How to Check Ball Joints

Ball joints are used to connect car's suspension system to control arms and steering knuckles. Ball joints allow your suspension system to move while the vehicle is steered. The number and location of your vehicle's ball joints will depend on the car's make and model and the kind of suspension system in use. If you experience difficulties with your steering or suspension, you may need to check your ball joints to make sure they're functioning properly.

Difficulty: Moderate

Instructions

1. Gain access to the vehicle's suspension system. Use the lift system in a professional garage to hoist your car overhead.

2. Locate the ball joints, and check to see whether they're in ideal working shape. Before you can adjust or grease your ball joints, you'll need to make sure the effort is actually needed.

3. Inspect ball joints that are classified as "lower load carrying." These joints are used on vehicles that have torsion bar or coil springs located on the control arm.

4. Find the "lower follower non-loaded" ball joints. They're located within rear-wheel drive cars and those that use the MacPherson suspension system.

5. Check the "upper load carrying" ball joints. These joints are used in vehicles that have a tension or spring bar located on the upper control arm.

6. Read the wear indicator located on the ball joint in question. Check to see how far the grease fitting boss protrudes from its housing on the ball joint. As long as you're able to feel any edge of the boss beyond the housing, it's in good shape. Once the boss is worn flush with the housing, it's time to find a replacement.

7. Replace all your ball joints at once. It's normal for ball joints to experience an equal amount of wear and tear, even if they're located on opposite sides of the vehicle. Joints that carry a load will show signs of wear more quickly than non-load bearing joints.

Tips & Warnings

• There are several telltale signs of ball joint problems within your vehicle's suspension system. Listen closely to see whether you hear any "clunking" sounds from beneath your car when you drive over bumps or rocky terrain.
• Problems with your ball joints can lead to wheel alignment issues. If your wheels are aligned improperly, this can make your vehicle less fuel-efficient and contribute to unnecessary and expensive wear on the tread of your tires.
• It takes a good deal of technical know-how to replace a vehicle's ball joints. Unless you know how to use a "ball joint fork" to separate a joint from a steering knuckle, chances are you'll need the help of a professional mechanic.
• Faulty ball joints in a car can be dangerous. If even a single ball joint breaks, your vehicle's entire suspension system can fail. This can cause you to lose control of your vehicle.
• Specific information on the placement and maintenance of ball joints can be found in your vehicle's owner's manual. Before you attempt to check ball joints, consult the manual.