all openings immediately after disconnecting lines and hoses to
prevent contamination. Failure to do so may result in brake system damage.
NOTE
Tag all lines and hoses for installation.
Disconnect vent air line (2) and service brake air line (1) from front brake chamber (4).
Remove ten nuts (7), washers (8), and brake spider (6) from steering knuckle housing (11).
Remove brake shoe spider and chamber assembly (5) from steering knuckle housing (11).
Remove spindle (3) from steering knuckle housing (11).
Remove axle shaft (10) from axle housing (12).
Remove washer (9) from axle shaft (10).

b. Cleaning and Inspection

1.
3-426

WARNING
Drycleaning solvent is flammable and toxic. Do not use near open flame and
always fave a fire extinguisher nearby when solvents are used. Use only in
well-ventilated places, wear protective clothing, and dispose of cleaning rags
in approved container. Failure to do this may result in injury or death to
personnel and or damage to equipment.
Clean steering knuckle housing (11) with drycleaning solvent.

TM 9-2320-272-24-1

3-154. FRONT AXLE SHAFT AND UNIVERSAL JOINT MAINTENANCE (Contd)

3-427

TM 9-2320-272-24-1

3-154. FRONT AXLE SHAFT AND UNIVERSAL JOINT MAINTENANCE (Contd)

2.
3.

NOTE
New configuration axle shafts have a CV joint in place of the
universal joint. Axle shafts are no longer repairable and must be
replaced if damaged.
Inspect axle shaft (5) for cracks and nicks at shaft splines (1). If shaft splines are cracked or nicked,
replace axle shaft (5).
Place short end (4) of axle shaft (5) in soft-jawed vise. Pull and push up and down on inner shaft (2) and
twist inner shaft (2). Replace axle shaft, (5) if any free play in universal or CV joint (3) is observed.

SOFT-JAWED VISE

NEW CONFIGURATION

e. Installation
1.
2.
3.
4.
5.
6.
7.

8.
3-428

Install washer (14) on axle shaft (15).
Lubricate universal joint (16) (if equipped), grease all bearing surfaces on axle shaft (15) and fill
steering knuckle cavity (19) with GAA grease.
Support axle shaft (15) and install in steering knuckle housing (18).
Repack steering knuckle cavity (19) with GAA grease.
Apply sealing compound to spindle (8) and align with mounting studs (17) on steering knuckle
housing (18). Ensure spindle (3) is slot end up.
Install brakeshoe spider and chamber assembly (10) over spindle (8) on steering knuckle
housing (18).
Install brake spider (11) on steering knuckle housing (18) with ten washers (13) and nuts (12).
NOTE
Male pipe threads must be wrapped with antiseize tape before
installation.
Connect vent air line (7) and service brake air line (6) to front brake chamber (9).

TM 9-2320-272-24-1

3-154. FRONT AXLE SHAFT AND UNIVERSAL JOINT MAINTENANCE (Contd)

FOLLOW-ON TASKS:

l
l
l

Install front hub and drum (M939A2) (para. 3-460).
Install front hub and drum (para. 3-223).
Start engine (TM 9-2320-272-10) and check for leaks at air lines and brake
chambers.
3-429

TM 9-2320-272-24-1

3-155. STEERING KNUCKLE BOOT MAINTENANCE
THIS TASK COVERS:
a. Removal
b. Cleaning and Inspection

c. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Torque wrench (Appendix E, Item 144)
MATERIALS/PARTS
Steering knuckle boot (seal) replacement kit
(Appendix D, Item 676)
Four lockwashers (Appendix D, Item 377)
Lockwire (Appendix D, Item 419)
Cleaning cloth (Appendix C, Item 21)
Adhesive (Appendix C, Item 5)

REFERENCES (TM)
LO 9-2320-272-12
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).

a. Removal
1.
2.
3.
4.
5.

6.

Remove four screws (4), lockwashers (3), and seal guard (5) from steering knuckle (2). Discard
lockwashers (3).
Remove twelve screws (7), safety wire (1), and retaining plate (6) from steering knuckle (2). Discard
safety wire (1).
Pull one side of steering knuckle seal (12) aside to expose inner retaining clamp screw (10).
Remove inner retaining clamp screw (10) and spacer (9) from inner retaining clamp (11).
Remove seal (12) and inner retaining clamp (11) from steering knuckle (2).
NOTE
Some seals may not have a zipper.
Open zipper (8) or cut to remove seal (12) from axle housing (13).

b. Cleaning and Inspection
1.
2.

Clean surface of steering knuckle (2), retaining plate (6), and steering knuckle seal (12) with
cleaning cloth. Ensure there is no dirt or dust is inside steering knuckle (2).
Inspect steering knuckle seal (12) for cracks, tears, and damaged zipper (8). Replace if cracked, torn,
or zipper (8) is damaged.

c. Installation
1.
2.
3.
4.

3-430

Place steering knuckle seal (12) on axle housing (13), with fabric side of zipper (8) facing steering
knuckle (2).
Close zipper (8) and apply large amount of adhesive to locks and fabric of zipper (8). Allow adhesive
to sit overnight.
Force inner lip of steering knuckle seal (12) into groove on axle housing (13). Ensure steering
knuckle seal (12) is aligned to holes in steering knuckle (2).
Position inner retaining clamp (11) to lip of seal (12) and install clamp screw (10) and spacer (9).

TM 9-2320-272-24-1

3-155. STEERING KNUCKLE BOOT MAINTENANCE (Contd)
5.
6.
7.
8.
9.

Lace zipper (8) locks with fine wire near edge of steering knuckle seal (13) and twist together.
Cut off excess zipper (8) and apply adhesive to exposed zipper (8) and fabric. Allow adhesive to sit
overnight.
Align seal retaining plate (6) to holes in steering knuckle (2) and install twelve screws (7). Ensure
notches in screw (7) heads are aligned so safety wire (1) can be installed.
Thread new safety wire (1) around each screw (7) and tie Off.
Install seal guard (5) on steering knuckle (2) with four new lockwashers (3) and screws (4). Tighten
screws (4) 130-170 lb-ft (176-231 N.m).

FOLLOW-ON TASK: Lubricate steering knuckle (LO 9-2320-272-12).
3-431

TM 9-2320-272-24-1

3-156. FRONT AXLE DRIVE FLANGE MAINTENANCE
THIS TASK COVERS:
a. Removal
b. Inspection

c. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Torque wrench (Appendix E, Item 144)
MATERIALS/PARTS
Gasket sealant (Appendix C, Item 30)

1.
2.
3.
4.

REFERENCES (TM)
LO 9-2320-272-12
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).

Remove ten screws (1) and washers (2) from axle drive flange (3).
Install two screws (1) in threaded holes (7) and turn screws (1) evenly until flange (3) separates
from hub (5).
Remove two screws (1) from axle drive flange (3).
Remove gasket (4) if present. Discard gasket (4) and/or clean gasket sealant or sealant remains
from mating surfaces.

b. Inspection
1.
2.

Inspect mating surfaces of axle drive flange (3) and hub (5) for burrs, cracks, and gouges. File down
surfaces having burrs. Replace axle drive flange (3) or hub (5) if cracked or gouged.
Inspect axle shaft (6) for damaged splines. Notify your supervisor if splines are damaged.

c. Installation
1.
2.

Coat surface of axle drive flange (3) with sealant and align with holes on hub (5).
Install axle drive flange (3) on hub (5) with ten washers (2) and screws (1). Tighten screws (1)
85-100 lb-ft (115-136 N.m).

FOLLOW-ON TASK: Lubricate axle assembly (LO 9-2320-272-12).
3-432

TM 9-2320-272-24-1

3-157. REAR AXLE SHAFT MAINTENANCE
THIS TASK COVERS:
a. Removal
b. Inspection

c. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Torque wrench (Appendix E, Item 144)
MATERIALS/PARTS
Gasket sealant (Appendix C, Item 30)

REFERENCES (TM)
LO 9-2320-272-12
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).

a. Removal
1.
2.
3.

Remove ten screws (1) and washers (2) from axle shaft flange (3).
Tap shaft flange (3) and remove axle shaft flange (3) and axle shaft (4) from axle housing (6).
Remove gasket (5) if present, from axle shaft flange (3). Clean gasket or sealant from mating
surfaces. Discard gasket (5).

b. Inspection
Inspect axle shaft (4) and axle housing (6) for cracks, burrs, and damaged splines on shaft. Replace axle
shaft (4) or axle housing (6) if cracked, burred, or shaft has damaged splines.
b. Installation
1.
2.
3.
4.

Coat surface of axle shaft flange (3) with sealant.
Position splined end of axle shaft (4) into axle housing (6). Ensure axle shaft (4) slides into splined
differential gear (7).
Align axle shaft flange (3) to hole in axle housing (6).
Install axle shaft flange (3) on axle housing (6) with ten washers (2) and screws (1). Tighten
screws (1) 80-105 lb-ft (108-142 N.m).

FOLLOW-ON TASK: Lubricate axle assembly (LO 9-2320-272-12).
3-433

TM 9-2320-272-24-1

3-158. CARRIER DIFFERENTIAL TOP COVER GASKET AND SIDE COVER GASKET
REPLACEMENT
THIS TASK COVERS:
a Top Cover Gasket Removal
b. Top Cover Gasket Installation

c. Side Cover Gasket Removal
d. Side Cover Gasket Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Torque wrench (Appendix E, Item 146)
MATERIALS/PARTS
Top cover gasket (Appendix D, Item 698)
Side cover gasket (Appendix D, Item 653)
Gasket sealant (Appendix C, Item 30)
Antiseize tape (Appendix C, Item 72)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Air reservoirs drained (TM 9-2320-272-10).
l Rear wheels chocked (TM 9-2320-272-10).
GENERAL SAFETY INSTRUCTIONS
Do not disconnect air lines before draining air
reservoirs.

WARNING
Do not disconnect air lines before draining air reservoirs. Small
parts under pressure may shoot out with high velocity, causing
injury to personnel.
a. Top Cover Gasket Removal

1.
2.
3.
4.

5.

3-434

NOTE
l Tag all air lines for installation.
l
Perform steps 1 through 4 for forward-rear and rear-rear axle
carrier differential top cover.
Remove four air lines (3) from adapters (2).
Remove two adapters (2) from manifolds (1).
Remove two screws (7), washers (6), and bracket (5) from carrier differential top cover (4).
Remove eight screws (7), washer (6), top cover (4), and gasket (8) from carrier differential housing (9).
Clean gasket remains from mating surfaces. Discard gasket (8).
NOTE
Perform step 5 for front axle carrier differential top cover.
Remove ten screws (7), washers (6), top cover (4), and gasket (8) from carrier differential housing (9).
Discard gasket (8).

TM 9-2320-272-24-1

3-158. CARRIER DIFFERENTIAL TOP COVER GASKET AND SIDE COVER GASKET
REPLACEMENT (Contd)

REAR AXLE

FRONT AND REAR AXLE
3-435

TM 9-2320-272-24-1

3-158. CARRIER DIFFERENTIAL TOP COVER GASKET AND SIDE COVER GASKET
REPLACEMENT (Contd)
b. Top Cover Gasket Installation
1.

2.

3.
4.
5.
6.

Apply gasket sealant to mating surfaces of top cover (4).
NOTE
Perform step 2 for front axle carrier differential top cover,
Install new gasket (8) and top cover (4) on front axle carrier differential housing (9) with ten
washers (6) and screws (7). Tighten screws (7) 27-34 lb-ft (37-48 N.m).
NOTE
l
Perform steps 3 through 6 for forward-rear and rear-rear axle
carrier differential top cover,
l
Male pipe threads must be wrapped with antiseize tape prior to
installation.
Install new gasket (8) and top cover (4) on carrier differential housing (9) with eight washer (6) and
screws (7). Tighten screws (7) 27-34 lb-ft (37-48 N.m).
Install bracket (5) on carrier differential top cover (4) with two washers (6) and screws (7). Tighten
screws (7) 27-34 lb-ft (37-48 N.m)
Install two adapters (2) on manifolds (1).
Install four air lines (8) on adapters (2).

REAR AXLE

3-436

FRONT AND REAR AXLE

TM 9-2320-272-24-1

3-158. CARRIER DIFFERENTIAL TOP COVER GASKET AND SIDE COVER GASKET
REPLACEMENT (Contd)
c. Side Cover Gasket Removal
1.
2.

Remove eight screws (13), washers (12), and carrier differential housing cover (11) from differential
housing (9).
Remove gasket (10) from differential housing (9). Discard gasket (10). Clean gasket remains from
carrier differential housing cover (11) and differential housing (9).

d. Side Cover Gasket Installation
1.
2.

Apply gasket sealant to mating surface of side cover (11) and differential housing (9).
Install new side cover gasket (10) and side cover (11) on differential housing (9) with eight
washers (12) and screws (13). Tighten screws (13) 27-34 lb-ft (37-48) N.m).

3-437

TM 9-2320-272-24-1

3-159. FRONT AND REAR AXLE BREATHER REPLACEMENT
THIS TASK COVERS:
a. Removal

b.

Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)

a. Removal
Remove breather assembly (1) from axle housing (2).
b. Installation
Install breather (1) on axle housing (2).

3-438

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).

TM 9-2320-272-24-1

3-160. FRONT AXLE SEAL REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
SPECIAL TOOLS
Oil seal installer tool (Appendix E, Item 91)
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Front axle shaft and universal joint removed
(para. 3-154).

MATERIALS/PARTS
Oil seal (M939/A1) (Appendix D, Item 496)
Oil seal (M939A2) (Appendix D, Item 495)

Remove oil seal (1) from steering knuckle housing (2). Discard oil seal (1).
b. Installation
Using oil seal installer, install new oil seal (1) in steering knuckle housing (2).

FOLLOW-ON TASK: Install front axle shaft and universal joint (para. 3-154).
3-439

TM 9-2320-272-24-1

3-161. FRONT SPRING AND MAIN LEAF REPLACEMENT
THIS TASK COVERS:
a. Front Spring Removal
b. Front Spring Main Leaf Removal

c. Front Spring Main Leaf Installation
d. Front Spring Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Torque wrench (Appendix E, Item 145)
C-clamps
MATERIALS/PARTS
Cotter pin (Appendix D, Item 49)
Two locknuts (Appendix D, Item 285)
Four lockwashers (Appendix D, Item 362)
Spring center bolt (Appendix D, Item 670)
Spring center nut (Appendix D, Item 669)
Antiseize tape (Appendix C, Item 72)
Cap and plug set (Appendix D, Item 14)
Powdered graphite (Appendix C, Item 31)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Air reservoirs drained (TM 9-2320-272 10).
l Right splash shield removed (TM 9-2320-272-10).
l Shock absorber removed (para. 3-166).
l Front wheels removed (TM 9-2320-272-10).

a. Front Spring Removal

1.
2.
3.
4.
5.

6.
7.

8.

3-440

NOTE
Steps 1 through 5 apply to right side of spring only.
Bend tabs (4) of steering cylinder dustcover (3) clear of steering cylinder (7) and right side spring
hanger (1).
Remove cotter pin (6) from steering cylinder (7). Discard cotter pin (6).
Back out cylinder adjusting plug (5).
Remove steering cylinder (7) from ball stud (2).
Remove steering cylinder dustcover (3) from ball stud (2).
CAUTION
Cap or plug all openings immediately after disconnecting lines or
hoses to prevent contamination. Failure to do so may result in
brake system damage.
Disconnect two air lines (15) from service brake chamber (14).
Place jack stands under frame (17) at rear of hanger (10).
NOTE
Support axle when removing U-bolts.
Remove four nuts (13), lockwashers (12), and shock absorber mounting plate (11) from two
U-bolts (9). Discard lockwashers (12).
NOTE
l Frame may have to be raised further to provide clearance for
U-bolts removal.
l If U-bolts must be forced, place a piece of wood between
hammer and bolt to prevent damage.

TM 9-2320-272-24-1

3-161. FRONT SPRING AND MAIN LEAF REPLACEMENT (Contd)
9.

Remove two U-bolts (9) and upper spring seat (8) from springs (16).

3-441

TM 9-2320-272-24-1

3-161. FRONT SPRING AND MAIN LEAF REPLACEMENT (Contd)

10.
11.
12.
13.
14.

3-442

NOTE
The spring pins in right spring hanger and left spring shackle
must be driven out from the inside. The remaining two pins can be
driven out from either side.
Remove pin retaining locknut (10) and screw (7) from spring hanger (1). Discard locknut (10).
Drive pin (9) out of spring hanger (1) and leaf spring eye (8).
Remove pin retaining locknut (13) and screw (11) from spring shackle (2). Discard locknut (13).
Drive pin (14) out of spring shackle (2) and leaf spring eye (12).
Lift spring assembly (6) from lower spring seat (3) and carefully move over rear axle (5) and tie
rod (4) to the ground.

TM 9-2320-272-24-1

3-161. FRONT SPRING AND MAIN LEAF REPLACEMENT (Contd)

1.
2.
3.
4.

1.
2.
3.
4.
5.

Compress spring assembly (6) with C-clamps and remove six nuts (17), screws (20), and spacers (18)
from six clips (19).
Remove nut (16) and spring center bolt (21) from spring assembly (6). Discard bolt (21) and nut (16).
Remove C-clamps from spring assembly (6).
Remove rebound leaf (15) from spring assembly (6), upper main leaf (23), and lower main leaf (22)
from spring assembly (6). Separate upper main leaf (23) and lower main leaf (22).

Position upper main leaf (23) into lower main leaf (22) and position both on spring assembly (6).
Ensure rounded spring eye ends face upward.
Position rebound leaf (15) over upper main leaf (23).
Compress spring assembly (6) with C-clamps and align center bolt holes on spring assembly (6)
leaves.
Install new spring center bolt (21) and new nut (16) through center holes in leaves and peen end of
new bolt (21) over nut (16).
Install six spacers (18) between ends of spring leaf clips (19) with six screws (20) and nuts (17).

3-443

TM 9-2320-272-24-1

3-161. FRONT SPRING AND MAIN LEAF REPLACEMENT (Contd)

1.
2.
3.
4.
5.
6.
7.
8.

9.
10.

11.
12.
13.
14.
15.
16.

3-444

Raise one end of spring (11) over tie rod (4) and axle (8).
Edge spring (11) forward until spring center bolt (23) enters hole in center of lower spring seat (3).
Position upper spring seat (13) over top of spring (11).
Place two U-bolts (1) over upper spring seat (13) and through holes in lower spring seat (3), with
long end toward wheel.
Install two U-bolts (1) on shock absorber mounting plate (5) with four new lockwashers (6) and
nuts (7). Tighten nuts (7) 350-400 lb-ft (475-542 N•m).
Raise spring (11) to frame (12) until spring eyes (20) and (17) align with holes in hanger (16) and
shackle (2).
Install pin (18) through front spring eye (17) and hanger (16) with screw (16) and new locknut (14).
Groove in pin (18) must be in position to angle of screw holes before screw (16) can be installed,
Install pin (22) through spring eye (20) and shackle (2) with screw (19) and new locknut (21).
Groove in pin (22) must be in position to angle of screw holes before screw (19) can be installed.
NOTE
All male pipe threads must be wrapped with antiseize tape prior
to installation.
Connect two air lines (10) to service brake chamber (9).
Remove jack stands.
NOTE
Steps 11 through 16 apply to right side of spring only.
Install steering cylinder dustcover (26) on ball stud (25).
Position steering cylinder (30) over ball stud (25).
Tighten cylinder adjusting plug (28) until cylinder (30) does not move on ball stud (25).
Tighten cylinder adjusting plug (28) slightly more if necessary to align slot with hole in cylinder (30).
Install steering cylinder (30) on ball stud (25) with new cotter pin (29).
Bend tabs (27) of steering cylinder dustcover (26) around steering cylinder (30) and spring hanger (24).

TM 9-2320-272-24-1

3-161. FRONT SPRING AND MAIN LEAF REPLACEMENT (Contd)

FOLLOW-ON TASKS: Install shock absorber (para. 3-166).
Install front wheels (TM 9-2320-272-10).
Install right splash shield (TM 9-2320-272-10).
3-445

TM 9-2320-272-24-1

3-162. FRONT SPRING SHACKLE REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Two locknuts (Appendix D, Item 285)
Screw (Appendix D. Item 570)

1.
2.
3.
4.
5.
6.
7.
8.
9.

1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.

3-446

REFERENCES (TM)
LO 9-2320-272-12
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Front wheels removed (para. 3-220 or 3-221).

Raise vehicle to remove load from spring (12). Place jack stands under frame (16).
Remove locknut (1) and screw (3) from hanger (2). Discard locknut (1).
Remove locknut (6) from shackle (4). Discard locknut (6).
Loosen screw (7) in shackle (4).
Remove grease fitting (10) and lower shackle pin (9) from shackle (4) and spring eye (11). Pin (9)
must be pushed through toward underside of vehicle.
Remove grease fitting (15) and upper shackle pin (14) from shackle (4) and hanger (2). Pin (14) must
be pushed through to underside of vehicle.
Remove shackle (4) from hanger (2).
Remove screw (7) from hanger (2). Discard screw (7).
Remove bushing (5) from shackle (4).

Install bushing (5) in shackle (4).
Loosely thread new screw (7) on shackle (4).
Install shackle (4) on hanger (2).
Install shackle pin (14) in shackle (4) and hanger (2). Ensure pin slot (13) is positioned downward to
allow installation of screw (3).
Install grease fitting (15) in shackle pin (14).
Install screw (3) and new locknut (1) on shackle (4) and hanger (2).
Lower vehicle until spring eye (11) aligns with holes in shackle (4).
Install shackle pin (9) in shackle (4) and spring eye (11). Make sure pin slot (8) is positioned
downward to allow installation of screw (7).
Install grease fitting (10) on shackle pin (9) and hanger (2).
Tighten new screw (7) and install new locknut (6) on shackle (4).
Remove jack stands .

TM 9-2320-272-24-1

3-162. FRONT SPRING SHACKLE REPLACEMENT (Contd)

FOLLOW-ON TASKS:

Lubricate shackle (LO 9-2320-272-12).
Install front wheel (para. 3-220 or 3-221).
3-447

TM 9-2320-272-24-1

3-163. FRONT SPRING BUSHING MAINTENANCE
THIS TASK COVERS:
a. Inspection
b. Removal

c. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Locknut (Appendix D, Item 285)
Bushing (Appendix D, Item 22)
Pin (Appendix D, Item 514)

REFERENCES (TM)
LO 9-2320-272-12
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Front wheels removed (para. 3-220 or 3-221).

1.
2.

Insert prybar between spring hanger (1) and front spring shackle (3).
Press down on front spring shackle (3). If movement is evident between front spring shackle (3) and
pin (2), perform task b.

1.
2.
3.
4.
5.
6.

Raise frame (4) to remove load from spring (12) and support with jack stands.
Remove locknut (7) and screw (8) from shackle (5). Discard locknut (7).
Remove grease fitting (11) from pin (10).
Remove pin (10) from shackle (5) and spring eye (13). Discard pin (10).
Remove spring (12) from shackle (5).
Remove bushing (6) from shackle (5). Discard bushing (6).

1.
2.
3.

Install new bushing (6) on shackle (5).
Lower frame (4) until spring eye (13) is aligned with holes in shackle (5).
Install new pin (10) in shackle (5) and spring eye (13). Make sure pin slot (9) is positioned
downward to allow installation of screw (8).
Install grease fitting (11) in pin (10).
Install screw (8) and new locknut (7) in shackle (5).

4.
5.

3-448

TM 9-2320-272-24-1

3-163. FRONT SPRING BUSHING MAINTENANCE (Contd)

FOLLOW-ON TASKS:

Lubricate shackle (LO 9-2320-272-12).
Install front wheels (para. 3-220 or 3-221).
3-449

TM 9-2320-272-24-1

3-164. FRONT SPRING BUMPER REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).

MATERIALS/PARTS
Two locknuts (Appendix D, Item 280)

Remove two locknuts (1) and front spring bumper (2) from frame rail (3). Discard locknuts (1).

Install front spring bumper (2) on frame rail (3) with two new locknuts (1).

3-450

TM 9-2320-272-24-1

3-165. REAR SPRING BUMPER REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Two locknuts (Appendix D, Item 280)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).

Remove two locknuts (1) and bumper (2) from bumper bracket (3). Discard locknuts (1).

Install bumper (2) on bumper bracket (3) with two new locknuts (1).

3-451

TM 9-2320-272-24-1

3-166. SHOCK ABSORBER AND MOUNTING PINS REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Two locknuts (Appendix D, Item 286)
Two locknuts (Appendix D, Item 294)
Four rubber bushings (Appendix D, Item 564)

1.
2.
3.
4.

1.
2.
3.

3-452

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).

Remove two locknuts (1) and washers (2) from mounting pins (4). Discard locknuts (1).
Remove two rubber bushings (3), shock absorber (5), and two rubber bushings (3) from mounting
studs (4). Discard rubber bushings (3).
Remove two locknuts (8) and screws (6) from mounting brackets (7). Discard locknuts (8).
Spread two mounting brackets (7) and remove mounting pins (4).

NOTE
Ensure pin slots are positioned to allow installation of screw.
Install two mounting pins (4) on mounting brackets (7) with two screws (6) and new
locknuts (8).
Position four rubber bushings (3) and shock absorber (3) on two mounting pins (4).
Install four rubber bushings (3) and shock absorber (5) on two mounting pins (4) with washers (2)
and new locknuts (1). Tighten locknuts (1) until seated and rubber bushings (3) are compressed.

TM 9-2320-272-24-1

3-166. SHOCK ABSORBER AND MOUNTING PINS REPLACEMENT (Contd)

3-453

TM 9-2320-272-24-1

3-167. REAR SPRING REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Torque wrench (Appendix E, Item 145)
MATERIALS/PARTS
Eight lockwashers (Appendix D, Item 363)

1.

2.
3.

4.

5.

3-454

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Front wheels chocked (TM 9-2320-272-10).
Rear wheels removed (para. 3-220 or 3-221).

Raise vehicle and place two jack stands under cross tube (1), two jack stands under both forwardrear hubs (5), and two jack stands under both rear-rear hubs (10). Position tops of jack stands under
cross tube (1) four inches above tops of jack stands to relieve pressure on rear springs (3).
Loosen two bolt clamps (9) on spring seat (8).
Remove four nuts (6) and lockwashers (7) from two U-bolts (2). Discard lockwashers (7).
NOTE
Step 4 applies to all models except M936 wrecker.
Remove two U-bolts (2) and upper spring saddle (4) from rear springs (3). It may be necessary to
raise frame to remove U-bolts (2).
NOTE
Step 5 applies to M936 wrecker only
Remove two U-bolts (2) and stabilizer beam (11) from rear springs (3).

TM 9-2320-272-24-1

3-167. REAR SPRING REPLACEMENT (Contd)

3-455

TM 9-2320-272-24-1

3-167. REAR SPRING REPLACEMENT (Contd)
6.

7.
8.
9.
10.
11.

12.

13.

3-456

Remove two nuts (15), washers (14), U-bolt (5), and U-bolt bracket (8) from spring brake chamber (13).
NOTE
Assistant will help with steps 7 through 10.
Remove nut (9), lockwasher (10), washer (11), washer (2), screw (1), and spring brake chamber
bracket (12) from upper spring bracket and wearpad (4). Discard lockwasher (10).
Remove two nuts (7), lockwashers (6), and screws (3) from upper spring bracket and wearpad (4).
Discard lockwashers (6).
Remove two nuts (25), washers (24), U-bolt (18), and U-bolt bracket (19) from service brake
chamber (17).
Remove nut (20), lockwasher (21), two washers (22), screw (16), and service brake chamber
bracket (23) from upper spring bracket and wear pad (4). Discard lockwasher (21).
Remove upper spring bracket and wear pad (4) from axle housing (26).
NOTE
Assistants will help with steps 12 and 13.
Remove spring assembly (27) from spring seat (28).
NOTE
Step 13 applies to M936 wrecker only.
Remove spring assembly (29) from spring seat (28).

TM 9-2320-272-24-1

3-167. REAR SPRING REPLACEMENT (Contd)

3-457

TM 9-2320-272-24-1

3-167. REAR SPRING REPLACEMENT (Contd)

NOTE
Assistants will help with steps 1 and 2.
Step 1 applies to M936 wrecker only.
1. Position spring assembly (3) on spring seat (4).
2. Position spring assembly (1) on spring seat (2).
3. Slide upper spring bracket and wearpad (5) on main leaves (7) and position on axle housing (6) over
dowel pin (8).
4. Install service brake chamber bracket (15) on upper spring bracket and wearpad (5) with screw (9),
two washers (10), new lockwasher (14), and nut (13). Do not tighten nut (13).
5. Install U-bolt bracket (12) on service brake chamber bracket (15) with U-bolt (11), two washers (16),
and nuts (17). Tighten nuts (17) 120-160 lb-ft (163-217 N•m).
6. Install spring brake chamber bracket (27) on upper spring bracket and wearpad (5) with screw (18),
two washers (19), new lockwasher (26), and nut (25). Do not tighten nut (25).
7. Install U-bolt bracket (24) on spring brake chamber (28) with U-bolt (21), two washers (29), and
nuts (30). Tighten nuts (30) 120-160 lb-ft (163-217 N•m).
NOTE
Assistant will help with steps 8 and 9.
8. Install two screws (20), new lockwashers (22), and nuts (23) on upper spring bracket and
wearpad (5). Tighten nuts (13), (23), and (25) 280-360 lb-ft (380-488 N•m).
9 . Install upper spring saddle (32) on spring seat (2) with two U-bolts (31), four new lockwashers (34),
and nuts (33). Tighten nuts (33) 300-400 lb-ft (407-542 N•m).
NOTE
Step 10 applies to M936 wrecker only.
10. Install stabilizer beam (36) on spring seat (4) with two U-bolts (37), four new lockwashers (39), and
nuts (38). Tighten nuts (38) 300-400 lb-ft (407-542 N•m).
11. Tighten two bolt clamps (35) on rear spring seat (2) or (4).

3-458

TM 9-2320-272-24-1

3-167. REAR SPRING REPLACEMENT (Contd)

FOLLOW-ON TASKS:

Install rear wheels (para. 3-220 or 3-221).
Start engine and road test vehicle (TM 9-2320-272-10).
Check U-bolts for tightness after road test.
3-459

TM 9-2320-272-24-1

3-168. REAR AXLES SPRING SEAT WEAR PADS AND UPPER BRACKET MAINTENANCE
THIS TASK COVERS:
a. R e m o v a l
b. I n s p e c t i o n

c. I n s t a l l a t i o n

INITIAL SETUP:
APPLICABLE MODELS
All
Tools
General mechanic’s tool kit (Appendix E, Item 1)
Torque wrench (Appendix E, Item 145)
MATERIAL/PARTS
Four lockwashers (Appendix D, Item 363)

1.
2.
3.
4.
5.
6.
7.
8.
9.

