How can I tell which ball joints need replaced?

Looseness in the wheel, clunking noises over bumps, torn or leaking grease boots, and unusual tire wear are the most reliable early signs that a ball joint may need replacing. A safe, careful inspection — including a test with the car raised and supported — helps determine which joints are worn and need service.

Ball joints connect the wheel hub to the suspension and let the wheel move with the suspension while steering. Worn ball joints can cause steering instability, abnormal tire wear, and compromised braking or handling, so identifying failing joints early can prevent in-road failures. This guide explains the common signs, how to inspect them safely, and what to expect during replacement.

Signs of Worn Ball Joints

The following checklist covers the most reliable indicators that a ball joint is wearing or failed.

• Excessive play or movement in the joint when you rock the wheel at the 12 and 6 o’clock positions or when testing with a pry bar.


• Clunking, knocking, or squeaking noises heard over bumps or during sharp turns.


• Steering feel that’s loose, vague, or that wanders, sometimes accompanied by a noticeable change in alignment after hitting bumps.


• Uneven or accelerated tire wear, especially on the inside or outside edges, that isn’t explained by alignment alone.


• Visible damage to the ball joint boot (cracks, tears) or signs of grease leaking around the joint.

Even a single sign can be meaningful, but multiple symptoms strongly suggest a worn ball joint and should prompt a professional inspection.

How to Inspect Ball Joints Safely

To confirm suspected wear, follow these steps carefully with the vehicle properly supported and secured.

1. Park on a level surface, engage the parking brake, and chock the wheels opposite the side you’re inspecting.


2. Loosen the lug nuts, lift the vehicle with a jack, and support it on jack stands rated for the vehicle’s weight.


3. Remove the wheel to access the front ball joints; inspect both the upper and lower joints for wear and tear.


4. With the wheel off, grab the top and bottom of the tire and rock the wheel vertically and horizontally to feel for unusual movement at the joint.


5. Use a pry bar to gently press on the control arm near the ball joint to check for any looseness or play in the joint itself.


6. Inspect the boot around each ball joint for cracks, tears, or signs of dried, leaking grease.


7. Look for signs of rust, corrosion, or metal-on-metal grinding around the joint area.

If you detect noticeable movement, torn boots, or missing grease, these are clear prompts to have the joints evaluated by a qualified mechanic.

When to Replace and What to Expect

Replacement decisions depend on the level of wear and the vehicle design. Ball joints that show play, grinding, or boot failure typically require replacement. Many cars use sealed ball joints or press-in units; some designs are serviceable, while others are not. Replacing ball joints often involves pressing new joints into the control arms or knuckles, and in some cases it’s necessary to replace the entire steering knuckle or related suspension components.

DIY versus Professional Replacement

In most cases, ball joint replacement is best left to a professional shop or a well-equipped DIYer because it requires special tools (presses or jigs), precise alignment, and care to avoid damaging surrounding suspension parts. If your vehicle uses non-serviceable (sealed) joints, the job is almost always done by a shop. When you do it yourself, be sure you have the correct parts for your exact make, model, and year, plus the appropriate torque specs and alignment checks.

Note that many mechanics recommend replacing ball joints in pairs (both sides) when wear is present on one side, to maintain consistent suspension geometry and steering behavior after repair.

Preventive Tips and Maintenance

Preventing premature wear extends the life of ball joints and preserves steering and tire lifespan. Use this checklist to maintain your front-end components.

• Inspect boots for cracks or tears at every major service interval and replace damaged boots promptly to prevent grease loss and contamination.


• Maintain proper wheel alignment; misalignment accelerates ball joint and tire wear, especially after pothole impacts or suspension repairs.


• Avoid hitting large potholes and speed bumps at high speed; rough impacts can bend or stress ball joints and knuckles.


• Follow vehicle manufacturer recommendations for inspecting suspension components as part of regular maintenance.


• If you notice handling changes, clunks, or uneven tire wear, have the front suspension inspected sooner rather than later.

Regular checks and timely replacements help maintain safe steering, even tire wear, and a smoother ride.

Summary

Worn ball joints often reveal themselves through looseness, clunking noises, boot damage, and uneven tire wear. A careful inspection — with the vehicle safely raised and the wheels removed — helps identify which joints are failing. When in doubt, have a professional diagnose and perform any necessary replacements, because proper suspension alignment and secure joints are essential for safe driving and reliable handling.

What is the average lifespan of a ball joint?

Ball joints typically last 70,000 to 150,000 miles depending on their usage and road conditions. Clunking noises, poor handling, pulling, and abnormal wearing of your tires are all signs of a worn ball joint. If you see uneven tread wear patterns on your tire, you should have your ball joints checked.

Do upper or lower ball joints wear out first?

Lower ball joints wear out first because they typically bear the majority of the vehicle's weight and absorb more shock from the road. The lower ball joint is often larger and takes more stress from potholes and bumps, leading to faster wear than the upper ball joint. 
This video explains when you should replace your ball joints: 28sThe Car Care NutYouTube · Feb 26, 2025

• Higher Load: The lower ball joint supports the weight of the front of the car, making it a primary load-bearing component. 
• Greater Impact: It also handles the most direct impact from road hazards like potholes, which accelerates wear. 
• Suspension Design: In many suspension designs, the lower ball joint handles more stress and load, causing it to fail sooner than the upper one. 

How do I know which ball joint is bad?

You can tell a ball joint is bad by listening for clunking or squeaking noises, especially over bumps, and by feeling vibrations or steering that wanders. A physical inspection can confirm this by using a pry bar to check for excessive play in the wheel or by looking for a worn-out wear indicator, if the joint has one. 
Signs while driving

• Noises: You may hear clunking, knocking, or squeaking sounds when driving over bumps or turning. 
• Vibrations: A worn ball joint can cause vibrations through the steering wheel or the floor of the car. 
• Steering issues: The steering wheel may feel loose, the car may "wander" or pull to one side, or alignment may become difficult. 
• Uneven tire wear: Ball joint wear can cause the tires to wear unevenly. 

How to perform a physical inspection

• Check for play: With the vehicle lifted and supported on jack stands, grab the top and bottom of the wheel and rock it back and forth. 
  • If you feel or hear excessive movement (clunking, grinding), the ball joint likely has play. 
  • Movement from the top indicates a possible upper ball joint issue, while movement from the bottom suggests a lower ball joint problem. 
• Use a pry bar: With the wheel off the ground, a mechanic can use a pry bar to check for vertical looseness between the ball joint stud and housing. 
• Look for a wear indicator: Some ball joints have a built-in wear indicator. 
  • If the collar around the grease fitting is flush with or below the joint housing, it's worn out. 
  • If there is a pin-style wear indicator, check if it has receded into the joint. 

What does a bad lower ball joint sound like?

A bad lower ball joint typically sounds like a clunking or knocking noise, especially when going over bumps, making turns, or braking. A squeaking sound can also occur if the protective boot is damaged, causing the joint to lose lubrication. As the ball joint becomes more worn, these sounds tend to get louder and more frequent. 
Common sounds

• Clunking/Knocking: This is the most frequent symptom. The sound is caused by the loose joint rattling as the suspension moves up and down over imperfections in the road. 
• Squeaking: A squeak can be heard when the rubber boot around the ball joint is torn, allowing the grease to escape and metal-on-metal friction to occur. 
• Grinding: In some cases, especially with significant wear, a grinding sound might be heard. 

When to listen for the sound

• When driving over bumps or uneven surfaces
• When turning the steering wheel, especially at low speeds
• When braking