Description
Since the introduction of the THM 4L60E transmission in 1993, there have been many major engineering design changes to improve durability and reliability. These changes have affected nearly every part used in the THM 4L60E.
This “Update Handbook” will explain each change, the parts affected by the change, and any parts interchangeability concerns created by the change. Beginning at the start of production for model year 2001, General Motors introduced a new transmission designated THM 4L65E with many engineering changes.
This unit is found in any vehicle with 5.3L or a 6.0L engine that was previously equipped with the THM 4L60E transmission. We will also cover the changes in the THM 4L65E transmission in this booklet. For the 2006 model year the 4L70E was introduced to be used behind the 6.0L or larger gas engines which received heavier duty parts to handle additional horsepower. There is no external way to distinguish the 4L70E from the 4L65E, however, the vehicle identification tag should have an M70 designation if the vehicle was originally equipped with a 4L70E. Also included will be the additions the 4L70E transmission received.
