Control Arm - Upper (Rear)

Control arms, bushings, and ball joints may not be common household terms for many vehicle owners. You may have never even heard of them, but they are critical components of your vehicle's suspension system that allow your tires to smoothly go up and down in a controlled fashion. Without them, your ride probably wouldn't be very enjoyable.

Most vehicles use either one or two control arms per wheel, on both the front and rear suspension. Many front-wheel drive vehicles only use a lower control arm, while trucks and SUVs often have both an upper and lower control arm. A control arm connects the wheel hub and steering knuckle to the frame of the vehicle. 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 flex and controlled movement according to road conditions and steering input from the driver. Control arms allow wheels to move up and down while preventing forward and rearward movement.

Control arm bushings usually consist of an outer metal sleeve, a durable rubber or polyurethane bushing, and an inner metal sleeve. Control arm bushings are important for driving comfort and handling. They cushion the suspension system which in turn controls noise and vibrations, and also provide a softer ride over bumps. Bushings can flex and move while retaining stiffness and the ability to return to their original shape and position.

Many suspension and steering joints utilise bushings when components need to be mounted together where vibration is a concern. Bushings are used in control arms, shock absorber mounts, stabilizer bars, stabilizer links, engine and transmission mounts, and other suspension and steering components. Bushings have a function similar to cartilage in joints of the body. Worn or damaged cartilage results in bone on bone contact and discomfort. Worn or damaged bushings can allow metal on metal contact, tire wear, discomfort, noises, and vibrations. Bushings deteriorate due to heat, age, exposure, heavy loads, salt, oils, and the stress of frequent movement.