An axle is a central shaft for a rotating wheel. On wheeled vehicles, the axle may be fixed to the wheels, rotating with them, or fixed to its surroundings, with the wheels rotating around the axle. The axles serve to transmit driving torque to the wheel, as well as to maintain the position of the wheels relative to each other and to the vehicle body. The axles in a system must also bear the weight of the vehicle plus any cargo. The rear axle beam is one of the major parts of vehicle suspension system. It houses the whole back load assembly. About 35 to 65 percent of the total vehicle weight are taken up by the rear axle.