What the heck is a Control Arm? You have your car in for a concern that it is pulling to the side when braking. You are informed that you need a new "Control Arm"! But what is that anyway? Control arms are an integral portion of independent suspension. These arms are generally made of iron or aluminum and a wishbone or triangle shape. Depending on the type of suspension system your car may have one or more control arms at each wheel. The metal arm has a combination of bushings and/or ball joints connecting to the adjacent suspension components.
What goes wrong with a Control Arm?
Outside of accident damage and rot the metal portion of the arm can last an extremely long amount of time. The failure on modern control arms is the joints and bushings that are attaching the arms to the suspension. In some cases we can save some expense by replacing just the end components. Your service advisor can direct you based on your particular situation and vehicle. The pulling described in this example was from a badly damaged bushing that allowed the arm to move mimicking steering input and turning one wheel of the car.
How does the Mechanic fix the Control Arm?
Control arms can be rebuilt or replaced. The mechanic will disassemble the suspension and remove the arm from the vehicle. Next he will inspect the condition of each component. In conjunction with your service advisor the most cost effective option will be determined. Then the arm will be rebuilt or replaced and reinstalled. After reassembly of the suspension system the mechanic will torque all of the suspension bolts and road test the vehicle. Following the extensive disassembly the vehicle will be brought in for a wheel alignment before final completion.