General Motors is an innovator of automatic transmissions, introducing the Hydra-Matic in 1940.^[1] This list includes some GM transmissions.

GM 3 Speed Transmission Dimensions GM Turbo 350 and 400 Transmission Measurements. Bellhousing pattern - Chevrolet, BOP, Fit-All. Muncie M62/M64 — 3-speed longitudinal transmission made by GM Muncie SM420 — 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. .The direct drive transmission can be used in both dirt & asphalt race cars.The racing transmission is based on a General Motors Saginaw 3-speed transmission that has a drop out counter shaft in high gear. In an unmodified transmission the input shaft spins the counter shaft and gears all of the time. Special design 300M input shaft 1-3/16 27 spline. Aircraft grade quality 7075-t6, billet aluminum forward drum. Eliminates 4.5lbs of rotating weight from transmission, with 10 times more strength. Reinforced 4140 billet insert. Heat treated billet steel forward clutch hub with large spline.

Automatic transmissions[edit]

Early models[edit]

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.

• 1940–1967 Hydra-Matic — Oldsmobile (now the trade name for all GM automatic transmissions)
• 1948–1963 Dynaflow — Buick
• 1950–1973 Powerglide — Chevrolet (also used by Pontiac, Holden, Vauxhall and Opel)
• 1968-1971 Torquedrive- Chevrolet ( Camaro and Chevy II, Nova. Manually shifted on Column. )
• 1957–1961 Turboglide — Chevrolet (V8 models only, except Corvette)
• 1958–1959 Flightpitch — Buick
• 1961–1963 Dual Path Turbine Drive — Buick
• 1961–1964 Roto Hydramatic — Oldsmobile/Pontiac (also used by Holden)
• 1964–1969 Super Turbine 300 — Buick/Oldsmobile/Pontiac (Oldsmobile Jetaway)
• 1968–1969 Torquedrive — Chevrolet (manually column shifted 2 speed automatic, 6 cyl only)
• 1956-1964 4 speed Controlled coupling HydraMatic, also known as Cadillac 315 or P 315 HydraMatic, Oldsmobile Jetaway, Pontiac Super HydraMatic.
• TempestTorque, ( Pontiac) a two speed based on Powerglide, but having the added feature of ' Split Torque ' dividing the engine power between mechanical connection and the torque converter in high gear.

Turbo-Hydramatic[edit]

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 transverseTurbo-Hydramatic 125, and the longitudinalTurbo-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

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

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

Light-duty rear wheel drive

• 1969–1998 TH180/TH180C/3L30 — 3-speed European/Asian model. Also manufactured and used by Holden as the Trimatic transmission.

Transverse front wheel drive

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

Longitudinal front wheel drive

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

Electronic Hydra-Matics[edit]

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.

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 front wheel drive GM vehicles, only with Cadillac NorthStar V8.

Second-generation longitudinal (Rear Wheel drive)

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

*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 (Society of Automotive Engineers) 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.^[2][3][4]

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^[5]

Hybrid and PHEV[edit]

• 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)^[6]
• 5ET50 (MKE) - Electronically controlled, continuously-variable automatic transaxle Transaxle (Full Hybrid, Ninth Generation Chevrolet Malibu)^[7]
• 4EL70 (MRD) - Electric Drive Unit Transmission (PHEV Cadillac CT6)

Other automatics[edit]

• 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 CVT250 — continuously variable transmission

Future[edit]

Manual transmissions[edit]

Longitudinal transmissions[edit]

• 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 — 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 T-50 transmission — 5-speed longitudinal manual - used by GM in its 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[edit]

• F23 — 5-speed transverse manual manufactured by Getrag
• 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
• MP2/MP3 — 5-speed manual developed by Saturn for use in the S-Series from 1991 to 2002

See also[edit]

References[edit]

1. ^'Hydra-Matic History: The First Automatic Transmission'. Ate Up With Motor. 2010-05-29. Retrieved 2014-01-15.
2. ^'Exclusive: An Inside Look At Ford's New 10 Speed Transmission'. http://www.thetruthaboutcars.com/. Retrieved 2015-03-16.External link in |publisher= (help)
3. ^Brooke, Lindsay. 'Ford and GM finally consummate 9- and 10-speed joint development'. articles.sae. SAE International. Retrieved 20 March 2016.
4. ^'Ford passes on GM's 9-speed automatic transmission'. Retrieved 2018-11-12.
5. ^Panait, Mircea. 'GM Hydra-Matic 9T50 Transmission Confirmed for Chevrolet Cruze, Malibu, Equinox'. autoevolution. Retrieved 2016-12-07.
6. ^'GM Service Insights, pg 23'(PDF). Archived from the original(PDF) on 2019-01-09. Retrieved 2019-07-16.
7. ^'GM Service Insights, pg 23'(PDF). Archived from the original(PDF) on 2019-01-09. Retrieved 2019-07-16.

