GM 4L80-E transmission

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4L80-E/4L85-E
Overview
Manufacturer General Motors
Production 1991–
Body and chassis
Class 4-speed longitudinal automatic transmission
Chronology
Predecessor Turbo-Hydramatic
Successor 6L80/6L90

The 4L80-E (and similar 4L85-E) was a series of automatic transmissions from General Motors. Designed for longitudinal engine configurations, the series included 4 forward gears. It was an evolution of the Turbo-Hydramatic 400, first produced in October 1963. 4L80-Es were optioned only in Chevrolet/GMC pickups, vans, and commercial vehicles, and the Hummer H1. It was also adopted by Rolls Royce in 1991 and modified, after extensive testing,[1] and used initially in the Bentley Continental R, and subsequently other Rolls Royce and Bentley vehicles.

The 4L80 and 4L85 were built at Willow Run Transmission in Ypsilanti, Michigan.

Gear ratios:

1 2 3 4 R
2.48 1.48 1.00 0.75 2.07

4L80-E[edit]

A Hydra-Matic 4L80 transmission at the Ypsilanti Automotive Heritage Museum

The 4L80-E (RPO MT1) is rated to handle engines with up to 440 ft·lbf (597 N·m) of torque.[2]

The 4L80-E is rated to max GVWR of 18,000 (Axle and vehicle dependent)[3]

The 4L80-E uses 2 shift solenoids, initially called Shift Solenoid A & Shift Solenoid B, later changed to comply with OBD II (On Board Diagnostics revision 2) regulations to 1-2 Shift Solenoid & 2-3 Shift solenoid. By activating and deactivating the solenoids in a predetermined pattern by the PCM, 4 distinct gear ratios can be achieved. The shift solenoid pattern, also sometimes referred to as solenoid firing order, is as follows;

Shift Solenoid Pattern[edit]

1-2 Solenoid 2-3 Solenoid
1st Gear On Off
2nd Gear On On
3rd Gear Off On
4th Gear Off Off

Applications[edit]

4L85-E[edit]

The 4L85-E (RPO MN8) is rated to handle vehicles with up to 460 ft·lbf (624 N·m) of torque.

The 4L85E is rated to handle vehicles with a GVWR of up to 18,000 lbs (dependent on axle ratio and vehicle)[4]

Applications:

Note: These transmissions have issues with early style 12 pin harnesses in which transmission fluid leaks around the harness and shorts the pinouts causing transmission to go into "limp mode" (some manuals say "limp home mode"). This issue can be easily rectified by simply cleaning the plug.[citation needed]

See also[edit]

References[edit]

  1. ^ Adcock, Ian (1992). Bentley Continental R. London: Osprey Publising. p. 113. ISBN 185532 260 9. 
  2. ^ "Archived copy". Archived from the original on 2013-12-22. Retrieved December 22, 2013. 
  3. ^ GM Powertrain. "07 Hydramatic 4L series". General Motors. Retrieved January 5, 2014. 
  4. ^ GM powertrain. "07 Hydramatic 4L Series Specs". General Motors. Retrieved January 5, 2014.