GM 4L80-E transmission

The 4L80-E (and similar 4L85-E) was a series of heavy-duty automatic transmissions from General Motors designed for longitudinal engine configurations. The 4L80-E was heavily based on the Turbo-Hydramatic 400 first produced in October 1963, adding electronic controls and an overdriven fourth gear. 4L80-Es were optioned only in Chevrolet/GMC pickups, Suburban 2500s, 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 4L80E and 4L85E were built at Willow Run Transmission in Ypsilanti, Michigan.

ManufacturerGeneral Motors
Body and chassis
Class4-speed longitudinal automatic transmission
PredecessorTurbo-Hydramatic 3L80

Gear ratios:

1 2 3 4 R
2.48 1.48 1.00 0.75 2.07


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 PatternEdit

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

No power results in 2nd Gear as 'Limp home mode'.



The 4L85-E (RPO MN8) is rated to handle vehicles with up to 690  ft·lbf (935 N·m) of torque [4] . The 4L85E is rated to handle vehicles with a GVWR of up to 18,000 lbs (dependent on axle ratio and vehicle)[5]


See alsoEdit


  1. ^ Adcock, Ian (1992). Bentley Continental R. London: Osprey Publishing. p. 113. ISBN 185532 260 9.
  2. ^ "Archived copy". Archived from the original on 2013-12-22. Retrieved December 22, 2013.CS1 maint: archived copy as title (link)
  3. ^ GM Powertrain. "07 Hydramatic 4L series". General Motors. Retrieved January 5, 2014.
  4. ^
  5. ^ GM powertrain. "07 Hydramatic 4L Series Specs". General Motors. Retrieved January 5, 2014.