I was wondering what it is that i am supposed to look for in the rear end if i take the diff cover off to inspect it. I have a whinning noise and i think there is something wong inside but \i am not sure what i am supposwed to be looking for or what i am supposed to do to determine where and what the problem is exactly. Can anyone give me any advise cause i dont want to make things worse by driving if it is the rear end. Thank you.