For anyone whom may be having a noise coming from the rear of their W126 Mercedes Benz when hitting bumps you might want to inspect your rear sway bar links. What I have found is that many times when people complain of a slight noise coming from the rear when hitting bumps is usually the result of worn rear sway bar links.

This noise is not a very loud rattle. It is possible for many other things to make noise back there such as the exhaust, springs or shocks, however the noise that is usually made by these are usually a lot louder and deeper than that of the sway bar links. The sway bar links are about 6 inches long and have a ball joint style stud on each end. One end connects to the chassis and the other connects to the sway bar. If the sway bar links are OEM they should be white in color.

Just grab them and wiggle them about. A good sway bar link will not have any slop. Usually a bar sway bar link will have a lot of play, and will almost feel like its going to pop off. It is amazing to me how long they will stay in tact making noise before they totally let loose. The good news is that the rear sway bar links are somewhat easy to replace. Please let me know if you are in need of photos to identify the rear sway bar links and I will post them up.