What Are Control Arms?

The suspension system in your car is the connection of your wheels, springs, shock absorbers, and other car parts which maximize contact between your tires and the road. A control arm, also sometimes referred to as an A-arm, is a fundamental aspect of your suspension system, connecting your car frame to the front wheel hubs.

Suspension components known as bushings and ball joints can be found on either end of a control arm. The primary function of the control arm is to guide the car's wheels up and down on the road and control proper steering.


How Do Control Arms Work?

The bushings that are connected to the control arms are flexible and cause the control arms to swing upwards and downwards when driving on rough terrain and other road surfaces so the car can stay on the road. A swivelling ball joint connected to the control arm enables the car to be turned in a specific direction.


The Anatomy of Control Arms

Most vehicles such as SUVs, trucks, and other four-wheel-drive vehicles will contain both upper and lower control arms, while other front-wheel drive vehicles may only have a lower control arm with a strut in place of an upper control arm.


The control arms are located in the front wheels, with the upper control arms attaching to the uppermost part and the lower control arms connecting to the bottom part of the wheel. Both control arms connect to the car’s front frame through 2 bushings which allow the arm to move up and down and absorb noise, vibration by preventing the metal to metal contact.


This is what creates a smooth ride and prevents wear and tear. The steering end of the control arm connects to a ball joint which attaches to the steel spindle, which bolts to the front wheel and is responsible for turning as you drive.


The Functions of Control Arms

The control arm enables the car’s frame and wheels to move simultaneously for proper maneuvering of the vehicle. To properly steer and keep a car on the road, you need a properly maintained control arm. The control arms are also what keep the geometry of your vehicle in proper alignment when you lift your car.


Control Arm Damage

Because the control arm is needed for proper steering and maintaining tire contact with the road, it should go without saying that damage to the control arm reduces your safety while driving. Various possible problems can arise within the control arm or connective parts, such as a:


  • Worn out ball joint - Wear and tear of the ball joint can cause safety hazards such as separation of the front wheel from the suspension, which can result in a loss of control of the car


  • Damage to the car frame -The frame may become rusted or can break on impact


  • Damage to bushings - Bushings may or may not be replaced separately from the control arm itself, but in some cases, an entirely new control arm will be needed. Damage to the bushings can occur when your car gets into an accident or bumps into a curb


Shop Our Selection of Control Arms

You must have any issues with the control arm or connecting parts repaired or replaced, as this is what keeps your car stable on the road and maintains proper steering. Without this safety feature, it is dangerous to drive on the road, and you may lose control of your vehicle. Browse our selection of upper and lower control arms at Toytec Lifts.