GM 4T80 transmission

Infobox Automobile
name=4T80-E
production=1993–
manufacturer=General Motors
class=4-speed transverse automatic transmission
predecessor=Turbo-Hydramatic 125
successor=6T70
similar=Ford AX4N
UltradriveThe 4T80 (and similar 4T80-E) is a series of automatic transmissions from General Motors. Designed for transverse engine configurations, the series includes 4 forward gears. The 4Txx family is an evolution of the original Turbo-Hydramatic 125 transverse automatic introduced in the early 1970s.

The 4T80-E transmission is electronically controlled and features an automatic overdrive transaxle with an electronically controlled torque converter clutch. The 4T80 originally used a viscous clutch, but this was changed in 2005.

The 4T80 is built at Willow Run Transmission in Ypsilanti, Michigan.

4T80-E

The "MH1" 4T80-E is able to handle vehicles up to 8000 lb (3629 kg) GVWR. The final drive ratio is 3.11:1, 3.48:1, or 3.71:1. The 4T80 uses a viscous torque converter clutch, which was replaced with an electronically-controlled torque converter clutch in 2005.

The 4T80-E is a hydramatic transmission and was developed for use with V8 front-wheel-drive cars, specifically for the Cadillac Northstar engine. It was designed with extreme power handling capabilities at the time. The 4T80-E first debuted in the Cadillac Allante in 1992 along with the Northstar Double Overhead Camshaft (DOHC) V8. It reportedly cost 80% more than a similar GM 4T60 transmission and weighed 60 lb (27 kg) more.

This transaxle has been used in many of GM's front drive large sedans. The Cadillac Division had exclusive usage of the 4T80-E until the 1995 Oldsmobile Aurora debuted. The Aurora had the 4.0L version of the Northstar V8 coupled to a 4T80-E. It wasn't until 2005 that Pontiac got usage of this transaxle in the Bonneville GXP which employed a 275 horsepower version of the Northstar 4.6L V8.

The 4T80-E is still in use today, on the Cadillac DTS and the Buick Lucerne (when equipped with the 4.6L Northstar).

Gear ratios:

Applications:
* 3.11:1
** 1994–2005 Cadillac Deville
** 1992-2002 Cadillac Eldorado
** 1992-2004 Cadillac Seville
** 2006 Cadillac DTS

* 3.71:1
** 1996–2005 Cadillac Deville Concours/DTS
** 1992-2002 Cadillac Eldorado ETC
** 1992-2004 Cadillac Seville STS
** 1995-1999 Oldsmobile Aurora Autobahn
** 2005–2006 Pontiac Bonneville GXP
** 2006 Buick Lucerne V8

References

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External links

* [http://media.gm.com/us/powertrain/en/product_services/2007/Photo%20Library/Transmissions/2007%20Automatics/07%204T80%20MH1%20LoR.jpgCutaway illustration of 4T80 transmission]

ee also

* List of GM transmissions