What You Need To Know About The GM 4T40E Transmission
Posted by Regis F. on Friday, December 21st, 2012
The 4T40E is a four speed automatic transaxle designed and built by General Motors. It was first used in 1995 in the Chevrolet Cavalier and Corsica, along with the Pontiac Sunfire. The transmission was used up through 2005 in many other vehicles, including the Daewoo Nubira and Lanos, the Chevrolet Malibu, the Pontiac Grand Am, the Oldmobile Alero and Cutlass, and the Saturn L-Series of vehicles. Let’s take a closer look at the 4T40E.
The 4T40E came with many different final drive ratio’s, including the following ratios: 3.91, 3.69, 3.63, 3.42, 3.29 and 3.05. The gear ratio was selected based on the engine and the weight of the cars it was going in.
The transmission was used to replace the TH-125 transaxle. The 4T40E was built at the General Motors transmission plant in Windsor, Ontario, Canada.
The 4T40E does not use a dipstick to measure the level of the transmission fluid. Instead it has a fill plug on the side of transmission (like a manual transmission). The fluid level should be up to the bottom of the fill level plug. If you only remove the pan it takes 7.4 quarts to refill the transmission up. If a new torque converter has been installed add another 2.6 quarts of oil. If the transmission has been completely rebuilt or re-manufactured, it will take a total of 10.6 quarts of oil.
There are some potential problems with the 4T40E:
- Like every other automatic transmission, overheating is a major cause for concern. It is recommended that an aftermarket cooler be installed in conjunction with the factory transmission cooler.
- Lack of maintenance is a potential problem that you might not be aware of when buying a used car with the 4T40E transmission. It is recommended that the fluid be changed every 25,000 miles. Ask for service records when buying a used car to verify that scheduled maintenance was done in accordance with the factory manual. Steer clear of vehicles with no paperwork outlining past maintenance.
- Failure of the 2-3 shift solenoid is a common problem. Because the solenoid is an electric-mechanical device it is easily destroyed by too much heat. The 2-3 solenoid is located inside the transmission and requires about 8 hours of labor to repair.
- Failure of the TCC PWM, which stands for Torque Converter Clutch Pulse Width Modulation solenoid. The TCC is located inside of the valve body and is part of the internal wire harness. It is highly recommended that the internal wire harness be replaced at the same time you replace the TCC.
- Failure of the forward clutch is another common problem. The symptoms are no forward gears, but the transmission still has reverse. Replacement of the forward clutch requires the removal of the transmission and complete disassembly of it.
- Failure of the input sprag clutch. The symptoms are the same as the failure of the forward clutch – no forward gears – but the transmission still has reverse. Replacement of the forward clutch also requires the removal and disassembly of the transmission.
The 4T40E is a fairly decent transmission when not subject to too much abuse. Like any other parts on your car, the transmission has a finite life span.