A Porsche 5 speed conversion is a nifty modification that makes your Type 1 VW really nice to drive! The Porsche transaxle is strong from the start because it is engineered for the power of a flat six engine. The close ratio gears of the Porsche tranny are able to keep your high performance engine in its power band, while the 5th gear ratio allows for easy highway cruising. However, this is not a “weekend mod” for newbies! The work involved in converting to a Porsche 5 speed tranny includes welding and custom fitment and should only be undertaken if you you have fabricating experience. You will also need to be prepared to do some fine tuning in order to achieve perfectly smooth shifting.

Type 1 VW Transmission Conversion to Porsche 5 Speed

An IRS rear suspension setup is required rather than a swing axle setup, because the Porsche box is only available in an IRS configuration, and can not be converted to swing axle. And of course, you will need to locate a good used Porsche 901/911 or 902 5 speed gear box.

Tips for Identifying an appropriate 5 speed Porsche Gear Box Candidate

Identification marks are located on the bottom of Porsche Gearboxes. Porsche 901 gear boxes were used in the Porsche model 911 from around 1965 to 1968. They were made of aluminum and had a push type clutch. Late 901 Porsche Gear boxes (1969-71) were made of magnesium. 1969 still used a push type clutch, but 1970/71 switched to a pull type clutch system.

The 902 Porsche Gearbox is found in the early Porsche model 912. The 902 is the same size and has the same internals as the 901, but different gear ratios. It is an appropriate gearbox to use for the 5 Speed Conversion outlined below.

A late model 914 Side Shift transmission can be used for a 5 speed conversion but requires additional work and components not covered in the article below. The Porsche 915 gearbox is larger and not the subject of this do it yourself conversion article.

3 Speed Transmission Rc Car

Step 1: Adapt the Rear Transmission Mounts

Adapting the rear tranny mounts to the 901 is done by drilling holes in the 901 to match the holes in the original beetle transaxle. We recommend a spare set of Urethane rear pad mounts because they do not have studs (they use nuts and bolts) so you can place the mount right over the area and mark it perfectly. Once the holes are marked, drill them. Use a bit that is just larger than 8mm so that the mounts fit nice and tight.

The nice thing about performing the rear mount adaptation first is that it gives you a static point to work off of for fitment to the VW pan. Now the transaxle can be coupled to the floorpan.

Step 2: Clearancing and Fitment

When you first lift up the 901 and try to fit it using the rear mounts as reference to where it needs to be, you will begin to realize how much larger and longer the 901 really is! Place a straight edge parallel to the ground and on top of the input shaft as a reference, then measure to the torsion tube one foot from the center on each side. With the beetle trans this measurement was 22.75 inches. It is important to have the 5 speed as far forward as possible because it is about 1 inch longer than the beetle trans. It’s far easier to modify the car to accept the new 901 location then modifying the body for an engine that sits 1″ further back! Clearance the frame horns for the sides of the gearbox and for the clutch tube bracket off the side of the box. Mark the areas to be clearanced using a paint pen or marker. It is good to clearance as little as possible to keep some strength in the frame horns. The input for the shifter on the 901 exits the bottom of the trans rather than the middle like a beetle. A hole must be cut into the bottom of the pan. In order to get the rear of the 901 as close to 22.75″ back from the torsion tube. Also lightly clearance the front of the trans and also the torsion tube. Do not remove any more material than necessary!

Step 3: Fabricating the Front Mounting System

With the rear mounts bolted down and a floor jack supporting the front of the trans, you can begin to figure out the front mounting system; you can’t buy this stuff, you have to make it! Keep using the straight edge on the bell housing and measure to the torsion tube to keep the bell housing parallel and square. It is helpful to have the floor pan upside down at this point for obvious reasons. It is possible to adapt the original 911 front mount. In this conversion, I elected to build my own mount system because the 911 mount needed over four inches added to its width to fit the way I wanted. I determined that a mount built from scratch would look and fit best. I used Volvo trans mounts. These are quite generic and I found at least four different brands. I selected the hardest rubber versions for maximum rigidity. These mounts will also make it simple to swap in solid aluminum mounts for the strip just like the Gene Berg intermediate mount. I welded ears to the outside of each frame horn for the Volvo trans mount studs to bolt to. With the mount position determined, and the trans in a static position, build a front mount.

