The rear wheel of agricultural tractor rotates forward and the front wheel rotates backward, which is the fault of differential. According to relevant data, the three functions of differential are to transmit power from engine to wheels. Act as a reduction gear. The two wheels are allowed to rotate at different speeds, so that the wheels on both sides run different distances in the form of pure rolling, which reduces the friction between the tire and the ground and ensures the turning stability of the tractor.