What Is Control Arm and How It Works?

September 27, 2019

Many people do not know about the control arm in their cars. Mechanics use this word and tell the drivers when control arm and control arm bushing needs to be replaced. This guide provides complete details about the control arms.

Control Arm in Cars

By definition, the control arm is the crucial component of the car’s suspension system and it is responsible for smooth movement of tires and wheels. The control arm maintains or controls the wheels and ensures they are in line with the car body. It moves up and down so that tires can travel.

How It Works?

Experts say the control arm connects the suspension system with the actual car frame. Ball joints and bushings keep these two parts joined together for safe movement of the wheels and tires. Thus the system connects the car wheels with the suspension system. The wheels then move according to the steering and as the driver wants them to move. 

It is important to understand that there can be two to four control arms in a single vehicle but it depends on the struts or shock system. However, most of the cars coming these days have two control arms in the front suspension system of the cars. There was a time when upper and lower control arms were used in vehicles but nowadays, only the lower control arm is provided. 

The discussion above proved the control arm and control arm bushing has an important job and it maintains the wheel alignment along with their movement. With failed control arm, the drivers will feel uncomfortable while driving.

Signs of Failing Control Arm 

As we have learned what the control arm in the vehicles is, it is important to understand when the control arm fails. Following are some signs that can help drivers and car owners figure out if it should be replaced. 

1. The Distance

Experts believe there is a certain distance limit when it comes to the performance of the control arm. When the car has covered 90,000 to 100,000 miles, the control should be replaced as they are no longer effective.

2. Potholes and Bumps

Another sign is if the drivers have been hitting their vehicles with the potholes and bumps. If you drive carelessly, this will happen. This reduces the life of the control arm and you will have to replace them before time.

3. Poor Tires

Some people believe the poor tires also show the control arm needs to be replaced. After years, the tires get wear and they are not as good as they were in the start. So this affects the performance of the control arm. 

4. Vibration of Steering Wheel

This is another indicator which tells the control arm system should be changed. If the wheel steering has a vibration or some sort of noise, the control arm has failed and should be replaced with the new one.


The control arm connects the suspension system in a car with the actual body frame. It maintains the wheel and tire movement and let them move up and down.

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