Step 4: Modifying the Frame Tunnel and Adapting the Shift Linkage

Now that the trans is located where it’s new home is going to be, it is time for shift linkage! There are three options for shift linkage. Adapt the Porsche parts, adapt the VW parts, or full custom. I chose to use the 911 components to have a proper reverse lockout and to retain the “Porsche Look”. It is hard to mistake the 911 shift lever!

The parts needed are the shifter, the shifter to shift rod connection link, the actual shift rod, and the special rear coupler. Pelican Parts sells the Porsche bushings to tighten everything up, and they are essentially the Aircooled.Net equivalent in the aftermarket Porsche parts business (good guys who know their stuff).

The first step is to modify the frame tunnel so that the 911 shifter can bolt down. It is best to have the actual clip of the tunnel from a 911 but I didn’t have this option. The 911 shifter uses two front bolts and one rear. The tunnel is flat and wide enough for the rear mounting bolt to fit; simply drill and tap. The front, however, is more of a challenge! The tunnel curves down too abruptly for the shifter to bolt down. The solution is to weld in some material to box this area in. Cut pie like slits into the metal needing to be boxed in. Next, pull the metal out and using body tools form it into a box shape. Next, a scrap piece of 14 gauge steel was welded in. Weld up the pie cuts and the piece of strip steel then dress it all up so it doesn’t look like you are some hack. 🙂

Repeat the above outlined shifter flange steps again for the right side of the tunnel. The curve of the tunnel and shifter flange area is less abrupt on the right side so less work is required. With this step finished the shifter now bolts down to the frame tunnelj, and would make Dr. Porsche proud!

Step 5: Connect the Shifter to the Transaxle

The Porsche shift rod is a much nicer piece than the Beetle shift rod. The Porsche rod has a pivoting rear coupler with splines that telescope in the actual shift rod for for/aft adjustment. The front of the shift rod uses a right-angle link piece that connects it to the bottom of the shifter. The shift rod is almost six inches too short to work right from the start with a 68+ pan (remember early pans have the shifter further foward). It also does not have enough S-bend down to interface with the transaxle. The rod must both be S-bent down and also lengthened.
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3 Speed Manual Transmission Chevy

Once you have the tweaked shift rod installed inside the tunnel it is time to build a shift rod bushing support. I bought a new shift rod bushing from Pelican Parts and built a sheet metal bracket to hold it in place. The bracket has to be welded inside the tunnel exactly like the stock beetle support. You can’t use the beetle part because the 911 shift rod is 1″ OD vs. the Beetles .75″ OD (approximate, actual numbers are metric). I cut a window in the side of the tunnel to position the shift rod support, and welded it in place, then welded up my access window. It helps to drill holes through the top of the tunnel and spot weld through them (welding upside down through the window cut in the side of the tunnel isn’t easy).

3 Speed Transmission On The Column

Now the shifter is installed, the shift rod is in place and positioned in the bushing and all is hooked up. At this point your shift rod will probably be a bit too long or two short to work. It needs to be fine tuned. We carry an adjustable shift coupler which solves this problem. It works just like an adjustable pushrod so that you can have a small amount of adjustment. You can purchase one or built your own.

Hopefully you can get all five gears plus reverse now!

Step 6: Axles and CV Joints

You can use stock length axles with the 901 because it is close to the same width as a stock transaxle (unlike a Bus tranny conversion). At least this makes the conversion easy in this one respect! The flanges on the early 901 transaxles are sized the same as a Beetle T1. The difference is they have four bolts and two dowels. The easiest solution here is to Timesert the flange so that it uses six bolts. This must happen if using the early small flanges or the late 911/01 (930 size) flanges. It is also possible to weld, drill, and tap the holes which formerly hosted dowel pins. The last choice is to drill out the CV joints and use dowel pins, but the simplest way is to just Timesert the flange.

Option 1:
901 flanges, stock beetle CV Joints inside and outside, stock beetle stub axles, and stock beetle axles. It doesn’t get much simpler than that!

Option 2:
901 flanges, Racing beetle axles, Porsche CVs on the inner, and Bus CVs on the outer. To use Type 2 (Bus) outer CVs you need early Porsche 944, Type 181, or aftermarket stub axles. The outer T2 joint is slightly thicker. The solution is to machine the joint to a thinner dimension, modify the axle, or just buy full floating beetle length Racing axles which don’t have the problem (because of full floating splines).

Option 3:
911/01 flanges, conversion beetle length axles with Porsche splines (unlike the above two choices which are VW splines), 930 joints, and Chromoly conversion stub axles. This is the strongest solution, but also the most expensive and heaviest.

We hope you enjoy this original article written by Aircooled.Net Guest Tech Writer, Steven Arndt – Please send any questions, comments, or suggestions to Steve via email to akt@cableone.net

article posted: May 29, 2003
article edited by ACN staff: Feb 25, 2012