What is Control Arm Assembly?
A control arm, commonly referred to as an A-arm, is a suspension component found on virtually all road-going passenger vehicles. It is a suspension link that connects the wheel hub and steering knuckles to the chassis. They are equipped with bushings and ball joints that allow it to flex and move according to road conditions and steering input from the driver. Over time, the bushings or ball joints on the control arm can wear out and cause all sorts of problems.
Symptoms of a Failing Control Arm Assembly
Steering problems are one of the first indications of a damaged control bushing. The steering may lose a bit of its responsiveness. At high speeds, it may even start 'wandering', or make the vehicle turn erratically. The driver can feel the wheel vibrate while in motion. The vehicle may start leaning to one side, to some degree, when taking sharp turns.
A sudden improvement in braking efficiency can, as strange as it may seem, be attributed to a damaged control arm bushing. This is because the forward and backward oscillation of the control arm is not achieved during braking due to bushing wear. However, this effect will not be constant, making braking unstable. Moreover, when the vehicle is braked suddenly, the front end will continue to oscillate forward.
When accelerating from a static position, a backward movement will be observed in the rear end of the car, along with the problem of erratic steering, as explained above. When speeding, or taking a turn at slow pace, the steering starts trembling, and a tugging effect is observed.
A bad bushing will compromise driving performance and comfort. Since the purpose of the control arm bushing is to cushion against small bumps, a damaged one will not be as effective, resulting in vibrations throughout the drive. In case of extreme damage, when the rubber bushing is completely worn out, the metal sleeves of the control arm will begun to rattle, resulting in an unpleasant 'clunking' noise from the front end, especially while turning or reversing.