Underdrive Clutch

Underdrive Clutch






The Underdrive piston, piston return spring and spring retainer are inside and to the front of the clutch retainer. These parts control the application of the Underdrive (UD) clutch. The underdrive clutch is named for its use in the three forward underdrive gear ranges: first, second and third.

The underdrive clutch is splined to the underdrive hub assembly. The underdrive shaft, which is secured to the underdrive hub, is splined to the rear sun gear. When the underdrive clutch is applied hydraulically, the rear sun gear is the input to the planetary gear-set in first, second and third gears.