GM 6L transmission

6L 45 · 6L 50 · 6L 80 · 6L 90
A Hydra-Matic 6L80 transmission at the Ypsilanti Automotive Heritage Museum
Overview
ManufacturerGeneral Motors
Production2005–present
Body and chassis
Class6-Speed Longitudinal
Automatic Transmission
RelatedAisin AWTF-80 SC
Ford 6R
ZF 6HP
Chronology
Predecessor4L60-E · 4L65-E
5L40-E · 5L50
Successor8L 45 · 8L 90

The 6L 50 (and similar 6L 45) is a 6-speed longitudinally-mounted automatic transmission produced by General Motors. It is very similar in design to the larger GM 6L 80 and 6L 90, and is produced at GM Powertrain plants in Toledo, Ohio; Silao, Guanajuato, Mexico; and by the independent Punch Powerglide company in Strasbourg, France.

This transmission features clutch to clutch shifting, eliminating the bands used on older transmission designs. The 6L 50 debuted for the 2007 model year on the V8-powered versions of the Cadillac STS sedan and Cadillac SRX crossover, and replaces the 5L40-E and 5L50 in GM's lineup. The 6L 45 version is used in certain BMW vehicles and the Cadillac ATS, as part of either rear-wheel drive and all-wheel drive powertrains.

The 6L 80 (and similar 6L 90) is a 6-speed automatic transmission built by General Motors at its Willow Run Transmission plant in Ypsilanti, MI. It was introduced in late 2005, and is very similar in design to the smaller 6L 45 and 6L 50, produced at GM Powertrain in Strasbourg, France.

It features clutch to clutch shifting, eliminating the one-way clutches used on older transmission designs. In February 2006 GM announced that it would invest $500 million to expand the Toledo Transmission plant in Toledo, Ohio to produce the 6L 80 in 2008. Torque rating 6L 80 590 lb⋅ft (800 N⋅m), 6L 90 885 lb⋅ft (1,200 N⋅m) and is adaptable to rear-wheel drive and all-wheel drive applications.

Gear Ratios[a]
Gear
Model
R 1 2 3 4 5 6 Total
Span
Span
Center
Avg.
Step
Compo-
nents
6L 45 · 6L 50 −3.200 4.065 2.371 1.551 1.157 0.853 0.674 6.035 1.655 1.433 3 Gearsets
2 Brakes
3 Clutches
6L 80 · 6L 90 −3.064 4.027 2.364 1.532 1.152 0.852 0.667 6.040 1.638 1.433
ZF 6HP All · 2000[b] −3.403 4.171 2.340 1.521 1.143 0.867 0.691 6.035 1.698 1.433
  1. ^ Differences in gear ratios have a measurable, direct impact on vehicle dynamics, performance, waste emissions as well as fuel mileage
  2. ^ for comparison purposes only