What happens when a control arm goes?

A control arm going bad can compromise steering, alignment, and overall vehicle safety, potentially leading to loss of control if not addressed promptly. If you notice unusual handling, noises, or tire wear, stop driving and have the suspension inspected by a professional.

Understanding the control arm and how it works

The control arm (often called an A‑arm) is a key suspension link that connects the wheel hub to the vehicle’s chassis. It typically pivots on bushings at the frame and carries a ball joint to connect to the steering knuckle. This arrangement helps maintain proper wheel alignment while allowing the wheel to move up and down with road irregularities.

Key components of a control arm

These parts work together to allow controlled wheel movement and maintain alignment during driving.

• Ball joint or ball joints


• Bushings (often polyurethane or rubber)


• Mounting points to the chassis and/or subframe


• The arm itself, usually cast or forged steel

Like any suspension part, the control arm and its fasteners are subject to wear, impact, and corrosion. When one of these parts fails, the suspension geometry can be altered, leading to handling changes and uneven tire wear.

Common symptoms of a failing control arm

Below are typical signs that a control arm or its associated components may be worn or damaged. If you notice any of these, have the suspension inspected promptly.

• Clunking or knocking noises from the front suspension, especially when going over bumps or making tight turns


• Steering feel that is loose, vague, or binding, sometimes accompanied by a wandering vehicle


• Vehicle pulls to one side or experiences uneven braking behavior


• Excessive or uneven tire wear along the edges


• Visible damage or play in the front suspension components during a roadside inspection

Addressing these symptoms early helps prevent further damage to the suspension and tires, and reduces the risk of a loss of control on the road.

Why control arms fail

Several factors can lead to a control arm needing replacement. Understanding these can help with maintenance planning and risk assessment.

• Worn or cracked bushings due to miles, weather exposure, and road salt


• Worn or damaged ball joints, which may be integrated into the arm or a separate part


• Impact damage from potholes, curbs, speed bumps, or collisions


• Corrosion and metal fatigue in regions with harsh winters or heavy road debris


• Loose or broken mounting bolts or worn mounting points

Because the control arm helps maintain wheel alignment, failure can quickly lead to misalignment, uneven tire wear, and unstable handling if not repaired promptly.

Repair options and maintenance considerations

When a control arm is diagnosed as failing, mechanics typically consider several repair paths depending on the vehicle design and the extent of wear or damage.

• Replacing the control arm assembly with an OEM or aftermarket part


• Replacing individual bushings or a ball joint on the arm if the design allows


• Replacing both control arms on the same axle to ensure balanced alignment


• Performing a wheel alignment after replacement to restore proper camber, toe, and caster


• Inspecting related components (tie rods, sway bar links, struts, and related joints) for wear and compatibility

Costs and timelines vary by vehicle and part availability, but addressing a faulty control arm promptly minimizes further suspension damage and reduces safety risks.

Safety guidance and practical steps if you suspect a bad control arm

If you notice sudden changes in handling, unusual noises, or pulling to one side, reduce speed, avoid rough roads, and seek professional inspection. Do not continue driving aggressively or long distances with suspected suspension failure, as the risk of a loss of control increases with continued use.

Mechanics can diagnose the root cause—whether it’s the arm itself, bushings, or a related component—and recommend replacement or repair options. After any replacement, insist on a wheel alignment to prevent abnormal tire wear and to restore stable steering.

Summary

The control arm is a foundational suspension link that preserves proper wheel alignment and steering response. When it goes bad, you may experience clunking noises, steering instability, pulling, and uneven tire wear, all of which raise safety concerns. Prompt diagnosis, appropriate replacement or repair of the arm or its joints, and a fresh wheel alignment are essential steps to restore safe handling and protect your tires and chassis health.

What happens if you drive with a bad control arm?

Driving with a bad control arm is extremely dangerous and can lead to a loss of vehicle control, especially at high speeds or during turns. You risk a complete suspension failure, which could cause a wheel to detach or a sudden loss of steering. A bad control arm also causes other serious issues like poor handling, vibrations, clunking noises, and uneven tire wear.
 
This video explains the symptoms of a bad control arm: 59sEasyAutoFixYouTube · Oct 5, 2024
Immediate and severe risks

• Loss of control: A failing control arm can cause you to lose the ability to steer, and the vehicle could veer unexpectedly. 
• Wheel detachment: In a worst-case scenario, a broken control arm can lead to a wheel coming off, which would almost certainly result in a severe accident. 
• Brake failure: A control arm could tear a brake line, leading to the loss of one or both front brakes. 

