There should be no space between the ball joint and the point of contact. If you see any space, or the wheel moves considerably, the joint needs to be replaced.
Typically, a solid ball joint replacement will run about $80 or $90 new. Compared to the several hundred to a thousand dollars they’ll charge at the shop, this can be a very cost-effective DIY project.
If it’s at all possible, try to work around the brake rotor, caliper, and the line without removing the assembly. If you do, you’ll have to bleed the brakes, making this a much bigger job.
If you’re working on a McPherson strut suspension remove the “pinch bolt” that clamps the ball joint stud.
With the wrench, remove the largest nut from the joint, replace with the new nut, and then drive the pickle fork between the control arm and the steering knuckle. You’ll probably have to hammer it, and don’t be afraid to get rough. This will probably ruin the gasket around the ball joint, so make sure you’ve got one to replace it. By putting the castellated nut on before hammering away, you’ll avoid having the ball joint pop completely out and drop onto the floor, or more likely your foot.
If your auto’s suspension uses pressed-in ball joints, you’ll need to remove the lower control arm and take the assembly to a mechanic with a hydraulic press, who can press the old ball joint out and the new ball joint in.
Generally, the specs will be about 44 pounds per foot on the screws and around 80 for other bolts. Always defer to the owner’s manual for accurate numbers, however.
Replacing a ball joint can affect alignment. If a ball joint is worn enough, and the vehicle was previously aligned, it might be wise have the vehicle realigned.
