Control Arm Bushing
A control arm bushing is a rubber or polyurethane cylindrical pad with a metal sleeve inside it. As its name suggests, a control arm bushing sits between a control arm and a vehicle’s frame, doing a couple of jobs at the same time. It is used to connect the control arm to the vehicle’s body, while helping to reduce friction between the arm and the connecting point in order to decrease vibration and noise.
The bushing is attached to the control arm with a large bolt that goes through the center of the metal sleeve inside the surrounding padding. As a general rule, a control arm features two bushings, each of which is used for one mounting point. This type of installation allows control arms to pivot, while staying properly secured, so the wheels can move up and down when going over potholes, bumps, and other road imperfections.
A faulty control arm bushing can cause a variety of problems, including, but not limited to the following ones:
Knocking or thumping sound coming from the control arm
Any abnormal noise from your control arms are an indicator of a problem with the bushing or the control arm itself. In most cases, this happens due to excessive wear of the metal sleeve inside the bushing which allows the control arm to bang around. The noises should be especially noticeable when driving over bumps.
Uneven tire wear
Worn-out or damaged bushings can’t keep the wheels properly aligned, allowing for some erratic movements. As a result, one or more of your tires can wear faster or unevenly.
Wandering and hard steering, and pulling to one side are usually caused by worn-out bushings. If you have to compensate for abnormal vehicle movements with the steering wheel, your control arm bushings need your attention.
Control arm bushing troubleshooting and replacement
A control arm bushing that is worn out or damaged must be replaced with a brand-new part. Depending on the design of your suspension system, the bushings can be either replaceable or not. Your mechanic will need to use a special tool to remove bad bushings if they are removable, or to replace the entire control arm assembly if your bushings are built into the control arms.
When replacing control arm bushings, tightening bushing fasteners must be done at the normal ride height, so the control arms, steering knuckles and other steering and suspension systems’ components can stand in their natural position.
Unless you’re a mechanic, we do not recommend you to replace control arm bushings yourself. This job should be left to a professional, who has all necessary equipment and tools to do the trick. A four-wheel alignment may also be required after the installation.