Sorry to piggy back this message to yours but I changed my rear control stabilizer bars and saw the same problem on my 87 260E. The dealer told me that I needed to drop everything back there to replace the bushing. If that is the case, might as well change all the bushings while everything is off.
Mine is making some ugly creaking and groaning noises.
Can anyone confirm this diagnosis.
1987 260E Charcoal Grey 157,000 Miles
1987 260E Forest Green 120,000 Miles