I have a 2007 silverado 1500 new body style with 45000 miles on it. Recently when the turck is good and warmed up at low speed turns I can hear a rubbing or grinding noise coming from right behind the steering wheel. I took it to my chevy dealer to have them look at it. They said the noise was coming for the steering gear and it would be 1000 bucks to replace it. What do you all think the noise could be coming from. I put some grease around the spot where the steering shafts exits through the firewall thinking it was rubbing there. IT doesn't do it when I first start it up, it only does it after 15 minutes of dirving or so.