3-460

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake ret (TM 9-2320-272-10)
Rear wheels removed (para. 3-220 or 3-221).

Using hydraulic jack, raise vehicle at rear-rear axle differential housing (14) and place jack stands
under wheel hubs (5).
Remove two nuts (16), washers (15), U-bolt (6), and U-bolt bracket (9) from spring brake chamber (13).
Remove nut (10), lockwasher (11), two washers (2), screw (1), and spring brake chamber bracket (12)
from upper spring bracket (4). Discard lockwasher (11).
Remove two nuts (26), washers (25), U-bolt (21), and U-bolt bracket (22) from service brake
chamber (20).
Remove nut (23), lockwasher (24), two washers (18), screw (17), and service brake chamber
bracket (19) from upper spring bracket (4). Discard lockwasher (24).
Remove two nuts (8), lockwashers (7), and screws (3) from upper spring bracket (4). Discard
lockwashers (7).
Place hydraulic jack under spring seat (31) and raise leaf spring assembly (32) until upper spring
bracket (4) is clear of axle housing (28) and dowel pin (30).
Slide upper spring bracket (4) from bottom leaf (29) and remove from leaf spring assembly (32).
Remove spring seat wearpad (27) from upper spring bracket (4).

TM 9-2320-272-24-1

3-168. REAR AXLES SPRING SEAT WEAR PADS AND UPPER BRACKET MAINTENANCE
(Contd)

3-461

TM 9-2320-272-24-1

3-168. REAR AXLES SPRING SEAT WEAR PADS AND UPPER BRACKET MAINTENANCE
(Contd)

1.
2.

Inspect spring seat wearpad (2) for cracks. Replace spring seat wearpad (2) if cracked.
Inspect upper spring bracket (1) for cracks. Replace upper spring bracket (1) if cracked.

1.
2.
3.

Install spring seat wearpad (2) in upper spring bracket (1).
Slide upper spring bracket (1) on bottom leaf (4) and install on axle housing (3) over dowel pin (5).
Lower hydraulic jack until leaf spring assembly (7) seats in upper spring bracket (1) and remove
hydraulic jack from spring seat (6).
Position spring brake chamber bracket (17) over upper spring bracket (1) and install with screw (8),
two washers (9), new lockwasher (16), and nut (15). Do not tighten nut (15).
Install service brake U-bolt bracket (14) between brake chamber (18) and brake chamber bracket (17)
with U-bolt (11), two washers (19), and nuts (20). Tighten nuts (20) 120-160 lb-ft (163-217 N•m).
Position service brake chamber bracket (23) over upper spring bracket (1) and install with
screw (21), two washers (22), new lockwasher (28), and nut (27). Do not tighten nut (27).
Install service brake U-bolt bracket (26) between service brake chamber (24) and brake chamber
bracket (23) with U-bolt (25), two washers (29), and nuts (30). Tighten nuts (30) 120-160 lb-ft
(163-217 N•m).
Install upper spring bracket (1) on spring brake chamber bracket (17) with two screws (10), new
lockwashers (12), and nuts (13). Tighten nuts (13) 280-360 lb-ft (380-488 N•m).
Tighten nuts (15) and (27) 280-360 lb-ft, (380-488 N•m).

4.
5.
6.
7.
8.
9.

3-462

TM 9-2320-272-24-1

3-168. REAR AXLES SPRING SEAT WEAR PADS AND UPPER BRACKET MAINTENANCE
(Contd)

FOLLOW-ON TASK: Install rear wheels (para. 3-220 or 3-221).
3-463

TM 9-2320-272-24-1

3-169. REAR SPRING SEAT MAINTENANCE
THIS TASK COVERS:
a. Removal
b. Cleaning and Inspection
c. Lubrication

d. Installation
e. Adjustment

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Torque wrench (Appendix E, Item 144)
Hook tester scale (Appendix E, Item 55)
MATERIALS/PARTS
Six lockwashers (Appendix D, Item 364)
Two felt washers (Appendix D, Item 111)
Seal assembly (Appendix D, Item 634)
Gasket (Appendix D, Item 161)
GAA grease (Appendix C, Item 28)
Lubricating oil (Appendix C, Item 50)
Drycleaning solvent (Appendix C, Item 71)

1.
2.
3.
4.
5.
6.

7.

REFERENCES (TM)
LO 9-2320-272-12
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Rear spring assembly removed (para. 3-167).
GENERAL SAFETY INSTRUCTIONS
Fire extinguisher will be kept nearby when
drycleaning solvent is used.
Drycleaning solvent is flammable and toxic. Do
not use near open flame.

Remove six screws (9) and lockwashers (8) from spring seat cap (10). Discard lockwashers (8).
Remove spring seat cap (10) and gasket (11) from spring seat (1). Discard gasket (11). Clean
gasket (11) remains from mating surfaces.
Remove locking nut (12) and key washer (13) from crosstube (2).
Remove bearing adjusting nut (14) and outer bearing (15) from crosstube (2).
Remove spring seat (1) from crosstube (2).
Remove wiper ring (3), washer (4), two felt washers (5), packing retainer (6), grease seal assembly (7),
and inner bearing (16) from spring seat (1). Discard felt washers (5) and grease seal assembly (7).
NOTE
Perform step 7 only when bearing races must be removed because of
cracked, pitted, or scored condition, or if bearings are to be installed.
Remove bearing races (17) and (18) from spring seat (1).

WARNING

1.
2.
3-464

Drycleaning solvent is flammable and toxic. Do not use near
open flame and always have a fire extinguisher nearby when
solvents are used. Use only in well-ventilated places, wear
protective clothing, and dispose of cleaning rags in approved
container. Failure to do this may result in injury or death to
personnel and/or damage to equipment.
Clean all parts in drycleaning solvent and allow to dry
Inspect all parts for cracks, pitting, or scoring. Replace parts as necessary if cracked, pitted, or
scored.

TM 9-2320-272-24-1

3-169. REAR SPRING SEAT MAINTENANCE (Contd)

3-465

TM 9-2320-272-24-1

3-169. REAR SPRING SEAT MAINTENANCE (Contd)

Pack grease on inside of spring seat (1) and repack inner bearings (4) and outer bearing (5) with GAA
grease (LO 9-2320-272-12).

1.

2.
3.
4.
5.
6.
7.

1.
2.

3.
4.
5.

3-466

NOTE
Perform step 1 if bearing races were removed.
Install bearing races (2) and (3) on spring seat (1).
NOTE
Soak felt washers with oil before installation.
Install wiper ring (7), washer (8), two new felt washers (9), and packing retainer (10) on
crosstube (6).
Install inner bearing (4) in spring seat (1)
Install new grease seal assembly (11) over inner bearing (4) side of spring seat (1).
Install spring seat (1) on crosstube (6).
Install outer bearing (5) in spring seat (1).
Install bearing adjusting nut (18) on crosstube (6).

Connect hook tester scale in bolt hole (19).
Tighten adjusting nut (18) and pull tester scale downward.
NOTE
Bearings are correctly adjusted when pull on scale required to
rotate seat is 25-33 lb (11-15 kg) This is equal to 15-20 lb-ft
(20-27 N•m) preload on bearings.
Note pull required to rotate spring seat (1) around crosstube (6).
Install key washer (17) and locking nut (16). Repeat steps 2 and 3 to ensure bearing adjustment
does not change. Tighten locking nut (16) 150-160 lb-ft (203-217 N•m).
Install new gasket (15) and spring seat cap (14) on spring seat (1) with six new lockwashers (12)
and screws (13). Tighten screw (13) 16-20 lb-ft (22-27 N•m).

TM 9-2320-272-24-1

3-169. REAR SPRING SEAT MAINTENANCE (Contd)

FOLLOW-ON TASK:

Install rear spring assembly (para 3-167).
Lubricate spring seat (LO 9-2320-272-12).
3-467

TM 9-2320-272-24-1

3-170. UPPER AND LOWER TORQUE ROD MAINTENANCE
THIS TASK COVERS:
a. Upper Torque Rod Removal
b. Lower Torque Rod Removal
c. Cleaning and Inspection
d. Disassembly

e.
f.
g.
h.

Assembly
Setting Preload for Upper Torque Rod
Upper Torque Rod Installation
Lower Torque Rod Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Torque wrench (Appendix E, Item 145)
Arbor press
Vise
MATERIALS/PARTS
Four cotter pins (Appendix D. Item 47)
Four slotted nuts (Appendix D), Item 658)
Eight lockwashers (Appendix D, Item 362)

EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Right rear spring assembly removed (for upper
torque rods only) (para. 3-167).
Two front-rear wheels removed (for lower torque
rods only) (para. 3-220 or 3-221).
GENERAL SAFETY INSTRUCTIONS
Eye shields must be worn when cleaning with a wire
brush.

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
TM 9-237

1.
2.
3.
4.
5.
6.
7.
8.
9.
10.

3-468

Remove four nuts (5), lockwashers (4), screws (3), and torque rod plate (6) from torque rod
bracket (1). Discard lockwashers (4).
Remove cotter pin (8) from upper torque rod (2) and spring seat bracket (9). Discard cotter pin (8).
Back off slotted nut (7) until even with ball shaft (10) and use slotted nut (7) as a striking surface.
Drive torque rod ball shaft (10) out of spring seat bracket (9).
Remove slotted nut (7) from ball shaft (10). Discard slotted nut (7).
Remove upper torque rod (2) with upper torque rod bracket (1) from spring seat bracket (9).
Place upper torque rod (2) and bracket (1) in vise.
Remove cotter pin (11) and back off slotted nut (13) until even with end of ball shaft (12). Discard
cotter pin (11).
Using nut (13) as striking surface, drive torque rod ball shaft (12) out of upper bracket (1).
Remove slotted nut (13) from ball shaft (12). Discard slotted nut (13).

TM 9-2320-272-24-1

3-170. UPPER AND LOWER TORQUE ROD MAINTENANCE (Contd)

3-469

TM 9-2320-272-24-1

3-170. UPPER AND LOWER TORQUE ROD MAINTENANCE (Contd)

1.
2.
3.
4.
5.
6.
7.
8.
9.
10.

Remove four nuts (8), lockwashers (9), screws (1), and upper spring bracket (14) from lower torque
rod bracket (10). Discard lockwashers (9).
Remove cotter pin (5) from lower torque rod (7) and slotted nut (4). Discard cotter pin (5).
Back off slotted nut (4) until even with end of torque rod ball shaft (6).
Using slotted nut (4) as striking surface, drive torque rod ball shaft (6) out of spring seat bracket (3).
Remove slotted nut (4) and lower torque rod (7) from spring seat bracket (3) and rear axle (2).
Discard slotted nut (4).
Place lower torque rod bracket (7) in vise.
Remove cotter pin (13) from lower torque rod (7) and slotted nut (12). Discard cotter pin (13).
Back off slotted nut (12) until even with end of torque rod ball shaft (11).
Using slotted nut (12) as striking surface, drive torque rod ball shaft (11) out of lower torque rod
bracket (10).
Remove slotted nut (12) from lower torque rod bracket (10). Discard slotted nut (12).

WARNING

1.
2.
3.
4.
5.

6.
7.
8.
9.

Eyeshields must be worn when cleaning with a wire brush. Flying
rust and metal particles may cause injury to personnel.
NOTE
Perform steps 1 through 8 for upper torque rod.
Clean rust from upper torque rod bracket (15) axle mating surface and dowel holes (16).
Inspect upper torque rod bracket (15) for breaks and cracks. Replace if broken or cracked.
Inspect upper torque rod plate (19) for breaks and cracks. Replace if broken or cracked.
Clean rear axle (2) and upper torque rod dowel (18) and upper spring bracket dowel (17).
Inspect upper torque rod dowel (18) and upper spring bracket dowel (17) for flat, broken, or out-ofround condition. Repeat if flat, broken, or out-of-round.
NOTE
Perform steps 6 and 7 only if dowels are to be replaced.
File weld securing upper torque rod bracket and upper spring bracket dowels (18) and (17) to rear
axle (2) and remove dowels (18) and (17).
Tap in new upper torque rod bracket dowel (18) and upper spring bracket dowel (17) in rear axle (2) and
spot-weld (TM 9-237). Dowel height must be 3/8 in. (9.53 mm).
Inspect upper and lower torque rods (7) around ball shafts (20) for breaks, cracks, and separation of
rubber from torque rods (2).
Clean and inspect lower torque rod bracket (10) for breaks and cracks. Replace if broken or cracked.

Using arbor press, remove two balls and bushings (20) from ends of torque rod (7).

3-470

TM 9-2320-272-24-1

3-170. UPPER AND LOWER TORQUE ROD MAINTENANCE (Contd)

3-471

TM 9-2320-272-24-1

3-170. UPPER AND LOWER TORQUE ROD MAINTENANCE (Contd)

NOTE
Ball and bushing must be pressed in on chamber side only.
Using arbor press, press balls and bushings (1) into torque rod (2) at chamber side (3).

1.

2.

3.
4.
5.

6.
7.
8.
9.

3-472

Position upper spring bracket (8) over upper spring bracket dowel (9).
NOTE
Perform step 2 for all models except M936/A1/A2 model vehicles.
Raise rear axle (10) until 6 in. (15.24 cm) is obtained between bottom of frame rail (7) and top of
spring bracket (8).
NOTE
Perform step 3 for M936/A1/A2 model vehicles only.
Raise rear axle (10) until 7-1/4 in. (18.4 cm) is obtained between bottom of frame rail (7) and top of
spring bracket (8).
Place ball shaft (4) on upper torque rod (5) in upper torque rod bracket (6) and install with new
slotted nut (12). Finger-tighten slotted nut (12).
Place upper torque rod (5) and upper torque rod bracket (6) over dowel (11) on rear axle (10) and
position torque rod ball shaft (4) in spring bracket (8).
NOTE
Ensure upper torque rod bracket is seated over dowel pin and ball
shaft is in spring seat bracket before alignment is made.
Scribe an alignment mark from upper torque rod bracket (6) to torque rod (5).
Remove upper torque rod (5) and upper torque rod bracket (6) from rear axle (10) and spring
bracket (8).
Place upper torque rod bracket (6) in vise with alignment marks aligned.
Tighten slotted nut (12) 350-400 lb-ft (475-542 N•m) and install new cotter pin (13).

TM 9-2320-272-24-1

3-170. UPPER AND LOWER TORQUE ROD MAINTENANCE (Contd)

3-473

TM 9-2320-272-24-1

3-170. UPPER AND LOWER TORQUE ROD MAINTENANCE (Contd)

1.

2.
3.

Place upper torque rod (4) and upper torque rod bracket (12) over inner dowel pin (11) on rear
axle (7) and torque rod ball shaft (5) in spring seat bracket (3).
CAUTION
Ensure upper bracket is seated over dowel pin before torque rod
plate is installed. If not, dowel pin will be damaged.
Install upper torque rod plate (10) and bracket (12) on axle (7) with four screws (6), new
lockwashers (8), and nuts (9). Tighten nuts (9) 280-360 lb-ft (380-488 N•m).
Install upper torque rod ball shaft (5) on spring seat bracket (3) with new slotted nut (1). Tighten
slotted nut (1) 350-400 lb-ft (475-542 N•m) and install new cotter pin (2).

CAUTION

1.
2.
3.
4.

3-474

Ensure 6 in. (15.24 cm) clearance remains between top of upper
spring bracket and bottom of frame rail for all vehicles except
M936/A1/A2 model vehicles. For the M936/A1/A2 model vehicles,
this clearance is 7-1/4 in. (18.4 cm). If clearance is not proper,
torque rods will be damaged.
Install lower torque rod (19) ball shaft (23) on lower torque rod bracket (20) with new slotted nut (24).
Install torque rod ball shaft (18) on spring seat bracket (15) with new slotted nut (16).
Tighten slotted nuts (16) and (24) to 350-400 lb-ft (475-542 N•m) and install new cotter pins (25)
and (17).
Install lower torque rod bracket (20) and upper spring bracket (26) on rear axle (14) with four
screws (13), new lockwashers (21), and nuts (22). Tighten nuts (22) 280-360 lb-ft (380-488 N•m). For
M936/A1/A2 model vehicles tighten nuts (22) 320-425 (434-576 N•m).

TM 9-2320-272-24-1

3-170. UPPER AND LOWER TORQUE ROD MAINTENANCE (Contd)

FOLLOW-ON TASKS:

If upper torque rod was replaced, install right rear spring assembly (para. 3-167).
If lower torque rod was replaced, install two front-rear tires (para. 3-220 or 3-221).
3-475

TM 9-2320-272-24-1

Section IX. COMPRESSED AIR AND BRAKE SYSTEM MAINTENANCE
3-171. COMPRESSED AIR AND BRAKE SYSTEM MAINTENANCE INDEX
PARA.
NO.
3-172.
3-173.
3-174.
3-175.
3-176.
3-177.
3-178.
3-179.
3-180.
3-181.
3-182.
3-183.
3-184.
3-185.
3-186.
3-187.
3-188.
3-189.
3-190.
3-191.
3-192.
3-193.
3-194.
3-195.
3-196.
3-197.
3-198.
3-199
3-200.
3-201.
3-202.
3-203.
3-204.
3-205.
3-206.
3-207.
3-208.
3-476

TITIE
Parking Brake Adjustment
Spring Brake Valve Maintenance
Parking Brake Lever and Switch Replacement
Parking Brake Cable and Bracket Replacement
Parking Brakeshoes Replacement
Parking Brakedrum Dustcover Replacement
Wheel Brakedrum Dustcovers Replacement
Brake Mechanism Checks and Adjustments (Front and Rear)
Brakeshoe Replacement
Service Brake Chamber Replacement
Combination Spring (Emergency) and Service Brake Chamber Replacement
Front Brake Spider Replacement
Rear Brake Spider Replacement
Wet Reservoir (Supply Tank) Safety Valve Replacement
Air Reservoir One-Way Check Valve Replacement
Front Relay Valve Replacement
Rear Relay Valve Replacement
Brake Chamber Air Manifold Tee Replacement
Front Limiting Valve Replacement
Washer Control Valve Replacement
Windshield Wiper Control Valve Replacement
Spring (Emergency) Brake Chamber Maintenance
Spring Parking Brake Valve Replacement
Spring Brake Dash Control Valve Replacement
Brake Pedal Maintenance
Brake Pedal (Treadle) Valve Replacement
Brake Pedal (Treadle) Valve (M936/A1/A2) Replacement
Brake Proportioning Valve Replacement
Wet Air Reservoir (Supply Tank) and Bracket Replacement
Wet Air Reservoir (Supply Tank) and Mounting Plate (M936/A1/A2) Replacement
Primary Air Reservoir (Supply Tank) Replacement
Secondary Air Reservoir (Supply Tank) Replacement
Emergency Spring Brake (Supply Tank) Air Reservoir Replacement
Air Reservoir Drainvalves Replacement
Air Compressor and Lines (M939A2) Replacement
Air Governor Maintenance
Air Couplings Replacement

PAGE
NO.
3-478
3-482
3-484
3-486
3-490
3-494
3-496
3-498
3-501
3-504
3-506
3-508
3-510
3-512
3-514
3-516
3-518
3-520
3-522
3-524
3-526
3-528
3-530
3-532
3-534
3-536
3-540
3-546
3-548
3-556
3-562
3-566
3-570
3-572
3-574
3-580
3-584

TM 9-2320-272-24-1

3-171. COMPRESSED AIR AND BRAKE SYSTEM MAINTENANCE INDEX (Contd)
PARA.
NO.
3-209.
3-210.
3-211.
3-212.
3-213.
3-214.
3-215.
3-216.

TITLE
Emergency and Trailer Coupling Hoses (M93l/A1/A2, M932/A1/A2) Replacement
Trailer Airbrake Hand Control Valve (M931/A1/A2, M932/A1/A2) Replacement
Alcohol Evaporator Replacement
Doublecheck Valve No. 1 Replacement
Doublecheck Valve No. 2 Replacement
Doublecheck Valve No. 2 (M93l/Al/A2, M932/Al/A2) Replacement
Doublecheck Valve No. 5 (M93l/A1/A2,M932/A1/A2) Replacement
Doublecheck Valve No. 3, No. 4, and Quick-Release Valve Replacement

PAGE
NO.
3-596
3-598
3-600
3-602
3-604
3-606
3-608
3-610

3-477

TM 9-2320-272-24-1

3-172. PARKING BRAKE ADJUSTMENT
THIS TASK COVERS:
a. Test
b. Minor Adjustment

c. Major Adjustment
d. Lever Arm Adjustment

INITIAL SETUP
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
REFERENCES (TM)
TM 9-2320-272-10

1.
2.
3.
4.

EQUIPMENT CONDITION
Wheels chocked (task c. only) (TM 9-2320-272-10).
Parking brake disengaged (TM 9-2320-272-10).
Transfer case shift lever in neutral
(TM 9-2320-272-10).
Transmission in neutral (TM 9-2320-272-10).
Transfer case-to-forward rear axle propeller shaft
removed (task c. only) (para. 3-150 or 3-151).

Start engine (TM 9-2320-272-10) and observe air pressure gauge (5) located inside vehicle cab until
air pressure builds to 90 psi (621 kPa).
Pull parking brake lever (3) up to engage.
Push in spring brake release control (6) on instrument panel (1) to release spring brakes.
Place transmission selector lever (4) in 1-5 (drive). If vehicle moves, perform task c.

Turn parking brake adjusting cap (2) clockwise to increase; counterclockwise to decrease braking action.

3-478

TM 9-2320-272-24-1

3-172. PARKING BRAKE ADJUSTMENT (Contd)

3-479

TM 9-2320-272-24-1

3-172. PARKING BRAKE ADJUSTMENT (Contd)

1.
2.

3.
4.
5.

1.
2.
3.
4.

3-480

Loosen adjusting nut (4) on parking brake cable (1) until parking brake lever (3) has free travel.
Push parking brake lever (3) clockwise with one hand while turning drum (2) clockwise with other
hand. If drum (2) turns freely when parking brake lever (3) is pushed clockwise, replace parking
brakeshoes (para. 3-176). If drum (2) stops, go to step 3.
NOTE
Assistant will help with step 3.
Pull parking brake lever inside vehicle cab up to engage (TM 9-2320-272-10).
Tighten adjusting nut (4) on parking brake cable (1) against parking brake lever (3) until drum (2)
does not move, then back off counterclockwise 1/2 turn.
Repeat step 1 until slight drag of brakeshoes against drum (2) is observed.

Position lever arm (7) horizontal to valve body (12).
Remove two locknuts (8), washers (9), mounting screws (5), and valve body (12) from bracket (6).
Discard locknuts (8).
Loosen setscrew (10), adjust valve lever (11), and tighten setscrew (10).
Install valve body (12) on bracket (6) with two mounting screws (5), washers (9), and new
lockwashers (8).

TM 9-2320-272-24-1

3-172. PARKING BRAKE ADJUSTMENT (Contd)

FOLLOW-ON TASKS:

Install transfer case-to-forward rear axle propeller shaft (para. 3-150 or 3-151).
Remove chocks and road test vehicle (TM 9-2320-272-10).
3-481

TM 9-2320-272-24-1

3-173. SPRING BRAKE VALVE MAINTENANCE
THIS TASK COVERS:
a. Removal
b. Adjustment

c. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Two locknuts (Appendix D, Item 283)
Gasket sealant (Appendix C, Item 30)

1.

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Wheels chocked (TM 9-2320-272-10).
Drain air reservoirs (TM 9-2320-272-10).
GENERAL SAFETY INSTRUCTIONS
Do not disconnect air lines before draining air
reservoirs.

Release parking brake lever (8) (TM 9-2320-272-10).
WARNING

2.
3.
4.

1.
2.

1.
2.

3-482

Do not disconnect air lines before draining air reservoirs. Small
parts under pressure may shoot out with high velocity, causing
injury to personnel.
NOTE
Tag air lines for installation.
Disconnect three air lines (4) from adapter assemblies (3), (6), and (5).
Remove adapter assemblies (3), (6), and (5) from valve body (1).
Remove two locknuts (9), washers (10), screws (2), and valve body (1) from parking brake
bracket (7). Discard locknuts (9).

Loosen setscrew (11) on valve lever (13) and position valve lever (13) parallel with valve body (1).
Tighten setscrew (11).
Position valve body (1) on parking brake bracket (7). Valve lever (13) must be parallel with cab floor.
If not, repeat step 1.

Install valve body (1) on parking brake bracket (7) with two screws (2), washers (10), and new
locknuts (9). Valve lever roller (12) must be aligned with parking brake lever (8).
Lift up parking brake lever (8). Ensure parking brake lever (8) contacts valve lever roller (12)
properly and release parking brake lever (8).

TM 9-2320-272-24-1

3-173. SPRING BRAKE VALVE MAINTENANCE (Contd)
CAUTION

3.
4.

Do not twist air lines. Twisted air lines will restrict air flow.
NOTE
Male pipe threads must be coated with gasket sealant before
installation.
Install adapter assemblies (6), (5), and (3) on valve body (1).
Connect three air lines (4) to adapter assemblies (3), (6), and (5).

FOLLOW-ON TASKS:

Start engine (TM 9-2320-272-10) and allow air pressure to build to normal
operating range. Check for air leaks at spring brake valve.
Set parking brake (TM 9-2320-272-10) and ensure spring brakes engage properly.
Remove chocks and road test vehicle (TM 9-2320-272-10)
3-483

TM 9-2320-272-24-1

3-174. PARKING BRAKE LEVER AND SWITCH REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Cotter pin (Appendix D, Item 46)
Four locknuts (Appendix D, Item 291)

1.
2.
3.
4.
5.
6.

7.
8.

1.
2.
3.
4.

3-484

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Wheels chocked (TM 9-2320-272-10).
Battery ground cable disconnected (para. 3-126).

Release parking brake lever (2) (TM 9-2320-272-101.
Turn adjusting cap (1) on parking brake lever (2) completely out.
Remove cotter pin (5), washer (6), and clevis pin (7) from cable clevis (14). Discard cotter pin (6).
Remove three locknuts (3), screws (9), spacer washer (10), and spring parking brake valve and
bracket (8) from parking brake housing (4) and brackets (13). Carefully set valve and bracket (8)
aside. Discard locknuts (3).
Remove parking brake housing (4) from parking brake brackets (13).
Disconnect wire (11) from wire (12) under vehicle cab.
NOTE
Assistant will help with step 7.
Remove locknut (18), wire (17), and screw (16) from cab floor (19). Discard locknut (18).
Remove parking brake switch (15) from brackets (13).

NOTE
Assistant will help with step 1.
Install wire (17) on cab floor (19) with screw (16) and new locknut (18).
Connect wire (11) to wire (12).
Install parking brake housing (4), spring parking brake valve and bracket (8), and parking brake
switch (16) on brackets (13) with three screws (9), spacer washer (10), and three new locknuts (3).
Install clevis pin (7) on cable clevis (14) with washer (6) and new cotter pin (5).

TM 9-2320-272-24-1

3-174. PARKING BRAKE LEVER AND SWITCH REPLACEMENT (Contd)

FOLLOW-ON TASKS:

Adjust parking brake (para. 3-172).
Connect battery ground cable (para. 3-126).
Remove chocks and road test vehicle (TM 9-2320-272-10).
3-485

TM 9-2320-272-24-1

3-175. PARKING BRAKE CABLE AND BRACKET REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Cotter pin (Appendix D, Item 46)
Eight locknuts (Appendix D, Item 291)
Four tiedown straps (Appendix D, Item 696)

1.

2.
3.
4.
5.
6.
7.
8.

3-486

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Wheels chocked (TM 9-2320-272-10).

Remove cotter pin (l), washer (2), clevis pin (3), and parking brake cable (6) from parking brake
lever (11). Discard cotter pin (1).
NOTE
Assistant will help with step 2.
Remove four locknuts (7), cable clamp bracket (5), four screws (10), and two parking lever
brackets (9) from cab floor (8). Discard locknuts (7).
Remove grommet (4) and parking brake cable (6) from cab floor (8).
Remove two locknuts (15), screws (13), cable clamp (12), and spacer (14) from cable clamp
bracket (5). Discard locknuts (15).
Remove four tiedown straps (18), screw (16), and two clamps (28) from parking brake cable (6).
Discard tiedown straps (18).
Remove two locknuts (22), screws (19), cable clamp (20), and spacer (21) from transfer case
bracket (26) and parking brake cable (6). Discard locknuts (22).
Remove nut (23) and parking brake cable (6) from brakedrum lever (24).
Remove two screws (25), washers (27), and transfer case bracket (26) from transfer case (17).

TM 9-2320-272-24-1

3-175. PARKING BRAKE CABLE AND BRACKET REPLACEMENT (Contd)

3-487

TM 9-2320-272-24-1

3-175. PARKING BRAKE CABLE AND BRACKET REPLACEMENT (Contd)

1.
2.
3.
4.
5.

6.
7.
8.
9.

3-488

Install transfer case bracket (13) on transfer case (2) with two washers (5) and screws (6).
Install threaded end of parking brake cable (4) on brakedrum lever (12) with nut (11).
Position spacer (9) between transfer case bracket (13) and clamp (8), and install parking brake
cable (4) on transfer case bracket (13) with spacer (9), clamp (8), two screws (7), and new locknuts (10).
Install parking brake cable (4) on cable clamp bracket (21) with clamp (26), spacer (27), two
screws (25), and new locknuts (28).
Install grommet (20) around cable (4) and in cab floor (23).
NOTE
Assistant will help with step 6.
Install cable clamp bracket (21) and two parking lever brackets (18) on cab floor (23) with four
screws (17) and new locknuts (22).
Install parking brake cable (4) on parking brake lever (24) with clevis pin (19), washer (16), and
new cotter pin (15).
Install four new tiedown straps (3) on parking brake cable (4).
Install two clamps (14) on transfer case (2) with screw (1).

TM 9-2320-272-24-1

3-175. PARKING BRAKE CABLE AND BRACKET REPLACEMENT (Contd)

FOLLOW-ON TASK: Adjust parking brake (para. 3-172).
3-489

TM 9-2320-272-24-1

3-176. PARKING BRAKESHOES REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP
APPLICABLE MODELS
All
SPECIAL TOOLS
Brake repair pliers (Appendix E, Item 20)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P

EQUIPMENT CONDITION
Wheels chocked (TM 9-2320-272-10).
TOOLS
Transfer case-to-forward rear axle propeller shaft.
General mechanic’s tool kit (Appendix E, Item 1)
removed (para. 3-150 or 3-151).
Torque wrench (Appendix E, Item 144)
NOTE
Parking brakeshoes should be replaced when parking brake lever
full travel is over 2.0 in. (5.1 cm).

1.
2.
3.
4.
5.
6.

