ZF 6HP transmission

6HP is ZF Friedrichshafen AG's trademark name for its 6-speed automatic transmission models (6-speed transmission with Hydraulic converter and Planetary gearsets) for longitudinal engine applications, designed and built by ZF's subsidiary in Saarbrücken. Released as the 6HP 26 in 2000, it was the first 6-speed automatic transmission in a production passenger car. Other variations of the first generation 6HP in addition to the 6HP 26, were 6HP19, and 6HP 32 having lower and higher torque capacity, respectively. In 2007, the second generation of the 6HP series was introduced, with models 6HP 21 and 6HP 28. A 6HP 34 was planned, but never went into production.

It uses the Lepelletier gear mechanism, an epicyclic/planetary gearset, which can provide more gear ratios with significantly fewer components. This means the 6HP 26 is actually lighter than its five-speed 5HP predecessors. The 6HP is the first transmission to use the Lepelletier gear mechanism.

The last 6HP automatic transmission was produced by the Saarbrücken plant in March 2014 after 7,050,232 units were produced. The ZF plant in Shanghai continued to produce the 6HP for the Chinese market.

The Ford 6R, GM 6L, and Aisin AWTF-80 SC transmissions are all based on the same globally patented Lepelletier gear mechanism. The AWTF-80 SC is the only one for transverse engine installation.