GM THM 125C / 3T40 Transaxle Automatic Transmission Rebuild Update Handbook - Softcover

Since the introduction of the THM 125 transaxle in model year 1980, there have been many major engineering changes.  These changes have effected nearly every part used in the THM 125 and THM 125C.

This update book will explain each change, the parts affected by the change, and any parts interchangeability problems created by the change.  This Update Book will cover all of the changes from start of production up through and including model year 1987, along with common problems, and fixes, for the THM 125 Transaxle.