2018 GMC Yukon Powertrain & Transmission Problems

The 2018 Yukon has been at the dealership several timeswaiting for a valve body for the transmission. There are valve body recalls for other year GM vehicles with the same transmission, but not for the 2018 model even though it appears to be the same part number. I don’t understand how this 2018 model apart of the recalls when it’s got the same issues as the newer ones. This is the second Yukon I’ve bought in the last seven years and the other one had the exact same issue.

I purchased my used GMC YUKON from a used car dealership 3/28/26. I signed the papers for the agreement while I was driving the vechicle home I lost power and it wouldn't go forward with gas applied. The check engine light came on, I pulled the suv over and it was towed. The code that popped up 0700 and 02723 both codes having to do with the transmission.

The 2018 Yukon Denali has been at the dealership for 7 weeks waiting for a valve body for the transmission. There are valve body recalls for other year GM vehicles with the same transmission, but not for the 2018 model even though it appears to be the same part number. The transmission was already replaced on this vehicle at 500 miles.

The contact owns a 2018 GMC Yukon. The contact stated after the vehicle was serviced, while driving 30 MPH and depressing accelerator pedal, the vehicle failed to respond. The contact stated that the vehicle hesitated, and the contact shifted to a lower gear to drive to the residence safely. A dealer was contacted. The vehicle was towed to the dealer where it was diagnosed and determined that the transmission needed to be replaced, and that the engine block was damaged. The transmission and engine block were replaced, and the vehicle was repaired. The manufacturer was not made aware of the failure. The failure mileage was 104,000.

My 2018 GMC Yukon SLE has a Transmission Failure and a engine oil coolant failure. The issues occurred while driving when the vehicle had to go into limp status to prevent the transmission from complete failure. I have taken the vehicle to the dealership 2x and they changed the fluid once and replaced the thermostat the second time. Neither case fixed the vehicle, it is currently in the shop for transmission and radiator w/ engine oil cooler replacement - $8200 The vehicle has been inspected by Aamco of Dover, DE and is awaiting inspection by warranty company 3rd party inspector. There are no warnings before the system is overheated and goes into limp status and at that point an alarm sounds in the car.

Dealership did a tune-up in June 2025 and had my truck for 2 weeks, no issues with transmission discovered or discussed. Now in September 2025, 2018 GMC Yukon has developed a torque converter shutter when driving between 40 and 50 mph. I took the vehicle to an independent shop who told me they had some computer tool to manually control the transmission, and there is an internal failure. There was a transmission flush completed hoping to gain results, however it was very short lived.

The contact owns a 2018 GMC Yukon. The contact stated that the message "Transmission Hot - Idle Engine" was intermittently displayed. The vehicle was taken to the dealer, where the TCM was reprogrammed, and the thermostat and the water pump were replaced; however, the failure persisted. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was approximately 101,000.

I am writing as a concerned owner of a 2018 GMC Yukon Denali, which I purchased in 2018. Over the past six years, I have encountered multiple critical issues with the vehicle, specifically with the transmission and motor mounts. These issues have been both recurring and costly to address, raising concerns over the reliability and safety of the vehicle. Recently, I experienced a complete transmission failure that required a full replacement, which was both unexpected and financially burdensome. Additionally, I have had to replace two motor mounts, further highlighting what appears to be a design or manufacturing flaw affecting multiple components within the vehicle. These problems are not isolated incidents, as I have come across numerous accounts from other GMC customers facing similar challenges with their transmissions and motor mounts. The recurring nature of these failures suggests a systemic issue that impacts not only me but many others, both financially and in terms of vehicle safety. I’d like to note that these issues were confirmed by authorized GM dealers. The motor mounts were diagnosed and replaced at Koons in Woodbridge, VA, with the drive motor mount diagnosed in 2023. The transmission was diagnosed, repaired, and inspected by Jack Winegardner Chevrolet in Fort Washington, MD, in August 2024. What is particularly concerning is the lack of any warning lights or messages alerting me to potential problems. For the motor mounts, I noticed snapping and clicking sounds when accelerating or stopping, along with significant shaking while driving. For the transmission, the vehicle began slipping and jerking when changing gears, a problem that became apparent only upon experiencing it firsthand. General Motors’ mission statement emphasizes a commitment to innovation, sustainability, and safety. However, the persistent issues with the Yukon Denali’s transmission and motor mounts seem to undermine these values, especially concerning driver and passenger safety. Fa

The vehicle will not go into reverse. The vehicle shifted into neutral while driving 30 mph in traffic and then shifted back to gear aggressively. No fault codes or check engine lights are displayed.

