2018 GMC Yukon Power Train

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 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.

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.

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.

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