GM 4T60-E transmission

4T60-E/4T65-E
Overview
Manufacturer General Motors
Production 1990–2011
Body and chassis
Class 4-speed transverse automatic transmission
Chronology
Predecessor Turbo-Hydramatic 125
Successor 6T70

The 4T60-E (and similar 4T65-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 late 1970s.

The "-E" transmission is electronically controlled and features an automatic overdrive transaxle with an electronically controlled torque converter clutch.

The 4T65 is built at Warren Transmission in Warren, Michigan.

4T60-E

Main article: Turbo-Hydramatic 125

In 1991 GM introduced the 4T60-E which was a 4T60 with electronic controls. By the mid-1990s, the 4T60-E was the transmission of choice in nearly every front-wheel drive GM vehicle with the exception of compacts. A heavy-duty 4T60-E HD was produced only in 1996 for the supercharged GM 3800 engine. The 4T60-E was phased out in favor of the 4T65 beginning in 1997.

The 4T60-E featured a 245mm torque converter with varying stall speed and gear ratios. Stall speed is the rpm(revolutions per minute) that the converter reaches maximum efficiency and is correlated with the engine and vehicle weight for the best combination of power and efficiency for the vehicle. (For example a '95 Beretta features a 1650rpm stall converter as opposed to '99 Century converter with a stall of 2095rpm.) Gear ratios are remarkable in the 4T60 family in that there are two points in which the transmission can have different gearing (the drive-chain sprockets and the differential) resulting in up to 12 different available gear ratios. The combined gearing of the two is the overall transaxle ratio and is called the "Final Drive Ratio", and the different ratios allow the use of the transmission in multiple applications based on the engine and vehicle.

Replacing a complete transaxle should only be done if a unit is verified to be the same as the unit it replaces, as in addition to the up to 12 variants of the Final Drive Ratio, different applications and years can and will have incompatible electrical connectors. The use of an incorrect transaxle will result in undesired operation, up to and including total non-functioning of the transaxle.

Gear ratios:

1 2 3 4 R
2.92 1.56 1.00 0.70 2.38

Applications:

4T65-E

The 4T65-E was introduced to replace the 4T60-E in 1997. The 4T65-E included a larger 258 mm torque converter for some models and many other changes to improve reliability. It is able to handle vehicles up to 6500 lb (2948 kg) GVWR with up to 280 ft·lbf (380 N·m) of torque. A number of final drive ratios are available, with many distinct models. Starting in mid year 2000 models, all 4T65-E models received an upgraded valve body. Starting in 2003 the internal electronics were changed, hardened 4th gear shaft, ratcheting sprags for input and third gear were added. The last application was the 2011 Chevrolet Impala as GM has transitioned to the 6T70 family transmissions for 2012.[1]

Models:

Gear ratios:

1 2 3 4 R
2.92 1.56 1.00 0.70 2.38

Applications:

4T65E-HD

The 4T65E-HD (code MN7) is a heavy duty version of the 4T65-E used with more powerful engines such as the LS4 V8 and L67/L32 supercharged V6.

Applications:

References

  1. ↑ Bowman, Zach. "Aging Chevy Impala gets standard 302-hp V6 for 2012". Autoblog.

See also

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