3-490

Remove thrust nut (6) and washer (5) from transfer output shaft (1).
Remove parking brakedrum (3) and transfer output shaft flange (4) from transfer output shaft (1).
Remove transfer output shaft flange (4) from parking brakedrum (3).
Remove eight studs (2) from parking brakedrum (3).
Using brake repair pliers, remove two brakeshoe return springs (8) from parking brakeshoes (9).
Remove two parking brakeshoes (9) and actuating plate (10) from brakeshoe backing plate (7).

TM 9-2320-272-24-1

3-176. PARKING BRAKESHOES REPLACEMENT (Contd)

3-491

TM 9-2320-272-24-l

3-176. PARKING BRAKESHOES REPLACEMENT (Contd)

1.
2.
3.
4.

3-492

Install actuating plate (5) against brakeshoe backing plate (8) so retainer opening (6) fits over
retaining stud (1) of backing plate (8).
Install two brakeshoes (4) on backing plate shoe studs (7) with two shoe return springs (2). Ensure
springs (2) are attached to inside holes (3) of brakeshoes (4).
Install eight stude (10) on parking brakedrum (11).
Install parking brakedrum (11) and transfer output shaft flange (12) on transfer output shaft (9)
with washer (13) and thrust nut (14). Tighten thrust nut (14) 450-600 lb-ft (610-814

TM 9-2320-272-24-l

3-176. PARKING BRAKESHOES REPLACEMENT (Contd)

3-493

TM 9-2320-272-24-1

3-177. PARKING BRAKEDRUM DUSTCOVER REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Torque wrench (Appendix E, Item 145)
MATERlALS/PARTS
Locknut (Appendix D, Item 287)

1.
2.

1.
2.

3-494

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Wheels chocked (TM 9-2320-272-10).
Parking brakeshoes removed (para. 3-176).

Remove locknut (1), washer (2), brake lever (8), and brake lever cam (7) from parking brakedrum
dustcover (4). Discard locknut (1).
Remove four screws (6), backing plate (5), and parking brakedrum dustcover (4) from backing plate
companion flange (3).

Install parking brakedrum dustcover (4) and backing plate (5) on backing plate companion flange (3)
with four screws (6). Tighten screws (6) 180-230 lb-ft (244-312 N-m).
Install brake lever (8) on parking brakedrum dustcover (4) with brake lever cam (7), washer (2), and
new locknut (1).

TM 9-2320-272-24-1

3-177. PARKING BRAKEDRUM DUSTCOVER REPLACEMENT (Contd)

FOLLOW-ON TASK: Install parking brakeshoes (para. 3-176).
3-495

TM 9-2320-272-24-1

3-178. WHEEL BRAKEDRUM DUSTCOVERS REPLACEMENT
THIS TASK COVERS:
a. Front Wheel Dustcovers Removal
b. Rear Wheel Dustcovers Removal

c. Front Wheel Dustcovers Installation
d. Rear Wheel Dustcovers Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERlALS/PARTS
Eight lockwashers (Appendix D, Item 365)

1.
2.

1.
2.

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).

Left and right front brakedrum dustcovers are replaced basically
the same. This procedure covers left front and rear brakedrum
dustcovers.
Remove four screws (1), lockwashers (2), and dustcovers (3) and (5) from left front brake assembly (4).
Discard lockwashers (2).
Remove four rubber plugs (6) from dustcovers (3) and (5).

Remove four screws (12), lockwashers (10), and two dustcovers (7) from left rear brake assembly (11).
Discard lockwashers (10).
Remove six rubber plugs (8) and two plastic plugs (9) from two dustcovers (7).

1.
2.

Install four rubber plugs (6) on dustcovers (3) and (5).
Install dustcovers (3) and (5) on left front brake assembly (4) with four new lockwashers (2) and
screws (1).

1.
2.

Install six rubber plugs (8) and two plastic plugs (9) on two dustcovers (7).
Install two dustcovers (7) on left rear brake assembly (11) with four new lockwashers (10) and
screws (12).

3-496

TM 9-2320-272-24-1

3-178. WHEEL BRAKEDRUM DUSTCOVERS REPLACEMENT (Contd)

3-497

TM 9-2320-272-24-1

3-179. BRAKE MECHANISM CHECKS AND ADJUSTMENTS (FRONT AND REAR)
THIS TASK COVERS:
a. Brakeshoe Check and Adjustment
b. Checking Brakeshoe Wear

c. Mechanism Inspection

INITIAL SETUP:
APPLICABLE MODELS
All
SPECIAL TOOLS
Brakeshoe adjusting tool (Appendix E, Item 21)
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
PERSONNEL REQUIRED
TWO

1.
2.
3.
4.
5.

3-498

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Spring (emergency) brake caged (TM 9-2320-272-10)
Front hub and drum removed (task c. only)
(para. 3-223 or 3-460).
Rear hub and drum removed (task c. only)
(para. 3-224 or 3-461).

Remove two rubber inspection hole covers (1) from brakedrum dustcovers (4).
Check brakeshoe lining (7) to brakedrum (6) clearance through inspection hole (5). Clearance should
be 0.020-0.040 in. (0.508-1.016 mm).
Remove two rubber adjusting hole covers (2) from brakedrum dustcovers (4).
Using brakeshoe adjusting tool through adjusting holes (3), rotate star wheel (8) until proper
clearance is obtained.
Install two rubber inspection hole covers (1) and two rubber adjusting hole covers (2) on brakedrum
dustcovers (4).

TM 9-2320-272-24-1

3-179. BRAKE MECHANISM CHECKS AND ADJUSTMENTS (FRONT AND REAR) (Contd)

3-499

TM 9-2320-272-24-1

3-179. BRAKE MECHANISM CHECKS AND ADJUSTMENTS (FRONT AND REAR) (Contd)

1.
2.
3.

1.
2.
3.
4.

Remove two rubber inspection hole covers (1) from brakedrum dustcover (3).
Inspect chamfer (4) on brakeshoe lining (5) through inspection hole (2). If brakeshoe lining (5) is
worn to depth of chamfer (4), replace brakeshoes (8) (para. 3-180).
Install two rubber inspection hole covers (1) on brakedrum dustcover (3).

Inspect brakeshoe linings (5) for cracks, chips, and oil contamination. If cracked, chipped, or
contaminated, replace brakeshoes (8) (pare. 3-180).
Inspect plunger seals (10). Notify DS maintenance if rotted or tom.
Inspect shoe return springs (9) for stretching, bluing, cracks, and uneven coils. Replace return
springs (9) showing any of these defects.
Inspect brake chambers (6) for cracks and bends at point where chamber (6) enters plunger (7).
Replace chamber(s) (6) if cracked or bent.

FOLLOW-ON TASKS:

3-500

Install front hub and drum (task c. only) (para. 3-223 or 3-460).
Install rear hub and drum (task c. only) (para. 3-224 or 3-461).

TM 9-2320-272-24-l

3-180. BRAKESHOE REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INlTlAL SETUP:
APPLICABLE MODELS
All

PERSONNEL REQUIRED
TWO

SPECIAL TOOLS
Brake repair pliers (Appendix E, Item 20)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P

TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Brakeshoe and lining assembly kit
(Appendix D, Item 17)

1.
2.

EQUIPMENT CONDlTlON
Spring (emergency) brake caged (TM 9-2320-272-10).
Front hub and drum removed (task c. only)
(para. 3-223 or 3-460).
Rear hub and drum removed (task c. only)
(para. 3-224 or 3-461).

Using brake repair pliers, remove two return springs (3) from brakeshoes (1).
Remove two brakeshoes (1) from each anchor plunger (4), adjustable plunger (5), and brakeshoe
retaining clips (2).

3-501

TM 9-2320-272-24-1

3-l80. BRAKESHOE REPLACEMENT (Contd)

Ensure arrow stamped on shoe web points to anchor plunger.
Brakeshoe and lining assemblies must be replaced in sets on
both sides of axle with linings coded to the color and
manufacturer.
Bear brake mechanisms have one adjusting plunger in each
plunger housing. Front brake mechanisms have two adjusting
plungers in rear of plunger housing.
Position two brakeshoes (1) into each anchor plunger (4), adjustable plunger (5), and brakeshoe
retaining clips (2) and secure with two return springs (3).

3-502

TM 9-2320-272-24-1

3-180. BRAKESHOE REPLACEMENT (Contd)

FOLLOW-ON TASKS: Install front hub and drum (task c. only) (para. 3-223 or 3-460).
Install rear hub and drum (task c. only) (para. 3-224 or 3-461).
Check brakeshoe-to-drum clearance and adjust if necessary (para. 3-179).
3-503

TM 9-2320-272-24-1

3-181. SERVICE BRAKE CHAMBER REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Antiseize tape (Appendix C, Item 72)
REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P

EQUIPMENT CONDITlON
Parking brake set (TM 9-2320-272-10).
Air reservoirs drained (TM 9-2320-272-10).
Wheel brakedrum dustcovers removed
(para. 3-178).
GENERAL SAFETY INSTRUCTIONS
Do not disconnect air lines before draining air
reservoirs.

Do not disconnect air lines before draining air reservoirs. Small
parts under pressure may shoot out with high velocity, causing
injury to personnel.

1.
2.
3.
4.

5.
6.
7.

1.
2.

3-504

Tag all lines for installation.
Disconnect service brake control line (6) from brake adapter (7).
Remove brake adapter (7) from service brake chamber (3).
Disconnect vent line (5) from elbow (4).
Remove elbow (4) from service brake chamber (3).
Perform step 5 for rear service brake only.
Remove two nuts (9), washers (10), U-bolt (12), and clamp (11) from service brake chamber (3).
Loosen collet nut (2) and remove service brake chamber (3) from actuator housing (8). Record
position for installation.
Remove collet nut (2) from service brake chamber (3).

Wrap all male pipe threads with antiseize tape before installation.
Install collet nut (2) on brake chamber (3).
Ensuring collet nut (2) is loose, install brake chamber (3) over wedge assembly (1) and into actuator
housing (8), with brake chamber (3) positioned for air line connection. Thread collet nut (2) to
bottom of brake chamber (3) and tighten 3/16 in. (4.8 mm) or 1-1/2 teeth.

TM 9-2320-272-24-1

3-181. SERVICE BRAKE CHAMBER REPLACEMENT (Contd)

3.
4.
5.
6.
7.

Perform step 3 for rear service brake only.
Install U-bolt (12) and clamp (11) on brake chamber (3) with two washers (10) and nuts (9).
Install elbow (4) on brake chamber (3).
Connect vent line (5) to elbow (4).
Install brake adapter (7) on brake chamber (3).
Connect service brake control line (6) to adapter (7).

FOLLOW-ON TASK: Install wheel brakedrum dustcovers (para. 3-178).
3-505

TM 9-2320-272-24-1

3-182. COMBINATION SPRING (EMERGENCY) AND SERVICE BRAKE CHAMBER
REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Antiseize tape (Appendix C, Item 72)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Air reservoirs drained (TM 9-2320-272-10).
Spring (emergency) brake caged (TM 9-2320-272-10).
GENERAL SAFETY INSTRUCTIONS
Do not disconnect air lines before draining air
reservoirs.

Do not disconnect air lines before draining air reservoirs. Small
parts under pressure may shoot out with high velocity, causing
injury to personnel.

1.
2.
3.
4.

Tag lines for installation.
Disconnect two vent lines (4) from tee (5).
Disconnect supply line (1) from elbow (3).
Disconnect control line (2) from elbow (13).
Loosen collet nut (10) and remove two nuts (6), washers (7), U-bolt (11), and bracket (8) from
combination spring and service brake chamber (12).

5.

Ensure wedge assembly does not fall out of plunger housing.
Remove combination spring and service brake chamber (12) from plunger housing (9) and pull
straight away from plunger.

1.
2.
3.
4.
5.

3-506

Wrap all male pipe threads with antiseize tape before installation.
Ensuring collet nut (10) is loose, install combination spring and service brake chamber (12) in plunger
housing (9) until secure, with service brake chamber (12) positioned for air line connections. Thread
collet nut (10) to bottom of service brake chamber (12) and tighten 3/16 in. (4.8 mm) or 1-1/2 teeth.
Connect control line (2) to elbow (13).
Connect supply line (1) to elbow (3).
Connect two vent lines (4) to tee (5).
Install U-bolt (11) and bracket (8) on service brake chamber (12) with two washers (7) and nuts (6).

TM 9-2320-272-24-1

3-182. COMBINATION SPRING (EMERGENCY) AND SERVICE BRAKE CHAMBER
REPLACEMENT (Contd)

FOLLOW-ON TASKS:

Uncage spring brake chamber (TM 9-2320-272-10).
Start engine (TM 9-2320-272-10) and allow air pressure to build to normal
operating range. Check for air leaks at combination spring brake chamber. Road
test vehicle.
3-507

TM 9-2320-272-2-1

3-l83. FRONT BRAKE SPIDER REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS

General mechanic’s tool kit (Appendix E, Item 1)
Torque wrench (Appendix E, Item 144)
MATERIALS/PARTS
Two lockwashers (Appendix D, Item 365)
Gasket sealant (Appendix C, Item 30)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITON
Brakeshoes removed (para. 3-180).
Service brake chamber removed (para. 3-181).

1.
2.

Remove nine nuts (6), washers (6), brake spider slinger (4), and brake spider (2) from studs (12).
Remove two nuts (10), lockwashers (9), screws (7), and clips (8) from brake spider (2). Discard
lockwashers (9).

1.
2.

Install two clips (8) on brake spider (2) with two screws (7), new lockwashers (9), and nuts (10).
Apply gasket sealant to spindle (11) and brake spider (2) mating surfaces.
Failure to tighten nuts in proper sequence can crack brake spider.

3.

3-508

Tighten front brake spider after installing front wheel dustcovers.
Install brake spider (2) and brake spider slinger (4) on studs (12) with anchor plunger (3) at
1 o’clock position (left side) and anchor plunger (1) at 11 o’clock position (right side) with nine
washers (5) and nuts (6). Tighten nuts (6) 110-145 lb-ft (149-196 N•m) in sequence shown.

TM 9-2320-272-24-l

3-183. FRONT BRAKE SPIDER REPLACEMENT (Contd)

FOLLOW-ON TASKS:

Install service brake chamber (para. 3-181).
Install brakeshoes (para. 3-180).
Start engine (TM 9-2320-272-10) and allow air pressure to build to normal
operating range. Check brake system for proper operation. Road test vehicle.
3-509

TM 9-2320-272-24-1

3-184. REAR BRAKE SPIDER REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Torque wrench (Appendix E, Item 144)
MATERIAL/PARTS
Two lockwashers (Appendix D, Item 365)
Gasket sealant (Appendix C, Item 30)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDlTlON
Brakeshoes removed (para. 3-180).
Service brake chamber removed (para. 3-181).
Combination spring (emergency) and service brake
chamber removed (para. 3-182).

All rear brake spiders are replaced basically the same. This
procedure covers right forward-rear axle.
a. Removal
1.
2.
3.
4.

1.
2.

3.
4.

3-510

Remove eight nuts (l), washers (2), screws (5), and washers (2) from brake spider (4).
Remove two screws (3) and washers (2) from inner side of rear axle housing flange (11).
Remove brake spider (4) from axle housing assembly (10).
Remove two nuts (9), lockwashers (8), screws (6), and clips (7) from brake spider (4). Discard
lockwashers (8).

Failure to tighten nuts in proper sequence can crack brake spider.
Install two clips (7) on brake spider (4) with screws (6), new lockwashers (8), and nuts (9).
Apply gasket sealant on rear axle housing (10) and brake spider (4) mating surfaces.
Assistant will help with step 3.
Position threaded holes 3 and 4 of brake spider (4) on axle housing mating surface at 3 and 9 o’clock
positions, and install two washers (2) and screws (3) through back of flange (11) into threaded holes 3
and 4 of brake spider (4).
Install eight washers (2), screws (5), washers (2), and nuts (1) through brake spider (4) and
flange (11). Tighten nuts (1) 110-145 lb-ft (149-196 N•m) in sequence shown.

TM 9-2320-272-24-1

3-184. REAR BRAKE SPIDER REPLACEMENT (Contd)

FOLLOW-ON TASKS:

Install combination spring (emergency) and service brake chamber (para. 3-182).
Install service brake chamber (para. 3-181).
Install brakeshoes (para. 3-180).
Check and adjust brakes (para 3-179).
Start engine (TM 9-2320-272-10) and allow air pressure to build to normal
operating range. Check brake system for proper operation. Road test vehicle.
3-511

TM 9-2320-272-24-1

3-185. WET RESERVOIR (SUPPLY TANK) SAFETY VALVE REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERlALS/PARTS
Antiseize tape (Appendix C, Item 72)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDlTlON
Parking brake set (TM 9-2320-272-10).
Air reservoirs drained (TM 9-2320-272-10).
GENERAL SAFETY INSTRUCTIONS
Do not remove safety valve before draining air
reservoirs.

Do not remove safety valve before draining air reservoirs. Small
parts under pressure may shoot out with high velocity, causing
injury to personnel.

Remove safety valve (1) from bushing (2) at inlet side of reservoir (3).

Wrap male pipe threads with antiseize tape before installation.
Install safety valve (1) in bushing (2) at inlet side of reservoir (3).

3-512

TM 9-2320-272-24-l

3-185. WET RESERVOIR (SUPPLY TANK) SAFETY VALVE REPLACEMENT (Contd)

FOLLOW-ON TASK: Start engine (TM 9-2320-272-10) and allow air pressure to build to normal operating
range. Check for air leaks at safety valve. Road test vehicle.
3-513

TM 9-2320-272-24-1

3-186. AIR RESERVOIR ONE-WAY CHECK VALVE REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERlALS/PARTS
Antiseize tape (Appendix C, Item 72)

EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Air reservoirs drained (TM 9-2320-272-10).
GENERAL SAFETY INSTRUCTIONS
Do not disconnect air lines before draining air
reservoirs.

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P

Do not disconnect air lines before draining air reservoirs. Small
parts under pressure may shoot out with high velocity, causing
injury to personnel.

1.
2.
3.

There is a one-way check valve mounted at inlet side of each
reservoir. All three check valves are replaced basically the same.
This procedure covers the spring brake one-way check.
Disconnect air line (1) from check valve adapter (2).
Remove check valve adapter (2) from check valve (3).
Remove check valve (3) from tee (4).

1.
2.
3.

Wrap all male pipe threads with antiseize tape before installation.
Install check valve (3) on tee (4).
Install check valve adapter (2) on check valve (3).
Connect air line (1) to check valve adapter (2).

3-514

TM 9-2320-272-24-1

3-186. AIR RESERVOIR ONE-WAY CHECK VALVE REPLACEMENT (Contd)

FOLLOW-ON TASK: Start engine (TM 9-2320-272-10) and allow air pressure to build to normal operating
range. Check for air leaks at check valve. Road test vehicle.
3-515

TM 9-2320-272-24-1

3-187. FRONT RELAY VALVE REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INlTlAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Two locknuts (Appendix D, Item 291)
Antiseize tape (Appendix C, Item 72)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Air reservoirs drained (TM 9-2320-272-10).
GENERAL SAFETY INSTRUCTIONS
Do not disconnect air lines before draining air
reservoirs.

Do not disconnect air lines before draining air reservoirs. Small
parts under pressure may shoot out with high velocity, causing
injury to personnel.

1.
2.
3.
4.
5.
6.

Tag lines and fittings for installation.
Scribe fitting directions for installation.
Disconnect vent lines (4), (9), and (11) from elbow (3) and tee (10).
Disconnect delivery lines (8) and (14) from elbows (7) and (13).
Disconnect control line (12) from elbow (6).
Disconnect supply line (16) from adapter (17).
Remove two locknuts (18), screws (15), and front relay valve (2) from bracket (1). Discard locknuts (18).
Remove elbows (3), (6), (7), and (13), tee (10), and adapters (6) and (17) from front relay valve (2).

1.
2.
3.
4.
6.
6.

Use fittings from old valve.
Wrap all male pipe threads with antiseize tape before
installation.
Install elbows (3), (6), (7), and (13), tee (10), and adapters (6) and (17) on front relay valve (2).
Install front relay valve (2) on bracket (1) with two screws (15) and new locknuts (18).
Connect supply line (16) to adapter (17).
Connect control line (12) to elbow (6).
Connect delivery lines (8) and (14) to elbows (7) and (13).
Connect vent lines (4), (9), and (11) to elbow (3) and tee (10).

3-516

TM 9-2320-272-24-1

3-187. FRONT RELAY VALVE REPLACEMENT (Contd)

FOLLOW-ON TASK: Start engine (TM 9-2320-272-10) and allow air pressure to build to normal operating
range. Check for air leaks at front relay valve. Road test vehicle.
3-517

TM 9-2320-272-24-l

3-188. REAR RELAY VALVE REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Two locknuts (Appendix D, Item 291)
Antiseize tape (Appendix C, Item 72)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Air reservoirs drained (TM 9-2320-272-10).
GENERAL SAFETY INSTRUCTIONS
Do not disconnect air lines before draining air
reservoirs.

Do not disconnect air lines before draining air reservoirs. Small
parts under pressure may shoot out with high velocity, causing
injury to personnel.

1.
2.
3.
4.
5.
6.

Tag lines and fittings for installation.
Scribe fitting directions for installation.
Disconnect vent lines (3) and (11) from elbows (2) and (12).
Disconnect delivery lines (8) and (15) from elbows (7).
Disconnect supply line (6) from adapter (5).
Disconnect control line (13) from elbow (10).
Remove two locknuts (17), screws (16), and rear relay valve (4) from bracket (1). Discard locknuts (17).
Remove elbows (2), (7), (10), and (12), and adapters (5), (9), and (14) from rear relay valve (4).

1.
2.
3.
4.
5.
6.

Use fittings from old valve.
Wrap all male pipe threads with antiseize tape before
installation.
Install elbows (2), (7), (10), and (12), and adapters (5), (9), and (14) on rear relay valve (4).
Install front relay valve (4) on bracket (1) with two screws (16) and new locknuts (17).
Connect supply line (6) to adapter (5).
Connect control line (13) to elbow (10).
Connect delivery lines (8) and (15) to elbows (7).
Connect vent lines (3) and (11) to elbows (2) and (12).

3-518

TM 9-2320-272-24-1

3-188. REAR RELAY VALVE REPLACEMENT (Contd)

FOLLOW-ON TASK: Start engine (TM 9-2320-272-10) and allow air pressure to build to normal operating
range. Check for air leaks at rear relay valve. Road test vehicle.
3-519

TM 9-2320-272-24-1

3-189. BRAKE CHAMBER AIR MANIFOLD TEE REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIAL/PARTS
Lockwasher (Appendix D, Item 354)
Antiseize tape (Appendix C, Item 72)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Air reservoirs drained (TM 9-2320-272-10).
GENERAL SAFETY INSTRUCTIONS
Do not disconnect air lines before draining air
reservoirs.

Do not disconnect air lines before draining air reservoirs. Small
parts under pressure may shoot out with high velocity, causing
injury to personnel.

1.
2.
3.
4.

1.
2.
3.
4.

3-520

All air manifold tees are replaced basically the same. This
procedure covers the rear primary relay tee. Notice that only
the two primary relay tees use a 45-degree elbow in addition to
a 90-degree elbow.
Tag air lines for installation.
Scribe fitting directions for installation.
Disconnect right service brake chamber air line (10) from elbow (9).
Disconnect relay valve line (1) from adapter (2).
Disconnect left service brake chamber air line (4) from adapter (3).
Remove screw (6), lockwasher (7), and air manifold tee (8) from mounting bracket (5). Discard
lockwasher (7).

If new tee is being installed, use fittings from old tee.
Wrap all male pipe threads with antiseize tape before
installation.
Install air manifold tee (8) on mounting bracket (5) with new lockwasher (7) and screw (6).
Connect left service brake chamber air line (4) to adapter (3).
Connect relay valve line (1) to adapter (2).
Connect right service brake chamber air line (10) to elbow (9).

TM 9-2320-272-24-l

3-189. BRAKE CHAMBER AIR MANIFOLD TEE REPLACEMENT (Contd)

FOLLOW-ON TASK: Start engine (TM 9-2320-272-10) and allow air pressure to build to normal operating
range. Check for air leaks at tee. Road test vehicle.
3-521

TM 9-2320-272-24-l

3-190. FRONT LIMITING VALVE REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Two locknuts (Appendix D, Item 299)
Antiseize tape (Appendix C, Item 72)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Air reservoirs drained (TM 9-2320-272-10).
GENERAL SAFETY INSTRUCTIONS
Do not disconnect air lines before draining air
reservoirs.

Do not disconnect air lines before draining air reservoirs. Small
parts under pressure may shoot out with high velocity, causing
injury to personnel.

Tag air lines for installation.
Scribe fitting directions for installation.
1.
2.
3.
4.
5.

Disconnect two front service brake control lines (4) from tee (6).
Disconnect doublecheck valve No. 1 control line (1) from adapter (2).
Disconnect vent line (11) from elbow (6).
Remove two locknuts (9), screws (7), and limiting valve (10) from mounting bracket (8). Discard
locknuts (9).
Remove tee (5), elbow (6), and adapters (2) and (3) from limiting valve (10).

1.
2.
3.
4.
5.

Wrap all male pipe threads with antiseize tape before installation.
Install adapters (3) and (2), tee (5), and elbow (6) on limiting valve (10).
Install limiting valve (10) on mounting bracket (8) with two screws (7) and new locknuts (9).
Connect vent line (11) to elbow (6).
Connect doublecheck valve No. 1 control line (1) to adapter (2).
Connect two front service brake control lines (4) to tee (5).

3-522

TM 9-2320-272-24-1

3-190. FRONT LIMITING VALVE REPLACEMENT (Contd)

FOLLOW-ON TASK: Start engine (TM 9-2320-272-10) and allow air pressure to build to normal operating
range. Check for air leaks at front limiting valve. Road test vehicle.
3-523

TM 9-2320-272-24-1

3-191. WASHER CONTROL VALVE REPLACEMENT
THIS TASK COVERS
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS

REFERENCES (TM)

All

TM 9-2320-272-10
TM 9-2320-272-24P

TOOLS

General mechanic"s tool kit (Appendix E, Item 1)
MATERIALS/PARTS

Antiseize tape (Appendix C, Item 72)

EQUIPMENT CONDITION

Air reservoirs drained (TM 9-2320-272-10),
GENERAL SAFETY INSTRUCTIONS

Do not dirconnect air liner before draining air
reservoirs.

Do not disconnect air lines before draining air reservoirs. Small
parts under pressure may shoot out with high velocity, causing
injury to personnel.

1.
2.
3.
4.

1.
2.

3.
4.

3-524

Remove
Remove
Remove
Remove

Install
Install
Install
Install

setscrew (6) and knob (7) from shaft (10).
retaining ring (8), nut (5), washer (4), and washer control valve (3) from instrument panel (9).
clamp (11) and washer bottle delivery line (12) from washer control valve (3).
manifold tee supply line (1) from elbow (2).

If new valve is being installed, use fittings from old valve.
Wrap all male pipe threads with antiseize tape before
installation.
manifold tee supply line (1) on elbow (2).
delivery line (12) on washer control valve (3) with clamp (11).
washer control valve (3) on instrument panel (9) with washer (4) and nut (5).
retaining ring (8) and knob (7) on shaft (10) with setscrew (6).

TM 9-2320-272-24-1

3-191. WASHER CONTROL VALVE REPLACEMENT (Contd)

FOLLOW-ON TASK: Start engine (TM 9-2320-272-10) and check for leaks and proper washer control valve
operation.
3-525

TM 9-2320-272-24-1

3-192. WINDSHIELD WIPER CONTROL VALVE REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P

TOOLS
General mechanic’s tool kit (Appendix E, Item 1) EQUIPMENT CONDITION
Parking b rake set (TM 9-2320-272-10).
MATERIALS/PARTS
Air reservoirs drained (TM 9-2320-272-10).
Lockwasher (Appendix D, Item 370)
GENERAL SAFETY INSTRUCTIONS
Antiseize tape (Appendix C, Item 72)
Do not disconnect air lines before draining air
reservoirs.

Do not disconnect air lines before draining air reservoirs. Small
parts under pressure may shoot out with high velocity, causing
injury to personnel.

3.
4.
5.
6.

Tag air lines for installation.
Remove setscrew (6) and remove knob (5) from shaft (4).
Remove nut (7), lockwasher (8), and control valve (10) from instrument panel (9). Discard
lockwasher (8).
Remove clamp (2) and disconnect wiper motor run delivery line (1) from adapter (3).
Disconnect manifold tee supply line (14) from adapter (15).
Remove clamp (12) and disconnect motor park delivery line (13) from adapter (11).
Remove adapters (3), (15), and (11) from control valve (10).

1.
2.
3.
4.
5.
6.

If new wiper control valve is being installed, use fittings from
old valve.
Clean all male pipe threads and wrap with antiseize tape before
installation.
Install adapters (3), (15), and (11) on control valve (10).
Connect motor park delivery line (13) to adapter (11) with clamp (12).
Connect manifold tee supply line (14) to adapter (15).
Connect wiper motor run delivery line (1) to adapter (3) with clamp (2).
Install control valve (10) on instrument panel (9) with new lockwasher (8) and nut (7).
Install knob (5) on shaft (4) with setscrew (6).

1.
2.

3-526

TM 9-2320-272-24-1

3-192. WINDSHIELD WIPER CONTROL VALVE REPLACEMENT (Contd)

FOLLOW-ON TASK: Start engine (TM 9-2320-272-10) and allow air pressure to build to normal operating
range. Check for air leaks at wiper control valve.
3-527

TM 9-2320-272-24-1

3-193. SPRING (EMERGENCY) BRAKE CHAMBER MAINTENANCE
THIS TASK COVERS:
a. Disassembly
b. Inspection

c. Assembly

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Torque wrench (Appendix E, Item 146)
REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P

EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10)
Air reservoirs drained (TM 9-2320-272-10).
GENERAL SAFETY INSTRUCTIONS
Do not disconnect air lines before draining air
reservoirs.

Do not disconnect air lines before draining air reservoirs. Small
parts under pressure may shoot out with high velocity, causing
injury to personnel.

1.
2.
3.
4.

Remove
Remove
Remove
Remove

tube (1) from elbow (2).
tube (10) from elbow (9).
nut (7), screw (6), clamp (3), and housing assembly (8) from nonpressure housing (5).
elbows (2) and (9) from housing assembly (8).

Inspect spring brake chamber diaphragm (4). Replace if cracked, torn, or split.

1.
2.
3.
4.

3-528

Install elbows (2) and (9) on housing assembly (8).
Install housing assembly (8) on nonpressure housing (5) with clamp (3), screw (6), and nut (7).
Tighten nut (7) 18-25 lb-ft (24-34 N•m).
Install tube (10) on elbow (9).
Install tube (1) on elbow (2).

