4x Rear Upper and Lower Tubular Control Arm Kits for Ford Mustang 1979-2004 57710972Introductions: The control arms are perpendicular to the axis of the vehicle, in automotive suspension, a control arm is a hinged suspension link between the chassis and the suspension upright or hub that carries the wheel. Control arms allow wheels to move up and down while preventing forward and rearward movement. They are typically equipped with bushings on the frame side of the vehicle and a ball joint on the wheel side of the vehicle that allow