OVERDRIVE SYSTEM FOR A FOUR WHEEL DRIVE VEHICLE

摘要

An overdrive system for a four-wheel drive vehicle has an automatic transmission the output of which is transmitted to front wheels and to rear wheels through a drive gear and a driven gear and a hydraulically operated four-wheel drive clutch. The system comprises an overdrive clutch for coupling an oil pump drive shaft of the automatic transmission to the driven gear. When the overdrive clutch is engaged, the rotation of the oil pump drive shaft is transmitted to the front wheels through the clutch and driven gear and drive gear for overdriving the vehicle.