I have had my 2005 GTO for 6 years now. The rear end is starting to whine and chattering. It had been worked on by the previous owner and has almost always whined. The chattering while turning has just started. Limited slip fluid did not help. There are options but I have been trying to find out if a differential from a C4 Vette will bolt in to my car. I read that the Dana 44 IRS version used in my GTO was also used in the vette. I am trying to fix this so I can sell the car.