2021 GMC YUKON XL Suspension Problems

When driving at slow speed and wheels turning right or left you can hear a humming coming from the suspension. Unable to identify the issue. When wheels get straight the humming goes away

12/16/25 (evening): Warnings began cycling across the screen: 1) Service ESC, 2) Vehicle Leveling for Stability, 3) Rear Axel System Off, 4) Engine symbol began flashing, and 5) Service Traction Control. I felt vibration/bouncing while driving as well. 12/17/25 9 AM: Took 2021 GMC Yukon Denali to GMC dealership. They ran a computer scan and reported a misfire, but nothing else appeared to be wrong. They told me that sometimes a low battery can cause the warning lights and messages to cycle. They recommended that I keep driving it and return if the warnings appeared again. 12/17/25 9:18 AM: I left the dealership. I drove 4.5 miles, and all the same warning lights came back on. When I pulled into a parking lot, it smelled like my engine was on fire, and dark smoke was coming from my rear exhaust pipe. I called a flatbed tow truck and had the...

Subject: Formal Complaint – Engine Failure in 2021 GMC Yukon Denali XL VIN: [XXX] Defect Number (GM): [XXX] GM Case Numbers: [XXX] / [XXX] / [XXX] Dear NHTSA Office of Defects Investigation, I am writing to formally report a critical mechanical failure in my 2021 GMC Yukon Denali XL, which resulted in a complete engine failure, rendering the vehicle inoperable and exposing my family to significant safety and financial risks. Despite following the recommended maintenance schedule and driving under normal conditions, the engine failed prematurely. The vehicle has been out of service for over four months, and I have yet to receive a definitive resolution or timeline from General Motors. I have incurred over $13,000 in out-of-pocket costs, including towing, repair estimates, rental vehicles, and continued loan payments on a non-functional vehicle. Key Details: Vehicle: 2021 GMC Yukon Denali XL VIN: [XXX] Failure Type: Total engine failure requiring full rebuild...

GMC currently has bulletin out on the issue and how to fix it. unfortunately this doesn't not fix it and I am going to have to replace my whole rear differential at only 60,500 miles. Gmc is well aware of the situation and has not done a recall. The fix the bulletin proposes would not work and there was over and inch of metal shaving found. This is a huge issue in the specific vehicle and the part to replace the rear differential isn't even available (national backorder with no ETA) leaving customers without a vehicle or solution for their faulty issues. GMC should be liable for their negligence and putting customers in potential harm if the vehicle is continued to be driven with a failing rear differential. The vehicle did not prompt any warning messages but the grinding sound was very loud. Bulletin No.: 21-NA-028 Date: January, 2023

VEHICLE HAS BEEN AT THE DEALER WITH GM INVOLVEMENT STARTING JANUARY 6TH AND IT HAS BEEN OUT OF THE REPAIR FACILITY FOR LESS THAN 2 WEEKS UP TO TODAY, 4/1/2021. THE VEHICLE HAS AN ADAPTIVE SUSPENSION SYSTEM THAT HAS NOT ONLY FAILED, BUT HAS CONTINUED TO FAIL AFTER MULTIPLE REPAIR ATTEMPTS. THERE SEEMS TO BE AN ISSUE WITH THIS NEW ADAPTIVE SUSPENSION, SPECIFICALLY WHEN THE 'VEHICLE ACCESS' OPTION IS TOGGLED IN THE SETTINGS. THIS HAS CAUSED MULTIPLE SAFETY WARNINGS; 'VEHICLE TOO HIGH, DRIVE SLOWLY VEHICLE UNSAFE' AND 'VEHICLE TOO LOW, DRIVE SLOWLY, VEHICLE UNSAFE'. DEALER AND GM HAVE REPLACES MILLIE PARTS, SOFTWARE AND SENSORS, TO NO AVAIL. THE MAJOR CONCERN IS THAT MOST OWNERS DON'T REALIZE THE RISK AND THIS IS A FLAW IN THE DESIGN WHICH COULD LEAD TO ACCIDENTS. MY VEHICLE HAD TO BE TOWED IN AT THE LAST RESURGENCE BECAUSE IT WAS NOT IN AS STATE TO...