ATSG 4L80E Transmission Repair Manual - GM THM4L80-E

The 4L80E is GM's heavy-duty overdrive automatic behind the big trucks, vans and SUVs - the 3/4-ton pickups, Suburbans, Express and Savana vans, Hummer H1 and the diesel and big-block applications from 1991 on. It is a strong unit, but it fails in predictable ways: burnt direct clutches, a cracked or worn 2-4 band, pump problems, and the electrical faults that throw pressure control and shift solenoid codes. Guessing your way through a 4L80E teardown is how you end up with a comeback. This ATSG manual is the reference that keeps that from happening.

ATSG (Automatic Transmission Service Group) writes these books with people who spend their days rebuilding these transmissions. Inside you get the full teardown and reassembly sequence, exploded views of the planetary and clutch assemblies, clutch and band clearance specs, air-check procedures for the valve body, line pressure and solenoid resistance values, the wiring and connector pinouts, and the diagnostic code charts for the electronic controls. It walks the actual problems techs hit - flare on the 1-2, no reverse, converter clutch codes - and points you at the cause instead of the parts cannon.

This is the manual to have open on the bench whether you are doing your first 4L80E or your fiftieth. It covers the electronically controlled THM4L80-E from its 1991 introduction forward. Paperback, standard 11 by 8.5 inch shop format, ships from the USA. Pair it with a master overhaul kit and the right solenoid pack and you have everything you need to bring the unit back correctly.