List of GM transmissions explained

This is a list of most transmissions produced or used in General Motors (GM) vehicles.

Automatic transmissions

Early models

GM's Automatic Safety Transmission (AST) was a semi-automatic transmission released in 1937. The first mass-produced fully-automatic transmission developed for passenger automobile use was the GM Hydramatic introduced in 1940.^[1] The Hydramatic was a big success, and had been installed in the majority of GM models by 1950. Throughout the 1950s, all GM Marques continued developing automatic transmission designs, both jointly and independently. Early models included:

• 1937–1939 Automatic Safety Transmission (AST) — Oldsmobile, Buick in 1938 only
• 1940–1967 Hydramatic — 4-speed Pontiac/Oldsmobile/Cadillac (totally different design than the later Turbo-Hydramatics)
• 1947–1952 Dynaflow — Buick's "2-speed CVT"
• 1950–1973 Powerglide — 2-speed Chevrolet (also used by Pontiac, Holden, Vauxhall and Opel).
• 1953-1955 Twin Turbine Dynaflow: the 1st redesign w/ 2 turbines & single stator.
• 1956-1957 Twin Turbine 2 Dynaflow: the 2nd redesign w/ 2 turbines & variable-pitch stator.
• 1956-1964 Dual-Coupling/Controlled-Coupling Hydramatic — Substantial redesign of the Hydramatic. (Aka Cadillac 315/P315 HydraMatic, Oldsmobile Jetaway/StratoFlight, Pontiac Super HydraMatic).
• 1957–1961 Turboglide — Chevrolet's constant-torque "3-speed CVT" (V8 models only, except Corvette)
• 1958–1959 Flightpitch/Triple Turbine Dynaflow — Buick's 3rd redesign w/ Triple Turbines
• 1961–1963 Buick's Dual-Path Turbine Drive
• 1961–1964 Roto Hydramatic — Compact Hydramatic-based 3-speed used by Oldsmobile, Pontiac, Holden, Vauxhall and Opel
• 1962-1972 TempestTorque — Powerglide-based 2-speed with "Split-Torque".
• 1964–1969 Super Turbine 300 — 2-speed (aka Buick ST-300, Oldsmobile Jetaway, Pontiac "Automatic")
• 1968–1971 Torque-Drive — Chevrolet's column-shifted 2-speed semi-automatic Powerglide (only w/ 6-cyl)

Turbo-Hydramatic 3-speed Automatics

Introduced in 1964, Turbo-Hydramatic use quickly spread across all GM divisions, and they became referred to simply as Hydramatics (like GM's original automatic of totally different design), except for the Super Turbine 400 model. By the 1970s, Turbo-Hydramatic variants had replaced all of GM's early automatic transmission designs. In Argentina, the Turbo Hydra-Matic was marketed as the "Chevromatic" in the 1970s. Starting in the early 1980s, the Turbo-Hydramatic was gradually supplanted by four-speed automatics, some of which continue to use the "Hydramatic" trade name.

Originally a medium-duty longitudinal rear-wheel drive design, other variants were later developed, including both light-duty and heavy-duty RWD versions, and both longitudinal and transverse front-wheel drive versions.

Medium-duty rear wheel drive

• 1964–1992 Super Turbine 400/TH400/3L80
• 1969–1986 TH350/TH350C/TH375B/TH250/TH250C
• 1972–1976 TH375 — Light duty version of TH400
• 1976–1987 TH200/TH200C
• 1981–1990 TH200-4R
• 1982–1993 TH700R4/4L60

Heavy-duty rear wheel drive

• 1971–1994 3L80HD (heavy duty version of TH400)

Light-duty rear wheel drive

• 1969–1998 TH180/TH180C/3L30 — European/Asian model. Used/manufactured by Holden as the Trimatic.

