Rear end/diff clunk?
I've noticed this a couple times (W211 E55) and am wondering if anyone else has experienced this. Every so often, when I'm backing up out of a parking spot or my garage, I'll get a seizable clunk that will come from the back end of the car. It doesn't happen all the time...but it only happens in reverse...and it only makes one "CLUNK" and then it's done. There are no other adverse signs or events that take place though...no jarring, tire screeching, leaks, squeeks, nothing...just the one clunk. It's on a perfectly smooth surface too so it's not suspension related as far as I can tell.
The first time it happened, I was all like WTF? Thought I hit something or ran something over. Now, I'm just curious as to what it is.
Could it be the diff doing weird stuff when unlocking? Something else weird pinion/ring related? Failing axles?



