Abstract: A motor vehicle frame assembly particularly adapted to support rear loading and provide antisway characteristics. The side rail of a motor vehicle main frame structure has a rear kick-up portion which extends to the rear end of the side rail, and a frame member is pivotally attached to the side rail, the frame member extending downwardly and outwardly from the kick-up portion. The rear axle of the motor vehicle is attached to the frame member near its rear end portion, providing rearward support for rear loading of the motor vehicle. A spring is interposed between the rear end portion of the frame member and the underside of the motor vehicle outwardly of the kick-up portion, providing antisway characteristics for the motor vehicle.