Longitudinal front wheel drive

• 1966–1978 TH425 — 3-speed
• 1979–1981 TH325 — 3-speed
• 1982–1985 TH325-4L — 4-speed

Transverse front wheel drive

• 1980–1999 TH125/TH125C/3T40 — 3-speed light-duty
• 1984–1994 TH440-T4/4T60 — 4-speed medium-duty

Turbo-Hydramatic Model Designations

Initially, models were designated with the letters TH/THM/ST followed by the series/version number. In 1987, GM switched to a simpler naming scheme for their transmissions (Example: 4L80E)

Electronic Hydra-Matics

The next-generation transmissions, introduced in the early 1990s, were the electronic Hydra-Matics, still 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 6L transmission.

First-generation longitudinal (Rear Wheel drive)

• 1991–2001 4L30-E — 4-speed light-duty (used in BMW, Cadillac, Isuzu, and Opel cars)
• 1992– 4L60-E/4L65-E — 4-speed medium-duty (used in GM trucks and rear-wheel-drive cars)
• 1991– 4L80-E/4L85-E — 4-speed heavy-duty (used in GM trucks)

First-generation transverse (Front Wheel drive)

• 1995–2010 4T40-E/4T45-E — 4-speed light-duty (used in smaller front wheel drive GM vehicles)
• 1991–2010 4T60-E/4T65-E/4T65E-HD — 4-speed medium-duty (used in larger front wheel drive GM vehicles)
• 1993–2010 4T80-E — 4-speed heavy-duty (used in large FWD GM vehicles, only with Cadillac NorthStar V8 and Related Oldsmobile V8)

Second-generation longitudinal (Rear Wheel drive)

• 2000–2007 5L40-E/5L50 — 5-speed medium-duty (used in Cadillac's Sigma vehicles)
• 2006–present 6L45 · 6L50 — 6-speed medium-duty (used in GM Sigma platform cars)
• 2005–present 6L80 · 6L90 — 6-speed heavy-duty (used in GM trucks and performance cars)
• 2014–present 8L 90 — 8-speed heavy-duty (used in GM trucks and performance cars)
• 2016–present 8L 45 — 8-speed light-duty (used in GM luxury cars)
• 2017–present 10L80 — Ford-GM 10-speed automatic (used in GM light trucks pickups and related SUVs)
• 2017–present 10L90 — Ford-GM 10-speed automatic (used in GM performance cars)

Second-generation transverse (Front Wheel drive)

• 2008–present 6T30/6T40/6T45 — 6-speed light-duty
• 2006–present 6T70/6T75 — 6-speed medium-duty
• 2016–present 9T50/9T65 Hydra-Matic – 9-speed^[2]

Hybrid and PHEV

• 2ML70 - 2-Mode Hybrid transmission.
• 4ET50 (MKA) - Electric Drive Unit Transaxle (First Generation Chevrolet Volt / Cadillac ELR)
• 5ET50 (MKV) - Electronically controlled, continuously variable automatic transaxle (Second Generation Chevrolet Volt)^[3]
• 5ET50 (MKE) - Electronically controlled, continuously variable automatic transaxle Transaxle (Full Hybrid, Ninth Generation Chevrolet Malibu)^[4]
• 4EL70 (MRD) - Electric Drive Unit Transmission (PHEV Cadillac CT6)

Other automatics

• Aisin AF33 — 5-speed transverse automatic made by Aisin AW Co., Ltd.
• Allison 1000 Series — 6-speed longitudinal automatic made by Allison Transmission
• Saturn MP6/MP7 — 4-speed automatic developed by Saturn for use in the S-series from 1991 to 2002
• VTi transmission — continuously variable transmission
• Tremec M1L transmission — 8-speed Dual-Clutch made by Tremec for the Chevrolet Corvette C8
• GM VT40/CVT-250 (RPO MRD) Introduced in 2019 — continuously variable transmission

