Shift Fork Mechanical System Overview

Fig 1: Overview Of Shift Fork Mechanical System

Courtesy of FORD MOTOR CO.

The shift system consists of two independent sub-systems for controlling the transaxle synchronizer pre - selections and engagements. Using this arrangement provides an independent control of the two transaxles and a mechanical interlock that prevents two gears within the same transaxle from being engaged simultaneously. The TCM houses two electric motors that mesh with and drive the first double gear wheel, which drives the second double gear which finally drives the shift drum. Gearing between the shift motors and the drums reduce speed and multiply torque. Position sensors in the TCM detect feedback of the motor angular position. Shift drum position is learned by the TCM during a teach-in process that involves rotating each drum against hard stops located on the shift drum and the transaxle housing.