I have had a roaring noise that comes from my rear end for a while now. And no, not from eating too many beans.
The problem I have though, is after I start up, I hear a weird roaring/groaning sound that seems to come from the rear end, and then goes away after a few seconds. I can't imagine what the noise could be. I plan to do my diff fluids soon, so I will see if that sound goes away then.
Bart