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 wear out and can cause all sorts of problems. Usually a problematic control arm assembly will produce a few symptoms that can alert the driver of a potential problem that should be serviced.
1. Steering wheel vibration
One of the first symptoms commonly associated with bad control arms is steering wheel vibrations. If the bushings or ball joints in the control arm become excessively worn it can cause wheel shimmy, which may cause vibrations that may be felt in the wheel. The vibrations may increase as you accelerate and smoothen out once you are traveling at speed.
2. Steering wandering
Another symptom commonly associated with bad or failing control arm assembly is steering wandering. Excessively worn ball joints or bushings can cause the vehicle’s steering alignment to shift, which may cause the steering to pull to the left or right when traveling down the road. This will require a constant correction from the driver in order to steer the vehicle straight.
3. Clunking noises
Clunking noises are another symptom of possible problems with the control arms on a vehicle. If the bushings or ball joints develop excessive play or looseness, this can cause them to knock during takeoff, or when the vehicle is traveling over rough terrain. The clunking sound will continuously get louder as the component wears or until it eventually breaks.
The control arms on a vehicle are very important suspension component, as they are the component that links the spindle, hubs, and therefore wheel to the vehicle’s chassis. When they become worn it can cause problems for the vehicle that may compromise handling, comfort, and safety. For this reason, if you suspect that your vehicle’s control arms may be bad or worn, have the vehicle’s suspension inspected by a professional technician, such as one from YourMechanic. They will be able to replace your control arm assembly if required.
This article originally appeared on YourMechanic.com as Symptoms of a Bad or Failing Control Arm Assembly and was authored by Ed Ruelas.