Wanted to check and see if anyone knows about a binding or grinding noise in the rear end of their 2006 c6 vet. Have taken mine to the dealership and they have not been able to diagnose the problem yet and can't find a techinical advisory for it. Mostly does it when turning normal corners or backing up. The service tech drove it to the bay to be looked at and heard it and said it should not be making that noise. Very similar to the noise my 1972 made when the posi traction grease needed to be changed. Any suggestions?