4L60E LB1 IN
2015-09-03
: Sonnax 4L60E-Lb1-In 4L60E-LB1-IN 600 file instruction uploads
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Instructions
High Performance TRANSMISSION Parts
PERFORMANCE
©2015 Sonnax Industries, Inc. 4L60E-LB1-IN 09-02-15
800-843-2600 • 802-463-9722 • F: 802-463-4059 • www.sonnax.com Page 1
1. Verify Correct Boost Valve Application
Before installing Sonnax line pressure booster kit, compare length of the OE boost sleeve to Son-
nax sleeve. Overall lengths must be the same. Most early-style pump bodies will use the long boost
assembly (4L60E-LB1). Some late production, early-style pump covers will use the short boost
assembly (Figures 1 and 2), even though the casting number and all other features are identical. In
most circumstances, comparing the original boost sleeve to the replacement is all that is required
for verication (Figures 1 and 2).
If you have a pump cover that is missing the boost sleeve it is possible to verify which length sleeve
belongs in the bore by measuring from the very inner point of the main pressure regulator valve
bore to the inner edge of the retaining ring groove. e distance for the long boost assembly is
4.740", and for the short boost assembly is 4.643".
Early-Style Pump Cover
Figure 2
Late-Style Pump Cover
GM 4L60-E, 4L65-E
Pressure Regulator
Spring
Large Ratio
Boost Assembly
(Long)
4L60-E
Pump
Line Pressure
Booster Kit
Part No.
4L60E-LB1
• Large Ratio Boost Assembly Long
• Pressure Regulator Spring
• O-Rings (2)
Patent No. 6,619,323
NOTE: Fits early-style pump.
Figure 1
Early Style (long)
1.907" 48.5mm
Use 4L60E-LB1
Late Style (short)
1.810" 46mm
Use 4L60E-LB2
2. Disassembly
a. Remove OE retainer and set aside for
reuse.
b. Remove and discard OE boost valve
and sleeve.
c. Remove OE bumper spring and set
aside for reuse.
d. Remove and discard OE large-diameter
pressure regulator spring.
Figure 3
Radial Wire Brush
3. Bore Preparation
O-rings included in this kit provide extra insur-
ance toward preventing cross leaks and should
always be installed.
a. Carefully inspect snap ring grooves, feed
holes or bore edges and de-burr if necessary
to reduce cutting. A non-abrasive tool such
as a radial wire brush (Figure 3) works best,
but the bore should always be thoroughly
cleaned after any de-burring.
b. Place the two O-rings into the grooves on
the boost sleeve, roll sleeve over bench to
resize the O-rings, then pre-lube O-rings.
Sonnax Slippery Stick™ (O-LUBE) or
Door Ease® are ideal for this purpose.
PERFORMANCE
High Performance TRANSMISSION Parts
LINE PRESSURE BOOSTER KIT 4L60E-LB1
©2015 Sonnax Industries, Inc. 4L60E-LB1-IN 09-02-15
800-843-2600 • 802-463-9722 • F: 802-463-4059 • www.sonnax.com Page 2
Instructions
4. Installation
a. Install OE small bumper spring and Sonnax pressure regulator spring.
b. With open end toward the two springs, carefully insert Sonnax valve/sleeve
assembly into pump cover, just far enough to reinstall OE retaining ring.
The Prescription for Optimum Pressure
Stronger pressure regulator springs raise pressure equal amounts at both idle and
maximum load. Many aftermarket “kit” springs are a compromise,
raising pressure too much at idle and not enough at maximum
loads (A in graph). Larger boost valves, on the other hand, have
a progressive eect on pressure, changing the rate of pressure in-
crease (B in graph).
e Sonnax large ratio boost valves and stronger pressure regulator
springs are designed to work together. is is an ideal combina-
tion: smooth engagements and lower load on the pump at idle,
but a greater increase in pressure as the transmission is worked
harder.
For a more in-depth look at raising line pressure, read e
Prescription for Optimum Pressure in the Sonnax online technical
library at www.sonnax.com.
Pump Tech
Good Pressure Depends on a Good Pump
Verify Pump Specifications
Excess clearance equals low pump volume and pressure.
Check for Wear
• If pivot is worn, replace with Sonnax pivot pin 65797.
• If vane has visible wear, replace with Sonnax pump vane 1280.
Shift Tech
For detailed information on drilling separator plate orices, read
Drilling Orices the Smart Way in the Sonnax online technical
library at www.sonnax.com.
Rotor, slide and vanes
.0005" to .002" Check with feeler gauge and straight edge over
pump face, or with Plastigauge and bolt complete pump together.
Too Loose = low pressure. Too Tight = no line rise, slide is stuck.
To check, remove all pump parts and seals, assemble halves with just
the pump slide and shake. You should hear pump slide moving inside.
OE
Retaining
Ring
Pressure
Regulator
Spring
OE Bumper
Spring
Figure 4
Large Ratio
Boost Assembly
Increases in Line Pressure
Stronger Springs vs. Larger Boost Valves
B
B
A
A
OE Springs
A -
B -
Key
Aftermarket “Kit” Springs
Sonnax Line Pressure
Booster Kits
Low EPC/Torque Signal Pressure High
Low Line Pressure High
Figure 5
Pump
Slide Spring
Pivot
Pin
Slide
Wiper
Seal
Pump Vane Wear
Worn
Valve Bore
Position valve at normal regulation in this opening.
It should not have side-to-side movement
Pump
