A Ball Joint is the pivot point between the control arm and the spindle or steering knuckle.
Most ball joints are made up of:
- A tapered shaft, threaded on one end with a ball on the other end
- A socket that holds the ball
- Usually, a rubber boot.
The shaft fits into the tapered hole on the spindle/knuckle and is held in place by a nut. The socket attaches the end of the control arm. The rubber boot keeps dirt and debris out of the joint.
What does it do?
The ball joint works like your hip or shoulder. It allows limited movement in any direction. The ball joint keeps the wheels properly aligned as they move up and down with the bumps in the road. It also allows the front wheels to turn left and right with the steering system.
Why are they important?
Ball joints hold the wheels in the correct position, relative to the road and the rest of the suspension. When they wear out, they no longer hold the wheel in position. Worn ball joints can cause:
- Noisy suspension
- Drifting steering
- Uneven tire wear
- Possibly even the wheel falling off the vehicle
When should they be replaced?
Most ball joints last a long time, sometimes 80,000 – 100,000 miles. Driving on bumpy, winding roads will wear them faster. Inspect Your Ball Joints when you notice any of the following:
- Clunking noises when you go over bumps
- Squeaking when the suspension moves
- Drifting to one side or the other when driving in a straight line
- Vibrations in the steering system
- Uneven tire wear