I've got an '85 300D with 251k on it. As of this past week I noticed a hollow thump sound in the rear when I accerlate from a light or when I turn. It sounds like it's coming from the rear passenger side and it only happens every so often. Any suggestions what to look for?

While I'm at it.... I've also noticed that when I brake, I sometimes hear a solid thud from the rear. I can't really distinguish which side though.

Thanks!!

Brian