GM Transmission Leak
Certain 2005 and older General Motors
cars and trucks equipped with a 4T65-E
automatic transmission may develop a
leak from the transmission case.
According to GM, the leakage is most
common in colder temperatures (20°F or
lower) and is caused by reverse servo
cover seal shrinking that creates gaps
between the case and servo cover.
While GM originally recommended
replacing the entire servo cover and
seal, the company now offers a new
seal designed to be used with the original