The final drive is a gear arrangement used at driven axles. It basically consists of the pinion, the ring gear and the differential. Mostly spiral bevel or hypoid gears are used. The final drive has three purposes:
The pinion transmits the torque and speed rectangular from the propeller shaft to the ring gear which is connected to the differential. Due to gear ratio torque is increasing whereas speed is decreasing. The differential allows different wheel speeds at cornering. This is necessary due to the longer way of the outside wheel. However the torque remains constant.