I have a 98 WS6 Trans AM that has rearend noise. I had my axle seals changed a couple of months ago by a dealership and they refilled the rearend with MOC lube and additive. I put about 600 miles on it and now it whines like crazy. Does anyone know if this is comparable with GM lube and additive since it has the limited slip differential? I called a GM dealership today and they have never heard of MOC. HELP!! Any feedback would be greatly appreciated.