Raise the front of the vehicle, removing the weight of the vehicle from the front suspension. Grasp the tire at the top and the bottom and move the bottom of the tire in an in-and-out motion. Check for any horizontal movement of the knuckle relative to the control arm. Replace the ball joints if you detect any looseness in the joint or if the ball joint seal is cut. You should also check ball stud tightness in the knuckle boss by shaking the wheel and feeling for movement of the stud end. Replace any worn or damaged parts.