Ricksierraowner

I bought my 2014 Sierra All Terrain SLT Crew Cab on Sept 3rd, since then I have had to replace the left front tire (20 inch sized) with only 500 miles because of a flat spot that made the truck sound like it had a thumping noise going down the highway, at 750 miles it went back again as I was complaining about a rough/vibrating feeling so they put that front left tire on the right rear and said I should be good to go, the vibration only got worse. I took the truck to my regular tire dealer for them to take a look at the balancing, after $40 spent they said the balancing was off an ounce on 2 of the 4 tires/wheels. However they told me that the vibration still did not go away and that I should take it back to the GMC dealership again. Sure enough when they checked it they could feel it as well. The service rep said there were recalls on certain components of the driveline but looking at my VIN he said they were swapped out so they will have to take apart the rear axle housing and the drive shaft, that was yesterday 10/31/14, I 'm told they will have to fiddle with it this coming Monday and the service rep said "Hopefully" we can figure out what it is. That is not comforting to hear a service rep say "Hopefully" when you have dropped almost $50K into a truck. I have owned GMC's for over 24 years and never had a ride problem before. The vehicle only has 2,000 miles now, this is very unsettling if they are not able to fix it.