'Don't know if your car has rear sway bar links like my 81 300D, but it very well may have,or something similar. I've noticed something in rear suspension area of my car squeaking, knocking and rattling since I bought it from friend about two months ago. It has been about to run me out of my mind, especially 'til about 10 days ago when found out what is causing it. Ends of sway bar links are badly worn and loose. Sway bar links are about Z-shaped bars about 4 to 5 inches long standing vertically immediately inside of each rear wheel. Flat bar forms middle of Z; bolts on each end form top and bottom of Z. Replacing my sway bar links, rear shocks and steering gear box tomorrow. 'Can hardly wait to get rid of that squeaking, rattling noise!!!
91 350 SDL. 81 300D