Manual transmissions

Longitudinal transmissions

• Aisin AR5/MA5 — 5-speed longitudinal manual made by Aisin
• Aisin AY6 — 6-speed longitudinal manual made by Aisin
• Getrag 260 — 5-speed longitudinal manual made by Getrag
• Muncie M20 — 4-speed longitudinal wide ratio manual transmission made by GM at their Muncie, Indiana factory
• Muncie M21 — 4-speed longitudinal close ratio manual transmission made by GM at their Muncie, Indiana factory
• Muncie M22 — 4-speed longitudinal heavy duty close ratio manual transmission made by GM at their Muncie, Indiana factory
• Saginaw M26/27 transmission — 3 and 4-speed longitudinal light duty (less than 300 hp) wide ratio manual transmission made by GM at their Saginaw, Michigan factory
• Muncie M62/M64 — 3-speed longitudinal transmission made by GM
• Muncie SM420 transmission — 4-speed manual used up to 1967, very similar to sm 465 except small changes to gear ratios and location of reverse.
• New Process Gear NP435 - 4-speed longitudinal transmission used in a select handful of 67-72 GM pickups
• New Process Gear A833 RPO MY6 or MM7 — 4-speed longitudinal A833 overdrive transmission made by New Process Gear for early to mid 1980s General Motors Light Trucks
• Muncie SM465 — 4-speed longitudinal manual used in 68- 91 Chevy 1/2 3/4 and 1 ton trucks
• New Venture Gear NV1500 — 5-speed longitudinal manual made by New Venture Gear
• New Venture Gear 3500/4500 — 5-speed longitudinal manual made by New Venture Gear
• Borg-Warner T-10 transmission — 4-speed longitudinal manual currently made by Richmond Gear; originally made by Borg-Warner
• Tremec T-5 — 5-speed longitudinal manual currently made by Tremec; originally made by Borg-Warner
• Borg-Warner R-10 overdrive - 3-speed manual transmission with electric overdrive used 1937-1964
• Borg-Warner R-11 overdrive - 3-speed manual transmission with electric overdrive Ford used them up until 1975 in trucks.
• Borg-Warner T-50 transmission — 5-speed longitudinal manual - used by GM in its RWD H-Body cars and a few other limited light duty applications from 1976 to 1978;
• Tremec T-56 — 6-speed longitudinal manual overdrive made by Tremec; formerly made by Borg-Warner
• Tremec TR-6060 — 6-speed longitudinal manual overdrive made by Tremec
• ZF S6-650 — 6-speed longitudinal manual made by ZF Friedrichshafen
• Tremec TR-6070 — 7-speed longitudinal manual overdrive made by Tremec

Transverse Transmissions

• F23 — 5-speed transverse manual manufactured by Getrag
• F25 — 5-speed transverse manual manufactured by Getrag
• M17 — 4-speed transverse manual manufactured by Muncie
• F35 — 5-speed transverse manual manufactured by Saab in Gothenburg, Sweden
• F40 — 6-speed transverse manual manufactured by FGP Germany
• Getrag 282 — 5-speed transverse manual designed by Getrag and manufactured by Muncie Getrag
• Getrag 284 — 5-speed transverse manual designed by Getrag and manufactured by Muncie Getrag
• M32 — 6-speed transverse manual manufactured by Fiat-GM Powertrain in Turin, Italy since 2004
• MP2/MP3 — 5-speed manual developed by Saturn for use in the S-Series from 1991 to 2002

Notes and References

1. Web site: Hydra-Matic History: The First Automatic Transmission . Ate Up With Motor . 2010-05-29 . 2014-01-15.
2. News: Panait . Mircea . GM Hydra-Matic 9T50 Transmission Confirmed for Chevrolet Cruze, Malibu, Equinox . autoevolution . 2016-12-07.
3. Web site: GM Service Insights, pg 23 . 2019-07-16 . https://web.archive.org/web/20190109210903/https://gmserviceinsights.com/wp-content/uploads/2016/09/Service-Insights-Vol-3-2016.pdf . 2019-01-09 . dead .
4. Web site: GM Service Insights, pg 23 . 2019-07-16 . https://web.archive.org/web/20190109210903/https://gmserviceinsights.com/wp-content/uploads/2016/09/Service-Insights-Vol-3-2016.pdf . 2019-01-09 . dead .