Other symptoms and consequences

• Poor handling: The vehicle may drift to one side, and maintaining a straight line will require constant steering adjustments. 
• Vibrations: You may feel vibrations in the steering wheel, floor, or seats, especially when driving over bumps. 
• Loud noises: Expect to hear clunking, banging, or knocking sounds when you drive over bumps or make turns. 
• Uneven tire wear: The misaligned wheel will cause your tires to wear out prematurely and unevenly. 
• Further damage: Ignoring the problem will cause damage to other suspension and steering components, increasing repair costs. 

What to do

• Do not drive: If you suspect a bad control arm, avoid driving the vehicle if possible. 
• Get it inspected immediately: Have a professional mechanic inspect the control arms as soon as possible to prevent a catastrophic failure. 

Can a broken control arm be fixed?

Yes, a control arm can often be repaired, but it's frequently more practical and recommended to replace the entire control arm assembly, especially if it's rusted or damaged. Some parts, like the ball joint or bushings, are sometimes serviceable and can be replaced individually, but this is often not the best long-term solution if other components are worn.
 
When to repair vs. replace

• Replace the entire assembly: This is often recommended because it's easier and ensures longevity by installing new bushings and a new ball joint simultaneously, which addresses all potential wear and tear at once. 
• Repair (individual parts): In some cases, a control arm can be "repaired" by replacing individual components like the ball joint or bushings. However, this is only feasible if the control arm itself is in good condition and not bent or significantly rusted. 
• When to definitely replace: A full replacement is necessary if the control arm itself is bent, cracked, or severely rusted. 
• If you're unsure: If you're not confident in your mechanical abilities, it's best to have a professional mechanic handle the repair or replacement. 

Important considerations

• Replace in pairs: If you need to replace a control arm, it is best to replace both the left and right sides to prevent uneven handling. 
• Post-replacement alignment: After replacing any control arm or its components, you must have a wheel alignment performed. 

How much would it cost to fix a control arm?

The average cost to replace a control arm is between $400 and $1,000, but it can range from under $300 to over $1,700, depending on the vehicle, parts, and labor rates. This total typically includes parts and labor for the control arm replacement, and an alignment is also necessary afterward, adding another $100 or more to the final price.
 
Cost breakdown

• Parts: Control arm parts can cost from about $80 for a basic model to over $400 for a specialty vehicle. Some complex control arm assemblies, especially for high-end cars, can be much more expensive.
• Labor: The labor cost is often the largest portion of the expense. It typically ranges from $150 to $300 or more, depending on the shop and how long the repair takes.
• Alignment: An alignment is crucial after a control arm replacement to ensure proper wheel alignment, and this typically costs $100 and up. 

Factors that influence the total cost

• Vehicle Make and Model: The cost of parts and labor varies significantly between different makes and models. A basic control arm for a common car will be cheaper than a specialized or heavy-duty one for a truck or luxury vehicle. 
• Part vs. Labor: The parts themselves are often only a portion of the total cost. Labor is a major factor, with some jobs requiring two to three hours per arm. 
• Type of Control Arm: Some control arms are simpler, while others are part of a larger assembly that includes ball joints and other components. 
• Location: Labor rates can vary based on your geographic location. 

How to save money

• DIY: If you have the right tools and skills, you can save on labor costs by replacing the control arm yourself. 
• Shop Around: Get quotes from multiple shops, including independent mechanics, to find a competitive price for both parts and labor. 
• Consider Aftermarket Parts: Some aftermarket parts may be more affordable than OEM (original equipment manufacturer) parts, but it's important to check the quality of the aftermarket part. 

What happens if my control arm breaks while I'm driving?

If a control arm breaks while driving, you will immediately and dangerously lose steering control, potentially causing the wheel to collapse and the vehicle to pull to one side. This is a critical safety failure that can result in a complete loss of vehicle control, making it an extremely dangerous situation.
 
This video demonstrates what happens when a control arm breaks while driving: 58sAutomotive affairsYouTube · Dec 14, 2024
Immediate consequences of a broken control arm

• Sudden loss of steering: The vehicle's steering will become unstable and you will lose the ability to control its direction. 
• Wheel collapse: The wheel on the affected side can shift out of position or even collapse, potentially causing further damage. 
• Vehicle pulling: The car will likely pull sharply to one side. 
• Collision risk: These combined issues create a high risk of collision, making it a severe safety hazard for yourself and other drivers. 

What to do if you suspect a broken control arm

• Pull over immediately: Safely steer the vehicle to the side of the road as quickly as possible and stop. 
• Do not drive the vehicle: Driving with a broken control arm is extremely dangerous and should be avoided. 
• Have the vehicle towed: Have the car towed to a repair shop for a professional inspection and replacement of the control arm and any other damaged suspension components.