Which parts fail
Components named in complaints (automatic and manual transmissions, CVT, axles, driveshaft, 4WD/AWD).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2018 GMC Sierra 1500 owners, lightly cleaned up (personal details are redacted by NHTSA).
The contact owns a 2018 GMC Sierra 1500. The contact stated while driving from a complete stop and depressing the accelerator pedal, the engine revved but the vehicle hesitated to respond. There was no warning light illuminated. The contact stated that the failure reoccurred several times. The vehicle was taken to the local dealer, where it was diagnosed that the transmission was slipping and needed to be replaced. The vehicle was repaired. Additionally, the contact stated while driving 60-65 MPH, the vehicle started vibrating and shuddering. The check engine warning light was illuminated. The contact was able to drive to her nearby destination. The vehicle was towed to a second dealer Liberty Chevrolet (105 Cooley Way, Villa Rica, GA 30180) where it was diagnosed that the driver's side lifters had failed and needed to be replaced. …
The contact owns a 2018 GMC Sierra 1500. The contact stated that the vehicle failed to shift into gear as needed. The vehicle was taken to the dealer, where the contact was informed that an unknown part was loose. The vehicle was repaired. Additionally, the contact stated that while driving at various speeds, there was an abnormally loud sound coming from underneath the vehicle near the transmission. The vehicle was taken to the dealer, where the contact was informed that no failure was found. The contact stated that while driving 55 MPH, the vehicle started to decelerate unintentionally. The contact stated that there was smoke coming from the brake pedal. The contact pulled over to the side of the road and allowed the vehicle to cool down however, the brakes locked up unexpectedly. The vehicle was driven to the dealer to be diagnosed. …
The contact owns a 2018 GMC Sierra 1500. The contact stated while driving 70 MPH, the vehicle started shaking violently, prompting the contact to pull over to the shoulder of the roadway. The vehicle returned to normal functionality, but upon the contact continuing to drive to his destination, the failure reoccurred. The contact stated that the RPM rapidly increased and the temperature gauge began to indicate that the engine 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 damages 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 contact owns a 2018 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the transmission vibrated. No warning lights were illuminated. The vehicle was taken to an independent mechanic, where it was diagnosed with a failing torque converter. The contact was informed that the torque converter needed to be replaced. The vehicle was not repaired. In addition, the contact was informed of a Manufacturer's warranty. The contact was informed of a Manufacturer's warranty for the 2018 GMC vehicle's transmission failure due to the incorrect oil being used during production of the torque converter. The dealer was made aware of the failure; however, the contact was informed that the manufacturer needed to approve the repair coverage. The manufacturer was made aware of the failure but provided no assistance. …
The contact owns a 2018 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the vehicle jerked abnormally hard. No warning lights were illuminated. The vehicle was taken to the dealer, where it was diagnosed with transmission failure. The contact was informed that the transmission needed to be replaced. The vehicle was repaired; however, the failure reoccurred. The vehicle was taken to the dealer, where it was diagnosed and determined that the transmission was failing. The contact was informed that the transmission needed to be replaced. The vehicle was not repaired. The contact was informed that the repair was not covered under warranty. The transmission was replaced two years ago. In addition, the contact stated that the original transmission had failed at 130,000 miles. The manufacturer was not made aware of the failure. …
The contact owns a 2018 GMC Sierra 1500. The contact stated that upon depressing the accelerator, the vehicle shuddered while upshifting. There was no warning light illuminated. The contact had taken the vehicle to a local dealer where they were unable to service the vehicle. The contact had also taken the vehicle to an independent mechanic who informed him that there was a TSB placed on the vehicle. He explained that the incorrect type of transmission fluid had been placed in the transmission which would cause the failure that he had experienced. The contact then called Sewell Buick GMC of Dallas (7474 Lemmon Ave, Dallas, TX 75209) where he was informed that he would be charged a diagnostic fee prior to the repair. The manufacturer was notified of the failure but offered no assistance. The vehicle was not repaired. The failure mileage was approximately 45,000.
The contact owns a 2018 GMC Sierra 1500. The contact stated while driving at an undisclosed speed, the engine temperature rose to 210 degrees and the vehicle started jerking. The contact stated that the failure also occurred while idling for a while, or while stopped at a traffic light while refueling, and before accelerating. The failure occurred once the engine temperature rose to 210 degrees. There were no warning lights illuminated. The vehicle was taken to a certified mechanic at a transmission shop who confirmed there was a failure with the transmission; however, the mechanic was unable to determine the cause of the failure. The dealer was contacted; however, the vehicle was not diagnosed or repaired. The manufacturer was not made aware of the failure. The failure mileage was 117,000.
The contact owns a 2018 GMC Sierra 1500. The contact stated that while driving at 45 MPH, the vehicle began to shudder, and he decreased the speed. The contact drove to his residence. The next day the vehicle was driving as expected until it became hot and began to shudder again. The transmission was not shifting as designed. The contact checked underneath the vehicle but failed to locate an issue with the transmission. The rear differential was hot and burned his fingers, but medical attention was not provided. The vehicle was taken to the local dealer, where it was diagnosed that the torque converter and transmission needed to be replaced. The vehicle was not repaired. The manufacturer was contacted, but no additional assistance was provided. The failure mileage was approximately 22,000.
The contact owns a 2018 GMC Sierra 1500. The contact stated that while driving on various occasions at various speeds, the check engine warning light illuminated, and the vehicle shuddered. Additionally, the drive(D) on the instrument panel started blinking. The contact stated that the engine revved, and the vehicle went into Safe Mode and the vehicle failed to accelerate as intended. The vehicle was pulled over to the side of the road and restarted. The vehicle was taken to an independent mechanic where it was diagnosed and determined that the transmission needed to be replaced. The vehicle was currently being repaired. The manufacturer was notified of the failure. The failure mileage was approximately 40,000.
8 speed transmission jerking, the torque convertor has been replaced 1 time already and having same issues as before. This time while in parking lot at store, was pulling into parking space, truck lundge forward during hard downshift hitting cart of person walking in front of truck. No damage and luckly barely hit the cart and not the person. I have also had the truck lunge forward when parking in my garage and hitting the garage wall in front. My truck is back at dealer again after hitting the cart in the parking lot. The 8 speed transmission issue from GM is a safety issue. My truck has already had first torque converter replaced and now having same issue with the new torque convertor
Transmission complaints in other Sierra 1500 years
Frequently asked questions
How common are transmission problems on the 2018 GMC Sierra 1500?
NHTSA has 131 complaints about the transmission & drivetrain of the 2018 GMC Sierra 1500, 43% of the model year's 305 complaints. The component named most often is automatic transmission › torque converter (3 mentions).
Is there a recall for 2018 GMC Sierra 1500 transmission problems?
No. NHTSA lists no transmission & drivetrain recall for the 2018 GMC Sierra 1500, though it has 7 recalls for other components. If the problem is widespread, a repair may still be covered by an extended warranty or a manufacturer service bulletin — ask a dealer.
At what mileage do 2018 GMC Sierra 1500 transmission problems start?
Half of the complaints with a recorded mileage happened before about 30,000 miles, and 38% before 25,000 miles.
Is it dangerous?
Owners linked 4 crashes, 0 fires and 3 injuries to transmission & drivetrain problems on this model year. If you notice symptoms, have the car checked before driving further.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.