List of GM transmissions


is an innovator of automatic transmissions, introducing the Hydra-Matic in 1940. This list includes some GM transmissions.

Automatic transmissions

Early models

The GM Hydra-Matic was a success and installed in the majority of GM models by 1950. Through the 1950s, all makers were working on their own automatic transmission, with four more developed inside GM alone. All of GM's early automatic transmissions were replaced by variants of the Turbo-Hydramatic by the 1970s.
The Turbo-Hydramatic was used by all GM divisions, and formed the basis for the company's modern Hydramatic line. The basic rear-wheel drive Turbo-Hydramatic spawned two front-wheel drive variants, the transverse Turbo-Hydramatic 125, and the longitudinal Turbo-Hydramatic 425. A third variant was the light-duty rear wheel drive Turbo-Hydramatic 180 used in many European models.
;Heavy-duty rear wheel drive
;Medium-duty rear wheel drive
;Light-duty rear wheel drive
;Transverse front wheel drive
;Longitudinal front wheel drive
The next-generation transmissions, introduced in the early 1990s, were the electronic Hydra-Matics based on the Turbo-Hydramatic design. Most early electronic transmissions use the "-E" designator to differentiate them from their non-electronic cousins, but this has been dropped on transmissions with no mechanical version like the new GM 6L80 transmission.
Today, GM uses a simple naming scheme for their transmissions, with the "Hydra-Matic" name used on most automatics across all divisions.
3/4/5/6L/T##-Elll
Number of forward gearsL=Longitudinal
T=Transverse		GVWR rating"E" for Electronic
"HD" for Heavy Duty

;First-generation longitudinal
;First-generation transverse
*This transmission is part of a joint-venture between General Motors and Ford Motor Company to split development of two transmissions, a longitudinal 10-speed and transverse 9-speed. Ford led the design of the 10-speed transmission, as well as filing the design patents for said transmission. According to an official report by the SAE the design of the 10-speed gearbox is essentially all Ford, while GM was responsible for designing the 9-speed 9T transverse automatic gearbox. As part of their joint-venture, Ford will let GM use the 10-speed transmission with rights to modify and manufacture it for their own applications. In-exchange for Ford's 10-speed transmission, General Motors will let Ford use its 9-speed transmission for front-wheel drive applications; Ford ultimately declined use of the 9T.
;Second-generation transverse

Manual transmissions

Longitudinal transmissions