E4OD

DESCRIPTION
This unit is a fully automatic, electronically controlled four-speed with a three element locking torque converter.

CONSTRUCTION

Sectional View Of Transmission:

The transmission consists of a converter clutch, six multiple disc friction clutches, one band, two sprag one way clutches, and a roller one way clutch.

OPERATION
The torque converter couples the engine to the transmission gear set. The input shaft transfers power into the transmission gear set. The power input is controlled by the application of the converter clutch, which is controlled by the Electronic Engine Control-IV(EEC-IV) system on gasoline engines or the transmission control system on diesel engine models. These controls, in conjunction with a hydraulic valve in the pump body, operate a piston plate clutch in the converter. The application of the piston plate effectively replaces the hydraulic coupling between the converter cover and the turbine with a mechanical coupling between the converter cover and the turbine hub. This mechanical coupling helps improve fuel economy and wide-open throttle performance by eliminating converter slip. Transmission shift selection in the Overdrive range and converter clutch operation are controlled by the Powertrain Control Module (PCM) on gasoline engine models or the transmission Electronic Control Assembly (ECA) on diesel engine models. They are calibrated to determine the optimum transmission state.