Very funny, my E300 just doing something similar. A sudden clattering in the drive train above 20 MPH. It sounds much like the sound made when sticking playing cards in bicycle spokes. It doesn't seem to be related to load.

I haven't tried running the drive train while suspended off the ground.

Any ideas? Is this the same problem?

__________________
-Evan


Benz Fleet:
1968 UNIMOG 404.114
1998 E300
2008 E63


Non-Benz Fleet:
1992 Aerostar
1993 MR2
2000 F250