Power transmission system for a four-wheel drive

摘要

A power transmission system for a four-wheel drive vehicle has front and rear wheel driving power transmission systems for transmitting the output of a transmission. A forward overrunning clutch and a reverse overrunning clutch are provided in one of the power transmission systems. One of the overrunning clutches can be selected in accordance with the operation of a driver of the vehicle. The overrunning clutch operates to transmit the power to corresponding wheels and to allow the selected wheels to rotate faster than the other wheels. A locking device is provided for locking both overrunning clutches.