Chris Kueny wrote:
My 1985 300TD has a noise coming from the rear, which I had my indy 'fix' last year. It has the following traits: It is clearly in time with speed, and sounds like hammering. It is most pronounced on hard acceleration, goes almost away while coasting, and if I decelerate, it also is loud, but somewhat different. Finally, it seems too slow to be the wheel, and I am hoping someone will tell me it is obviously the flex disc, The indy said my right rear brake was sticking, and rebuilt the caliper. It sounds like it is coming from the passenger's side, but if it were the flex disk, is it possible that the muffler would shield that sound from the drivers side? Last year I took a very good hard look and detected nothing out of order, hence the indy. It started back shortly after I got it back, then went away for most of the summer/fall. Anyone have an idea? Or some tests I can do to narrow down the problem? Thanks in advance for any and all suggestions.
Sure sounds like a flex disc, or maybe the center carrier bearing? You didn't mention getting under there yourself recently for a good look-see; I'd do so quickly as a busted flex disc will ruin your entire day (and car.) See http://www.dieselgiant.com/Mercedes%20flex%20disc%20failure.htm for what to look for and a good scarin'. A bad differential mount can cause clunking noises as well, but yours sounds worse than that. Cars can play lots of acoustical games; you might be chasing your tail pinpointing it by ear.
Tom
