No part of any ATSG publication may be reproduced, stored in any retrieval system or transmitted in any form or
by any means, including but not limited to electronic, mechanical, photocopying, recording or otherwise,
without written permission of Automatic Transmission Service Group. This includes all text illustrations,
tables and charts.
"Portions of materials contained herein have been reprinted under
license from General Motors Corp, Service & Parts Operations."
The information and part numbers contained in this booklet have
been carefully compiled from industry sources known for their
reliability, but ATSG does not guarantee its accuracy.
Copyright © ATSG 2003
FIELD SERVICE CONSULTANT
This booklet contains the general description, diagnosis charts, and the procedures necessary to overhaul, repair
or service the General Motors THM 4T80-E four speed automatic overdrive transaxle. This information will
assist you in training your technicians to provide your customers with the best possible transmission service that
The THM 4T80-E is a fully automatic, front wheel drive, electronically controlled transaxle. It provides four
forward speeds with 4th gear being overdrive. Shift points are controlled by the Powertrain Control Module
(PCM) with two shift solenoids. Oil pressure is supplied by two gear type pumps. Oil pressure is regulated by
the PCM using a Pressure Control Solenoid. Shift schedule and TCC apply rates are also controlled by the PCM
and are influenced by many inputs from various sensors on the vehicle.
AUTOMATIC TRANSMISSION SERVICE GROUP
18639 S.W. 107TH AVENUE
MIAMI, FLORIDA 33157