TM 9-2320-272-24-1

3-193. SPRING (EMERGENCY) BRAKE CHAMBER MAINTENANCE (Contd)

FOLLOW-ON TASK: Start engine (TM 9-2320-272-10) and allow air pressure to build to normal operating
range. Check for air leaks at spring brake chamber. Road test vehicle.
3-529

TM 9-2320-272-24-1

3-194. SPRING PARKING BRAKE VALVE REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INlTIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Antiseize tape (Appendix C, Item 72)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Air reservoirs drained (TM 9-2320-272-10).
GENERAL SAFETY lNSTRUCTlONS
Do not disconnect air lines before draining air
reservoirs.

Do not disconnect air lines before draining air reservoirs. Small
parts under pressure may shoot out with high velocity, causing
injury to personnel.

Use care to prevent excessive twisting when removing air lines.

1.
2.
3.
4.

Tag air lines and fittings for installation.
Disconnect transfer case vent line (6) from adapter (3).
Disconnect reservoir supply line (5) from adapter (4).
Disconnect doublecheck control line (7) from elbow (8).
Remove two screws (2) and valve (1) from mounting bracket (9).

1.
2.
3.
4.

If new spring parking brake valve is being installed, use fittings
from old valve.
Wrap all male pipe threads with antiseize tape before
installation.
Install valve (1) on mounting bracket (9) with two screws (2).
Connect doublecheck control line (7) to elbow (8).
Connect reservoir supply line (5) to adapter (4).
Connect transfer case vent line (6) to adapter (3).

3-530

TM 9-2320-272-24-1

3-194. SPRING PARKING BRAKE VALVE REPLACEMENT (Contd)

FOLLOW-ON TASK: Start engine (TM 9-2320-272-10) and allow air pressure to build to normal operating
range. Ensure spring brake chamber releases spring when parking brake is applied.
Road test vehicle.
3-531

TM 9-2320-272-24-l

3-l95. SPRING BRAKE DASH CONTROL VALVE REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Toque wrench (Appendix E, Item 146)
MATERIALS/PARTS
Antiseize tape (Appendix C, Item 72)

EQUIPMENT CONDlTlON
Parking brake set (TM 9-2320-272-10).
Spring brake pressure switch removed
(para. 3-100).
GENERAL SAFETY INSTRUCTIONS
Do not disconnect air lines before draining air
reservoirs.

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P

Do not disconnect air lines before draining air reservoirs. Small
parts under pressure may shoot out with high velocity, causing
injury to personnel.

1.
2.
3.
4.
6.

1.
2.
3.
4.
6.

3-532

Tag air lines for installation,
Disconnect doublecheck valve air line (5) from elbow (4).
Disconnect air line (3) from elbow (2).
Remove pin (7) and valve knob (9) from dash control valve assembly (6).
Remove nut (8) and dash control valve assembly (6) from instrument cluster (1).
Remove elbows (2) and (4) from dash control valve assembly (6).

Wrap all male pipe threads with aniseize tape before installation,
Install elbows (2) and (4) on dash control valve assembly (6).
Install dash control valve assembly (6) on instrument cluster (1) with nut (8). Tighten nut (8)
150-300 lb-in. (17-34 N•m).
Install valve knob (9) on dash control valve assembly (6) with pin (7).
Connect air line (3) to elbow (2).
Connect doublecheck valve air line (5) to elbow (4).

TM 9-2320-272-24-1

3-195. SPRING BRAKE DASH CONTROL VALVE REPLACEMENT (Contd)

FOLLOW-ON TASKS: Install spring brake pressure switch (para. 3-100).
Start engine (TM 9-2320-272-10) and allow air pressure to build to normal
operating range. Check for air leaks at dash control valve. Check valve for proper
operation. Road test vehicle.
3-533

TM 9-2320-272-24-1

3-196. BRAKE PEDAL MAINTENANCE
THIS TASK COVERS:
a. Removal
b. Installation

c. Adjustment

INITIAL SETUP:
APPLICABLE MODELS
All

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P

TOOLS
General mechanic’s tool kit (Appendix E, Item 1) EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
MATERlALS/PARTS
Two cotter pins (Appendix D, Item 48)

1.
2.
3.
4.
5.

Remove return spring (5) from brake pedal (9) and cab (2).
Remove cotter pin (11), fulcrum pin (13), and brake pedal (9) from brake pedal valve (1). Discard
cotter pin (11).
Remove jamnut (3) and pedal stop (4) from brake pedal valve (1).
Remove cotter pin (7), roller pin (10), and two rollers (6) from brake pedal (9). Discard cotter pin (7).
Remove rubber pad (8) from brake pedal (9).

1.
2.
3.
4.
5.

Install
Install
Install
Install
Install

rubber pad (8) on brake pedal (9).
two rollers (6) on brake pedal (9) with roller pin (10) and cotter pin (7).
pedal stop (4) on brake pedal valve (1) with jamnut (3). Do not tighten jamnut (3).
brake pedal (9) on brake pedal valve (1) with fulcrum pin (13) and cotter pin (11).
return spring (5) on brake pedal (9) and cab (2).

Use hand pressure to depress brake pedal (9) only until rollers (6) contact plunger (12), and position
pedal stop (4) against brake pedal (9). Tighten jamnut (3).

3-534

TM 9-2320-272-24-l

3-196. BRAKE PEDAL MAINTENANCE (Contd)

FOLLOW-ON TASK: Road test vehicle (TM 9-2320-272-10).
3-535

TM 9-2320-272-24-1

3-197. BRAKE PEDAL (TREADLE) VALVE REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All except M936/A1/A2

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P

TOOLS
General mechanic’s tool kit (Appendix E, Item 1) EQUIPMENT CONDITION
Air reservoirs drained (TM 9-2320-272-10).
MATERIALS/PARTS
Brake pedal removed (para. 3-196).
Three locknuts (Appendix D, Item 288)
Protective control box removed (para. 3-115).
Antiseize tape (Appendix D, Item 72)
GENERAL SAFETY INSTRUCTIONS
Do not disconnect air lines before draining air
reservoirs.

Do not disconnect air lines before draining air reservoirs. Small
parts under pressure may shoot out with high velocity, causing
injury to personnel.

1.
2.
3.
4.
5.
6.

3-536

Tag air lines for installation.
Disconnect two air lines (2) from brake pedal valve adapters (1).
Disconnect air hoses (4) and (8) from adapters (7) and (9).
Remove adapters (7) and (9) from tee (10).
Disconnect air hose (6) from adapter (5).
Remove adapter (5) from firewall (3).
Remove tee (10) and pipe (11) from firewall (3).

TM 9-2320-272-24-l

3-197. BRAKE PEDAL (TREADLE) VALVE REPLACEMENT (Contd)

3-537

TM 9-2320-272-24-l

3-197. BRAKE PEDAL (TREADLE) VALVE REPLACEMENT (Contd)
7.
8.
9.
10.
11.
12.

Remove
Remove
Remove
Remove
Remove
Remove

1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.

If new brake pedal valve is being installed, use attaching parts
and fittings from old brake pedal valve.
Fittings must be cleaned and inspected for cracks and stripped
threads.
Wrap all male pipe threads with antiseize tape before
installation.
Install pressure relief valve (11) in brake pedal valve (9).
Install two brake pedal valve adapters (12) in brake pedal valve (9).
Install three studs (10) in brake pedal valve (9).
Install brake pedal valve (9) on firewall (8) with three new locknuts (1).
Install adapters (2), (5), and (7) on firewall (8).
Install air hoses (3), (4), and (6) on adapters (2), (5), and (7).
Install pipe (20) and tee (19) on firewall (8).
Install adapter (15) on firewall (8).
Connect air hose (16) to adapter (15).
Install adapters (14) and (18) on tee (19).
Connect air hoses (13) and (17) to adapters (14) and (18).
Connect two air lines (21) to brake pedal valve adapters (22).

3-538

air hoses (3), (4), and (6) from adapters (2), (5), and (7).
adapters (2), (5), and (7) from firewall (8).
three locknuts (1) and brake pedal valve (9) from firewall (8). Discard locknuts (1).
three studs (10) from brake pedal valve (9).
two brake pedal valve adapters (12) from brake pedal valve (9).
pressure relief valve (11) from brake pedal valve (9).

TM 9-2320-272-24-1

3-l97. BRAKE PEDAL (TREADLE) VALVE REPLACEMENT (Contd)

FOLLOW-ON TASKS:

Install protective control box (para. 3-115).
Install brake pedal (para. 3-196).
Start engine (TM 9-2320-272-10) and allow air pressure to build to normal
operating range. Check for air leaks and proper brake operation. Road test
vehicle.
3-539

TM 9-2320-272-24-l

3-l98. BRAKE PEDAL (TREADLE) VALVE (M936/A1/A2) REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
M986/A1/A2
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Three locknuts (Appendix D, Item 288)
Antiseize tape (Appendix C, Item 72)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDlTlON
Parking brake set (TM 9-2320-272-10).
Air reservoirs drained (TM 9-2320-272-10).
Brake pedal removed (para. 3-196).
Protective control box removed (para. 3-115).
GENERAL SAFETY INSTRUCTIONS
Do not disconnect air lines before draining air
reservoirs.

Do not disconnect air lines before draining air reservoirs. Small.
parts under pressure may shoot out with high velocity, causing
injury to personnel.

1.
2.
3.
4.
5.
6.

3-540

Disconnect two air lines (2) from brake pedal valve adapters (1).
Disconnect air hoses (4) and (10) from adapters (7) and (9).
Remove adapters (7) and (9) from tee (8).
Remove air hose (6) and adapter (6) from firewall (3).
Remove tee (8) and pipe (13) from firewall (3).

Remove air hose (11) and adapter (12) from firewall (3).

TM 9-2320-272-24-1

3-198. BRAKE PEDAL (TREADLE) VALVE (M936/A1/A2) REPLACEMENT (Contd)

3-541

TM 9-2320-272-24-1

3-198. BRAKE PEDAL (TREADLE) VALVE (M936/A1/A2) REPLACEMENT (Contd)
7.
8.
9.
10.
11.
12.
13.
14.
15.

Disconnect two air hoses (5) from elbows (4).
Remove two elbows (4) from control valves (3).
Disconnect air hoses (7) and (8) from adapters (6).
Remove two adapters (6) from control valves (3).
Remove two control valves (3) and adapter (2) from firewall (9).
Remove three locknuts (1) and brake pedal valve (10) from firewall (9). Discard locknuts (1).
Remove three studs (11) from brake pedal valve (10).
Remove two brake pedal valve adapters (13) from brake pedal valve (10).
Remove pressure relief valve (12) from brake pedal valve (10).

b. Installation

1.
2.
3.
4.
5.
6.
7.
8.
9.

3-542

NOTE
l
If new brake pedal valve is being installed, use attaching parts
and fittings from old brake pedal valve.
l
Fittings must be cleaned and inspected for cracks and stripped
threads.
l
Wrap all male pipe threads with antiseize tape before
installation.
Install pressure relief valve (12) on brake pedal valve (10).
Install two brake pedal valve adapters (13) on brake pedal valve (10).
Install three studs (11) on brake pedal valve (10).
Install brake pedal valve (10) on firewall (9) with three new locknuts (1).
Install adapter (2) and two control valves (3) on firewall (9).
Install two adapters (6) on control valves (3).
Connect air hoses (7) and (8) to adapters (6).
Install two elbows (4) on control valves (3).
Connect two air hoses (5) to elbows (4).

TM 9-2320-272-24-1

3-198. BRAKE PEDAL (TREADLE) VALVE (M936/A1/A2) REPLACEMENT (Contd)

3-543

TM 9-2320-272-24-1

3-198. BRAKE PEDAL (TREADLE) VALVE (M936/A1/A2) REPLACEMENT (Contd)
10.
11.
12.
13.
14.
15.

3-544

Install adapter (12) and air hose (11) on firewall (3).
Install pipe (13) and tee (8) on firewall (3).
Install adapter (5) and air hose (6) on firewall (3).
Install adapters (7) and (9) on tee (8).
Connect air hoses (4) and (10) to adapters (7) and (9).
Connect two air lines (2) to brake pedal valve adapters (1).

TM 9-2320-272-24-1

3-198. BRAKE PEDAL (TREADLE) VALVE (M936/A1/A2) REPLACEMENT (Contd)

FOLLOW-ON TASKS: l Install protective control box (para. 3-115).
l Install brake pedal (para. 3-196).
l Start engine (TM 9-2320-272-10) and allow air pressure to build to normal
operating range. Check for air leaks and proper brake operation. Road test
vehicle.
3-545

TM 9-2320-272-24-1

3-199. BRAKE PROPORTIONING VALVE REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Two locknuts (Appendix D, Item 299)
Two tiedown straps (Appendix D, Item 684)
Adhesive sealant (Appendix C, Item 4)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l
l

Parking brake set (TM 9-2320-272-10).
Air reservoirs drained (TM 9-2320-272-10).

GENERAL SAFETY INSTRUCTIONS
Do not disconnect air lines before draining air
reservoirs.

a. Removal

1.
2.
3.
4.

WARNING
Do not disconnect air lines before draining air reservoirs. Small
parts under pressure may shoot out with high velocity, causing
injury to personnel.
NOTE
Tag air lines and fittings for installation.
Remove two tiedown straps (8) from air lines (1), (7), and (9). Discard tiedown straps (8).
Disconnect air lines (1), (3), (7), and (9) from elbow (10), adapter (4), elbow (5), and adapter (6).
Remove elbows (10) and (5) and adapters (4) and (6) from brake proportioning valve (2).
Remove two locknuts (11), screws (12), and brake proportioning valve (2) from bracket (13). Discard
locknuts (11).

b. Installation

1.
2.
3.
4.

3-546

NOTE
l If new brake proportioning valve is being installed, use
attaching parts and fittings from old brake proportioning valve.
l
Fittings must be cleaned and inspected for cracks and stripped
threads.
l Apply adhesive sealant to all male pipe threads before
installation.
Install brake proportioning valve (2) on bracket (13) with two screws (12) and new locknuts (11).
Install elbows (10) and (5) and adapters (4) and (6) on brake proportioning valve (2).
Connect air lines (1), (3), (7), and (9) to elbow (10), adapter (4), elbow (5), and adapter (6).
Install two new tiedown straps (8) on air lines (1), (7), and (9).

TM 9-2320-272-24-1

3-199. BRAKE PROPORTIONING VALVE REPLACEMENT (Contd)

FOLLOW-ON TASK: Start engine (TM 9-2320-272-10) and allow air pressure to build to normal operating
range. Check for air leaks and proper brake operation. Road test vehicle.
3-547

TM 9-2320-272-24-1

3-200. WET AIR RESERVOIR (SUPPLY TANK) AND BRACKET REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All except M936/A1/A2

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P

TOOLS
General mechanic's tool kit (Appendix E, Item 1) EQUIPMENT CONDITION
l Parking brake ret (TM 9-2320-272-10).
MATERIALS/PARTS
l Air reservoirs drained (TM 9-2320-272-10).
Eight locknuts (Appendix D, Item 291)
GENERAL SAFETY INSTRUCTIONS
Antiseize tape (Appendix C, Item 72)
Do not disconnect air lines before draining air
reservoirs.
WARNING
Do not disconnect air lines before draining air reservoirs. Small
parts under pressure may shoot out with high velocity, causing
injury to personnel.
a. Removal

1.
2.
3.
4.
5.
6.
7.
8.

3-548

NOTE
Tag air liner for installation.
Disconnect drain line (12) from adapter (11).
Disconnect primary tank air line (14) from elbow (13).
Disconnect auxiliary air line (1) from elbow (2).
Disconnect trailer emergency air line (6) from elbow (3).
Disconnect secondary tank air line (4) from adapter (5).
Disconnect supply tank input air line (15) from elbow (16).
Remove four locknuts (8), two U-bolts (7), and supply tank (9) from two support brackets (10).
Discard locknuts (8).
Remove four locknuts (18), screws (17), and two support brackets (10) from frame brace (19).
Discard locknuts (18).

TM 9-2320-272-24-1

3-200. WET AIR RESERVOIR (SUPPLY TANK) AND BRACKET REPLACEMENT (Contd)

3-549

TM 9-2320-272-24-1

3-200. WET AIR RESERVOIR (SUPPLY TANK) AND BRACKET REPLACEMENT (Contd)

9.
10.
11.
12.

13.
14.
15.
16.
17.
18.
19.
20.

3-550

NOTE
Perform steps 9 through 14 for M934/A1/A2 vehicles.
Disconnect secondary tank air line (1) from adapter (2).
Disconnect trailer emergency air line (5) from elbow (6).
Remove four screws (11) and support plate (9) from frame (12).
Remove four locknuts (10), two U-bolts (8), and supply tank (7) from support plate (9). Discard
locknuts (10).
CAUTION

Remove
Remove
Remove
Remove
Remove
Remove
Remove
Remove

Open-end wrench must be used to anchor tank boss fittings when
connecting or disconnecting associated fittings. Damage to tank
bosses may result if open-end wrench is not used.
adapter (2), shutoff valve (3), and elbow (4) from supply tank (7).
elbow (6) from supply tank (7).
adapters (26) and (25) from supply tank (7).
elbow (18), relief valve (19), nipple (17), and reducer (16) from tee (15).
elbow (13), shutoff valve (14), tee (15), and nipple (27) from supply tank (7).
adapter (21), shutoff valve (22), nipple (23), and elbow (24) from supply tank (7).
elbow (20) from supply tank (7).
elbow (30), safety valve (28), reducer (29), and tee (31) from supply tank (7).

TM 9-2320-272-24-1

3-200. WET AIR RESERVOIR (SUPPLY TANK) AND BRACKET REPLACEMENT (Cod)

M934/A1/A2 VEHICLE

VAN MODEL M934/A1/A2

3-551

TM 9-2320-272-24-1

3-200. WET AIR RESERVOIR (SUPPLY TANK) AND BRACKET REPLACEMENT (Contd)
b. Installation
CAUTION

1.
2.
3.
4.
5.
6.
7.

8.
9.
10.
11.

3-552

Open-end wrench must be used to anchor tank boss fittings when
connecting or disconnecting associated fittings. Damage to tank
bosses may result if open-end wrench is not used.
NOTE
l If new reservoir is being installed, fittings from old reservoir
may be used. Fittings must be cleaned and inspected for cracks
and stripped threads.
l
Wrap male pipe threads with antiseize tape before installation.
Install adapters (18) and (19) on supply tank (17).
Install nipple (20), tee (7), reducer (8), nipple (9), relief valve (11), elbow (10), shutoff valve (6), and
elbow (5) on supply tank (17).
Install elbow (16), nipple (15), shutoff valve (14), and adapter (13) on supply tank (17).
Install elbow (12) on supply tank (17).
Install tee (26), reducer (24), safety valve (23), and elbow (25) on supply tank (17).
Install two support brackets (4) on frame braces (1) with four screws (2) and new locknuts (3).
Install supply tank (17) on two support brackets (4) with two U-bolts (22) and four new locknuts (21).
NOTE
Perform steps 8 through 11 for M934/A1/A2 vehicles.
Install elbow (30) on supply tank (17).
Install elbow (29), shutoff valve (28), and adapter (27) on supply tank (17).
Install support plate (31) on frame (35) with four screws (34).
Install supply tank (17) on support plate (31) with two U-bolts (33) and four new locknuts (32).

TM 9-2320-272-24-1

3-200. WET AIR RESERVOIR (SUPPLY TANK) AND BRACKET REPLACEMENT (Contd)

M934/A1/A2 VEHICLE

VAN MODEL M934/A1/A2
3-553

TM 9-2320-272-24-1

3-200. WET AIR RESERVOIR (SUPPLY TANK) AND BRACKET REPLACEMENT (Contd)
12.
13.
14.
15.
16.
17.
18.
19.

3-554

Connect
Connect
Connect
Connect
Connect
Connect
Connect
Connect

supply tank input air line (11) to elbow (12).
secondary tank air line (3) to adapter (5).
trailer emergency air line (6) to elbow (4).
auxiliary air line (1) to elbow (2).
primary tank air line (10) to elbow (9).
drain line (8) to adapter (7).
trailer emergency air line (16) to elbow (15).
secondary tank air line (13) to adapter (14).

TM 9-2320-272-24-1

3-200. WET AIR RESERVOIR (SUPPLY TANK) AND BRACKET REPLACEMENT (Contd)

FOLLOW-ON TASK: Start engine (TM 9-2320-272-10) and allow air pressure to build to normal operating
range. Check for air leaks. Road test vehicle.
3-555

TM 9-2320-272-24-1

3-201. WET AIR RESERVOIR (SUPPLY TANK) AND MOUNTING PLATE (M936/A1/A2)
REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
M936/A1/A2

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P

TOOLS
General mechanic’s tool kit (Appendix E, Item 1) EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
MATERIALS/PARTS
l Air reservoirs drained (TM 9-2320-272-10).
Four locknuts (Appendix D, Item 291)
GENERAL SAFETY INSTRUCTIONS
Antiseize tape (Appendix C, Item 72)
Do not disconnect air lines before draining air
reservoirs.
WARNING
Do not disconnect air lines before draining air reservoirs. Small
parts under pressure may shoot out with high velocity, causing
injury to personnel.
CAUTION
Anchor tank boss fittings with an open-end wrench before
removing connecting fittings. Failure to do so may result in
damage to equipment.
a. Removal
1.
2.
3.
4.
5.
6.
7.

3-556

Disconnect primary tank air line (1) from elbow (2).
Disconnect trailer emergency air line (5) from elbow (6).
Disconnect auxiliary air line (3) from elbow (4).
Disconnect supply tank input air line (16) from adapter (15).
Disconnect secondary tank air line (14) from adapter (13).
Disconnect drain line (12) from adapter (11).
Remove four locknuts (9), two U-bolts (8), and supply tank (7) from support plate (10). Discard
locknuts (9).

TM 9-2320-272-24-1

3-201. WET AIR RESERVOIR (SUPPLY TANK) AND MOUNTING PLATE (M936/A1/A2)
REPLACEMENT (Contd)

3-557

TM 9-2320-272-24-1

3-201. WET AIR RESERVOIR (SUPPLY TANK) AND MOUNTING PLATE (M936/A1/A2)
REPLACEMENT (Contd)
8.
9.
10.
11.
12.
13.

Remove four screws (1) and support plate (3) from frame (2).
Remove elbow (20), shutoff valve (21), and elbow (22) from supply tank (14).
Remove elbow (13) from supply tank (14).
Remove elbow (9), relief valve (10), nipple (11), and reducer (12) from supply tank (14).
Remove adapters (16) and (15) from supply tank (14).
Remove adapters (7) and (4), safety valve (19), reducer (18), shutoff valve (5), tees (8) and (17), and
nipple (6) from supply tank (14).

b. Installation
NOTE
If new reservoir is being installed, fittings from old reservoir
may be used. Fittings must be cleaned and inspected for cracks
and stripped threads.
l
Wrap male pipe threads with antiseize tape before installation.
Install nipple (6), tees (8) and (17), shutoff valve (5), reducer (18), safety valve (19), and
adapters (7) and (4) on supply tank (14).
Install adapters (15) and (16) on supply tank (14).
Install reducer (12), nipple (11), relief valve (10), and elbow (9) on supply tank (14).
Install elbow (13) on supply tank (14).
Install elbow (22), shutoff valve (21), and elbow (20) on supply tank (14).
Install support plate (3) on frame (2) with four screws (1).
l

1.
2.
3.
4.
5.
6.

3-558

TM 9-2320-272-24-1

3-201. WET AIR RESERVOIR (SUPPLY TANK) AND MOUNTING PLATE (M936/A1/A2)
REPLACEMENT (Contd)

3-559

TM 9-2320-272-24-1

3-201. WET AIR RESERVOIR (SUPPLY TANK) AND MOUNTING PLATE (M936/A1/A2)
REPLACEMENT (Contd)
7.
8.
9.
10.
11.
12.
13.

3-560

Install supply tank (6) on support plate (9) with two U-bolts (7) and four new locknuts (8).
Connect drain line (11) to adapter (10).
Connect secondary tank air line (13) to adapter (12).
Connect supply tank input air line (1) to adapter (14).
Connect auxiliary air line (2) to elbow (3).
Connect trailer emergency air line (4) to elbow (5).
Connect primary tank air line (15) to elbow (16).

TM 9-2320-272-24-1

3-201. WET AIR RESERVOIR (SUPPLY TANK) AND MOUNTING PLATE (M936/A1/A2)
REPLACEMENT (Contd)

FOLLOW-ON TASK: Start engine (TM 9-2320-272-10) and allow air pressure to build to normal operating
range. Check for air leaks. Road test vehicle.
3-561

TM 9-2320-272-24-1

3-202. PRIMARY AIR RESERVOIR (SUPPLY TANK) REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Air reservoirs drained (TM 9-2320-272-10).
TOOLS
l Toolbox and step removed (para. 3-302).
General mechanic’s tool kit (Appendix E, Item 1) l Primary low air pressure switch removed
(para. 3-99).
MATERIALS/PARTS
GENERAL SAFETY INSTRUCTIONS
Four locknuts (Appendix D, Item 291)
l Do not disconnect air lines before draining air
Antiseize tape (Appendix C, Item 72)
reservoirs.
REFERENCES (TM)
l Do not touch hot exhaust system components with
bare hands.
TM 9-2320-272-10
TM 9-2320-272-24P
APPLICABLE MODELS
All except M936/A1/A2

WARNING
l

l

NOTE
Primary reservoir is located below the cab on right side frame
rail above secondary reservoir.
l Tag air lines for installation.
Disconnect wet reservoir supply line (6) from elbow (7).
Disconnect drain line (8) from elbow (9).
Disconnect primary relay valve supply line (1) from elbow (10).
Disconnect supply line (2) from adapter (4).
Disconnect treadle valve supply line (3) from adapter (4).
NOTE
Assistant will help with steps 6 and 7.
Remove two locknuts (11) and screws (13) from clamps (12). Discard locknuts (11).
Remove two locknuts (11), screws (13), clamps (12), and reservoir (5) from clamps (14). Discard
locknuts (11).
l

1.
2.
3.
4.
5.

6.
7.

3-562

Do not disconnect air lines before draining air reservoirs. Small
parts under pressure may shoot out with high velocity, causing
injury to personnel.
Do not touch hot exhaust system components with bare hands.
Injury to personnel may result.

TM 9-2320-272-24-1

3-202. PRIMARY AIR RESERVOIR (SUPPLY TANK) REPLACEMENT (Contd)

3-563

TM 9-2320-272-24-1

3-202. PRIMARY AIR RESERVOIR (SUPPLY TANK) REPLACEMENT (Contd)
b. Installation
NOTE
If installing new reservoir, use old reservoir fittings.
l
Wrap all male pipe threads with antiseize tape before
installation.
Install reservoir (5) on two clamps (14) with clamps (12), screws (11), and new locknuts (13).
Install two screws (11) and new locknuts (13) on clamps (12).
Connect treadle valve supply line (3) to adapter (4).
Connect supply line (2) to adapter (4).
Connect primary relay valve supply line (1) to elbow (10).
Connect drain line (8) to elbow (9).
Connect wet reservoir supply line (6) to elbow (7).
l

1.
2.
3.
4.
5.
6.
7.

3-564

TM 9-2320-272-24-1

3-202. PRIMARY AIR RESERVOIR (SUPPLY TANK) REPLACEMENT (Contd)

FOLLOW-ON TASKS: l Install primary low air pressure switch (para. 3-99).
l Install toolbox and step (para. 3-302).
l Start engine (TM 9-2320-272-10) and allow air pressure to build to normal
operating range. Check for air leaks at primary air reservoir. Road test vehicle.
3-565

TM 9-2320-272-24-1

3-203. SECONDARY AIR RESERVOIR (SUPPLY TANK) REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All except M936/A1/A2

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P

TOOLS
General mechanic’s tool kit (Appendix E, Item 1) EQUIPMENT CONDITION
Soft-jawed vise
l Parking brake set (TM 9-2320-272-10).
l Air reservoirs drained (TM 9-2320-272-10).
MATERIALS/PARTS
l Toolbox and step removed (para. 3-302).
Four locknuts (Appendix D, Item 291)
GENERAL SAFETY INSTRUCTIONS
Antiseize tape (Appendix C, Item 72)
l Do not disconnect air lines before draining air
reservoirs.
l Do not touch hot exhaust system components with
bare hands.
WARNING
l

l

Do not disconnect air lines before draining air reservoirs. Small
parts under pressure may shoot out with high velocity, causing
injury to personnel.
Do not touch hot exhaust system components with bare hands.
Injury to personnel may result.

a. Removal
NOTE
Secondary reservoir is located below the cab on the right side
frame rail below primary reservoir.
l Tag air lines for installation.
Disconnect wet reservoir supply line (8) from elbow (7).
Disconnect drainvalve line (11) from adapter (10).
Disconnect supply line (14) from elbow (13).
Disconnect supply line (15) from adapter (16).
Disconnect two wires (1) from secondary low-air pressure switch (2).
NOTE
Assistant will support reservoir during steps 6 and 7.
Remove four locknuts (20), screws (18), and two support clamps (19) from hangers (17). Discard
locknuts (20).
Remove secondary reservoir (5) from two hangers (17) and place in soft-jawed vise.
Remove secondary low-air pressure switch (2), adapter (3), and fitting (4) from secondary reservoir (5).
Remove elbow (7) and check valve (6) from secondary reservoir (5).
Remove adapters (10) and (9) from secondary reservoir (5).
Remove elbow (13), adapter (16), and fitting (12) from secondary reservoir (5).
Remove secondary reservoir (5) from vise.
l

1.
2.
3.
4.
5.

6.
7.
8.
9.
10.
11.
12.

3-566

TM 9-2320-272-24-1

3-203. SECONDARY AIR RESERVOIR (SUPPLY TANK) REPLACEMENT (Contd)

3-567

TM 9-2320-272-24-1

3-203. SECONDARY AIR RESERVOIR (SUPPLY TANK) REPLACEMENT (Contd)
b. Installation

1.
2.
3.
4.
5.
6.

7.
8.
9.
10.
11.
12.

3-568

NOTE
l
If installing new reservoir, use old reservoir fittings.
l
Wrap all male pipe threads with antiseize tape before
installation.
Place secondary reservoir (5) in soft-jawed vise.
Install fitting (12), adapter (16), and elbow (13) on secondary reservoir (5).
Install adapters (9) and (10) on secondary reservoir (5).
Install check valve (6) and elbow (8) on secondary reservoir (5).
Install fitting (4), adapter (3), and secondary low-air pressure switch (2) on secondary reservoir (5).
Remove secondary reservoir (5) from soft-jawed vise.
NOTE
Assistant will support reservoir during step 7.
Install secondary reservoir (5) on two hangers (17) with support clamps (19), four screws (18), and
new locknuts (20).
Connect two wires (1) to secondary low-air pressure switch (2).
Connect supply line (15) to adapter (16).
Connect supply line (14) to elbow (13).
Connect drainvalve line (11) to adapter (10).
Connect wet reservoir supply line (7) to elbow (8).

