Solved my C230 1998 rear end problem. Noise due to low lube and
consequent scuffed pinion gear. Needed ear plugs to drive. So found a
low mileage (38K) one at a specialty dismantler for $300. I contacted a
local high school auto shop. The kids loved putting it in..less than 2
hrs with good instructor supervision. Simple job up on a lift. Just
bolts to take out and install. Kids got $100 pizza/hamburger gift
certificate. The local independent MB shop had quoted me $800 dollars
to put it in and $1500+ for a new differential or $1000 for a used one.
So now the car sound like brand new and the MB dealers didn't make out
on my account.. :+)

Larry