Originally Posted by Doru

Lift the rear and try to move the wheel 9 o'clock and 3 o'clock, then 6 o'clock and 12 o'clock. if the there is movement change the rear suspension components.
If there is no movement, let the air out in the air suspension, then try to move the wheel. If it moves, then only the ball joints are shot (usually they are the first to fail - the other components might last twice as much as the ball joints, but you will strain them with bad ball joints and fail quicker). The process of changing the ball joints is very easy provided you have the correct press for it. It took me about 30-45 min/side, and only the ball joints were toast.

GL