What it does
Ball joints are pivots that connect the control arms to the steering knuckle, the part your wheel bolts to. They let the wheel move up and down and turn at the same time. Like a hip joint, they're a ball in a socket, sealed with a rubber boot.
Common symptoms
- Clunking or knocking from the front over bumps, potholes or in turns
- Creaking, clicking or grinding from the front end
- Vibration through the steering wheel or front suspension
- Loose or wandering steering
- Uneven front tire wear
What to look for
- Safety first: if you lift the vehicle, use jack stands on solid, level ground. Never get under a vehicle held up only by a jack.
- Shake test: with the wheel off the ground, grab the tire at 12 and 6 o'clock and rock it in and out. A clunk or movement you can see at the joint means it's worn. If the wheel moves but the joint doesn't, suspect the wheel bearing instead.
- Pry test: lever the tire up from underneath and watch the joint for up-and-down play. Go easy so you don't knock the vehicle off the stand.
- Check the boot: a torn or missing boot lets dirt in and wears the joint out fast.
- Know the spec: some ball joints are allowed a small amount of play from the factory, so check the spec for your vehicle.
Could be something else
A loose wheel bearing shows up in the same shake test. Tie rods, sway bar links and strut mounts can all clunk too. Clicking that's worse when turning is more often a CV joint.
Is it safe to drive?
No. If a ball joint separates, the wheel can fold under the vehicle, and at highway speed that can be catastrophic. Get it checked as soon as you notice symptoms.
Related: Bad tie rod end symptoms · Bad wheel bearing symptoms
Think it's your ball joints? Northwoods can check it right where your vehicle sits, anywhere in the greater Twin Ports area.