Two problems related to automatic transmission have been reported for the 2018 GMC Sierra 1500. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2018 GMC Sierra 1500 based on all problems reported for the 2018 Sierra 1500.
The contact owns a 2018 GMC sierra. The contact stated that while driving at 70 mph, the vehicle began to shake violently, prompting him to pull to the shoulder of the roadway. The vehicle returned to normal functionality, but upon the contact continuing on to his destination, the failure reoccurred. The contact stated that the rpm's rapidly increased and the temperature gauge began to indicate that the vehicle was overheating. No warning lights were illuminated. The vehicle was taken to an independent mechanic, who diagnosed a failure with the auxiliary transmission oil cooler line, resulting in damage to the transmission. The contact was informed that the transmission needed to be replaced. The vehicle was not repaired. After investigating the failure, the contact related the failure to special coverage adjustment n182188930. The manufacturer was notified of the failure and referred the contact to the NHTSA hotline for assistance. The failure mileage was 131,000.
The contact owns a 2018 GMC sierra. The contact stated while driving 50 mph the contact felt the vehicle shaking hard without any warning. The vehicle was not diagnosed. The vehicle was taken to the dealer, and they stated that they may needed to flash the transmission oil. The vehicle was not repaired. The manufacturer was not contacted. The failure mileage was 71,000.