I've been working on improving the clunking from the rear of my 91 560 SEL.
Just replaced the rear shocks and made a significant inprovement in the ride
and noise. The ball joints atop the shocks were severly worn and creating
considerable noise over pavenment seams and bumps.
The shock issue took awhile to discover, since the shock mount ball joints
were covered with boots.
There is still a bit of hollow "clunking" from the rear of the vehicle.
It's not bad, just a little annoying. I'm looking for suggestions on any
rubber, bushings or anything else that I might consider replacing to quiet
the ride an dtighten things up. I think it's possible, having ridden in
another similar vintage 560sel that was much tighter and quiet.
I only have 115,000 miles on the car. I have replaced the rear sub frame
mounts and removed the golf balls from the spare tire well.........That
helped just a bit :)
Car still drives like a dream. I'm just a freak about road noise.