GM 4L80E Transmissions: How to Rebuild & Modify

by Eric McClellan

Overview

Learn how to rebuild and modify the GM 4L80E transmission!

As the successor to the venerable and popular Turbo Hydra-matic 400 (TH400), the 4L80E was the next flag bearer in GM’s line of automatic transmissions. While serving as the smaller, lighter cousin to the 4L85E, the abundance of 4L80E transmissions manufactured between 1991 and 2013 ensures that these highly capable 4-speed overdrive units will be in service for years to come.

Automatic transmissions are often seen as mysterious and overly complicated, but much of the guesswork has been simplified to its basic elements in this easy-to-follow guide. This book covers the process of identifying the best versions, tearing down the 4L80E, rebuilding, reassembly, and troubleshooting. Upgrades that are available for the 4L80E, which is a popular topic among performance fans and transmission swappers, are also included.

This detailed, step-by-step instructional manual is authored by racer and builder Eric McClellan. Meticulous step-by-step photos of the rebuild process are featured along with torque specs and unique identification of all major and most minor components.

Product Details

ISBN-13:	9781613255698
Publisher:	CarTech
Publication date:	07/27/2021
Pages:	128
Product dimensions:	8.50(w) x 11.00(h) x 0.38(d)

About the Author

Eric McClellan is a lifelong Chevy Corvette, and Camaro enthusiast. He has authored two previous General Motors-related titles: How to Build Max Performance LT1/LT4 Engines with Myron Cottrell and Swap LS Engines into Camaros and Firebirds (1967-1981). Eric has contributed to countless articles for automotive magazines. He handbuilt many street and race cars and currently enjoys his rare-optioned C6 Z06/Z07.

Table of Contents

Dedication 4

Acknowledgments 4

Chapter 1 History, Identification, and Evolution 5

4L80E versus 4L60E 6

1991-1996 16

1994-1996 17

1997-1999 17

2000-2003 17

2004-and-Up 18

Basic Information 21

Buyer's Guide 26

Chapter 2 Disassembly 29

Work Area 29

Tools and Supplies 30

Cleaning 32

Disassembly 33

Chapter 3 Reassembly 57

Preparation 57

Rear Main Seal 60

Rear Output Shaft Assembly 60

Nylon Seals 61

Center Support 61

Output Carrier Assembly 65

Intermediate Clutch and Direct Clutch Housing 68

Forward Clutch Housing Assembly 71

Fourth Clutch Assembly 78

Overdrive Unit Assembly 79

Oil Pump 84

Shift Kit Modifications 92

Intermediate Servo Piston 92

Reverse Servo 93

Clutch Piston Engagement Check 94

Valve Body 95

Shift Solenoids 101

Accumulator Housing 106

Retainer Pin 112

Wiring Harness 117

Oil Filter 120

Pan Gasket 121

Chapter 4 Troubleshooting 123

Common Failures 127

Appendix 128