2020 GMC Yukon XL transmission problems

Filed Sep 21, 2026 · Transmission · MO

The transmission failed on August 8, 2026, while I was driving on a highway. I moved safely to the shoulder, but the vehicle became inoperable and required towing. The loss of propulsion in active highway traffic created a potentially hazardous situation. My GMC Bommarito Buick GMC dealership advised that GM cannot currently supply the required replacement transmission. The dealer has no estimated delivery date and does not know when GM can supply the unit. The vehicle has been out of service for over four weeks, with no definite repair or return-to-service date. I am concerned that the inability to provide a replacement transmission may indicate unusually high demand or a broader issue. I identified other recent the federal safety agency complaints involving 2020 GMC Yukon XL vehicles reporting 10-speed transmission failures and difficulty obtaining replacements, including ODI complaints 11711773 and 11747021. I request that the federal safety agency evaluate this complaint with similar reports. I respectfully request that the federal safety agency consider whether: • These transmissions are experiencing premature or unusually frequent failures. • Valve-body, internal, or other component defects may contribute. • Failures can cause sudden loss of propulsion, unexpected shifting, loss of power, or other safety-related conditions. • The replacement-transmission shortage is connected to an unusually high failure rate. • GM has sufficient replacement units and repair components available. • Available complaints, dealer information, and manufacturer information warrant further investigation or action. I request that this complaint be associated with my VIN and reviewed with other complaints involving 2020 GMC Yukon XL Denali vehicles and other GMC, Cadillac, and Chevrolet models equipped with the 10-speed 10L800-speed automatic transmission. I believe the circumstances warrant review as a potential broader vehicle-safety issue, rather than solely an individual parts-availability problem.

Filed Jun 28, 2026 · Transmission · KY

Without any indications of a problem our transmission began making a loud whining noise. The evening before it was fine and the next morning on startup the noise just began. The Vehicle only has 45,000 miles on it and the transmission had been serviced at the recommend manufacturer interval. Took it immediately to my auto repair shop where it was diagnosed as a transmission failure (they has seen this before) and told not to drive until replaced due to safety issues related to the failure. Unfortunately, due to a shortage of these needed 10 speed transmission I waited over a month for the vehicle to be repaired. The shop contacted GM to inquire about any warranty help but was told there was none.

Filed Jan 18, 2026 · Transmission · MN

My 10 speed transmission on my 2020 Yukon XL Denali experienced a total failure. The vehicle will not move under its own power. General Motors has ZERO information on when a replacement Transmission will be available. Some info online shows it could be months. I am told that one dealership out of Eden Prairie, MN has over 40 on back order and some since August 2025. They claim the issue stems from a valve body. Their communication has been terrible and no one within GM that I have spoken to has any information on what is being done. This is completely unacceptable and I believe it is part of a larger issue. They are making it seem like it’s not important and that needs to change.

Filed Jan 6, 2026 · Transmission · KS

I was traveling along i80 and suddenly the vehicle shutdown. I put the transmission in Neutral and coasted to a stop. Once stopped, I check It would not start or even turnover at that point. I still had all electrical services and such. The vehicle. I was stranded on i80. Then had to be towed to the nearest GM Dealer in Evanston Wyoming. Heritage Chevrolet GMC. It was left there for diagnosis where their technician, several days later diagnosed it with a bad engine. There was no warning or check engine light that appeared. I even have a picture from a little while earlier while driving earlier that morning. It took it because I was surprised it was getting 28mpg in v8 mode. but I am glad I had that photo to show no diagnostic lights were on.

Filed Aug 4, 2025 · Transmission · RI

The transmission failed while driving it and no warning lights were visible on the dashboard before hand or afterwards ..the vehicle is presently at a legitimate transmission repair shop and needs a new transmission supposedly this particular vehicle is evidently not included in the recall although the make and model are listed as part of the recall.

Filed Jun 27, 2025 · Engine, Transmission · PA

Driving and vehicle started making noise and lost ability to accelerate fully. Mechanic stated he’s had numerous issues with this model with lifter and camshaft damage especially with the 6.2l engine which has a recall on the 2021-25 models but not the 2020. $5,000+ to fix at this point.

Filed May 22, 2025 · Driver assistance, Transmission · 46,000 miles · WI

The contact owns a 2020 GMC Yukon XL. The contact stated while driving at an undisclosed speed, the rear passenger side tire seized. The contact stated the vehicle was skidding, and the contact noticed an unusual sound. The vehicle was taken to an unknown dealer, but was not diagnosed or repaired. The contact related the failure to an unknown recall; however, the VIN was not included. The manufacturer was made aware of the failure, but no assistance was provided. The contact was advised to contact the federal safety agency Hotline to report the failure. The failure mileage was approximately 46,000.

Filed Mar 28, 2025 · Transmission · NC

I possess a 2020 GMC Yukon XL. During multiple highway drives, I experienced a persistent loss of power. When accelerating from a stop, the vehicle struggled to shift gears smoothly, resulting in a rough, jerking motion. I opted to take the car to the dealership; however, before I could reach it, the vehicle lost all power and failed to change gears entirely. I am fortunate this complete loss of power and ability to change gears did not occur while I was on a busy highway. I purchased the car when it had 63,000 miles, and at 120,000 miles, the dealership informed me that the transmission had completely failed. A replacement of the transmission will be necessary.

Filed Jan 22, 2025 · Transmission · VA

Lifter failure Car could not be driven and were stranded at night in the dark. The car had to be towed but the tow truck did not arrive until morning. It was an EXPENSIVE repair at GMC dealership. GMC confirmed this was the issue Car started to make a loud noise, so I stopped driving. It is NOT an old car - 2020 and happened December 2024 GMC said it is not something they will cover

Filed Aug 2, 2024 · Engine, Transmission · 102,000 miles · AL

The contact owns a 2020 GMC Yukon XL. The contact stated that while his wife was driving approximately 65 MPH, the transmission started to slip out gear and the vehicle was losing motive power. The contact's wife had not observed any warning lights. The contact’s wife drove the vehicle back to the residence and while attempting to place the vehicle in park(P), the vehicle failed to respond. The contact had the vehicle towed to an independent mechanic who diagnosed the vehicle and determined that the transmission needed to be replaced. The vehicle was repaired; however, the contact stated while driving approximately 65 MPH, the check engine warning light illuminated. The contact was able to drive the vehicle to the residence. The contact stated that while attempting to restart the vehicle, the vehicle was idling roughly with white smoke coming from the exhaust pipe. The contact drove the vehicle to a different independent mechanic who performed an engine pressure test and determined that the engine needed to be replaced. The vehicle was not repaired. The manufacturer was not informed of the failure. The failure mileage was approximately 102,000.