Tire Sidewall problems of the 2008 GMC Sierra 1500

Tire size: 265 75 r16. All four tires inside wall has failed about two inches all the way around the rim. The tires were purchased sometime in 2018 and are a little above the 50. 000 mile warranty. They were inspected by ntb technicians in lancaster and also in canal winchester ohio. They will only replace one tire for free but l think and believe l can’t be the only one with 4 of these tires failing in the same vehicle. All four tires have failed. No inspection by police or insurance has been performed. No warning signs at all other l got under the vehicle to inspect a small oil leak and that is when l saw the problem. I want to reiterate, what are the odds am the only one with all four tires failure?.

Truck shakes between 45 and 60. Does it all the time. Took to GMC dealer and they check it out and said it was the way the truck was get used to it. Called detroit and got the same thing. It's not right. It all started with around 14,000 miles . The truck didn't do it at all until then. The service station that I use to service it found the tires to be out of round and the sidewalls were coming undone. Put a new set of tires on and it helped a little bit but not a great deal. They also told me to put weight in the box to help. I tried and it didn't help. All I want is the truck made right.