Super problems, when to replace, repair cost

The control arm is an important part of the front suspension. It connects the steering knuckle (the part that holds the front wheel) to the vehicle's frame or body, see the photo. To allow the up and down movement of the suspension, the control arm is attached to the vehicle's chassis or body through flexible rubber bushings called To allow front wheels to turn, the outer end of the control arm is connected to the steering knuckle though a ball joint.

In most cars and trucks, a control arm is made in the shape of letter "A" or "L" with two ends attached to the chassis. In some cars, a control arm is a single link with a ball joint on one end and a rubber bushing on another end. Control arms have a very important role holding both front wheels on the road. If a control arm is worn out, damaged or bent, the vehicle is NOT SAFE to drive.

There are a few reasons why a control arm may need to be replaced. in many cars, a ball joint is built into the control arm as one piece and cannot be replaced separately. In this case, the whole control arm will need to be replaced if a ball joint shows some wear. 

A ball joint is an extremely important component. If it wears out, the front wheel can separate from the lower suspension causing the vehicle to lose control. In this photo, a ball joint has separated while driving, although the owner was very lucky that it happened at slow speed. If this had happened on the highway, the outcome could have been much worse.

Worn out or torn control arm bushings is another reason a control arm may need to be replaced. In some cars, control arm bushings can be replaced separately, but it involves higher labor costs. Often, the whole control arm is replaced if the bushings are worn out.