shocks, sudden loss...
 

almost overnight.... soft rear end and rattle from underneath rear..87 420sel (120,000) soft rear end Any help appreciated.

Hi marketwize2003,
you will have to look under the car and see whether there is oil on the side of the shocks, which would indicate they are in need of replacement. Sometimes it's hard to see due to the plastic protective sleeve. Bielstein makes regular and HeavyDuty versions and they are around $100 each. I used the regulars as I prefer softer suspension and don't pull anything.
They are relatively easy to replace; you need to remove the back seat, the backrest of the rear seat (3 little screws on each side and middle, watch for sharp edges) and then there are 2 plastic covers that you pry out and voila, the upper mounting is in view. 2 bolts at the bottom. Replace the rubber donuts at the top, too.
Now the noise can be the plastic sway bar links or the sway bar bushings. They are also easy to replace. Subframe mounts or differential mount is a bit more difficult. The differential bushing should not have that triangle notch at the bottom so high (see picture)
Good luck
Reinhard Kreutzer