Hey everyone. I have a 2003 ML350 that has been my baby. 135K miles and has been bulletproof until a week ago. While approaching a stop sign I got the slight smell of something burning, and then a clunking noise. The noise only happens when i am moving. When in drive, at a stop or when in park, the engine in completely silent but when I start moving, either forward or backwards, it sunds like something smacking the floorboards of the truck. I have crawled underneath and I cannot see anything blatantly broken or out of place. Any help would be greatly appreciated.

Thanks in advance,
Aaron

 

Also, the smell seems to have gone away, even though I haven't driven it much since this happened

 

Check the drive shaft center support bearing. If this breaks you will hear a ton of noise and will break other stuff. Better get it checked out. Very common issue on those ML's.
Grab the drive shaft and move it up and down. Im betting it needs replacement.