After stopping and then go, like at a light or stop sign, on acceleration SUV will go slightly forward and stalls and high rev for a second and car feels like it’s dying or losing power and starts back up. I feel unsafe and that the car might stop middle of intersection from stop-and-go. Sometimes while driving I lose power driving and stepping on gas pedal has a few second lag time to pick back up. I’ve never had this issue before or any of my vehicles and I bought it new and we are original owners.

No warning light presented to warn of transmission issues. While driving is hesitating sluggish when accelerating and stalling around 60mph then shifts . Putt Putt then pick up a bit then back down.

May 31st 2022-While driving on the highway, I lost control of my power steering. Luckily my husband was with me to drive it back home. June 1st 2022-Took it to a service center and was told it needed a part to fix the problem. We ordered the part, which would not be delivered until may 6th 2022. June 4th 2022- Went to drive, made it a couple blocks down the road when the ABS, electronic stability control, & the engine light came on. So I turned around to take it back home, only now my power steering was completely out, my car would not shift out of first gear. After arriving home, I attempted to put it in park but was unable to. My motor shut off but would not allow me to place it in park or turn the electric power off. The only option I had was to disconnect the battery. I let it sit for a few hours, reconnected the battery, now my car will not start at all. I am now unable to take my car to the dealership due to power failure Note: June 2nd & 3rd, my vehicle was not driven I did contact my local dealer to check if there were any open recalls, was told no

NHTSA's recall number 25V-274. This vehicle should fall under this recall it happed to the this motor at 58k miles and I had to put a whole motor in it at 58k miles in 2022. The Yukon Denali has the L87 V8. I bought the new motor threw GM so it should be tied to this vin number

2014-2018 Chevy and GMC's have a problem with cycling of the thermostat that causes stress fractures on the radiator leading to coolant leaks. Attached are GM bulletins on the 2014 and 2015 models. As one can see they have provided special coverage on the 2014 models to 5 years or 100000 miles for this problem.(Bulletin 15829) This is not true of the 2015 through 2018 like mine. Although they use similar verbiage in the bulletin P11513A and P11513F. It should be noted that Bulletin P11513A and F also applies to 2015 Cadillac Escalade Models, 2015 Chevrolet Suburban, Tahoe, 2015 GMC Sierra Denali, Yukon Models, Yukon Denali Models Equipped with 4.3L, 5.3L or 6.2L Engine (RPOs LV1, LV3, L83 or L86). ***Basically this is a safety hazard because when traveling highway speeds it puts car into reduced power mode and you can only drive very slow on highway or be stranded on side which is just as dangerous ***

I WAS DRIVING MY VEHICLE AND EXITING THE HW. THE REAR WHEEL OF THE DRIVER SIDE BROKE OFF AND SEPARATED FROM THE CAR WHICH CAUSED MY CAR TO HIT THE CEMENT BEERIER ON FRONT AND THE SIDE OF THE DRIVER SIDE OF THE VEHICLE. THEN THE CAR TURNED 180 DEGREES AND HIT THE BEERIER ON THE PASSENGER SIDE AND THE REAR OF THE CAR. THE AIR BAGS NEVER DEPLOYED AND WE DISCOVERED THAT THE WHEEL BROOK OFF OF THE REAR AXE. NO DAMAGE TO THE WHEEL. SEVERAL INDUSTRY EXPORTS STATED THAT THIS SHOULD NEVER HAPPEN.

I brought my 2018 yukon denali to dealer to see if there was a recall on the transmission. Warm or cold didn't matter because the truck jerks and slips constantly. Even when decelerating it will shift wrong and clunk. I have been complaining about this since the first year I bought it. This truck is a safety hazard when crossing traffic while turning. I have been to the gmc dealer many times and no recall.