How Much Do You Know About The GM 4T65E Transmission?
Posted by Regis on Tuesday, January 1st, 2013
The 4T65E is a four speed automatic transmission made by general motors. It was designed for cars where the engine was transversely mounted. The 4T65E originated from the early three speed Turbo Hydramatic 125 transmission. This transmission is electronically controlled, including an electronically controlled lockup torque converter. The 4T65E is also referred to as a transaxle, meaning the transmission and drive axle assembly is housed in one case.
The 4T65E was first put into production in 1997, following in the footsteps of the 4T60E transmission. It served duty in the Pontiac Grand Prix, Montana, Aztec, Bonneville, along with the Chevy Lumina, Monte Carlo, Venture, Malibu and Impala, and a handful of Buick and Oldsmobile models.
It was equipped with five different types of torque converter, ranging from 9.6 inches up to 10.2 inches. The transmission was equipped with a 2.92 first gear ratio and a 0.70 overdrive gear ratio. The 4T65E was used in cars weighing up to 6500 pounds and with motors that made up to a max of 280 ft. lbs. of torque.
The 4T65E was also available in a heavy duty version, referred to as the 4T65E-HD. This heavy duty version was designed to go behind higher horse power LS V8 small blocks and high output turbo charged V6 engines.
Common problems with the 4T65E are as follows:
Solenoid failures: The transmission is controlled by electrical solenoids that receive a signal from the computer telling it when to shift. Over time the solenoids will burn up and fail. Overheating the transmission helps contribute to early solenoid failure.
PCS failure: The PCS (Pressure Control Solenoid) can fail just like any other solenoids in the transmission. The PCS controls the line pressure in the transmission.
Over firm 1-2 and 2-3 shifts: Probably caused by the failing of the PCS solenoid.
Sipping on initial takeoff: The first thing that should come to mind is that the fluid needs changed. I recommend a full drain and flush service to make sure the cooler and lines and cleaned of any debris. Installing a shift improver kit can also help cure this problem.
No fourth gear: The cause of this problem is the splines wearing off the clutch hub shaft. Later model transmissions were equipped with hardened shafts that help reduce the occurrence of this problem.
No movement in any gear: This is usually a bad sign and most likely will require the transmission to be removed and rebuilt or replaced with a re-manufactured unit. Causes range from a broken input shaft, broken drive chain/sprocket, low fluid level, clogged filter and stripped converter splines to a broken input clutch drum shaft.
No reverse: Common causes of this problem are a blown sealing lip on the reverse servo, worn reverse booster valve/sleeve or a partially blown channel plate gasket.
The 4T65E is not a bad little transmission, but does have its share of issues. Be sure to do your homework before buying a car equipped with the 4T65E and make sure the owner shows you all the maintenance paper work before you exchange any of your hard earned cash.