What is control arm?
A control arm is a hinged suspension link between the chassis and the suspension upright or hub that carries the wheel.
What is control arm bushing?
Control arms are connected to the frame or body of a vehicle through flexible bushings, called control arm bushings. Those bushings are cushions made of rubber, polyurethane (often shortened to "poly" or "urethane") or other materials. They're mounted on car suspension and steering joints to absorb road bumps, control the amount of movement in the joints and reduce noise and vibration.
What happed the control arm bushings wear?
When bushings wear, they allow more movement. The driver may feel a shimmy from the front of the vehicle, or hear clunking or rattling noises on rough roads, when turning the wheel or in hard braking. Drivers may also experience poor handling or loose steering. Failure of rear suspension bushings may be harder to detect as they don't involve the steering system and may be less affected by cornering.
when bushings wear, it puts more stress on the joints and connected parts. Like bone-on-bone contact, worn bushings can allow metal-on-metal contact. Worn control-arm bushings can allow the vehicle's front end to slip out of alignment and cause premature tire wear.
Installation of Control Arm Bushings
It is important to install high quality bushings as they are durable and reliable. Pre-lubricated designs also support lowered or raised cars where geometry has been altered. When installing bushings, inspect other components in the suspension system to minimize damage, wear and eliminate failure. This should be done in both loaded and unloaded modes.