TM 9-2320-272-24-1

3-203. SECONDARY AIR RESERVOIR (SUPPLY TANK) REPLACEMENT (Contd)

FOLLOW-ON TASKS: l Install toolbox and step (para. 3-302).
l Start engine (TM 9-2320-272-10) and allow air pressure to build to normal
operating range. Check for air leaks at secondary air reservoir. Road test vehicle.
3-569

TM 9-2320-272-24-1

3-204. EMERGENCY SPRING BRAKE (SUPPLY TANK) AIR RESERVOIR REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Four locknuts (Appendix D, Item 276)
Antiseize tape (Appendix C, Item 72)
REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P

EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Air reservoirs drained (TM 9-2320-272-10).
l Toolbox and step removed (para. 3-302).
GENERAL SAFETY INSTRUCTIONS
l Do not disconnect air lines before draining air
reservoirs.
l Do not touch hot exhaust system components with
bare hands.

WARNING
l

l

Do not disconnect air lines before draining air reservoirs. Small
parts under pressure may shoot out with high velocity, causing
injury to personnel.
Do not touch hot exhaust system components with bare hands.
Injury to personnel may result.

a. Removal
NOTE
Spring brake reservoir is located on the left frame rail next to
air cleaner.
l Tag air lines for installation.
Disconnect air lines (5), (6), and (7) from elbows (10), (8), and (9).
Remove four locknuts (4), washers (3), two U-bolts (11), and emergency reservoir (1) from two
support brackets (2). Discard locknuts (4).
l

1.
2.

b. Installation
NOTE
If installing new reservoir, use old reservoir fittings. Wrap all
male pipe threads with antiseize tape before installation.
l
When installing emergency tank, ensure emergency tank
drainvalve port faces downward and toward front of vehicle.
Install emergency reservoir (1) on two support brackets (2) with two U-bolts (11), four washers (3),
and new locknuts (4).
Connect air lines (5), (6), and (7) to elbows (10), (8), and (9).
l

1.
2.

3-570

TM 9-2320-272-24-1

3-204. EMERGENCY SPRING BRAKE (SUPPLY TANK) AIR RESERVOIR REPLACEMENT (Contd)

FOLLOW-ON TASKS:

l
l

Install toolbox and step (para. 3-302).
Start engine (TM 9-2320-272-10) and allow air pressure to build to normal
operating range. Check for air leaks. Road test vehicle.
3-571

TM 9-2320-272-24-1

3-205. AIR RESERVOIR DRAINVALVES REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Two locknuts (Appendix D, Item 274)
Antiseize tape (Appendix C, Item 72)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Air reservoirs drained (TM 9-2320-272-10).
GENERAL SAFETY INSTRUCTIONS
Do not disconnect air lines before draining air
reservoirs.

WARNING
Do not disconnect air lines before draining air reservoirs. Small
parts under pressure may shoot out with high velocity, causing
injury to personnel.
a. Removal

1.
2.
3.

NOTE
If removing more than one drainvalve, tag air lines for
installation.
Disconnect air drain line (8) from coupling adapter (7).
Remove two locknuts (2), U-bolt (6), and drainvalve coupling (5) from bracket (1) at rear of right cab
access step (4). Discard locknuts (2).
Remove coupling adapter (7) and drainvalve (3) from drainvalve coupling (5).

b. Installation

1.
2.
3.

3-572

NOTE
Wrap all male pipe threads with antiseize tape before installation.
Install drainvalve (3) and coupling adapter (7) on drainvalve coupling (5).
Install drainvalve coupling (5) on bracket (1) of right cab access step (4) with U-bolt (6) and two new
locknuts (2).
Connect air drain line (8) to coupling adapter (7).

TM 9-2320-272-24-1

3-205. AIR RESERVOIR DRAINVALVES REPLACEMENT (Contd)

FOLLOW-ON TASK: Start engine (TM 9-2320-272-10) and allow air pressure to build to normal operating
range. Check for air leaks at drainvalve. Road test vehicle.
3-573

TM 9-2320-272-24-1

3-206. AIR COMPRESSOR AND LINES (M939A2) REPLACEMENT
THIS TASK COVERS:
a. Removal

b. Installation

INITIAL SETUP:
APPLICABLE MODELS
M939A2

PERSONNEL REQUIRED
TWO

REFERENCES (TM)
TOOLS
General mechanic’s tool kit (Appendix E, Item 1) TM 9-2320-272-10
Torque wrench (Appendix E, Item 144)
TM 9-2320-272-24P
MATERIALS/PARTS
Four bushings (Appendix D, Item 21)
Gasket (Appendix D, Item 162)
Two locknuts (Appendix D, Item 289)
Gasket (Appendix D, Item 163)
Antiseize tape (Appendix C, Item 72)

EQUIPMENT CONDITION
l Air reservoirs drained (TM 9-2320-272-10).
l Coolant drained (para. 3-53).

a. Removal
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.

3-574

Remove clamp (5) and hose (6) from power steering pump (3).
Disconnect supply line (4) from power steering pump (3).
Remove two screws (2), washers (1), power steering pump (3), and gasket (8) from air compressor (7).
Discard gasket (8).
Disconnect air outlet tube (26) from elbow (27).
Remove air governor tube (9) from elbow (28).
Remove water outlet tube (19) and two bushings (14) from elbow (15) and air compressor (7).
Discard bushings (14).
Remove water inlet tube (18) and two bushings (17) from elbow (16) and air compressor (7). Discard
bushings (17).
Remove elbows (15) and (16) from engine block (20).
Remove screw (21) and air inlet tube (13) from engine block (20).
Loosen two hose clamps (10) and remove air inlet tube (13) from air inlet connector (24).
Loosen clamp (12) and remove air inlet tube (13) from adapter (11).
Remove adapter (11) from engine block (20).
Remove oil supply hose (23) from fitting (25) and elbow (22).
Remove elbow (22) from engine block (20).

TM 9-2320-272-24-1

3-206. AIR COMPRESSOR AND LINES (M939A2) REPLACEMENT (Contd)

3-575

TM 9-2320-272-24-1

3-206. AIR COMPRESSOR AND LINES (M939A2) REPLACEMENT (Contd)
15.
16.
17.
18.

Remove two screws (12), clamp (11), and air outlet tube (10) from spacer (8).
Remove two screws (9) and spacer (8) from engine block (7) and brace (5).
Remove two screws (6) and brace (5) from air compressor (4).
Remove two locknuts (3), washers (2), air compressor (4), and gasket (1) from gear housing (13).
Discard locknuts (3) and gasket (1).

b. Installation
1.
2.
3.
4.

5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.

3-576

Install new gasket (1) and air compressor (4) on gear housing (13) with two washers (2) and new
locknuts (3). Tighten locknuts (3) 55 lb-ft (75 N.m).
Install brace (5) on air compressor (4) with two screws (6).
Install spacer (8) on engine block (7) and brace (5) with two screws (9).
Install air outlet tube (10) on spacer (8) with clamp (11) and two screws (12).
NOTE
Wrap all male pipe threads with antiseize tape before installation.
Install elbow (26) on engine block (7).
Install oil supply hose (27) on fitting (29) and elbow (26).
Install adapter (16) on engine block (7).
Install air inlet tube (18) on adapter (16) with clamp (17). Tighten clamp (17).
Install air inlet tube (18) on air inlet connector (28) with two hose clamps (15). Tighten hose
clamps (15).
Install air inlet tube (18) on engine block (7) with screw (25).
Install elbows (20) and (21) on engine block (7).
Install two new bushings (22) and water inlet tube (23) on elbow (21) and air compressor (4).
Install two new bushings (19) and water outlet tube (24) on elbow (20) and air compressor (4).
Install air governor tube (14) on elbow (32).
Connect air outlet tube (30) to elbow (31).

TM 9-2320-272-24-1

3-206. AIR COMPRESSOR AND LINES (M939A2) REPLACEMENT (Contd)

3-577

TM 9-2320-272-24-1

3-206. AIR COMPRESSOR AND LINES (M939A2) REPLACEMENT (Contd)
16.
17.
18.

Install new gasket (8) and power steering pump (3) on air compressor (7) with two washers (1) and
screws (2).
Connect supply line (4) to power steering pump (3).
Install hose (6) on power steering pump (3) with clamp (5).
CAUTION
When filling cooling system, ensure drainvalve on aftercooler is
open. Failure to do so may result in damage to equipment.

3-578

TM 9-2320-272-24-1

3-206. AIR COMPRESSOR AND LINES (M939A2) REPLACEMENT (Contd)

FOLLOW-ON TASK: Fill cooling system (para. 3-53).
3-579

TM 9-2320-272-24-1

3-207. AIR GOVERNOR MAINTENANCE
THIS TASK COVERS:
a. Removal
b. Installation

c. Testing
d. Adjustment

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Antiseize tape (Appendix C, Item 72)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Air reservoirs drained (TM 9-2320-272-10).
l Right splash shield removed (TM 9-2320-272-10).
GENERAL SAFETY INSTRUCTIONS
Do not disconnect air lines before draining air
reservoirs.

WARNING
Do not disconnect air lines before draining air reservoirs. Small
parts under pressure may shoot out with high velocity, causing
injury to personnel.
a. Removal
1.
2.
3.

Disconnect governor supply air line (2) and governor-to-horn supply line (8) from tee (7).
Disconnect governor-to-compressor unloader line (4) from adapter (3).
Remove two screws (6), washers (5), and air governor (1) from cab cowl (9).

b. Installation
NOTE
If installing new governor, use fitting from old governor.
l
Wrap all male pipe threads with antiseize tape before
installation.
Install air governor (1) on cab cowl (9) with two washers (5) and screws (6).
Connect governor-to-compressor unloader line (4) to adapter (3).
Connect governor supply air line (2) and governor-to-horn supply line (8) to tee (7).
l

1.
2.
3.

3-580

TM 9-2320-272-24-1

3-207. AIR GOVERNOR MAINTENANCE (Contd)

3-581

TM 9-2320-272-24-1

3-207. AIR GOVERNOR MAINTENANCE (Contd)
c. Testing

1.

2.

NOTE
Whenever governor is tested, instrument panel primary air gauge
is used.
Start engine (TM 9-2320-272-10) and allow air pressure to build to normal operating range.
NOTE
Engine speed must be adjusted to 1,275 rpm before performing
step 2.
Check air pressure gauge (4) for air compressor cut-out pressure. Air governor (1) should stop
pressure buildup at 130 psi (896 kPa). If not, perform adjustment.

d. Adjustment

1.
2.
3.

4.

3-582

NOTE
Whenever governor is adjusted, instrument panel primary air
gauge is used.
Loosen locknut (2) and turn adapter (3) clockwise to raise pressure; counterclockwise to lower
pressure.
Depress brake pedal until pressure drops and air compression starts to build up pressure. Air
governor (1) should stop pressure buildup at 130 psi (896 kPa). If not, repeat step 1.
Tighten locknut (2) when correct air pressure is reached.
NOTE
After air compression cut-out pressure is adjusted, perform step 4.
Check air pressure gauge (4) for air compressor cut-in pressure by depressing brake pedal
repeatedly. Air governor (1) should stop pressure buildup above 80 psi (552 kPa). If not, replace air
governor (1).

TM 9-2320-272-24-1

3-207. AIR GOVERNOR MAINTENANCE (Contd)

FOLLOW-ON TASKS: l Install right splash shield (TM 9-2320-272-10).
l Road test vehicle (TM 9-2320-272-10).
3-583

TM 9-2320-272-24-1

3-208. AIR COUPLINGS REPLACEMENT
THIS TASK COVERS:
a. Front Air Couplings Removal
b. Rear Air Couplings Removal
(M923/A1/A2)
c. Rear Air Couplings Removal
(M929/A1/A2, M931/A1/A2, M934/A1/A2
M936/A1/A2)

d. Front Air Couplings Installation
e. Rear Air Couplings Installation
(M923/A1/A2)
f. Rear Air Couplings Installation
(M929/A1/A2, M931/A1/A2, M934/A1/A2,
M936/A1/A2)

INITIAL SETUP:
APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
Soft-jawed vise
MATERIALS/PARTS
Six lockwashers (Appendix D, Item 366)
Twelve locknuts (Appendix D, Item 313)
Antiseize tape (Appendix D, Item 72)

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
l Parking brake set (TM 9-2320-272-10).
l Air reservoirs drained (TM 9-2320-272-10).
l Right and left splash shields removed
(TM 9-2320-272-10).
GENERAL SAFETY INSTRUCTIONS
Do not disconnect air lines before draining air
reservoirs.

WARNING
Do not disconnect air lines before draining air reservoirs. Small
parts under pressure may shoot out with high velocity, causing
injury to personnel.
a. Front Air Couplings Removal
1.

2.
3.
4.
5.
6.
7.

8.

9.
3-584

Remove dummy couplings (1) and (15) and S-hook (12) from air coupling (2) and bracket (5).
Dummy coupling (1) has a built-in check valve.
NOTE
Perform steps 2 and 3 for emergency coupling on left side of
vehicle.
Remove air coupling (2) from pipe nipple (14).
Remove pipe nipple (14) from valve (13).
Disconnect air line (11) from elbow (10).
Disconnect elbow (10) from adapter (4).
Remove nut (9), lockwasher (8), adapter (4), identification plate (6), and bracket (5) from frame rail (7).
Discard lockwasher (8).
Remove adapter (4) from elbow (3).
NOTE
Perform step 8 for service coupling on right side of vehicle.
Remove elbow (3) from air coupling (2).
NOTE
Perform step 9 for emergency coupling on left side of vehicle.
Remove elbow (3) from valve (13).

TM 9-2320-272-24-1

3-208. AIR COUPLINGS REPLACEMENT (Contd)

3-585

TM 9-2320-272-24-1

3-208. AIR COUPLINGS REPLACEMENT (Contd)
b. Rear Air Couplings Removal (M923/A1/A2)
1.
2.
3.
4.
5.
6.

7.
8.

9.
10.
11.

3-586

Remove dummy coupling (9) and S-hook (8) from air coupling (10) and bracket (11).
Remove air coupling (10) and pipe nipple (7) from valve (12).
Disconnect air line (1) from elbow (2).
Remove elbow (2) from pipe coupling (3).
Remove pipe coupling (3) from adapter (4).
Remove four locknuts (15). washers (14), screws (6), bracket (11), and plate (13) from frame rail (5).
Discard locknuts (15).
NOTE
Perform step 7 for emergency coupling on right side of vehicle.
Loosen nut (18) from adapter (4).
Remove valve (12) from elbow (16).
NOTE
Perform step 9 for service coupling on left side of vehicle.
Remove elbow (16) and pipe coupling (17) from adapter (4).
Remove elbow (16) from adapter (4).
Remove nut (18), lockwasher (19), identification plate (20), and adapter (4) from frame rail (5).
Discard lockwasher (19).

TM 9-2320-272-24-1

3-208. AIR COUPLINGS REPLACEMENT (Contd)

3-587

TM 9-2320-272-24-1

3-208. AIR COUPLINGS REPLACEMENT (Contd)
c. Rear Air Couplings Removal (M929/A1/A2, M931/A1/A2, M934/A1/A2, M936/A1/A2)

1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.

3-588

NOTE
Left and right (service and emergency) rear couplings are removed
the same way.
Remove dummy coupling (10) and S-hook (13) from air coupling (9) and bracket (14).
Remove air coupling (9) from pipe nipple (11).
Disconnect air line (1) from adapter (2).
Remove adapter (2) from connector (21).
Remove nut (3) and lockwasher (4) from connector (21). Discard lockwasher (4).
Remove two screws (8) and identification plate (12) from bracket (14).
Remove two locknuts (17), washers (16), screws (5), plate (6), and bracket (14) from frame rail (7).
Discard locknuts (17).
Remove pipe nipple (11) from elbow (15).
Place valve (18) in soft-jawed vise and remove elbow (15) from valve (18).
Remove connector (21) from elbow (20).
Remove elbow (20) from pipe nipple (19).
Remove pipe nipple (19) from valve (18).
Remove valve (18) from soft-jawed vise.

TM 9-2320-272-24-1

3-208. AIR COUPLINGS REPLACEMENT (Contd)

3-589

TM 9-2320-272-24-1

3-208. AIR COUPLINGS REPLACEMENT (Contd)
d. Front Air Couplings Installation
NOTE
Fittings must be cleaned and inspected for cracks and stripped
threads.
l
Wrap all male pipe threads with antiseize tape before
installation.
l Perform step 1 for emergency coupling on left side of vehicle.
Install elbow (3) in valve (13).
NOTE
Perform step 2 for service coupling on right side of vehicle.
Install elbow (3) in air coupling (2) and place air coupling (2) in soft-jawed vise.
Install adapter (4) in elbow (3) and remove air coupling (2) from vise.
Install identification plate (6), bracket (5), and adapter (4) in frame rail (7) with new lockwasher (8) and
nut (9).
Install elbow (10) on adapter (4).
Connect air line (11) to elbow (10).
NOTE
Perform steps 7 and 8 for emergency coupling on left side of
vehicle.
Install pipe nipple (14) in valve (13).
Install air coupling (2) on pipe nipple (14).
Install dummy couplings (15) and (1) and S-hook (12) on air coupling (2) and bracket (5).
l

1.

2.
3.
4.
5.
6.

7.
8.
9.

3-590

TM 9-2320-272-24-1

3-208. AIR

3-591

TM 9-2320-272-24-1

3-208. AIR

1.

2.
3.
4.
5.

6.
7.
8.
9.
10.
11.

3-592

NOTE
Fittings must be cleaned and inspected for cracks and stripped
threads.
Wrap all male pipe threads with antiseize tape before
installation.
Install adapter (4) and identification plate (20) in frame rail (5) with new lockwasher (19) and nut (18).
Do not tighten nut (18).
NOTE
Perform steps 2 and 3 for service coupling on left side of vehicle.
Install pipe coupling (17) on adapter (4).
Install elbow (16) on pipe coupling (17).
Install valve (12) and pipe nipple (7) on elbow (16).
Install plate (13) and bracket (11) on frame rail (5) with four screws (6), washers (14), and new
locknuts (15).
NOTE
Perform step 6 for emergency coupling on right side of vehicle.
Tighten nut (18).
Install pipe coupling (3) on adapter (4).
Install elbow (2) in pipe coupling (3).
Connect air line (1) to elbow (2).
Install air coupling (10) on pipe nipple (7).
Install dummy coupling (9) and S-hook (8) on air coupling (10) and bracket (11).

TM 9-2320-272-24-l

3-208. AIR

3-593

TM 9-2320-272-24-1

3-208. AIR

1.
2.
3.
4.
5.
6.
7.

3-594

NOTE
Left and right (service and emergency) rear couplings are
installed the same way.
Fittings must be cleaned and inspected for cracks and stripped
threads.
Wrap all male pipe threads with antiseize tape before
installation.
Install bracket (14) and plate (6) on frame rail (7) with two screws (5), washers (16), and new
locknuts (17).
Install identification plate (12) on bracket (14) with two screws (8).
Install valve (18), pipe nipple (19), elbow (20), connector (21), elbow (15), and pipe nipple (11) on
bracket (14) and plate (6) with new lockwasher (4) and nut (3).
Install adapter (2) in connector (21).
Connect air line (1) to adapter (2).
Install air coupling (9) on pipe nipple (11).
Install dummy coupling (10) and S-hook (13) on air coupling (9) and bracket (14).

TM 9-2320-272-24-1

3-208. AIR

FOLLOW-ON TASKS:

Install right and left splash shields (TM 9-2320-272-10).
Start engine (TM 9-2320-272-10) and allow air pressure to build to normal
operating range. Check for air leaks and road test vehicle.
3-595

TM

9-2320-272-24-l

3-209. EMERGENCY

THIS TASK COVERS:
a. Removal

APPLICABLE MODELS
M931/A1/A2, M932/A1/A2
Tools
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Lockwasher (Appendix D, Item 366)
Antiseize tape (Appendix C, Item 72)

b. Installation

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake ret (TM 9-2320-272-10).
Air reservoirs drained (TM 9-2320-272-10).
GENERAL SAFETY INSTRUCTIONS
Do not disconnect air lines before draining air
reservoirs.

Do not disconnect air lines before draining air reservoirs. Small
parts under pressure may shoot out with high velocity, causing
injury to personnel.

1.
2.
3.
4.
6.
6.
7.
8.

1.
2.
3.
4.
5.
6.
7.
8.

3-596

Remove coupling (1) from adapter (2).
Remove adapter (2) from coupling hose (3).
Remove coupling hose (3) from adapter (12).
Remove adapter (12) from cutoff valve (4).
Remove cutoff valve (4) from adapter (11).
Remove air line (9) from elbow (8).
Remove elbow (8) from adapter (11).
Remove nut (7), lockwasher (6), adapter (11), and identification plate (5) from frame hole (10).
Discard lockwasher (6).

NOTE
Wrap all male pipe threads with antiseize tape before installation.
Insert adapter (11) through identification plate (5) and frame hole (10) and install with new
lockwasher (6) and nut (7).
Install elbow (8) on adapter (11).
Install air line (9) on elbow (8).
Install cutoff valve (4) on adapter (11).
Install adapter (12) on cutoff valve (4).
Install coupling hose (3) on adapter (12).
Install adapter (2) on coupling hose (3).
Install coupling (1) on adapter (2).

TM 9-2320-272-24-l

FOLLOW-ON TASK: Start engine (TM 9-2320-272-10) and allow air pressure to build to normal operating
range. Check for air leaks and road test vehicle.
3-597

TM 9-2320-272-24-1

3-210. TRAILER

THIS TASK COVERS:
a. Removal

APPLICABLE MODELS
M931/A1/A2, M932/A1/A2
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Antiseize tape (Appendix D, Item 72)

b. Installation

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Air reservoirs drained (TM 9-2320-272-10).
GENERAL SAFETY INSTRUCTIONS
Do not disconnect air lines before draining air
reservoirs.

Do not disconnect air lines before draining air reservoirs. Small
parts under pressure may shoot out with high velocity, causing
injury to personnel.

1.
2.
3.
4.
5.

1.
2.
3.
4.
5.

3-598

NOTE
The airbrake hand control valve is mounted on the upper
steering column opposite the turn signal control.
Tag air lines for installation.
Disconnect vent line (10) from adapter fitting (9).
Disconnect delivery line (11) from adapter fitting (12).
Disconnect line (8) from adapter fitting (7).
Remove two screws (4), washers (3), tab (2), clamp (5), and control valve (1) from upper steering
column (6).
Remove three adapter fittings (7), (9), and (12) from control valve (1).

NOTE
If new valve is being installed, use fittings from old valve.
Wrap all male pipe threads with antiseize tape before
installation.
Install three adapter fittings (7), (9), and (12) on control valve (1).
Install control valve (1) on upper steering column (6) with clamp (5), tab (2), two washers (3), and
screws (4).
Connect line (8) to adapter fitting (7).
Connect delivery line (11) to adapter fitting (12).
Connect vent line (10) to adapter fitting (9).

TM 9-2320-272-24-1

3-210. TRAILER

FOLLOW-ON TASK: Start engine (TM 9-2320-272-10) and allow air pressure to build to normal operating
range. Check for air leaks at hand control valve. Road test vehicle.
3-599

TM 9-2320-272-24-1

3-211. ALCOHOL

THIS TASK COVERS:
a. Removal

APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Three locknuts (Appendix D, Item 313)

b. Installation

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITlON
Parking brake set (TM 9-2320-272-10).
Hood raised and secured (TM 9-2320-272-10).
GENERAL SAFETY INSTRUCTIONS
Do not smoke during removal of alcohol evaporator
container.

Do not smoke when removing alcohol evaporator container. Injury
may result from improper handling of alcohol evaporator.

1.
2.
3.

Remove alcohol evaporator container (7) from left side of engine.
Hold tube adapter (6) firmly in place and disconnect fitting (51 from adapter (6).
Remove three locknuts (11, screws (4), and cap (3) from engine-mounted bracket (2). Discard
locknuts (1).

1.
2.
3.

Install cap (3) on engine-mounted bracket (2) with three screws (4) and new locknuts (1).
Hold adapter (6) firmly in place and connect fitting (5) to adapter (6).
Install alcohol evaporator container (7) on left side of engine.

3-600

TM 9-2320-272-24-1

3-211. ALCOHOL

FOLLOW-ON TASK: Fill alcohol evaporator container as required (TM 9-2320-272-10).
3-601

TM 9-2320-272-24-1

3-212. DOUBLECHECK

THIS TASK COVERS:
a. Removal

APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Locknut (Appendix D, Item 299)
Antiseize tape (Appendix C, Item 72)

b. Installation

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Air reservoirs drained (TM 9-2320-272-10).
GENERAL SAFETY INSTRUCTIONS
Do not disconnect air lines before draining air
reservoirs.

Do not disconnect air lines before draining air reservoirs. Small
parts under pressure may shoot out with high velocity, causing
injury to personnel.

1.
2.
3.
4.
5.
6.

NOTE
Doublecheck valve No. 1 is located inside the front left frame
rail and left of the front axle differential.
Tag air lines for installation.
Disconnect line (1) from doublecheck valve No. 1 adapter (2).
Disconnect line (12) from valve adapter (11).
Disconnect line (9) from tee (10).
Remove tee (10) from doublecheck valve No. (3).
Disconnect line (5) from valve adapter (7).
Remove locknut (8), screw (4), and doublecheck valve No. 1 (3) from frame rail (6). Discard locknut (8).

1.
2.
3.
4.
5.
6.

NOTE
If new doublecheck valve is being installed, use fittings from old
doublecheck valve.
Wrap all male pipe threads with antiseize tape before
installation.
Position doublecheck valve No. 1 (3) against frame rail (6) and install with screw (4) and new locknut (8).
Connect line (5) to valve adapter (7).
Install tee (10) on doublecheck valve No. 1 (3).
Connect line (9) to tee (10).
Connect line (12) to valve adapter (11).
Connect line (1) to doublecheck valve No. 1 adapter (2).

3-602

TM 9-2320-272-24-1

3-212. DOUBLECHECK

FOLLOW-ON TASK: Start engine (TM 9-2320-272-10) and allow air pressure to build to normal operating
range. Check for air leaks at doublecheck valve No. 1. Road test vehicle.
3-603

TM 9-2320-272-24-1

3-213. DOUBLECHECK

THIS TASK COVERS:
a. Removal

APPLICABLE MODELS
All except M931/A1/A2 and M932/A1/A2
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Locknut (Appendix D, Item 299)
Antiseize tape (Appendix C, Item 72)

b. Installation

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Air reservoirs drained (TM 9-2320-272-10).
GENERAL SAFETY INSTRUCTIONS
Do not disconnect air lines before draining air
reservoirs.

Do not disconnect air lines before draining air reservoirs. Small
parts under pressure may shoot out with high velocity, causing
injury to personnel.

1.
2.
3.
4.
5.
6.

1.
2.
3.
4.
5.
6.
3-604

NOTE
Doublecheck valve No. 2 is located left of the transfer case
parking brakedrum inside left frame rail.
Tag air lines for installation.
Disconnect two wires (6) from stoplight switch (5).
Disconnect treadle valve control line (7) from doublecheck valve No. 2 (3).
Disconnect secondary relay valve control line (9) from elbow (8).
Disconnect doublecheck valve No. 1 output line (10) from elbow (11).
Disconnect primary relay valve control line (13) from valve adapter tee (12).
Remove locknut (2), screw (1), and doublecheck valve No. 2 (3) from left frame rail (4). Discard
locknut (2).

NOTE
If new doublecheck valve is being installed, use fittings from old
check valve.
Wrap all male pipe threads with antiseize tape before
installation.
Position doublecheck valve No. 2 (3) against frame rail (4) and install with screw (1) and new locknut (2).
Connect treadle valve control line (7) to doublecheck valve No. 2 (3).
Connect secondary relay valve control line (9) to elbow (8).
Connect doublecheck valve No. 1 output line (10) to elbow (11).
Connect primary relay valve control line (13) to valve adapter tee (12).
Connect two wires (6) to stoplight switch (5).

TM 9-2320-272-24-1

3-213. DOUBLECHECK

FOLLOW-ON TASK: Start engine (TM 9-2320-272-10) and allow air pressure to build to normal operating
range. Check for air leaks at doublecheck valve No. 2. Road test vehicle.
3-405

TM 9-2320-272-24-1

3-214. DOUBLECHECK

THIS TASK COVERS:
a. Removal

APPLICABLE MODELS
M931/A1/A2, M932/A1/A2

b. Installation

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P

TOOLS
General mechanic’s tool kit (Appendix E, Item 1) EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
MATERIALS/PARTS
Air reservoirs drained (TM 9-2320-272-10).
Locknut (Appendix D, Item 299)
GENERAL SAFETY INSTRUCTIONS
Antiseize tape (Appendix C, Item 72)
Do not disconnect air lines before draining air
reservoirs.

1.
2.
3.
4.

1.
2.
3.
4.

3-606

Do not disconnect air lines before draining air reservoirs, Small
parts under pressure may shoot out with high velocity, causing
injury to personnel.
NOTE
Doublecheck valve No. 5 is used with airbrake kits on
M931/A1/A2 and M932/A1/A2 model vehicles. It is located inside
the left frame rail in back of the stoplight switch.
Tag air lines for installation.
Disconnect two wires (6) from stoplight switch (5).
Disconnect doublecheck valve No. 5 control line (8) from adapter tee (9).
Disconnect protection valve control line (10) and trailer handbrake control line (7) from doublecheck
valve No. 2 (3).
Remove locknut (2), screw (1), and doublecheck valve No. 2 (3) from left frame rail (4). Discard
locknut (2).

NOTE
If new doublecheck valve is being installed, use fittings from old
check valve.
Wrap all male pipe threads with antiseize tape before
installation.
Position doublecheck valve No. 2 (3) against left frame rail (4) and install with screw (1) and new
locknut (2).
Connect protection valve control line (10) and trailer handbrake control line (7) to doublecheck valve
No. 2 (3).
Connect doublecheck valve No. 5 control line (8) to adapter tee (9).
Connect two wires (6) to stoplight switch (5).

