Just like a your hips and their sockets help you move smoothly, ball joints allow your car's front end to move up and down and left to right as well as turn for steering. Ball joints usually last a long time, but they can wear down over time or from extreme driving conditions. Here's how to check your ball joints:

  1. Listen to the suspension Listen to the sound of your suspension while you're driving around. If you hear any abnormal bumping, rattling or scraping coming from the front end, it could indicate your suspension is having problems, which could mean your ball joints are worn out [source: 2CarPros].
  2. Look under the car Locate the ball joint under the steering knuckle. Some suspensions have an upper and lower ball joint. The lower joint takes more abuse and usually wears out first. Check if the rubber boots on the joints are in one piece. If they are torn or gone, the joint probably needs replacing [source: Bumbeck]. If there is excessive lubricant leaking from the joint, you might only need to replace the rubber cover. Also look for rust dust that would indicate metal on metal friction [source: 2CarPros].
  3. Test the steering and suspension If you can't tell simply by looking at the joints, you'll have to get under there and fiddle around. Jack the front end of the vehicle up and secure the car on stands. Try to move the joint around with your hands, there shouldn't be any play if the joint is in good condition. Turn the steering wheel side to side and feel for any excessive or choppy movement. Move the road wheels by hand to see how they feel too. Try pushing and pulling on the road wheels to feel for any give. If the wheels move around too much, your ball joint probably needs replacing [source: Bumbeck].