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 80 800 Nm, 6L 90 1200 Nm and is adaptable to rear-wheel drive and all-wheel drive applications.

Specifications

Basic concept

A conventional planetary gearset and a compound Ravigneaux gearset is combined in a Lepelletier gear mechanism, to reduce both the size and weight. It was first realized with the 6HP from ZF Friedrichshafen. Like all transmissions realized with Lepelletier transmissions, the 6L also dispenses with the use of the direct gear ratio, making it one of the very few automatic transmission concepts without such a ratio. It also has the capability to achieve torque converter lock-up on all 6 forward gears, and disengage it completely when at a standstill, significantly closing the fuel efficiency gap between automatic and manual transmissions.

Technical data

Applications

6L 45 · MYA

6L 50 · MYB

6L 80 · MYC

6L 90 · MYD