The ball joints on your car or truck are typically found in the front suspension, and they allow the front steering knuckle to lift up and down with the corresponding movement of the vehicle. When you need to work on the suspension, you sometimes have to separate the ball joint from the steering knuckle. Occasionally, you will get a frozen ball joint, which becomes very difficult to remove. If that happens, you can try a few steps, starting with the least aggressive and ramping up to the most aggressive to separate the ball joint.
Park the vehicle and set the parking brake. Lift the front wheels off the ground with the jack and put jack stands under the frame or chassis, then take off the front wheels with the tire iron.
Put the jack underneath the lower control arm and lift it up until the head of the jack contacts the arm. Pull the cotter pin out of the upper control arm ball joint with the needle-nose pliers, then unbolt the upper control arm ball joint nut from the upper control arm with an open-end wrench. Spray the penetrating spray in the gap between the ball joint and the steering knuckle.
Strike the side of the steering knuckle with the sledgehammer to attempt to wedge the ball joint free from the steering knuckle. Attempt this several times and if it does not break free, then proceed to the next step.
Insert the pickle fork between the upper control arm ball joint and the steering knuckle. Strike the end of the pickle fork with the sledgehammer to try to wedge the pickle fork between the ball joint and the steering knuckle, breaking the two apart. Attempt this several times, and if it doesn't work, proceed to the next step.
Install the pickle fork attachment to the air hammer and the air hammer to the air compressor. Insert the pickle fork into the suspension just like you did in step 4, but now pull the trigger on the air hammer to push the pickle fork forward. Do this until the ball joint separates.
