Control Arm Replacement
What is a control arm?
The control arm connects the steering knuckle to the frame or body of a vehicle. The wheel is held on to a hub connected to the steering knuckle. The knuckle allows the wheel to steer left and right and is attached to the control arm(s). The control arm allows allow the wheel to travel up and down over bumps and helps to position the wheel in the proper alignment.
How does the control arm work?
The control arm is connected on one end to the steering knuckle (to which the wheel is attached by way of the hub and bearing assembly) by a ball and socket called a ball joint. It is attached at the other end to the vehicle frame or body. When a car goes over a bump, the control arm pivots up and down with the wheel and allows the vehicle body to remain stable. On the frame/body side, the control arm has a bushing (or pair of bushings) that allows it to pivot.
What are the symptoms related to a bad control arm?
The actual control arm may last the lifetime of the vehicle. The control arm bushings, on the other hand, often wear out as a vehicle approaches 100k miles. A control arm is prone to damage if the vehicle is in a crash or encounters a large pothole. If the bushings are worn out, the suspension will make a squeaking sound when going over bumps. If they are severely worn, a knocking sound may be heard as the control arm makes metal-to-metal contact with the bushing bracket. If the control arm is damaged or bent, tire wear may be uneven and the vehicle may pull to one side or wander.
Can I drive with a control arm problem?
If the control arm on a vehicle is damaged in a crash or impact with a pothole or parking block, the suspension will be out of alignment and cause uneven tire wear and poor vehicle handling. The control arm should be replaced as soon as possible. If the control arm bushings are worn, the result will be an annoying squeak when the car goes over bumps. In this case, the car can be driven. But if the bushings wear out considerably, metal-on-metal contact may happen between the control arm and the bushing bracket. This can cause further suspension damage and the control arm or bushing should be replaced.