TM 9-2320-272-24-1

3-214. DOUBLECHECK

FOLLOW-ON T A S K Start engine (TM 9-2320-272-10) and allow air pressure to build to normal operating
range. Check for air leaks at doublecheck valve No. 2. Road test vehicle.
3-607

TM 9-2320-272-24-1

3-215. DOUBLECHECK

THIS TASK COVERS:
a. Removal

APPLICABLE MODELS
M931/A1/A2 and M932/A1/A2
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Locknut (Appendix D, Item 291)
Antiseize tape (Appendix C, Item 72)

b. Installation

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Air reservoirs drained (TM 9-2320-272-10).
Do not disconnect air lines before draining air
reservoirs.

1.
2.
3.
4.
5.
6.

Do not disconnect air lines before draining air reservoirs. Small
parts under pressure may shoot out with high velocity, causing
injury to personnel.
NOTE
Doublecheck valve No. 5 is used with airbrake kits on
M931/A1/A2 and M932/A1/A2 model vehicles. It is located inside
the left frame rail in back of the stoplight switch.
Tag air lines for installation.
Disconnect primary relay valve control line (14) from valve adapter tee (13).
Disconnect doublecheck valve No. 1 output line (11) from valve elbow (12).
Disconnect secondary relay valve control line (10) from valve elbow (9).
Disconnect doublecheck valve No. 2 control line (6) from bushing (5).
Disconnect treadle valve control line (7) from valve adapter tee (8).
Remove locknut (3), screw (1), and doublecheck valve No. 5 (4) from frame rail (2). Discard locknut (3).

1.
2.
3.
4.
5.
6.

NOTE
If new valve is being installed, use fittings from old valve.
Wrap all male pipe threads and wrap with antiseize tape before
installation.
Position doublecheck valve No. 5 (4) against frame rail (2) and install with screw (1) and new locknut (3).
Connect treadle valve control line (7) to valve adapter tee (8).
Connect doublecheck valve No. 2 control line (6) to bushing (5).
Connect secondary relay valve control line (10) to valve elbow (9).
Connect doublecheck valve No. 1 output line (11) to valve elbow (12).
Connect primary relay valve control line (14) to valve adapter tee (13).

3-608

TM 9-2320-272-24-l

3-215. DOUBLECHECK

FOLLOW-ON TASK: Start engine (TM 9-2320-272-10) and allow air pressure to build to normal operating
range. Check for air leaks at doublecheck valve No. 5. Road test vehicle.
3-609

TM 9-2320-272-24-1

3-216. DOUBLECHECK

THIS TASK COVERS:
a. Removal

APPLICABLE MODELS
All
TOOLS
General mechanic’s tool kit (Appendix E, Item 1)
MATERIALS/PARTS
Five locknuts (Appendix D, Item 299)
Eight lockwashers (Appendix D, Item 354)
Tiedown strap (Appendix D, Item 694)
Antiseize tape (Appendix C, Item 72)

1.
2.
3.
4.
5.
6.
7.
8.
9.

10.
11.
12.

3-610

b. Installation

REFERENCES (TM)
TM 9-2320-272-10
TM 9-2320-272-24P
EQUIPMENT CONDITION
Parking brake set (TM 9-2320-272-10).
Air reservoirs drained (TM 9-2320-272-10).
GENERAL SAFETY INSTRUCTIONS
Do not disconnect air lines before draining air
reservoirs.

Do not disconnect air lines before draining air reservoirs. Small
parts under pressure may shoot out with high velocity, causing
injury to personnel.
NOTE
Tag air lines for installation.
Remove locknut (4), screw (3), and clamp (5) from front step brace (1). Discard locknut (4)
Remove and discard tiedown strap (2).
Remove eight screws (6), lockwashers (24), and access box cover (22) from step box access (17).
Discard lockwashers (24).
Disconnect air lines (14), (15), and (16) from doublecheck valve No. 4 (18).
Disconnect air lines (9), (13), and (14) from doublecheck valve No. 3 (21).
Disconnect air lines (10), (12), and (13) from quick-release valve (7).
Remove locknut (19), washer (20), screw (23), and doublecheck valve No. 4 (18) from access box
cover (22). Discard locknut (19).
Remove locknut (19), washer (20), screw (23), and doublecheck valve No. 3 (21) from access box
cover (22). Discard locknut (19).
Remove two locknuts (19), screws (23), and quick-release valve (7) from access box cover (22).
Discard locknuts (19).
NOTE
Position valves in soft-jawed vise to remove fittings.
Remove two fittings (8) and fitting (5) from doublecheck valve No. 4 (18).
Remove two fittings (8) and fitting (11) from doublecheck valve No. 3 (21).
Remove three fittings (8) from quick-release valve (7).

TM 9-2320-272-24-1

3-611

1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.

3-612

Install three fittings (2) on quick-release valve (1).
Install two fittings (2) and fitting (6) on doublecheck valve No. 3 (16).
Install two fittings (2) and fitting (5) on doublecheck valve No. 4 (12).
Install quick-release valve (1) on access box cover (16) with two screws (17), washers (14), and new
locknuts (13).
Install doublecheck valve No. 3 (16) on access box cover (16) with screw (17), washer (14), and new
locknut (13).
Install doublecheck valve No. 4 (12) on access box cover (16) with screw (17), washer (14), and new
locknut (13).
Connect air lines (4), (6), and (7) to quick-release valve (1).
Connect air lines (3), (7), and (8) to doublecheck valve No. 3 (16).
Connect air lines (8), (9), and (10) to doublecheck valve No. 4 (12).
Install access box cover (16) on step box access (11) with eight new lockwashers (18) and screws (19).
Install new tiedown strap (21).
Install clamp (24) on front step brace (20) with screw (22) and new locknut (23).

TM 9-2320-272-24-1

3-216. DOUBLECHECK

FOLLOW-ON TASK: Start engine (TM 9-2320-272-10) and allow air pressure to build to normal operating
range. Check for air leaks at doublecheck valve No. 3, No. 4, and quick-release valve.
Road test vehicle.
3-613/(3-614 blank)

TM 9-2320-272-24-1

INDEX
Para
A
Accelerator linkage (M939/A1)
maintenance:
Adjustment.. ....................... 3-42c
Installation ......................... 3-42b
Removal.............................. 3-42a
Accelerator linkage (M939A2)
maintenance:
Adjustment.. ....................... 3-43f
Assembly.. .......................... 3-43d
Cleaning and inspection ...... 3-43c
Disassembly.. ..................... 3-43b
Installation.. ....................... 3-43e
Removal.............................. 3-43a
Accelerator pedal, bracket, rod,
and stopscrew replacement:
Installation.. ....................... 3-41b
Removal .............................. 3-41a
Accelerator pedal, bracket, rod,
and stopscrew replacement:
Installation.. ....................... 3-41b
Removal .............................. 3-41a
AFC fuel pump filter
replacement:
Installation.. ....................... 3-31b
Removal.............................. 3-31a
Aftercooler and tubes
(M939A2) replacement:
Installation.. ....................... 3-76b
Removal.............................. 3-76a
Air cleaner assembly and
mounting bracket
maintenance:
Inspection ........................... 3-15b
Installation.. ....................... 3-15c
Removal............................... 3 - 1 5 a
Air cleaner hose (M939A2)
maintenance:
Assembly ............................ 3-13d
Disassembly ....................... 3-13b
Inspection ........................... 3-13c
Installation ......................... 3-13e
Removal.............................. 3-13a
Air cleaner indicator and tube
maintenance:
Cleaning and inspection...... 3-12c
Installation.. ....................... 3-12d
Removal .............................. 3-12b
Testing ............................... 3-12a

Para Page

Page

3-124
3-124
3-124
3-128
3-128
3-128
3-126
3-128
3-126
3-123
3-123
3-123
3-123
3-108
3-108
3-218
3-216

3-52
3-54
3-52
3-48
3-48
3-48
3-49
3-48
3-44
3-46
3-44
3-42

Air cleaner intake pipe
(M939/A1) maintenance:
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal.. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Air compressor and lines
(M939A2) replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal ..............................
Air compressor coolant lines
(M939A2) replacement:
Cleaning and inspection......
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Air compressor coolant supply
and return tubes (M939/A1)
maintenance:
Inspection. . . . . . . . . . . . . . . . . . . . . . . . . . .
Return tube installation . . . . .
Return tube removal . . . . . . . . . . .
Supply tube installation . . . . .
Supply tube removal. . . . . . . . . . .
Air couplings replacement:
Front air couplings
installation . . . . . . . . . . . . . . . . . . . . . . .
Front air couplings removal
Rear air couplings
installation (M923/A1/A2)
Rear air couplings removal
(M923/A1/A2) . . . . . . . . . . . . . . . . . . . .
Rear air couplings
installation (M929/A1/A2,
M931/A1/A2, M934/A1/A2,
M936/A1/A2) . . . . . . . . . . . . . . . . . . . .
Rear air couplings removal
(M929/A1/A2,
M931/A1/A2,
M934/A1/A2,
M936/A1/A2) . . . . . . . . . . . . . . . . . . . .
Air Fuel Control (AFC) tube
(M939A2) maintenance:
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal.. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Air gauge replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal.. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Air governor maintenance:
Adjustment . . . . . . . . . . . . . . . . . . . . . . . . .
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3-14b
3-14c
3-14a

3-50
3-50
3-50

3-206b 3-576
3-206a 3-574
3-57b
3-57c
3-57a

3-168
3-168
3-168

3-55c
3-55e
3-55b
3-55d
3-55a

3-161
3-163
3-161
3-162
3-160

3-208d 3-590
3-208a 3-584
3-208e 3-592
3-208b 3-586

3-208f 3-594

3-208c 3-588
3-18b
3-18c
3-18a

3-61
3-61
‘3-61

3-87b
3-87a

3-252
3-252

3-207d
3-207b
3-207a
3-207c

3-582
3-580
3-580
3-582

Index 1

TM 9-2320-272-24-l

INDEX (Contd)
Para
Air manifold tee, brake
chamber, replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-189b
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-189a
Air reservoir (supply tank),
primary, replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-202b
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-202a
Air reservoir (supply tank),
secondary, replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-203b
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-203a
Air reservoir drainvalves
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-205b
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-205a
Air reservoir one-way check
valve replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-186b
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-186a
Air reservoir, emergency spring
brake (supply tank),
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-204b
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 3-204a
Airbrake hand control valve
(M931/A1/A2, M932/A1/A2),
trailer, replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-210b
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-210a
Alcohol evaporator
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-211b
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-211a
Alternator and mounting
bracket (M939/A1)
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-79b
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-79a
Alternator drivebelts
(M939/A1) maintenance:
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-78b
Installation and
Adjustment . . . . . . . . . . . . . . . . . . . . . . . 3-78c
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-78a
Alternator pulley M939/A1)
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-81b
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-81a

Index 2

Page

3-520
3-520
3-564
3-562
3-568
3-566
3-572
3-572
3-514
3-514

3-570
3-570

3-598
3-598
3-600
3-600

3-226
3-224

Alternator, mounting bracket,
and pulley (M939A2)
maintenance:
Adjustment.. .......................
Alternator and mounting
bracket installation.. ........
Alternator and mounting
bracket removal.. ..............
Pulley installation ..............
Pulley removal.. ..................
Army petroleum, oils, and
lubricants (POL). ..................
Asssembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Atomizer (M939/A1), ether,
replacement:
Installation.. .......................
Removal.. ............................
Atomizer and temperature
sensor (M939A2), ether,
replacement:
Installation.. .......................
Removal.. ............................
Auxiliary outlet socket and
receptacle (M936/A1/A2)
replacement:
Installation.. .......................
Removal.. ............................
Axle breather, front and rear,
replacement:
Installation.. .......................
Removal.. ............................
Axle seal, front, replacement:
Installation.. .......................
Removal.. ............................
Axle shaft, rear, maintenance:
Inspection.. .........................
Installation.. .......................
Removal.. ............................

Para

Page

3-80e

3-230

3-80d

3-230

3-80a
3-80c
3-80b

3-228
3-230
3-229

1-8
2-18

1-2
2-58

3-37b
3-37a

3-117
3-117

3-38b
3-38a

3- 118
3-118

3-110b 3-298
3-110a 3-298
3-159b 3-438
3-159a 3-438
3-160b 3-439
3-160a 3-439
3-157b 3-433
3-157c 3-433
3-157a 3-433

B
3-222
3-222
3-222
3-232
3-232

Battery box cover replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Battery box replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Battery cable and terminal
adapter replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3-123b 3-332
3-123a 3-332
3-128b 3-342
3-128a 3-342
3-124b 3-334
3-124a 3-334

TM 9-2320-272-24-1

INDEX (Contd)
Para
Battery ground cable
maintenance:
Connection.. . . . . . . . . . . . . . . . . . . . . . . . .
Disconnection.. . . . . . . . . . . . . . . . . . . . .
Battery maintenance:
Inspection and cleaning . . . . . .
Installation... . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Blackout light maintenance:
Assembly . . . . . . . . . . . . . .. . . . . . . . . . . . . .
Disassembly . . . . . . . . . . . . . . . . . . . . . . .
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Boot, steering knuckle,
maintenance:
Cleaning and inspection. . . . . .
Installation. . . . . . . . . . . . . . . . . . . . . . . . .
Removal.. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Box, battery, replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal.. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bracket (M939A2), surge tank
and, replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal.. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bracket, parking brake cable
and, replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bracket, rod, and stopscrew,
accelerator pedal,
replacement:
Installation. . . . . . . . . . . . . . . . . . . . . . . . .
Removal.. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bracket, wet air reservoir
(supply tank) and,
replacement:
Installation . . . . . . . . . . . . . . . . . . . . .. . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Brackets (M939A2), upper
radiator hoses and,
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . ..........
Brake chamber air manifold
tee replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Brake chamber, air manifold
tee, replacement:
Installation. . . . . . . . . . . . . . . . . . . . . . . . .
Removal.. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3-126b 3-338
3-126a 3-338
3-125b 3-336
3-125c 3-337
3-125a 3-336
3-117c
3-117b
3-117d
3-117a

Para

Page

3-308
3-308
3-308
3-308

3-155b 3-430
3-155c 3-430
3-155a 3-430
3-128b 3-342
3-128a 3-342
3-62b 3-184
3-62a 3-184
3-175b 3-488
3-175a 3-486

3-41b 3-123
3-41a 3-123

3-200b 3-552
3-200a 3-548

3-58b 3-170
3-58a 3-170
3-189b 3-520
3-189a 3-520
3-189b 3-520
3-189a 3-520

Brake chamber, combination
spring (emergency) and
service, replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . .. . . . .
Brake chamber, service,
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Brake chamber, spring
(emergency), maintenance:
Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Disassembly . . . . . . . . . . . . . . . . . . . . . . .
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . .
Brake lever and switch,
parking, replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal s.............................
Brake mechanism checks and
adjustments (front and rear):
Brakeshoe check and
adjustment . . . . . . . . . . . . . . . . . . . . . . .
Checking brakeshoe wear . . .
Mechanism inspection . . . . . . . . .
Brake pedal (treadle) valve
(M936/A1/A2) replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Brake pedal (treadle) valve
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Brake pedal maintenance:
Adjustment . . . . . . . . . . . . . . . . . . . . . . . . .
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Brake proportioning valve
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Brake spider, front,
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . ........................
Brake spider, rear,
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Brake valve, spring parking,
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Page

3-182b 3-506
3-182a 3-506
3-181b 3-504
3-181a 3-504
3-193c 3-528
3-193a 3-528
3-193b 3-528
3-174b 3-484
3-174a 3-484

3-179a 3-498
3-179b 3-500
3-179c 3-500
3-198b 3-542
3-198a 3-540
3-197b 3-538
3-197a 3-536
3-196c 3-534
3-196b 3-534
3-196a 3-534
3-199b 3-546
3-199a 3-546
3-183b 3-508
3-183a 3-508
3-184b 3-510
3-184a 3-510
3-194b 3-530
3-194a 3-530

Index 3

TM 9-2320-272-24-1

INDEX (Contd)
Para
Brake valve, spring,
maintenance:
Adjustment . . . . . . . . . . . . . . . . . . . . . . . . .
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Brake, parking, adjustment:
Lever arm adjustment . . . . . . . .
Major adjustment . . . . . . . . . . . . . . .
Minor adjustment . . . . . . . . . . . . . . .
Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Brakedrum dustcover, parking,
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Brakeshoe replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Brakeshoes, parking,
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Breather, transmission
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bumper, front spring,
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bumper, rear spring,
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bushing, ether thermal close
valve and, replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . ...
Bushing, front spring,
maintenance:
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bypass tubing, fuel drain
(M939/A1) and, replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Index 4

Page

Para

Page

C
3-173b 3-482
3-173c 3-482
3-173a 3-482
3-172d
3-172c
3-172b
3-172a

3-480
3-480
3-478
3-478

3-177b 3-494
3-177a 3-494
3-180b 3-502
3-180a 3-501
3-176b 3-492
3-176a 3-490
3-136b 3-372
3-136a 3-372
3-164b 3-450
3-164a 3-450
3-165b 3-451
3-165a 3-451
3-36b 3-116
3-36a 3-116
3-163a 3-448
3-163c 3-448
3-163b 3-448
3-17b
3-17a

3-58
3-56

Cab heat shield, rear exhaust
pipe, support bracket and,
maintenance:
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cable and bracket, parking
brake, replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cable, transmission
modulator, maintenance:
Adjustment . . . . . . . . . . . . . . . . . . . . . . . . .
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Capacitor, governor piping
maintenance:
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Carrier differential top cover
gasket and side cover gasket
replacement:
Side cover gasket
installation . . . . . . . . . . . . . . . . . . . . . . .
Side cover gasket removal. . . .. .
Top cover gasket
installation . . . . . . . . . . . . . . . . . . . . . . .
Top cover gasket removal....
Central Tire Inflation System
(CTIS) operation . . . . . . . . . . . . . . . . . . .
Central Tire Inflation System
(CTIS) troubleshooting . . . . . . . . . .
Characteristics, capabilities,
and features, equipment . . . . . . .
Check valve, air reservoir oneway, replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Circuit breaker replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cleaning, general . . . . . . . . . . . . . . . . . . . .
Cluster, instrument,
maintenance:
Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Disassembly . . . . . . . . . . . . . . . . . . . . . . .
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3-49b 3-142
3-49c 3- 142
3-49a 3-142
3-175b 3-488
3-175a 3-486
3-145c 3-400
3-145b 3-400
3-145a 3-398
3-135b 3-366
3-135c 3-368
3-135a 3-364

3-158d 3-437
3-158c 3-437
3-158b 3-436
3-158a 3-434
1-25

1-78

2-25

2-267

1-13

1-5

3-186b 3-514
3-186a 3-514
3-105b 3-288
3-105a 3-288
2- 14
2-54
3-83c
3-83b
3-83d
3-83a

3-242
3-242
3-244
3-238

TM 9-2320-272-24-1

INDEX (Contd)
Para

Page

Clutch (M939/A1), fan drive,
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-75b 3-214
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-75a 3-214
Clutch actuator (M939/A1), fan
drive, maintenance:
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-73b 3-210
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-73c 3-210
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 - 7 3 a 3 - 2 1 0
Combination spring
(emergency) and service brake
chamber replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-182b 3-506
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-182a 3-506
Composite light and bracket,
front and rear, replacement:
Composite light lamp
installation . . . . . . . . . . . . . . . . . . . . . . . 3-118n 3-320
Composite light lamp
removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-118m 3-320
Front composite light
installation . . . . . . . . . . . . . . . . . . . . . . . 3-118b 3-311
Front composite light
removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-118a 3-310
Installation (M923/A1/A2).. 3-118d 3-312
Installation (M929/A1/A2).. 3-118h 3-314
Installation (M931/A1/A2).. 3-118j 3-316
Installation (M934/A1/A2).. 3-1181 3-318
Installation (M936/A1/A2).. 3-118f 3-313
Removal (M923/A1/A2)....... 3-118c 3-312
Removal (M929/A1/A2)....... 3-118g 3-314
Removal (M931/A1/A2)....... 3-118i 3-316
Removal (M934/A1/A2)....... 3-118k 3-318
Removal (M936/A1/A2)....... 3-118e 3-313
Compressed air and brake
system operation . . . . . . . . . . . . . . . . . . 1-23
1-55
Compressed air and brake
2-177
system troubleshooting . . . . . . . . . 2-23
Contact, brush, horn,
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-102b 3-282
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-102a 3-282
Control box, protective,
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-115b 3-304
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-115a 3-304
Control cable, throttle,
maintenance:
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-45b 3-136
Installation.. . . . . . . . . . . . . . . . . . . . . . . . 3-45c 3-136
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-45a 3-134

Control switch, floodlight,
maintenance:
Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Disassembly . . . . . . . . . . . . . . . . . . . . . . .
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Control system operation . . . . . . . .
Control valve, front axle
engagement, transfer case,
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Control valve, lock-in, transfer
case front axle, replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Control valve, washer,
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Control valve, windshield
wiper, replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal ..............................
Coolant hoses and lines
(M939A2) replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Coolant hoses and tubes
(M939/A1) replacement:
Radiator inlet hoses and
tube installation . . . . . . . . . . . . . . .
Radiator inlet hoses and
tube removal . . . . . . . . . . . . . . . . . . . . .
Radiator outlet hoses and
tee installation . . . . . . . . . . . . . . . . .
Radiator outlet hoses and
tee removal . . . . . . . . . . . . . . . . . . . . . . .
Surge tank hose installation
Surge tank hose removal.....
Thermostat housing hose,
radiator bypass tube, and
hose installation . . . . . . . . . . . . . . .
Thermostat housing hose,
radiator bypass tube, and
hose removal . . . . . . . . . . . . . . . . . . . . .
Transmission oil cooler
hoses and tube installation
Transmission oil cooler
hoses and tube removal....

Para

Page

3-120d
3-120b
3-120c
3-120e
3-120a
1-20

3-324
3-324
3-324
3-325
3-324
1-25

3-144b 3-396
3-144a 3-396
3-147b 3-404
3-147a 3-404
3-191b 3-524
3-191a 3-524
3-192b 3-526
3-192a 3-526
3-56b
3-56a

3-166
3-164

3-54j

3-158

3-54a

3-154

3-54g

3-156

3-54d
3-54h
3-54c

3- 156
3-156
3-156

3-54i

3-158

3-54b

3-154

3-54f

3-156

3-54e

3-156

Index 5

TM 9-2320-272-24-1

INDEX (Contd)
Para Page
Coolant liner (M939A2), air
compressor, replacement:
Cleaning and inspection......
Installation.... . . . . . . . . . . . . . . . . . . . . .
Removal...............................
Coolant lines (M939A2), air
compressor, replacement:
Cleaning and inspection......
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Coolant liner (M939A2),
turbocharger and,
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal...............................
Coolant supply and return
tuber (M939/A1), air
compressor, maintenance:
Inspection . . . . . . . . . . . . . . . . . . . . . ......
Return tube installation . . . . .
Return tube removal...........
Supply tube installation . . . . .
Supply tube removal....,......
Cooling system servicing:
Cleaning and flushing
system ..............................
Depressurizing system . . . . . . . . . . . .
Draining system. . . . . . . . . . . . . . . . .
Filling system .................... . .
Coupling hoses (M931/A1/A2,
M932/A1/A2, emergency and
trailer, replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal..............................
Couplings, air, replacement:
Front air couplings
installation . . . . . . . . . . . . . . . . . . . . . . .
Front air couplings removal
Rear air couplings
installation (M923/A1/A2)
Rear air couplings removal
(M923/A1/A2) . . . . . . . . . . . . . . . . . . .
Rear air couplings
installation (M929/A1/A2,
M931/A1/A2, M934/A1/A2,
M936/A1/A2) . . . . . . . . . . . . . . . . . . . .
Rear air couplings removal
(M929/A1/A2,
M931/A1/A2,
M934/A1/A2,
M936/A1/A2) . . . . . . . . . . . . . . . . . . . .

Index 6

3-57b
3-57c
3-57a
3-57b
3-57c
3-57a

3-21b
3-21a

3-168
3-168
3-168
3-168
3-168
3-168

3-70
3-68

3-55c
3-55e
3-55b
3-55d
3-55a

3-161
3-163
3-161
3-162
3-160

3-53c
3-53a
3-53b
3-53d

3-150
3-150
3-150
3-152

3-209B 3-596
3-209a 3-596
3-208d 3-590
3-208a 3-584
3-208e 3-592
3-208b 3-586

3-208f 3-594

3-208c 3-588

Para
Couplings, air, replacement:
Front air couplings
installation . ..... . . . . . . . . . . . . . . . . . 3-208d
Front air couplinga removal 3-208a
Rear air couplings
installation (M923/A1/A2) 3-208e
Rear air couplings removal
(M923/A1/A2) . . . . . . . . . . . . . . . . . . . 3-208b
Rear air couplings
installation (M929/A1/A2,
M931/A1/A2, M934/A1/A2,
M936/A1/A2. . . . . . . . . . . . . . . . . . . . 3-208f
Rear air couplings removal
(M929/A1/A2,
M931/A1/A2, M934/A1/A2,
M936/A1/A2) . . . . . . . . . . . . . . . . . . . . 3-208c
Cover, battery box,
replacement:
Installation........................
3-123b
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . .... 3-123a
Cover, fuel filter and,
maintenance:
Cleaning and inspection...... 3-30c
Installation (M939/A1) . . . . . . . 3-30d
Installation (M939A2) . . . . . . . . 3-30e
Removal (M939/A1) . . . . . . . . . . . . 3-30b
Removal (M939A2) . . . . . . . . . . . . . 3-30a
Crankcase breather and tube
maintenance:
Breather and tube
installation (M939/A1). . . . . 3-2e
Breather and tube removal
(M939/A1). . . . . . . . . . . . . . . . . . . . . . . . . 3-2a
Breather tube
installation (M939A2)....... 3-2d
Breather tube removal
(M939A2) .......................... 3-2b
Cleaning and inspection...... 3-2c

Page

3-590
3-584
3-592
3-586

3-594

3-588
3-332
3-332
3-106
3-106
3-107
3-105
3-104

3-6
3-2
3-4
3-4
3-4

D
Dash control valve, spring
brake, replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . .. . . . .
Data plates, description of......
Data, equipment . . . . . . . . . . . . . . . . . . . .
Description and data index,
equipment . . . . . . . . . . . . . . . .............
Description of data plates . . . . . . .
Description of major
components, location and . . . . . .

3-195b
3-195a
1-17
1-16

3-532
3-532
1-24
1-22

1-12
1-17

1-5
1-24

1-14

1-16

TM 9-2320-272-24-1

INDEX (Contd)
Para Page
Destruction of Army materiel to
prevent enemy use................ 1-3
Differences between models.... 1-15
1-20
Dipstick, dipstick tube,
transmission, maintenance:
Installation.........................
3-134c 3-362
Inspection ............................. 3-134b 3-362
Removal .............................. 3-134a 3-362
Disassembly, general.............. 2-17
2-58
Doublecheck valve No. 1
replacement:
Installation.... . . . . . . . . . . . . . . . . . . . . . . . . 3-212b 3-602
Removal. . . . . . . . . . . . . . . .... . . . . . . . ... 3-212a 3-602
Doublecheck valve No. 2
(M931/A1/A2, M932/A1/A2
replacement:
Installation.... . . . . . . . . . . . . . . . . . . . . . 3-214b 3-606
Removal............................... 3-214a 3-606
Doublecheck valve No. 5
(M931/A1/A2, M932/A1/A2)
replacement:
Installation. . . . . . . . .. . . . . . . . . . . 3-215b 3-608
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 3-215a 3-608
Doublecheck valves No. 3,
No. 4, and quick-release valve
replacement:
Installation. . . . . . . . . . . . . . . . . . . . . . . . . 3-216b 3-612
Removal. . . . .. . . . . . . . . . . . . . . . . . . . . . . . . 3-216a 3-610
Drainvalves, air reservoir,
replacement:
Installation.... . . . . . . . . . . . . . . . . . . . . . 3-205b 3-572
Removal .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-205a 3-572
Drainvalves, air reservoir,
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-205b 3-572
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-205a 3-572
Drive flange, front axle,
maintenance:
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-156b 4-432
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-156c 4-432
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-156a 3-432
Drivebelt (M939/A1), water
pump, maintenance:
Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . 3-67a 3-196
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-67c 3-198
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-67d 3-198
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-67b 3-198
Drivebelt and drivebelt
tensioner (M939A2), fan,
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-71b 3-206
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-71a 3-206

Para
Drivebelt tensioner (M939A2),
fan drivebelt and,
replacement:
Installation.........................
Removal...............................
Drivebelts (M939A1), fan,
maintenance:
Adjustment.... ................... . . .
Inspection ............................
Installation.........................
Removal.............................
Drivebelts, alternator
(M939/A1), maintenance:
Inspection ...........................
Installation and
adjustment . . . . . . . . . . . . . . . . . . . . . . .
Removal..............................
Driveshaft (M939/A1),
tachometer maintenance:
Installation.........................
Removal..............................
Driveshaft, speedometer
maintenance:
Inspection ..........................
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Dustcover, parking brakedrum,
replacement:
Installation. . . . . . . . . . . . . . . . . . . . . . . . . .
Removal..............................
Dustcovers, wheel brakedrum,
replacement:
Front wheel dustcovers
installation . . . . . . . . . . . . . . . . . . . . . . .
Front wheel dustcovers
removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rear wheel dustcovers
installation . . . . . . . . . . . . . . . . . . . . . . .
Rear wheel dustcovers
removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Page

3-71b 3-206
3-71a 3-206
3-70a
3-70c
3-70d
3-70b

3-204
3-205
3-205
3-204

3-78b 3-222
3-78c 3-222
3-78a 3-222
3-89b 3-256
3-89a 3-256
3-90b 3-260
3-90c 3-260
3-90a 3-258
3-177b 3-494
3-177a 3-494

3-178c 3-496
3-178a 3-496
3-178d 3-496
3-178b 3-496

E
Electrical gauges replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-86b 3-250
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-86a 3-250
Electrical switches
replacement:
Accessory switches
installation . . . . . . . . . . . . . . . . . . . . . . . 3-107b 3-292

Index 7

TM 9-2320-272-24-l

INDEX (Contd)
Para
Accessory switches
removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Battery and starter
switch installation . . . . . . . . . . . .
Battery and starter
switch removal . . . . . . . . . . . . . . . . . .
Electrical system
troubleshooting . . . . . . . . . . . . . . . . . . . . .
Electrical systems operation . . .
Emergency and trailer coupling
hoses (M931/A1/A2,
M932/A1/A2) replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Emergency spring brake
(supply tank) air reservoir
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Emergency spring brake
(supply tank), air reservoir,
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Emergency stop control cable
maintenance:
Inspection.. .........................
Installation.. .......................
Removal..............................
Engine AOAP valve
maintenance:
Installation .........................
Oil sampling.. .....................
Removal...............................
Engine oil cooler (M939A2)
maintenance:
Assembly.. ..........................
Cleaning and inspection ......
Disassembly.. .....................
Installation.. .......................
Removal..............................
Engine oil filter maintenance:
Cleaning and inspection......
Draining oil.. .......................
Filter shell and bolt
assembly (M939/A1). ........
Filter shell and bolt
disassembly (M939/A1). ...
Oil filter installation.. .........
Oil filter removal .................
Equipment characteristics,
capabilities, and features.. ...
Equipment data .....................

