Basic Synchronizer Hardware Operation

As in manual transaxle operation, gear pre-selection is made by sliding the synchronizer sleeve towards a speed gear. This causes the internal splines of the synchronizer sleeve to bridge a gap between the output hub and the external spline feature of the speed gear, thus transmitting speed and torque between the gear and output shaft. Synchronizers are small cone wet friction clutches mounted to the transaxle output shaft. They are used to bring the rotation speed of the engaging speed gear in sync with the output shaft speed. After synchronous speed has been attained the final power flow connection is made possible and the synchronizer sleeve is permitted to pass by and engage the external spline teeth on the speed gear.