2026 GMC Sierra 3500

4 complaints on file, page 1 of 1.

1. Filed Aug 29, 2026Failure Aug 26, 2026North Ogden, UTWheels

   The vehicle was delivered from the factory with a severe size mismatch between its primary rolling stock and its emergency spare tire. The truck features factory-installed 20-inch wheels and tires but was manufactured and shipped with an undersized 18-inch spare tire assembly secured underneath the bed. On a heavy-duty 3500-series truck built for heavy towing and hauling, utilizing a drastically different tire diameter during an emergency road event forces the rear differential and transfer case to spin at mismatched speeds. This creates an immediate risk of sudden mechanical drivetrain failure, loss of vehicle control, or compromised braking stability while operating under load on public highways. Consumers relying on factory equipment during emergency roadside scenarios should not be exposed to hidden mechanical hazards due to factory assembly omissions. Upon discovering the factory defect, the local dealership attempted remediation by supplying a shop take-off wheel and an aged, three-year-old tire (DOT 2223). This highlights that while individual dealerships scramble to fix these factory omissions with makeshift inventory, consumers purchasing new heavy-duty vehicles are still absorbing compromised, aged safety equipment due to lack of manufacturing quality control. I have also filed a complaint with GM and have requested immediate remediation with a correct new tire and wheel and am waiting for a response.

   NHTSA complaint 11760574
2. Filed Aug 29, 2026Failure Aug 26, 2026North Ogden, UTWheels

   The vehicle was delivered from the factory with a severe size mismatch between its primary rolling stock and its emergency spare tire. The truck features factory-installed 20-inch wheels and tires but was manufactured and shipped with an undersized 18-inch spare tire assembly secured underneath the bed. On a heavy-duty 3500-series truck built for heavy towing and hauling, utilizing a drastically different tire diameter during an emergency road event forces the rear differential and transfer case to spin at mismatched speeds. This creates an immediate risk of sudden mechanical drivetrain failure, loss of vehicle control, or compromised braking stability while operating under load on public highways. Consumers relying on factory equipment during emergency roadside scenarios should not be exposed to hidden mechanical hazards due to factory assembly omissions. Upon discovering the factory defect, the local dealership attempted remediation by supplying a shop take-off wheel and an aged, three-year-old tire (DOT 2223). This highlights that while individual dealerships scramble to fix these factory omissions with makeshift inventory, consumers purchasing new heavy-duty vehicles are still absorbing compromised, aged safety equipment due to lack of manufacturing quality control. I have also filed a complaint with GM and have requested immediate remediation with a correct new tire and wheel and am waiting for a response.

   NHTSA complaint 11760573
3. Filed Jul 8, 2026Failure Jun 2, 2026500 milesChruchville, VAPower train, Service brakes, Hydraulic

   The contact owns a 2026 GMC Sierra 3500. The contact stated that while driving at 35-40 MPH on the interstate and towing a loaded trailer, the vehicle experienced reduced braking performance. No warning lights illuminated. The local dealer was contacted and informed that the brakes performed differently. Additionally, the dealer stated that the transmission was not downshifting. The vehicle was not diagnosed or repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 500.

   NHTSA complaint 11749030
4. Filed Jun 16, 2026Failure Jun 10, 2026Springfield, ORElectrical system, Fuel/propulsion system, Power train

   Have been driving it on four separate occasions and the engine will start running rough and shut off leaving me with no power brakes or power steering. Once when I was going about 30 miles an hour the other three times when I was coming to a stop with a trailer on just took it in Kendall Chevrolet for the first time they are still working on it but unable to duplicate the problem this is a very serious safety concern for myself and possibly for others that have the same issue

   NHTSA complaint 11744605