What Is A Control Arm & What Some Bad Control Arm Symptoms

A car’s steering and suspension systems contain some of the most important yet frequently disregarded mechanical parts. These parts ensure safe journeys and are required for effective vehicle functioning. Each component must be kept in top shape to function as intended.

The control arms of a car are among the most expensive of all steering and suspension-related parts. In the end, these assemblies connect the front wheels of a car to the corresponding frame mounts.

In addition to allowing the wheels of a vehicle to swivel up and down, control arms also enable the frame to remain in a fixed position. Given this information, replacing outdated or dysfunctional control arms is crucial.

Also, this replacement needs to be completed quickly. Fortunately, when a control arm begins to show signs of wear, one or more symptoms frequently appear, alerting drivers to the need for such maintenance.

What Is a Control Arm on a Car?

The control arm is an essential part of a car’s steering and suspension system. This part is attached to the frame of a vehicle at one end and an outboard-mounted hub at the other. Bushings are positioned inside the frame mounts of a control arm to prevent excessive wear from constant movement.

Each vehicle’s front wheel can move vertically in response to the car’s frame thanks to the control arms. Specialty shocks and struts soften this movement and create a smooth ride without severe vibration. A pivoting component called a ball joint attaches a control arm’s outer end to the corresponding wheel hub.

Car wheel and suspension detail of lifted automobile at repair service station.

Upper and lower control arms are standard in trucks and SUVs, and they work together to hold the seat to which they are attached. However, some cars have lower control arms. A control arm’s precise dimensions frequently vary from one vehicle type to the next.

5 Bad Control Arm Symptoms

There are several secondary symptoms that a poor control arm frequently exhibits, some of which are often more prominent than others. While trying to diagnose the problem, recognizing these symptoms can be incredibly helpful.

1.     Unreasonable vibration

The occupants of a car might quickly feel excessive vibration, which is yet another sign of a poor control arm. This vibration is frequently described as a constant shutter or shimmy, whose intensity varies with pace.

When the wear on the control arm increases, this vibration only seems to get worse. Among other things, excessive shaking or vibration may be a sign of faulty motor mounts.

2.     Steering that is unresponsive or unstable

In extreme circumstances, worn control arms can make a car’s steering sluggish or unstable, resulting in poor straight-line performance and unacceptable cornering capabilities. Drivers frequently need to correct their steering far more regularly because of this.

3.     Tire wear that isn’t even or regular

Tire wear that is uneven or irregular is another obvious indicator of excessive control arm wear. Although it can occur across the whole tread area of a tire, this wear frequently shows up around the inner or outer margins of the tread. When forced to replace tires before they should, this might result in wasteful spending.

A woman checking her car tire.

4.     Strange road noises

The first indication of control arm tiredness is frequently strange noises coming from the vehicle’s front end. These sounds, which frequently resemble popping, clicking, or metallic clicking, are frequently most audible when moving over bumps or uneven terrain. These noises can occasionally sound like a CV joint failing.

5.     Visual Damage

Standing next to your car and focusing on the tires will obscure the control arms. As you jack up your vehicle, the control arms are visible. Lift your car up and inspect the suspension of each wheel if you suspect your control arms are failing. It is necessary to replace the A-shaped part holding the spring or strut if it is visually harmed.

Can You Drive With a Bad Control Arm?

Being aware that it is never a good idea—and should never be attempted—to drive a car with a damaged or malfunctioning control arm. In addition to being ineffective, going in this way is also very dangerous. The cause of this is found in the control arm’s structural makeup. Wheel ends and frames of vehicles are connected directly via control arms.

There is a risk of death if this link should ever break while being used. The steering would become, at best unpredictable and may potentially cause an accident at any speed if a control arm were to fail while in use entirely. In addition, there is a high probability that such a failure will result in secondary damage to a person’s vehicle.

Can Control Arms Cause “Death Wobble”?

Any slack steering or suspension parts underneath the front end of a car can be a surefire cause of “death wobble.” The intense shaking or swaying known to happen in the front future of numerous vehicles across a wide range of speeds is known as “death wobble,” a common term used to describe it.

This condition might be very alarming for everyone traveling with you. The truth is that death wobble, even that provided by a damaged control arm, can happen when there is too much play in any front-end component. Deteriorated bushings or loose or damaged control arm mounting nuts are other potential causes.

How A Control Arm Is Inspected

Control arms and many other suspension components cannot be thoroughly inspected at a drive-through fast-lube location. Only when the car is hoisted up can the control arms be inspected.

This occurred to the car’s owner: for the previous 12 months, he had only been to a fast-lube shop, where they overlooked an old ball joint. Are there any signs that a ball joint or poor control arm bushings are malfunctioning? You might hear a popping or clunking sound when accelerating and decelerating or going over bumps.

Mechanic repairing front wheel in the garage.

A car may occasionally feel shaky and “wander” while braking or traveling over uneven terrain. Yet, the symptoms may only sometimes be apparent. This is one of the reasons it’s crucial to get your car inspected at least once a year by a qualified mechanic when it is lifted on a hoist at a garage.

When Do The Control Arms Need To Be Replaced?

Essential components of the front suspension of a car are the control arms. A vehicle is declared unsafe if a control arm is worn out or damaged beyond what a car manufacturer deems acceptable. Control arms and other front-end components have been better in quality recently, yet they still malfunction.

Local vehicle repair businesses won’t leave the company anytime soon because control arms and other front-end components are still a concern for some contemporary electric automobiles.

One “lower” control arm is on each side of the front suspension system with MacPherson struts typical of contemporary automobiles. Rubber bushings that are used to join the inner side of the arm to the subframe or body help to reduce vibration and noise from the road.

As the car travels over bumps, the pivot points provided by the bushings allow the control arm to move up and down. The steering knuckle, which supports the front wheel, is connected to the control arm’s outer end through a ball joint. A stabilizer (sway) bar attached to both lower control arms or struts keeps the car stable in turns. Check this front suspension diagram for more information.

Control Arm Replacement Cost

The cost of replacing a control arm might differ dramatically from one make and model of vehicle to the next. This results mainly from inconsistencies between the price of a control arm and the number of labor hours needed to replace it. The going labor wage varies significantly amongst shops, another primary concern.

As a result, a replacement will typically cost more at a car dealership repair department than in a garage run by a freelance mechanic. Taking everything into account, one should budget between $150 and $400 to replace a single control arm, though in some cases the cost may be much more.

Is An Alignment Necessary After Replacement?

The cost of an alignment is not truly necessary when one or more control arms on a vehicle need to be replaced. This is because the control arm itself does not preserve any crucial adjustment locations. Instead, since a control arm doesn’t need to be individually adjusted for caster, camber, or toe, it is most simply categorized as a solid-state component.

Yet, an alignment would be a worthwhile investment if any incident brought on the need to replace your vehicle’s control arm. This is because the same impact that might harm a control arm can also seriously damage several other front-end components.


Go your automobile to a shop for a comprehensive suspension check if you’re experiencing any of the symptoms mentioned above. If you’re a DIY enthusiast, put your car on jack stands and carefully inspect the control arms and front steering for any problems.

If your control arm or another suspension link or arm fails while driving, you should slow down the vehicle and, if possible, move it off the road. It’s essential to remember that you might not be able to guide the car if the control arm fails. Remember to adjust your vehicle after replacing anything related to the control arm.

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About Matthew Webb

Hi, I am Matthew! I am a dedicated car nerd! During the day, I am a journalist, at night I enjoy working on my 2 project cars. I have been a car nerd all my life, and am excited to share my knowledge with you!