Index 8

Page

3-107a 3-292
3-107d 3-293
3-107c 3-292
2-22
1-22

2-92
1-45

3-209b 3-596
3-209a 3-596

3-204b 3-570
3-204a 3-570

3-204b 3-570
3-204a 3-570
3-44b
3-44c
3-44a

3-132
3-132
3-130

3-10c
3-10a
3-10b

3-40
3-38
3-40

3-4d
3-4c
3-4b
3-4e
3-4a

3-14
3-14
3-14
3-16
3-12

3-5d
3-5a

3-20
3-18

3-5e

3-20

3-5c
3-5f
3-5b

3-20
3-21
3-20

1-13
1-16

1-5
1-22

Para
Equipment description and
data index . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-12
Ether atomizer (M939/A1)
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-37b
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-37a
Ether atomizer and
temperature sensor (M939A2)
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-38b
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-38a
Ether cylinder and valve
replacement:
Ether cylinder installation . . . . . . 3-35d
Ether cylinder removal........ 3-35a
Ether valve installation . . . . . . 3-35c
Ether valve removal . . . . . . . . . . . . 3-35b
Ether start fuel pressure
switch (M939/A1)
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-34b
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-34a
Ether start switch
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-33b
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-33a
Ether thermal close valve and
bushing replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-36b
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-36a
Ether tubing replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-39b
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-39a
Ether, atomizer (M939/A1),
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-37b
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-37a
Ether, atomizer and
temperature sensor
(M939A2), replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-38b
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-38a
Evaporator, alcohol,
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-211b
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-211a
Evaporator, alcohol,
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-211b
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-211a
Exhaust stack replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-48b
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-48a

Page
1-5
3-117
3-117

3- 118
3-118
3-115
3-114
3-115
3-114

3-113
3-113
3-112
3-112
3-116
3-116
3-120
3-120
3-117
3-117

3-118
3-118
3-600
3-600
3-600
3-600
3-140
3-140

TM 9-2320-272-24-l

INDEX (Contd)
Para
F
Failsafe warning module
replacement:
Installation.. .......................
Removal..............................
Fan actuator (M939A2), fan
clutch and, maintenance:
Cleaning and inspection ......
Installation.. .......................
Removal..............................
Fan and fan shroud (M939A2)
maintenance:
Inspection ...........................
Installation.. .......................
Removal..............................
Fan blade, radiator,
(M939/A1) replacement:
Installation.. .......................
Removal..............................
Fan clutch and fan actuator
(M939A2) maintenance:
Cleaning and inspection ......
Installation.. .......................
Removal..............................
Fan drive clutch (M939/A1)
replacement:
Installation.. .......................
Removal..............................
Fan drive clutch actuator
(M939/A1) maintenance:
Inspection.. .........................
Installation.. .......................
Removal..............................
Fan drivebelt and drivebelt
tensioner (M939A2)
replacement:
Installation .........................
Removal..............................
Fan drivebelts (M939A1)
maintenance:
Adjustment.. .......................
Inspection ...........................
Installation.. .......................
Removal..............................
Fan shroud (M939/A1),
radiator, replacement:
Installation.. .......................
Removal ..............................

3-106b 3-290
3-106a 3-290
3-74b
3-74c
3-74a

3-212
3-213
3-212

3-64b
3-64c
3-64a

3-188
3-188
3-188

3-72b
3-72a

3-208
3-208

3-74b
3-74c
3-74a

3-212
3-213
3-212

3-75b
3-75a

3-214
3-214

3-73b
3-73c
3-73a

3-210
3-210
3-210

3-71b
3-71a

Para

Page

3-206
3-206

3-70a
3-70c
3-70d
3-70b

3-204
3-205
3-205
3-204

3-63b
3-63a

3- 186
3- 186

Fan shroud (M939A2), fan
and, maintenance:
Inspection ...........................
Installation.. .......................
Removal.. ............................
Filler cap and spout, fuel tank,
replacement:
Installation.. .......................
Removal.. ............................
Filter, AFC fuel pump,
replacement:
Installation.. .......................
Removal..............................
Flasher, turn signal,
replacement:
Installation.. .......................
Removal.. ............................
Flex hose, fuel selector valve,
replacement:
Installation.. .......................
Removal ..............................
Floodlight control switch
maintenance:
Assembly.. ..........................
Disassembly.. .....................
Inspection.. .........................
Installation.. .......................
Removal..............................
Floodlight maintenance:
Assembly.. ..........................
Disassembly .......................
Installation.. .......................
Removal.. ............................
Floodlight sealed beam lamp
and door (M936/A1/A2)
replacement:
Installation.. .......................
Removal.. ............................
Forward-rear to rear-rear
propeller shaft replacement:
Installation.. .......................
Removal.. ............................
Front and rear axle breather
replacement:
Installation.. .......................
Removal.. ............................
Front and rear composite light
and bracket replacement:
Composite light lamp
installation.. .....................

Page

3-64b 3-188
3-64c 3-188
3-64a 3-188
3-25b
3-25a

3-78
3-78

3-31b 3-108
3-31a 3-108
3-114b 3-303
3-114a 3-303
3-23b 3-74
3-23a 3-74
3-120d
3-120b
3-120c
3-120e
3-120a

3-324
3-324
3-324
3-325
3-324

3-121c
3-121b
3-121d
3-121a

3-328
3-326
3-328
3-326

3- 119b 3-322
3-119a 3-322
3-151b 3-420
3-151a 3-420
3-159b 3-438
3-159a 3-438

3-118n 3-320

Index 9

TM 9-2320-272-24-1

INDEX (Contd)
Para Page
Composite light lamp
r e m o v a l ... ........ .................. 3-118m
Front composite light
installation.. ..................... 3-118b
Front composite light
removal.. ........................... 3-118a
Installation (M923/A1/A2) . . 3-118d
Installation (M929/A1/A2) . . 3-118h
Installation (M931/A1/A2) . . 3-118j
Installation (M934/A1/A2) . . 3-118l
Installation (M936/A1/A2) . . 3-118f
Removal (M923/A1/A2) ....... 3-118c
Removal (M929/A1/A2) ....... 3-118g
Removal (M931/A1/A2) ....... 3-118i
Removal (M934/A1/A2) ....... 3-118k
Removal (M936/A1/A2) ....... 3-118e
Front axle drive flange
maintenance:
Inspection ........................... 3-156b
Installation.. ....................... 3-156c
Removal.. ............................ 3-156a
Front axle seal replacement:
Installation.. ....................... 3-160b
Removal.............................. 3-160a
Front axle shaft and universal
joint maintenance:
Cleaning and inspection ...... 3-154b
Installation.. ....................... 3-154e
Removal .............................. 3-154a
Universal joint assembly.. .. 3-154d
Universal joint disassembly 3-154c
Front brake spider
replacement:
Installation.. ....................... 3-183b
Removal.............................. 3-183a
Front exhaust pipe
replacement:
Installation.. ....................... 3-50b
Removal.. ............................ 3-50a
Front hub and drum
(M939/A1) maintenance:
Cleaning and inspection...... 3-223b
Installation.. ....................... 3-223d
Lubrication.. ....................... 3-223c
Removal.............................. 3-223a
Front limiting valve
replacement:
Installation.. ....................... 3-190b
Removal.. ............................ 3-190a
Front relay valve replacement:
Installation.. ....................... 3-187b
Removal.. ............................ 3-187a

Index 10

3-320
3-311
3-310
3-312
3-314
3-316
3-318
3-313
3-312
3-314
3-316
3-318
3-313
4-432
4-432
3-432
3-439
3-439
3-426
3-429
3-426
3-428
3-428
3-508
3-508
3-144
3-144
3-640
3-640
3-640
3-638
3-522
3-522
3-516
3-516

Para

Page

Front spring and main leaf
replacement:
Front spring main leaf
installation.. ..................... 3-161c 3-443
Front spring main leaf
removal.. ........................... 3-161b 3-443
Front spring installation ..... 3-161d 3-444
Front spring removal.. ........ 3-161a 3-440
Front spring bumper
replacement:
Installation.. ....................... 3-164b 3-450
Removal.. ............................ 3-164a 3-450
Front spring bushing
maintenance:
Inspection.. ......................... 3-163a 3-448
Installation.. ....................... 3-163c 3-448
Removal.. ............................ 3-163b 3-448
Front spring shackle
replacement:
Installation.. ....................... 3-162b 3-446
Removal.. ............................ 3-162a 3-446
Front sump tube maintenance:
Inspection.. ......................... 3 9 b
3-36
Installation.. ....................... 3-9c
3-36
Removal.. ............................. ..3-9a
3-36
Front, axle, seal, replacement:
Installation.. ....................... 3-160b 3-439
Removal.. ............................ 3-160a 3-439
Front-wheel drive lock-in
switch replacement:
Installation.. ....................... 3-101b 3-280
Removal.. ............................ 3-101a 3-280
Fuel drain and bypass tubing
(M939/A1) replacement:
Installation.. ....................... 3-17b 3-58
Removal.. ............................ 3-17a 3-56
Fuel filter and cover
maintenance:
Cleaning and inspection ...... 3-30c 3-106
Installation (M939/A1). ...... 3-30d 3-106
Installation (M939A2). ....... 3-30e 3-107
Removal (M939/A1) ............ 3-30b 3-105
Removal (M939A2) ............. 3-30a 3- 104
Fuel injector tube (M939A2)
maintenance:
Cleaning and inspection ...... 3-19b 3-64
Installation.. ....................... 3-19c 3-64
Removal.. ............................ 3-19a 3-62
Fuel level sending unit
replacement:
Installation.. ....................... 3-92b 3-264
Removal.. ............................ 3-92a 3-264

TM 9-2320-272-24-l

INDEX (Contd)
Para
Fuel pressure switch, ether
start, (M939/A1)
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel pressure transducer
(M939/A1) replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel primer pump (M939/A1)
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel pump filter, AFC,
replacement:
Installation. . . . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel pump with VS governor
filter replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal...... . . . . . . . . . . . . . . . . . . . . . . . .
Fuel selector valve flex hose
replacement:
Installation . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel selector valve switch
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel selector valve, mounting
bracket, and indicator plate
maintenance:
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel system (M939A2),
priming:
Priming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel tank (M936/A1/A2)
maintenance:
Draining . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fuel tank filler cap and spout
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Page

3-34b
3-34a

3-113
3-113

3-96b
3-96a

3-271
3-271

3-40b
3-40a

3-122
3-122

3-31b
3-31a

3-108
3-108

3-32b
3-32a

3-110
3-110

3-23b
3-23a

3-74
3-74

Fuel tank hangers and
retaining straps
maintenance:
Inspection.. .........................
Installation.. .......................
Removal.. ............................
Fuel tank lines (M939A2)
replacement:
Installation.. .......................
Removal ..............................
Fuel tank maintenance:
Draining.. ...........................
Inspection.. .........................
Installation.. .......................
Removal ..............................
Fuel transfer pump and supply
lines (M939A2) maintenance:
Cleaning and inspection ......
Installation.. .......................
Removal.. ............................

Para

Page

3-28b
3-28c
3-28a

3-94
3-94
3-92

3-29b
3-29a

3-100
3-96

3-26a
3-26c
3-26d
3-26b

3-80
3-82
3-82
3-80

3-20b
3-20c
3-20a

3-66
3-67
3-66

3-87b
3-87a
2-18
2- 14
2-17
2- 15

3-252
3-252
2-58
2-54
2-58
2-56

2-6
2-16
2-5
1-11

2-2
2-57
2-1
1-3

G

3-109b 3-296
3-109a 3-296

3-24b
3-24c
3-24a

3-76
3-77
3-76

3-22

3-72

3-27a
3-27c
3-27d
3-27a

3-84
3-88
3-88
3-84

3-25b
3-25a

3-78
3-78

Gauge, air, replacement:
Installation.. .......................
Removal.. ............................
General assembly.. .................
General cleaning.. ...................
General disassembly ..............
General inspection.. ................
General inspection and
servicing instructions ............
General repair.. ......................
General service upon receipt.. .
Glossary.. ...............................
Governor piping and capacitor
maintenance:
Inspection.. .........................
Installation.. .......................
Removal..............................
Governor, air, maintenance:
Adjustment.. .......................
Installation.. .......................
Removal.. ............................
Testing ...............................
Governor, air, maintenance:
Adjustment.. .......................
Installation.. .......................
Removal.. ............................
Testing ...............................

3-135b 3-366
3-135c 3-368
3-135a 3-364
3-207d
3-207b
3-207a
3-207c

3-582
3-580
3-580
3-582

3-207d
3-207b
3-207a
3-207c

3-582
3-580
3-580
3-582

Index 11

TM 9-2320-272-24-1

INDEX (Contd)
Para
Ground cable, battery,
maintenance:
Connection . . . . . . . . . . . . . . . . . . . . . . . . . .
Disconnection . . . . . . . . . . . . . . . . . . . . . .
Ground strap replacement:
Ground strap (M939/A1)
installation . . . . . . . . . . . . . . . . . . . . . . .
Ground strap (M939A2)
installation . . . . . . . . . . . . . . . . . . . . . . .
Ground strap (M939/A1)
.............................
Ground strap (M939A2)
removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Page

3-126b 3-338
3-126a 3-338
3-129b 3-344
3- 129d 3-346
3-129a 3-344
3-129c 3-346

H
Hand control valve
(M931/A1/A2, M932/A1/A2),
trailer airbrake, replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-210b
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-210a
Hangers and retaining straps,
fuel tank, maintenance:
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-28b
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-28c
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-28a
Harness, instrument cluster,
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-130b
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-130a
Harness, wiring, repair:
Female cable connector
(with sleeve) . . . . . . . . . . . . . . . . . . . . . . 3-131c
Male cable connector . . . . . . . . . . . 3-131b
Plug assembly . . . . . . . . . . . . . . . . . . . . 3-131d
Receptacle assembly . . . . . . . . . . . 3-131e
Terminal-type cable
connector . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-131a
Head, oil cooler filter,
transmission, replacement:
Oil cooler filter
installation . . . . . . . . . . . . . . . . . . . . . . . 3-139d
Oil cooler filter head
installation . . . . . . . . . . . . . . . . . . . . . . . 3-139c
Oil cooler filter head
removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-139b
Oil cooler filter removal....... 3-139a
Headlight maintenance:
Alignment . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-116c
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-116b
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-116a

Index 12

3-598
3-598
3-94
3-94
3-92
3-348
3-348
3-350
3-350
3-350
3-350
3-349

3-377
3-377
3-376
3-376
3-306
3-306
3-306

Para
High-beam selector switch
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Horn contact brush
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Horn switch replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Horn, solenoid, and bracket
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Hose (M939A2), air cleaner,
maintenance:
Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Disassembly . . . . . . . . . . . . . . . . . . . . . . .
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation.........................
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Hoses and brackets (M939A2),
upper radiator, replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Hoses and lines (M939A2),
coolant, replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Hoses and tubes (M939/A1),
coolant, replacement:
Radiator inlet hoses and
tube installation . . . . . . . . . . . . . . .
Radiator inlet hoses and
tube removal . . . . . . . . . . . . . . . . . . . . .
Radiator outlet hoses and
tee installation . . . . . . . . . . . . . . . . .
Radiator outlet hoses and
tee removal . . . . . . . . . . . . . . . . . . . . . . .
Surge tank hose installation
Surge tank hose removal. . . . .
Thermostat housing hose,
radiator bypass tube, and
hose installation . . . . . . . . . . . . . . .
Thermostat housing hose,
radiator bypass tube, and
hose removal . . . . . . . . . . . . . . . . . . . . .
Transmission oil cooler
hoses and tube installation
Transmission oil cooler
hoses and tube removal . . . .

Page

3-112b 3-301
3-112a 3-301
3- 102b 3-282
3-102a 3-282
3-104b 3-286
3-104a 3-286
3-103b 3-285
3-103a 3-284
3-13d
3-13b
3-13c
3-13e
3-13a

3-48
3-48
3-48
3-49
3-48

3-58b
3-58a

3-170
3-170

3-56b
3-56a

3-166
3-164

3-54j

3-158

3-54a

3-154

3-54g

3-156

3-54d
3-54h
3-54c

3- 156
3- 156
3- 156

3-54i

3- 158

3-54b

3-154

3-54f

3-156

3-54e

3- 156

TM 9-2320-272-24-l

INDEX (Contd)
Para

Page

Hoses, oil cooler, transmission,
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3- 142b 3-388
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-142a 3-384
Housing (M939A2),
thermostats and,
maintenance:
Cleaning and inspection...... 3-66b 3-193
Installation (external
bypass) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-66e 3-194
Installation (internal
bypass) . . . . . . . . . . . . . . . . . . . . . . . . . . ... 3-66c 3-193
Removal (external bypass). . 3-66d 3- 194
Removal (internal bypass) . . 3-66a 3-192
Hydraulic system operation..... 1-24
1-71
I
Indicator lamp, turn signal
control and, replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Indicator panel light and lamp
replacement:
Lamp installation . . . . . . . . . . . . . . .
Lamp removal . . . . . . . . . . . . . . . . . . . .
Light assembly installation.
Light assembly removal......
Indicator plate, fuel selector
valve, mounting bracket, and,
maintenance:
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inspection and servicing
instructions, general . . . . . . . . . . . . .
Inspection and servicing
instructions, specific.. . . . . . . . . . . . .
Inspection, general . . . . . . . . . . . . . . . . . .
Instrument cluster harness
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Instrument cluster
maintenance:
Assembly ............................
Disassembly . . . . . . . . . . . . . . . . . . . . . . .
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Instrument panel replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3-113b 3-302
3-113a 3-302
3-84d
3-84c
3-84b
3-84a

3-246
3-246
3-246
3-246

3-24b 3-76
3-24c 3-77
3-24a 3-76
2-6

2-2

2-7
2-15

2-2
2-56

3-130b 3-348
3-130a 3-348
3-83c
3-83b
3-83d
3-83a

3-242
3-242
3-244
3-238

Para
Intake pipe (M939/A1), air
cleaner, maintenance:
Inspection . . . . . . . . . . . . . . . . . . . . .......
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Isolator (M939A2),
transmission mounting
bracket replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal..............................

Page

3-14b 3-50
3-14c 3-50
3-14a 3-50

3-137b 3-373
3-137a 3-373

L
Lamp and door (M936/A1/A2),
floodlight, sealed beam,
replacement:
Installation.. .......................
Removal..............................
Light switch, main,
replacement:
Installation.. .......................
Removal..............................
Light, blackout, maintenance:
Assembly ............................
Disassembly.. .....................
Installation.. .......................
Removal.. ............................
Light, head-, maintenance:
Alignment.. .........................
Installation .........................
Removal..............................
Lights, bracket and side
marker, replacement:
Lamp installation.. .............
Lamp removal ....................
Light installation.. ..............
Light removal.. ...................
Limiting valve, front,
replacement:
Installation.. .......................
Removal.. ............................
Lines (M939A2), air
compressor and, replacement:
Installation.. .......................
Removal.. ............................
Lines (M939A2), fuel tank,
replacement:
Installation.. .......................
Removal ..............................

3-119b 3-322
3-119a 3-322
3-108b 3-294
3-108a 3-294
3-117c
3-117b
3- 117d
3-117a

3-308
3-308
3-308
3-308

3-116c 3-306
3-116b 3-306
3-116a 3-306
3-122d
3-122a
3-122c
3-122b

3-330
3-330
3-330
3-330

3-190b 3-522
3-190a 3-522
3-206b 3-576
3-206a 3-574
3-29b 3-100
3-29a 3-96

3-85b 3-248
3-85a 3-248

Index 13

TM 9-2320-272-24-1

INDEX (Contd)
Para Page
Linkage (M939/A1),
accelerator, maintenance:
Adjustment........ ................. 3-42c
Installation ......................... 3-42b
Removal.............................. 3-42a
Linkage (M939/A1),
accelerator, maintenance:
Adjustment ......................... 3-42c
Installation.. ....................... 3-42b
Removal.............................. 3-42a
Linkage (M939A2), accelerator,
maintenance:
Adjustment
..................................................... 3 - 4 3 f
Assembly
3-43d
Cleaning and inspection ...... 3-43c
Disassembly ....................... 3-43b
Installation.. ....................... 3-43e
Removal.............................. 3-43a
Linkage (M939A2), accelerator,
maintenance:
Adjustment ......................... 3-43f
Assembly ............................ 3-43d
Cleaning and inspection...... 3-43c
Disassembly.. ..................... 3-43b
Installation.. ....................... 3-43e
Removal.............................. 3-43a
List of abbreviations.. ............. 1-10
Location and description of
major components.. ............... 1-14
Lock-in control valve, transfer
case front axle, replacement:
Installation.. ....................... 3-147b
Removal.............................. 3-147a
Lock-in switch, front wheel,
replacement:
Installation.. ....................... 3-101b
Removal.. ............................ 3-101a
Lower torque rod, upper and,
maintenance:
Assembly ............................ 3-170e
Cleaning and inspection ...... 3-170c
Diassembly.. ....................... 3-170d
Lower torque rod
installation.. ..................... 3-170h
Lower torque rod removal ... 3-170b
Setting preload for upper
torque rod.. ....................... 3-170f
Upper torque rod
installation.. ..................... 3-170g
Upper torque rod removal ... 3-170a

Index 14

Para

Page

M
3-124
3-124
3-124
3-124
3-124
3-124
3-128
3-128
3-128
3-126
3-128
3-126
3-128
3-128
3-128
3-126
3- 128
3-126
1-3
1-16
3-404
3-404
3-280
3-280
3-472
3-470
3-470
3-474
3-470
3-472
3-474
3-468

Main leaf, front spring and,
replacement:
Front spring main leaf
installation........................ 3-161c 3-443
Front spring main leaf
r e m o v a l .. ............ . . . . . . . . . . . . . . . . . . . . . 3-161b 3-443
Front spring installation..... 3-161d 3-444
Front spring removal . . . . . . . . . . 3-161a 3-440
Main light switch replacement:
Installation. . . . . . . . . . . . . . . . . . .. .. .. . 3-108b 3-294
Removal . . . . . . . . . . . . . . . . . . . . . . . . .. .. 3-108a 3-294
Maintenance forms, records,
and reports II......................... 1-2
1-1
Manifold return hose
(M939/A1), surge tank,
radiator vent hose and,
replacement:
Radiator vent and manifold
return hoses installation... 3-61d 3-182
Radiator vent and manifold
return hoses removal . . . . . . . . . 3-61a 3-180
Surge tank installation. . . . . . . 3 - 6 1 c 3 - 1 8 2
Surge tank removal . . . . . . . . . . . . . 3-61b 3-180
Mechanical troubleshooting,
unit level. . . . . . . . . . . . . . . . . ............... 2-21
2-61
Models, differences between.... 1-16
1-20
Mount (M939/A1), oil cooler,
transmission, replacement:
Oil cooler installation . . . . . . . . . .. 3-140d 3-379
Oil cooler mount
installation . . . . . . . . . . . . . . . . . . . . . . . 3-140c 3-378
Oil cooler mount removal . . . . 3-140b 3-378
Oil cooler removal ... . . . . . . . . . . . . 3-140a 3-378
Mount (M939A2), oil cooler,
transmission, replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-141b 3-382
Removal.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-141a 3-380
Mounting bracket, air cleaner
assembly and, maintenance:
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-15b 3-52
Installation. . . . . . . . . . . . . . . . . . . . . . . . . 3-15c 3-54
Removal.. . . . . . . . . . . . . . . . . . . . . . . . . .. . . . .3 - 1 5 a 3 - 5 2

TM 9-2320-272-24-1

INDEX (Contd)
Para Page
Mounting bracket, alernator,
pulley (M939A2)
maintenance:
Adjustment.......................
Alternator and mounting
bracket installation . . . . . . . . . .
Alternator and mounting
bracket removal ...............
Pulley installation ..............
Pulley removal ....................
Mounting bracket, alternator
(M939/A1), replacement:
Installation.........................
Removal..I...........................
Mounting bracket, fuel selector
valve, and indicator plate
maintenance:
Inspection ............................
Installation ...........................
Removal. . . . . . . . . . . . . . . . . . . . ..........
Mounting ping, shock absorber
and, replacement:
Installation.........................
RemovalI.............................
Mounting plate (M936/A1/A2).
wet air reservoir (supply
tank) and, replacement:
Installation.........................
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Muffler and shield
maintenance:
Inspection ...........................
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal .............................

3-80e 3-230
3-80d

3-230

3-80a 3-228
3-80c 3-230
3-80b 3-229
3-79b 3-226
3-79a 3-224

3-24b 3-76
3-24c 3-77
3-24a 3-76
3-166b 3-452
3-166a 3-452

3-201b 3-558
3-201a 3-556
3-51b
3-51c
3-51a

3-146
3-146
3-146

Neutral start switch,
transmission, replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . . 3-98b
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-98a

3-273
3-273

N

Para

Page

Oil pressure sending unit
replacement:
Installation
3-91b 3-262
Removal .............................. 3-91a 3-262
Oil pump pickup hose
maintenance:
Inspection ........................ 3-7b
3-32
Installation .......................... 3-7c
3-32
Removal............................. 3-7a
3-32
Oil pump return hose
maintenance:
Inspection . . . . . . . . . . . . . . . . . . . . . . . . .. . 3-8b
3-34
Installation. . . . . . . . . . . . . . . . . . . . . . . . . . 3-8c
3-34
Removal............................... 3-8a
3-34
Oil service, transmission.
instructions:
Draining oil . . . . . . . . . . . . . . . . . . . . . . 3-133a 3-354
Governor filter
installation . . . . . . . . . . . . . . . . 3-133e 3-358
Governor filter removal . . . . . . . 3-133d 3-358
Oil filter installation . . . . . . . . . . . 3-133c 3-356
Oil filter removal................. 3-133b 3-356
Replenishing oil . . . . . . . . . . . . . . . . . . 3-133f 3-360
One-way check valve, air
reservoir, replacement:
Installation........................
3-186b 3-514
3-186a 3-514
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operation reference index,
principles of . . . . . . . . . . . . . . . . . . . . . . . . . . 1-19
1-25
Operation, general, principles
of . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-18
1-25
Operation:
Central tire inflation system
(CTIS) operation
1-25
1-78
Compressed air and brake
system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-23
1-25
Control system . . . . . . . . . . . . . . . . . . . . . . 1-20
1-25
Electrical systems................. 1-22
1-45
Hydraulic system . . . . . . . . . . . . . . . . . . . 1-24
1-71
1-34
Power system. . . . . . . . . . . . . . . . . . . . . . . . 1-21
P

0
Official nomenclature ..............
Oil dipstick tube maintenance:
Inspection ...........................
Installation (M939/A1). ......
Installation (M939A2)........
Removal (M939/A1). ...........
Removal (M939A2) .............

1-5

1-2

3-3c
3-3d
3-3e
3-3a
3-3b

3-8
3-10
3-10
3-8
3-8

Panel light and lamp, indicator
replacement:
Lamp installation . . . . . . . . . . . . . . . 3-84d
Lamp removal . . . . . . . . . . . . . . . . . . . . 3-84c
Light assembly installation. 3-84b
Light assembly removal...... 3-84a
Panel, instrument
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-85b
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-85a

3-246
3-246
3-246
3-246
3-248
3-248

Index 15

TM 9-2320-272-24-l

INDEX (Contd)
Para Page
Parking brake adjustment:
Lever arm adjustment.. ...... 3-172d 3-480
Major adjustment.. ............. 3-172c 3-480
Minor adjustment.. ............. 3-172b 3-478
Test .................................... 3-172a 3-478
Parking brake cable and
bracket replacement:
Installation.. ....................... 3-175b 3-488
Removal.............................. 3-175a 3-486
Parking brake lever and switch
replacement:
Installation.. ....................... 3-174b 3-484
Removal.............................. 3-174a 3-484
Parking brakedrum dustcover
replacement:
Installation.. ....................... 3-177b 3-494
Removal.............................. 3-177a 3-494
Parking brakeshoes
replacement:
Installation.. ....................... 3-176b 3-492
Removal.............................. 3-176a 3-490
Pedal, brake, maintenance:
Adjustment.. ....................... 3-196c 3-534
Installation.. ....................... 3-196b 3-534
Removal.............................. 3-196a 3-534
Pipe, front exhaust,
replacement:
Installation.. ....................... 3-50b 3-144
Removal............................... 3-50a 3-144
Power system operation.. ........ 1-21
1-34
Preparation for storage or
1-2
shipment .............................. 1-4
Pressure switch, 5th gear lockup, transmission
replacement:
Installation.. ....................... 3-138b 3-374
Removal.............................. 3-138a 3-374
Pressure switch, spring brake,
replacement:
Installation.. ....................... 3-100b 3-278
Removal .............................. 3-100a 3-278
Preventive Maintenance
Checks and Services (PMCS),
unit:
2-2
General ............................... 2 - 8
2-2
Intervals ............................. 2 - 9
2-3
Reporting repairs.. .............. 2-10
General service and
2-3
inspection procedures........ 2-11
2-3
Specific PMCS procedures ... 2-12

Index 16

Para
Primary air reservoir (supply
tank) replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Primary and secondary low air
pressure switch replacement:
Primary switch
installation . . . . . . . . . . . . . . . . . . . . . . .
Primary switch
removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Secondary switch
installation . . . . . . . . . . . . . . . . . . . . . . .
Secondary switch
removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Primary, air reservoir (supply
tank), replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Primer pump (M939/A1), fuel,
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Priming fuel system (M939A2):
Priming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Principles of operation
reference index . . . . . . . . . . . . . . . . . . . . . .
Principles of operation, general
Propeller shaft, forward-rear to
rear-rear, replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Propeller shaft, transfer case
to forward-rear axle,
maintenance:
Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cleaning and inspection......
Disassembly . . . . . . . . . . . . . . . . . . . . . . .
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Propeller shaft, transfer caseto-front axle, replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Propeller shaft, transmissionto-transfer case,
maintenance:
Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Disassembly . . . . . . . . . . . . . . . . . . . . . . .
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Page

3-202b 3-564
3-202a 3-562

3-99b

3-274

3-99a 3-274
3-99d

3-276

3-99c

3-276

3-202b 3-564
3-202a 3-562
3-40b
3-40a

3- 122
3-122

3-22

3-72

1-19
1-18

1-25
1-25

3-151b 3-420
3-151a 3-420

3-150d
3-150c
3-150b
3-150e
3-150a

3-416
3-414
3-414
3-416
3-412

3-149b 3-410
3-149a 3-410

3-148c
3-148b
3- 148d
3-148a

3-408
3-408
3-408
3-406

TM 9-2320-272-24-l

INDEX (Contd)
Para
Proportioning valve, brake,
replacement:
Installation.. .......................
Removal.. ............................
Protective control box
replacement:
Installation.. .......................
Removal.. ............................
Pulley (M939/A1), alternator,
replacement:
Installation.. .......................
Removal..............................
Pulley, alternator, (M939/A1)
replacement:
Installation.. .......................
Removal.. ............................
Pulse sensor (M939/A1),
tachometer replacement:
Installation.. .......................
Removal.. ............................
Pulse sensor (M939A2),
tachometer, replacement:
Installation.. .......................
Removal..............................
Pump (M939/A1), water,
replacement:
Installation.. .......................
Removal ..............................
Pump (M939A2), water,
maintenance:
Cleaning and inspection ......
Installation.. .......................
Removal.. ............................

