What Is A Control Arm And How Does It Work?

The control arm is one of the essential components of a suspension system, connecting the front wheel to the vehicle's frame. It allows the driver to steer the car while the wheel moves up and down with the road surface. For that reason, it plays a vital role in your vehicle's handling, stability, and drivability.

In this post, we'll cover:

  • What is a control arm?
  • How does a control arm work?
  • What happens when a control arm goes bad?

What Is A Control Arm?

GM control arm

A control arm is a wishbone or A-shaped component that is part of the front wheel suspension. Its shape allows it to connect the wheel to the frame and suspension of the vehicle.

Many vehicles have an upper and a lower control arm for each front wheel, providing a sturdier connection and increased wheel control and stability. However, some vehicles that use a MacPherson-type suspension use a strut to replace the upper control arm and only have a lower control arm.

How Does A Control Arm Work?

The control arm connects the front wheel to the frame of the vehicle. This connection pivots with the vehicle's motion, stabilizing the wheel and allowing it to move in unison with the other parts of the suspension. It literally is the arm that controls wheel movement, coordinating how the wheel, suspension, and steering work together so you can drive the vehicle.

A ball joint on the control arm serves as the steering system's pivot point, allowing the wheel to turn left or right while rotating. A hinged joint connects the control arm to the frame allowing the wheel to move up or down. Both sides of the control arm work together, allowing the motion necessary to keep the front wheel in contact with the road.

What Happens When A Control Arm Goes Bad?

Control arms typically wear out over time due to worn ball joints, bushings, or damage from hard use. A damaged or improperly functioning control arm will exhibit symptoms including:

  • Excessive vibration in the front suspension or steering wheel
  • Poor front-end alignment or uneven tire wear
  • Excessive play in the steering
  • Unusual clunking or grinding noises
  • Wheels that feel "wobbly" or loose
  • The car pulls to one side when braking

If you notice one or more of the above symptoms, it's important to check out your front suspension and make any necessary repairs as soon as possible.

GM Parts Center Sells Genuine GM Control Arms

To find the right control arms for your GM car or truck, check out our parts catalog. We only sell genuine GM accessories and parts for your Chevrolet, Buick, GMC, Cadillac, Pontiac, Saturn, Hummer, or Oldsmobile, all of which are backed by GM's replacement parts warranty and come with our price match guarantee.

Got questions? Our FAQ page contains lots of helpful information, or you can contact us if you have questions about your vehicle.