Control system for split axle drive mechanism in part-time four-wheel

Abstract

In a part-time four-wheel drive vehicle equipped with a transfer device adapted to change the operating mode of the vehicle drive system from a two-wheel drive mode to a four-wheel drive mode in response to engagement of a hydraulically operated clutch mechanism provided therein and with a split axle drive mechanism in the form of a differential which includes a clutch mechanism disengageable for disconnecting a pair of side shafts of the differential from a set of non-driven split axle parts when the two-wheel drive mode is selected at the transfer device and engageable for connecting the side shafts to the non-driven split axle parts when the four-wheel drive mode is selected at the transfer device, a control system for the split axle drive mechanism includes a pressure switch arranged to detect a hydraulic pressure applied to the clutch mechanism of the transfer device to be operated when applied with a predetermined hydraulic pressure after engagement of the clutch mechanism of the transfer device and an actuator arranged to effect engagement of the clutch mechanism of the differential in response to operation of the pressure switch and to disengage the clutch mechanism of the differential when the pressure switch is rendered inoperative.