Page

3-199b 3-546
3-199a 3-546
3-115b 3-304
3-115a 3-304
3-81b 3-232
3-81a 3-232
3-81b
3-81a

3-232
3-232

3-94b
3-94a

3-268
3-268

3-95b 3-270
3-95a 3-270
3-68b 3-200
3-68a 3-200
3-69b 3-202
3-69c 3-202
3-69a 3-202

R
Radiator (M939/A1)
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-59b
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-59a
Radiator (M939A2)
maintenance:
Cleaning and inspection.. . . . . 3-60b
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-60c
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-60a
Radiator fan blade (M939/A1)
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-72b
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-72a
Radiator fan shroud (M939/A1)
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-63b
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-63a

3-174
3-172
3-177
3-178
3- 176
3-208
3-208

Radiator hoses and brackets
(M939A2), upper,
replacement:
Installation.. .......................
Removal.. ............................
Radiator vent hose, manifold
return hose, and surge tank,
(M939/A1) replacement:
Radiator vent and manifold
return hoses installation...
Radiator vent and manifold
return hoses removal ........
Surge tank installation .......
Surge tank removal.. ...........
Rear axle shaft maintenance:
Inspection ...........................
Installation.. .......................
Removal.. ............................
Rear axles spring seat wear
pads and upper bracket
maintenance:
Inspection.. .........................
Installation.. .......................
Removal.. ............................
Rear brake spider
replacement:
Installation.. .......................
Removal.. ............................
Rear exhaust pipe, support
bracket, and cab heat shield
maintenance:
Inspection.. .........................
Installation.. .......................
Removal.. ............................
Rear relay valve replacement:
Installation.. .......................
Removal.. ............................
Rear spring bumper
replacement:
Installation.. .......................
Removal.. ............................
Rear spring replacement:
Installation.. .......................
Removal.. ............................
Rear spring seat maintenance:
Adjustment.. .......................
Cleaning and inspection ......
Installation.. .......................
Lubrication.. .......................
Removal.. ............................

Para

Page

3-58b
3-58a

3-170
3-170

3-61d

3- 182

3-61a
3-61c
3-61b

3- 180
3-182
3-180

3-157b 3-433
3-157c 3-433
3-157a 3-433

3-168b 3-462
3-168c 3-462
3-168a 3-460
3-184b 3-510
3-184a 3-510

3-49b
3-49c
3-49a

3- 142
3- 142
3-142

3-188b 3-518
3-188a 3-518
3-165b 3-451
3-165a 3-451
3-167b 3-458
3-167a 3-454
3-169e
3-169b
3-169d
3-169c
3-169a

3-466
3-464
3-466
3-466
3-464

3-186
3-186
Index 17

TM 9-2320-272-24-1

INDEX (Contd)
Para
Rear, axle, shaft, maintenance:
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-157b
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-157c
Removal . . . . . . . . . . . . . . . . . . . . . ......... 3-151a
Receptacle (M936/A1/A2),
auxiliary outlet socket and,
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-110b
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-110a
Receptacle, slave, replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-127b
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-127a
Relay valve, front,
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-187b
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-187a
Relay valve, rear, replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-188b
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-188a
Repair, general . . . . . . . . . . . . . . . . . . . . . . . 2-16
Reporting Equipment
Improvement
Recommendations (EIRs);
reporting of errors and
recommending improvements 1-6
Reservoir (supply tank) and
bracket, wet air, replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-200b
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-200a
Reservoir (supply tank) and
mounting plate, wet air,
(M936/A1/A2) replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-201b
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-201a
Retaining straps, fuel tank
hangers and, maintenance:
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-28b
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-28c
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-28a
Return tubes (M939/A1), air
compressor coolant supply
and, maintenance:
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-55c
Return tube installation . . . . . 3-55e
Return tube removal . . . . . . . . . . . 3-55b
Supply tube installation . . . . . 3-55d
Supply tube removal . . . . . . . . . . . 3-55a

Index 18

Page
3-433
3-433
3-433

3-298
3-298
3-340
3-340
3-516
3-516
3-518
3-518
2-57

1-2
3-552
3-548

3-558
3-556
3-94
3-94
3-92

3- 161
3-163
3- 161
3-162
3- 160

Return tubes (M939/A1), air
compressor coolant supply
and, maintenance:
Inspection. . . . . . . . . . . . . . . . . . . . . . . . . . .
Return tube installation . . . . .
Return tube removal . . . . . . . . . . .
Supply tube installation . . . . .
Supply tube removal . . . . . . . . . . .
Rod, stopscrew, accelerator
pedal, bracket and,
replacement:
Installation... . . . . . . . .. . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . ........
Rod, tie, maintenance:
Inspection. . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal.. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Para

Page

3-55c
3-55e
3-55b
3-55d
3-55a

3-161
3-163
3-161
3- 162
3-160

3-41b 3-123
3-41a 3-123
3-153b 3-424
3-153c 3-424
3-153a 3-424

S
Safety valve, wet reservoir
(supply tank), replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Seal, front, axle, replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Secondary air reservoir (supply
tank) replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Secondary low air pressure
switch, primary and,
replacement:
Primary switch
installation . . . . . . . . . . . . . . . . . . . . . . .
Primary switch
removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Secondary switch
installation . . . . . . . . . . . . . . . . . . . . . . .
Secondary switch
removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Secondary, air reservoir (supply
tank), replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Selector switch, high-beam,
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . .............

3-185b 3-512
3-185a 3-512
1-1
1-1
3-160b 3-439
3-160a 3-439
3-203b 3-568
3-203a 3-566

3-99b

3-274

3-99a

3-274

3-99d

3-276

3-99c

3-276

3-203b 3-568
3-203a 3-566
3-112b 3-301
3-112a 3-301

TM 9-2320-272-24-l

INDEX (Contd)
Para
Sending unit, fuel level,
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Sending unit, oil pressure,
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Sending unit, water
temperature, replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Service brake chamber
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Service brake chamber,
combination spring
(emergency) and,
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Service upon receipt, general.. .
Shackle, front spring,
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Shaft, rear, axle, maintenance:
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Shield, muffler and,
maintenance:
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Shock absorber and mounting
pins replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Shroud (M939/A1), radiator
fan, replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Side cover gasket, carrier
differential top cover gasket
and, replacement:
Side cover gasket
installation . . . . . . . . . . . . . . . . . . . . . . .
Side cover gasket removal. . .
Top cover gasket
installation . . . . . . . . . . . . . . . . . . . . . . .
Top cover gasket removal....

Page

3-92b 3-264
3-92a 3-264
3-91b
3-91a

3-262
3-262

3-93b 3-266
3-93a 3-266
3-181b 3-504
3-181a 3-504

3-182b 3-506
3-182a 3-506
2-5
2- 1
3-162b 3-446
3-162a 3-446
3-157b 3-433
3-157c 3-433
3-157a 3-433
3-51b
3-51c
3-51a

3-146
3-146
3-146

3-166b 3-452
3-166a 3-452
3-63b
3-63a

3-186
3-186

3-158d 3-437
3-158c 3-437

Para

Page

Side marker lights and bracket
replacement:
Lamp installation . . . . . . . . . . . . . . . 3-122d 3-330
Lamp removal . . . . . . . . . . . . . . . . . . . . 3-122a 3-330
Light installation . . . . . . . . . . . . . . . . 3-122c 3-330
Light removal . . . . . . . . . . . . . . . . . . . . . 3-122b 3-330
Slave receptacle replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-127b 3-340
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-127a 3-340
Solenoid (M939A2), throttle
control, replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-46b 3-138
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-46a 3-138
Solenoid, bracket, horn and,
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-103b 3-285
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-103a 3-284
Specific inspection and
servicing instructions . . . . . . . . . . . . 2-7
2-2
Speedometer and tachometer
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-88b 3-254
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-88a 3-254
Speedometer driveshaft
maintenance:
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-90b 3-260
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-90c 3-260
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-90a 3-258
Spout, fuel tank, filler cap and,
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-25b 3-78
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-25a 3-78
Spring (emergency) and service
brake chamber, combination,
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-182b 3-506
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3-182a 3-506
Spring (emergency) brake
chamber maintenance:
Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-193c 3-528
Disassembly . . . . . . . . . . . . . . . . . . . . . . . 3-193a 3-528
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-193b 3-528
Spring and main leaf, front,
replacement:
Front spring main leaf
installation . . . . . . . . . . . . . . . . . . . . . . . 3-161c 3-443
Front spring main leaf
removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-161b 3-443
Front spring installation.....
3-161d 3-444
Front spring removal . . . . . . . . . . 3-161a 3-440

3-158b 3-436
3-158a 3-434

Index 19

TM 9-2320-272-24-l

INDEX (Contd)
Para Page
Spring brake (supply tank),
emergency, air reservoir,
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Spring brake dash control
valve replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Spring brake pressure switch
replacement:
Installation... . . . . . . . . . . . . . . . . . . . . . .
Removal.. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Spring brake valve
maintenance:
Adjustment. . . . . . . . . . . . . . . . . . . . . . . . .
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal.. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Spring bumper, front,
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal.. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Spring bumper, rear,
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Spring bushing, front,
maintenance:
Inspection. . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Spring parking brake valve
replacement:
Installation... . . . . . . . . . . . . . . . . . . . . . .
Removal.. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Spring seat wear pads and
upper bracket, rear axles,
maintenance:
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal.. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Spring seat, rear,
maintenance:
Adjustment . . . . . . . . . . . . . . . . . . . . . . . . .
Cleaning and inspection......
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Lubrication. . . . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Spring shackle, front,
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal.. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Index 20

3-204b 3-570
3-204a 3-570
3-195b 3-532
3-195a 3-532
3-100b 3-278
3-100a 3-278
3-173b 3-482
3-173c 3-482
3-173a 3-482
3-164b 3-450
3-164a 3-450
3-165b 3-451
3-165a 3-451
3-163a 3-448
3-163c 3-448
3-163b 3-448
3-194b 3-530
3-194a 3-530

3-168b 3-462
3-168c 3-462
3-168a 3-460
3- 169e
3-169b
3-169d
3-169c
3-169a

3-466
3-464
3-466
3-466
3-464

3-162b 3-446
3-162a 3-446

Para
Spring, rear, replacement:
Installation.. .......................
Removal.. ............................
Stack, exhaust, replacement:
Installation.. .......................
Removal.. ..............................
Start switch, ether,
replacement:
Installation.. .......................
Removal.. ............................
Starter replacement:
Installation.. .......................
Removal..............................
STE/ICE troubleshooting.. ......
Steering knuckle boot
maintenance:
Cleaning and inspection ......
Installation.. .......................
Removal.. ............................
Stop control cable, emergency,
maintenance:
Inspection.. .........................
Installation .........................
Removal.. ............................
Stoplight switch replacement:
Installation.. .......................
Removal ..............................
Stopscrew, accelerator pedal,
bracket, rod, and,
replacement:
Installation.. .......................
Removal.. ............................
Strap, ground, replacement:
Ground strap (M939/A1)
installation.. .....................
Ground strap (M939A2)
installation.. .....................
Ground strap (M939/A1)
removal.. ...........................
Ground strap (M939A2)
removal.. ...........................
Supply and return tubes
(M939/A1), air compressor
coolant, maintenance:
Inspection.. .........................
Return tube installation .....
Return tube removal.. .........
Supply tube installation.. ...
Supply tube removal.. .........

Page

3-167b 3-458
3-167a 3-454
3-48b
.3-48a

3-140
3-140

3-33b
3-33a

3-112
3-112

3-82b 3-236
3-82a 3-234
2-24
2-219
3-155b 3-430
3-155c 3-430
3-155a 3-430
3-44b
3-44c
3-44a

3-132
3-132
3-130

3-111b 3-300
3-111a 3-300

3-41b
3-41a

3-123
3-123

3-129b 3-344
3-129d 3-346
3-129a 3-344
3-129c 3-346

3-55c
3-55e
3-55b
3-55d
3-55a

3-161
3-163
3-161
3-162
3-160

TM 9-2320-272-24-l

INDEX (Contd)
Para
Supply lines (M939A2), fuel
transfer pump and,
maintenance:
Cleaning and inspection...... 3-20b
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-20c
Removal. . . . . . . . . . . . . . . . . . . . . . . . ...... 3-20a
Surge tank and bracket
(M939A2) replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-62b
Removal.............................. 3-62a
Surge tank, radiator vent hose,
and manifold return hose
(M939/A1) replacement:
Radiator vent and manifold
return hoses installation... 3-61d
Radiator vent and manifold
return hoses removal . . . . . . . . 3-61a
Surge tank installation....... 3-61c
Surge tank removal . . . . . . . . . . . . . 3-61b
Switch, horn, replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-104b
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-104a
Switch, parking brake lever
and, replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-174b
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-174a
Switch, stoplight, replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3- 111b
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-111a
Switches, electrical,
replacement:
Accessory switches
installation . . . . . . . . . . . . . . . . . . . . . . . 3-107b
Accessory switches
removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-107a
Battery and starter
switch installation . . . . . . . . . . . . 3- 107d
Battery and starter
switch removal . . . . . . . . .......... 3-107c

Page

3-66
3-67
3-66
3-184
3-184

3-182
3- 180
3-182
3- 180
3-286
3-286
3-484
3-484
3-300
3-300

3-292
3-292
3-293
3-292

T
Tachometer driveshaft
(M939/A1) maintenance:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-89b
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-89a
Tachometer pulse sensor
(M939/A1) replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-94b
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-94a

3-256
3-256
3-268
3-268

Para

Page

Tachometer pulse sensor
(M939A2) replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-95b 3-270
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-95a 3-270
Tachometer, speedometer and,
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-88b 3-254
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-88a 3-254
Tank and bracket (M939A2),
surge, replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-62b 3-184
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-62a 3-184
Temperature sensor (M939A2),
ether atomizer and,
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-38b 3-118
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-38a 3-118
Terminal adapter, battery
cable and, replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-124b 3-334
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-124a 3-334
Thermal close valve and
bushing, ether, replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-36b 3-116
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-36a 3-116
Thermostat (M939/A1)
maintenance:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-65c 3- 190
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-65a 3-190
Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-65b 3-190
Thermostats and housing
(M939A2) maintenance:
Cleaning and inspection...... 3-66b 3-193
Installation (external
bypass) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 - 6 6 e 3 - 1 9 4
Installation (internal
bypass) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-66c 3-193
Removal (external bypass).. 3-66d 3-194
Removal (internal bypass) . . 3-66a 3-192
Throttle control cable
maintenance:
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-45b 3- 136
Installation . . . . . . . .................. 3 - 4 5 c 3 - 1 3 6
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-45a 3-134
Throttle control solenoid
(M939A2) replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-46b 3- 138
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-46a 3-138
Tie rod maintenance:
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-153b 3-424
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-153c 3-424
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-153a 3-424

Index 21

TM 9-2320-272-24-1

INDEX (Contd)
Para Page
Toe-in check and adjustment:
Toe-in adjustment . . . . . . . . . . . . . .
.......................
Top cover gasket and ride
cover gasket, carrier
differential, replacement:
Side cover gasket
installation.......................
Side cover gasket removal. . .
Top cover gasket
installation. . . . . . . . . . . . . .. . . . . . . . .
Top cover gasket removal. . . .
Torque rod, upper and lower.
maintenance:
Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cleaning and inspection......
Disassembly.........................
Lower torque rod
installation. . . . . . . . . . . . . . . . . . . . . . . ..
Lower torque rod removal . . .
Settting preload for upper
...........................
Upper torque rod
installation.......... . . . . . . . . . . . . . . . . . .
Upper torque rod removal
Trailer airbrake hand control
valve M931/A1/A2,
M932/A1/A2) replacement:
lnstallation . . . .. . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Trailer coupling hoses
(M931/A1/A2, M932/A1/A2,
emergency and, replacement:
Installation. ... . . . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . .. . . .. . .
Transducer (M939/A1), fuel
pressure, replacement:
Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Transfer case front axle
engagement control valve
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Transfer case front axle lock-in
control valve replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . .. . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Transfer case interlock valve
replacement:
Installation. . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Index 22

3-152b 3-422
3-152a 3-422

3-158d 3-437
3-158c 3-437
3-158b 3-436
3-158a 3-434
3-170e 3-472
3-170c 3-470
3-170d 3-470
3-170h 3-474
3-170b 3-470
3-170f 3-472
3-170g 3-474
3-170a 3-468

3-210b 3-598
3-210a 3-598

3-209b 3-596
3-209a 3-596
3-96b 3-271
3-96a 3-271

3-144b 3-396
3-144a 3-396
3-147b 3-404
3-147a 3-404
3-143b 3-394
3-143a 3-392

Para
Transfer case to forward-rear
axle propeller shaft
maintenance:
Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cleaning and inspection,.....
Disassembly .. . . . . . . . . . . . . . . . . . . . . . . .
Installation. . . . . . . . . . . . . . . . .. . . . . .
Removal .. . . . . . . . . . . . . . . . . . . . . . . . . . . ..
Transfer case-to-front axle
propeller shaft replacement:
Installation.. . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Transmission 5th gear lock-up
pressure switch replacement:
Installation. . . . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Transmission breather
replacement:
Installation. . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . .
Transmission dipstick tube
and dipstick maintenance:
Installation .. . . . . . . . . . . . . . . . . . . . . . . . .
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Transmission modulator and
cable maintenance:
Adjustment . . . . . . . . . . . . . . . . . . . . . . . . .
Installation . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Transmission mounting
bracket and isolator
(M939A2) replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . .. . . . . . . . . . .. . . . . .
Transmission neutral start
switch replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Transmission oil cooler and
mount (M939/A1)
replacement:
Oil cooler installation..........
Oil cooler mount
installation . . . . . . . . . . . . . . . . . . . . . . . .
Oil cooler mount removal . . . .
Oil cooler removal . . . . . . . . . . . . . . .
Transmission oil cooler and
mount (M939A2)
replacement:
Installation .. . . . . . . . . . . . . . . . . . . . . . . ..
Removal . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . ..

3-150d
3-150c
3-150b
3-1508
3-150a

Page

3-416
3-414
8-414
8-416
3-412

3-149b 3-410
3-149a 3-410
3-138b 3-374
3-138a 3-374
3-136b 3-372
3-136a 3-372
3-134c 3-362
3-134b 3-362
3-134a 3-362
3-145c 3-400
3-145b 3-400
3-145a 3-398

3-137b 3-373
3-137a 3-373
3-98b 3-273
3-98a 3-273

3-140d 3-379
3- 140c 3-378
3-140b 3-378
3-140a 3-378

3-141b 3-382
3-141a 3-380

TM 9-2320-272-24-1

INDEX (Contd)
Para Page
Transmission oil cooler Alter
and head replacement:
Oil cooler filter
installation. .. . . . . . . . . . . . . . . . . . . . . .
Oil cooler Altar head
installation. . . . . . . . . .. . .. .. . . . . . . . .
Oil cooler filter head
..............................
Oil cooler filter removal. . . . . . .
Transmission oil cooler hoses
replacement:
Installation. . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Transmission oil service
instructions:
Draining oil. . . . . . . . . . . . . . . . . . . . . . . . . .
Governor filter
installation. . . . . . . . . . . . . . . . . . . . . . .
Governor Alter removal . . . . . . .
Oil Alter installation. . . . . . . . . . .
Oil filter removal. . . . . . . . . . . . . . . . .
Repleniehing oil . . . . . . . . . . . . . . . . . .
Transmission temperature
transmitter replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal..............................
Tranrmisrion-to-transfer case
propeller shaft maintenance:
Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Disassembly . . . . . . . . . . . . . . . . . . . . . . .
Installation . . . . . . . . . . . . . . . . . . . . . . . ...
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Transmitter, transmission
temperature, replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal. .. . . . . . . . . . . . . . . . .. . . . . . . . .. .
Troublerhooting, Central Tire
Inflation System (CTIS) . . . . . . . .
Troubleshooting, compressed
air and brake system............
Troubleshooting, electrical
system . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . .
Troubleshooting, mechanical,
unit level. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Troubleshooting, STEACE
symptom index . . . . . . . . . . . . . . . . . . .
Tube (M939A2) Air Fuel
Control AFC), maintenance:
Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3-139d 3-377
3-139c 3-377
3-139b 3-976
3-139a 3-376
3-142b 3-388
3-142a 3-384
3-133a 3-354
3-133e
3-133d
3-133c
3-133b
3-133f

3-368
3-358
3-356
3-356
3-360

3-97b 3-272
3-97a 3-272
3-148c
3-148b
3-148d
3-148a

3-408
3-408
3-408
3-406

3-97b 3-272
3-97a 3-272
2-25

2-267

2-23

2-177

2-22

2-92

2-21

2-61

2-24

2-219

3-18b 3-61
3-18c 3-61
3-18a 3-61

Para
Tube, air cleaner indicator and,
maintenance:
Cleaning and inspection. . . . . . 3-12c
Installation. . . . . . . . . . . . . . . . . . . . . . . . . .. 3-12d
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-12b
Testing . . . . . . . . . . . . . . . . . . . . . .. . . . . . ... . . . . 3-12a
Tuber (M989/A1), coolant
hoses and, replacement:
Radiator inlet hoses and
3-54j
tube installation. . . . . . . . . . . . . . . .
Radiator inlet borer and
3-54a
tube removal. . . . . . . . . . . . . . . . . . . . .
Radiator outlet homer and
3-54g
tee installation . . . . . . . . . . . . . . . . .
Radiator outlet hoses and
3-54d
tee removal. . . . . . . . . . . . . . . . . . . . . . . 3-54h
Surge tank hose installation
Surge tank hose removal. . . . . 3-54c
Thermortat housing hose,
radiator bypass tube, and
hose installation. . . . . . . . . . . . . . . 3-54i
Thermostat housing hose,
radiator bypass tube, and
hose removal. . . . . . . . . . . . . . . . . . . . . 3-54b
Transmission oil cooler
horer and tube installation 3-54f
Transmission oil cooler
hoses and tube removal. . . . 3-54e
Tuber (M939A2), aftercooler
and, replacement:
Installation. . . . . . . . . . . . . . . . . . . . .. . . .
3-76b
3-76a
Removal..............................
Tubes (M939A2), aftercooler
and, replacement:
Installation. . . . . . . . . . . . . . . . . . . . . . . . . 3-76b
3-76a
Removal . . . . . . . . . . . . . . . . . . . . . . .. .
Tubing, ether, replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-39b
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-39a
Turbocharger and coolant lines
(M999A2) replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-21b
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 3-21a
Turn signal control and
indicator lamp replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-113b
Removal. . . . . . . . . . . . . .. . . . . . . . . . . . . . . . 3-113a
Turn signal flasher
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-114b
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-114a

Page

3-44
3-44
3-46
3-44
3-158
3-154
8-156
3-156
3-156
3-156
3-158
3-154
3-156
3-156
3-218
3-216
3-218
3-216
3-120
3-120
3-70
3-68
3-302
3-302
3-903
3-303

Index 23

TM 9-2320-272-24-1

INDEX (Contd)
Para Page
U
Unit Preventive Maintenence
Checks and Services (PMCS):
General. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-8
2-2
2-2
Intervals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-9
Reporting repairs . . . . . . . . . . . . . . . . 2- 10
2-3
General service and
inspection procedures... . . . . . 2-11
2-3
Specific PMCS procedures . . . 2-12
2-3
Universal joint, front axle shaft
and, maintenance:
Cleaning and inspection...... 3-154b 3-426
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3- 154e 3-429
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-154a 3-426
Universal joint assembly . . . . 3-154d 3-428
Universal joint disassembly 3-154c 3-428
Upper and lower torque rod
maintenance:
Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-170e 3-472
Cleaning and inspection...... 3-170c 3-470
Diassembly . . . . . . . . . . . . . . . . . . . . . . . . . 3-170d 3-470
Lower torque rod
installation . . . . . . . . . . . . . . . . . . . . . . . 3-170h 3-474
Lower torque rod removal... 3-170b 3-470
Setting preload for upper
torque rod . . . . . . . . . . . . . . . . . . . . . . . . . 3-170f 3-472
Upper torque rod
installation . . . . . . . . . . . . . . . . . . . . . . . 3-170g 3-474
Upper torque rod removal... 3-170a 3-468
Upper bracket, rear axles
spring seat wear pads and,
maintenance:
Inspection . . . . . . . . . . . . . . . . . . . . . . . . .. 3-168b 3-462
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-168c 3-462
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-168a 3-460
Upper radiator hoses and
brackets (M939A2)
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-58b 3-170
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 - 5 8 a 3 - 1 7 0
Use of metric system . . . . . . . . . . . . . . . 1-9
1-3
V
Valve (M936/A1/A2), brake
pedal (treadle), replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . . 3-198b 3-542
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-198a 3-540

Index 24

Para
Valve cover (M939A2)
maintenance:
Cleaning and inspection......
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Valve No. 1, doublecheck,
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Valve No. 1, doublecheck,
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Valve No. 2 (M931/A1/A2,
M932/A1/A2), doublecheck,
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Valve No. 2, doublecheck,
(M931/A1/A2, M932/A1/A2)
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Valve No. 2, doublecheck,
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Valve No. 2, doublecheck,
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Valve No. 2, doublecheck,
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Valve No. 5, doublecheck,
(M931/A1/A2,M932/A1/A2)
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Valve switch, fuel selector,
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Valve, brake pedal (treadle),
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Valve, Check, air reservoir oneway, replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3-6b
3-6c
3-6a

Page

3-26
3-26
3-22

3-212b 3-602
3-212a 3-602
3-212b 3-602
3-212a 3-602

3-214b 3-606
3-214a 3-606

3-214b, 3-606
3-214a 3-606
3-213b 3-604
3-213a 3-604
3-213b 3-604
3-213a 3-604
3-213b 3-604
3-213a 3-604

3-215b 3-608
3-216a 3-608
3-109b 3-296
3-109a 3-296
3-197b 3-538
3-197a 3-536
3-186b 3-514
3-186a 3-514

TM 9-2320-272-24-l

INDEX (Contd)
Para
Valve, ether cylinder and,
replacement:
Ether cylinder installation . .
Ether cylinder removal . . . . . . . .
Ether valve installation . . . . . .
Ether valve removal . . . . . . . . . . . .
Valve, interlock, transfer case,
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Valve, spring brake,
maintenance:
Adjustment . . . . . . . . . . . . . . . . . . . . . . . . .
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Valves No. 3, No. 4,
doublecheck and quickrelease valve replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
. Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
VS governor filter, fuel pump
with, replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3-35d
3-35a
3-35c
3-35b

3-115
3-114
3-115
3-114

3-143b 3-394
3-143a 3-392
3-173b 3-482
3-173c 3-482
3-173a 3-482

3-216b 3-612
3-216a 3-610
3-32b
3-32a

3-110
3-110

W
Warning module, failsafe,
replacement:
Installation.. .......................
Removal..............................
Warranty information.. ...........
Washer control valve
replacement:
Installation.. .......................
Removal..............................
Water pump (M939/A1)
replacement:
Installation.. .......................
Removal ..............................
Water pump (M939A2)
maintenance:
Cleaning and inspection......
Installation.. .......................
Removal.. ............................
Water pump drivebelt
(M939/A1) maintenance:
Adjustment.. .......................
Inspection.. .........................
Installation.. .......................
Removal ..............................

3-106b 3-290
3-106a 3-290
1-7
1-2
3-191b 3-524
3-191a 3-524
3-68b 3-200
3-68a 3-200
3-69b 3-202
3-69c 3-202
3-69a 3-202
3-67a
3-67c
3-67d
3-67b

Para

Page
Water temperature sending
unit replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wet air reservoir (supply tank)
and bracket replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wet air reservoir (supply tank)
and mounting plate
(M936/A1/A2) replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wet reservoir (supply tank)
safety valve replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wheel (M939A1/A2), tire and,
maintenance:
Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Disassembly . . . . . . . . . . . . . . . . . . . . . . .
Wheel brakedrum dustcovers
replacement:
Front wheel dustcovers
installation . . . . . . . . . . . . . . . . . . . . . . .
Front wheel dustcovers
removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Rear wheel dustcovers
installation . . . . . . . . . . . . . . . . . . . . . . .
Rear wheel dustcovers
removal . . . . . . . . . . . . . . . . . . . . . . . . .
Windshield wiper control valve
replacement:
Installation . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wiring harness repair:
Female cable connector
(with sleeve) . . . . . . . ...............
Male cable connector . . . . . . . . . . .
Plug assembly . . . . . . . . . . . . . . . . . . . .
Receptacle assembly . . . . . . . . . . .
Terminal-type cable
connector . . . . . . . . . . . . . . . . . . . . . . . . . . .

Page

3-93b 3-266
3-93a 3-266
3-200b 3-552
3-200a 3-548

3-201b 3-558
3-201a 3-556
3-185b 3-512
3-185a 3-512
3-221b 3-634
3-221a 3-630

3-178c 3-496
3-178a 3-496
3-178d 3-496
3-178b 3-496
3-192b 3-526
3-192a 3-526
3-131c
3-131b
3-131d
3-131e

3-350
3-350
3-350
3-350

3-131a 3-349

3-196
3-198
3-198
3-198

Index 25/(lndex 26 blank)

By Order of the Secretary of the Army:

DENNIS J. REIMER
General, United States Amy
Chief of Staff

Administrative Assistant to the
Secretary of the Army
04909

DlSTRIBUTlON: T o b e d i s t r i b u t e d i n a c c o r d a n c e w i t h t h e i n i t i a l d i s t r i b u t i o n
number (IDN) 381074 requirements for TM 9-2320-272-24-1.

*U. S. GOVERNMENT PRINTING OFFICE:1998-646-039/80044

PIN: 076654-000



---

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