This article relies largely or entirely on a single source. (April 2019)
The 4T40-E and 4T45-E are a series of automatic transaxles from General Motors. Designed for transverse engine configurations, the series includes 4 forward gears. The 4Txx family replaced the Turbo-Hydramatic 125 transverse three speed automatic introduced in 1980.
|Body and chassis|
|Class||4-speed transverse automatic transmission|
|Successor||GM 6T40 transmission|
The "-E" series is electronically controlled and features an automatic overdrive transaxle with an electronically controlled torque converter clutch. Since non-electronic versions of these transmissions do not exist, it is conventional to refer to these models as simply 4T40 and 4T45, leaving out the "-E".
The "MN4" 4T40E is able to handle vehicles up to 4000 lb (1814 kg) GVWR. The final drive ratio can vary depending on the car's curb weight and engine power output. 3.91, 3.63, 3.29, 3.05, 3.69, and 3.42 are all of the available ratios used in the 4T40 (and 4T45) transmission; Made possible by using combinations selected from 3 different sprocket combinations (32/38, 35/35, 33/37) and 2 differentials (3.29, 3.05). It is designed for 1.5–3.1 L engines producing up to 190 ft·lbf (258 N·m) of torque.
Minor design changes provided the 4T40E an increased torque capacity, producing the 4T45E. The "MN5" 4T45E is able to handle vehicles up to 4,500 lb (2,041 kg) GVWR. Final drive ratios include 3.63, 3.29, 3.05, and 3.91. This same transmission is used in the Saturn Vue Green Line hybrid vehicle with the addition of an auxiliary oil pump and hybrid-aware electronics. It is designed for 3.0–3.5 L engines producing up to 205 ft·lbf (278 N·m) of torque, but was also commonly mated to some versions of GM's 4-cylinder Ecotec line.
- "Saturn Vue Green Line Uses New, Less Complex Hybrid System". General Motors press release. Archived from the original on March 15, 2006. Retrieved January 9, 2006.