Control Arm and Ball Joint Replacement: Signs and What to Expect

What do ball joints and control arms do?

Control arms are the hinged links that hold each front wheel to the car's frame and let it move up and down over bumps. Ball joints are the pivots at the outer end of those arms. MOOG, a suspension parts maker, describes ball joints as connecting the wheel hubs to the control arms and providing universal pivoting movement between them. That pivot is what lets the wheel steer and ride over bumps at the same time.

How they are built affects the repair. On some vehicles the ball joint is part of the control arm, so the whole arm is replaced as one unit. On others the ball joint is a separate part pressed or bolted into the arm or steering knuckle, and can be replaced on its own. MOOG says ball joints may last 70,000 miles or more, depending on driving habits and road conditions.

What are the signs you need ball joint replacement?

According to MOOG, worn ball joints tend to show up this way:

• Clunking. Usually the first sign is a faint, intermittent clunk from the front suspension that gets louder over time, often over bumps or when turning.
• Steering feel. Steering that feels sloppy or stiff, or a car that drifts or wanders over bumps.
• Vibration. Loose ball joints can contribute to front-end shimmy that you feel through the seat, steering wheel or brake pedal.
• Uneven tire wear. Inner or outer tread edges wearing faster than the rest of the tire.

Potholes speed things up. AAA says a hard pothole impact can knock wheels out of alignment and bend or even break suspension parts, and that changes in handling, excessive vibration or uneven tire wear can point to damaged or worn parts. If your car also pulls or the steering wheel shakes, see car pulls to one side or steering wheel shaking.

Can a mobile mechanic do it in the driveway?

Part of it, often yes. Part of it, no. Here is the plain breakdown.

• Inspection: yes. Checking ball joints needs a jack, jack stands and hand tools. MOOG describes raising the wheel so the suspension is unloaded, then checking for play with a pry bar or by rocking the tire, and measuring it with a dial indicator. Some manufacturers allow a small amount of play, so the check is against the spec for your vehicle.
• Bolt-in control arms with the ball joint built in: usually yes. Swapping a complete arm is common driveway work on jack stands.
• Pressed-in ball joints: it depends. These are pushed into the arm or knuckle under force. MOOG's installation instructions for one pressed-in lower ball joint call for a suitable press tool both to remove the old joint and to install the new one. Some mobile mechanics carry a portable ball joint press; others will refer the job to a shop. Ask before booking.
• Wheel alignment afterward: shop. The same MOOG instructions end with aligning the front end to specifications and recommend a wheel balance check. Alignment needs alignment equipment, which mobile mechanics generally don't carry, so plan on a separate stop at a shop.

Skipping the alignment is a false saving. AAA notes that neglected suspension parts, including ball joints, can throw alignment off, and lists pulling, an off-center steering wheel, uneven tire wear and steering wheel vibration as signs of misalignment. See what a mobile mechanic can and can't do for the general limits.

What does the job involve?

1. Inspection and quote. The mechanic raises the car, supports it on jack stands, checks each joint for play and looks at the tie rod ends, bushings and CV boots nearby. No one should work under a car held up only by a jack.
2. Separate the joint. The wheel comes off, and the ball joint stud is separated from the steering knuckle.
3. Replace the part. Either the complete control arm is unbolted and replaced, or the old ball joint is pressed out and the new one pressed in.
4. Torque to spec. Every suspension fastener is tightened to the vehicle maker's torque values. This is safety-critical work, not a job for guesswork.
5. Test and refer. The mechanic road-tests the car and tells you to book an alignment soon, or books it with a partner shop.

Worn ball joints often show up alongside other worn steering parts. If a tie rod end has play too, see tie rod replacement; doing both before one alignment saves a second alignment later.

How much does ball joint replacement cost?

This site's standard price table does not have a row for ball joints or control arms, so the mechanic quotes after looking. The price depends on whether you need the joint alone or the whole arm, upper or lower, one side or both, whether a press is needed, and the parts brand. The alignment is a separate charge at the shop that does it.

These related charges come from the price table, based on prices that mechanics we list publish on their own websites:

Prices vary by vehicle and city. Ask for a written estimate that lists parts and labor per side. See mobile mechanic cost for the full table.

What should you ask before booking?

• Is my ball joint part of the control arm, or a separate pressed-in or bolted-in part?
• If it is pressed in, do you carry a ball joint press, or will you refer this to a shop?
• Is the quote for one side or both? Upper, lower or both?
• Are the parts OEM or aftermarket, and what warranty covers parts and labor?
• Where should I get the alignment done afterward, and how soon?

A mechanic who can see the car will know more than any guide.

What to do next

A clunk from the front end is worth checking before it gets louder. Find a mobile mechanic in your city, or send a request with your year, make and model, when you hear the noise (bumps, turns, braking), and whether you have hit a pothole or curb recently. If you also hear clicking only when turning, our guide to a clicking noise when turning covers CV joints, which can sound similar.