2001 slk 320 differential
I've got a 2001 slk 320 that was recently stolen, mishandled, and driven until the engine seized. The engine has been replaced and is the car is running, but now the dealer is saying that the differential is making a noise. The car was recovered in another city so I haven't been able to drive it myself and hear the noise yet, but I'm pretty sure it wasn't making any noise previously.
The service rep is telling me that the differential is failing due to "normal wear and tear" and that they checked the fluid level and it is normal (the car has 55k miles on it). I've never owned a car that needed a differential replaced, so is it likely this failure is the result of normal wear and tear? Could the failure be the result of the engine seizing? I only know at a very high level what a differential does so I don't know what could have happened in a case like this.
(I've been told the engine seized because the car was driven over something that knocked the oil pan loose. It was abandoned by the side of the road so it was driven until it wouldn't go any further).
Thank you for any information