2021 Chevrolet Suburban Complaints

POWER TRAIN — Filed 07/09/2026

What component or system failed or malfunctioned, and is it available for inspection upon request? (On our 2021 gasoline suburgan, the rear wheels locked up at free-way speeds, which nearly caused a possibly fatal accident. The lock released but it appears the strain caused rear differential gear teeth to break and the rear differential now needs to be replaced for the vehicle to operate properly.) How was your safety or the safety of others put at risk? (The sudden rear wheel lockup at freeway speeds resulted in temporary loss of control of the vehicle and significant surprise to the driver, who, after swerving into the adjacent lane was able to gain control of the steering and stop the vehicle. Had there been another vehicle in the other lane the MVA could have been fatal for 9 people in the suburban and any other vehicle involved.) Has the problem been reproduced or confirmed by a dealer or independent service center? (The rear differential damage was confirmed by a dealer.) Has the vehicle or component been inspected by the manufacturer, police, insurance representatives or others? (No.) Were there any warning lamps, messages or other symptoms of the problem prior to the failure, and when did they first appear? (No warning or messages. This has happened 3 times over 3 years, always on extended trips 9-12 hours in duration. The first two times nearly caused an accident but no differential damage. This third time, the differential was immediately damaged due to the incident. We have since learned that this is an issue with 2022 suburbans, for which a recall has been issued. A recall has also been issued for 2021 DIESEL suburbans. However, no recall has been issued to gasoline 2021 suburbans, but apparently needs to be.)

POWER TRAIN,UNKNOWN OR OTHER — Filed 06/29/2026

COMPONENT: The 10-speed automatic transmission failed on 6/29/26, locking the vehicle completely in neutral. The neutral override could not be disengaged even by dealership technicians. Vehicle is currently at [XXX] Chevrolet, [XXX] and is available for inspection. SAFETY RISK: I have 3 young children who are regular passengers. The failure occurred without warning. Had it happened at highway speed in oncoming traffic, I would have had no ability to move the car — creating a direct risk of a serious or fatal collision. CONFIRMED BY DEALER: Yes. Don Hewlett Chevrolet received the vehicle on 6/30/26 and confirmed the failure is directly related to two active federal recalls: NHTSA #24V-797 (10-speed transmission valve body failure/wheel lockup) and NHTSA #22V-036 (driveshaft assembly/loss of propulsion). Vehicle has been unrepaired for 13 days with no timeline provided. OTHER INSPECTIONS: Vehicle has been in possession of Don Hewlett Chevrolet since 6/30/26. No manufacturer representative, police, or insurance inspection has occurred. WARNING SIGNS: None. No warning lamps, messages, or symptoms appeared before the failure. The power train locked suddenly and completely without any prior indication on 6/29/26. Despite the dealer confirming this is recall-related, they have indicated I may owe partial repair costs. Under 49 U.S.C. § 30120, GM must remedy recalls at no charge regardless of mileage or warranty. I am requesting NHTSA investigate both the failure and GM's attempt to charge the owner for federally mandated recall repairs. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

ENGINE — Filed 02/02/2026

I had a recall serviced on a Friday which was completed by the dealership. My car sat all weekend and was not driven until Monday AM which was fine. After work, there were several warning lights that popped up and it was making a terrible noise. I was unable to drive home and had to have my car towed to the dealership. Following there inspection, my engine had to be replaced due to a known issue with this engine and GM. Cylinder #2 misfire, lost compression - lifter had spun in guide, camshaft is damaged - engine needs to be replaced. Unfortunately, I was just out of warranty so it was either pay $12,000+ for a new engine or walk away from a car that I love. I just don't understand why if GM knows this is an issue, why there is not some sort of recall on it.

EXTERIOR LIGHTING — Filed 04/13/2026

2021 SUBURBAN LT. Driver side headlamp adjuster failed while driving. Wife struggles to see at night so when the adjuster failed the driver side headlamp faced right to the ground causing no projected illuminating light. We attempted to adjust the light when she arrived home but it would not adjust due to the leveler failing and breaking. Looking into the matter we found out that numerous people with those, suburban's and even Silverado's that share the same parts have also reported the part failing due to the leveling being so thin and driving over bumpy roads will cause the weight of the lamp to snap and break. Its a growing concern yet dealerships are charging customers over 1400 to replace the whole assembly as it is one seal piece. There was no indication of it starting to fail just the moment it went from fine to facing the ground. We tried to run through extended warranty but claimed denied stating us touching the leveler to adjust it is what caused it to break. We tried to prove our case that doing research they would find to be common but no luck. its a safey matte.r

ENGINE AND ENGINE COOLING — Filed 03/20/2026

The contact owns a 2021 Chevrolet Suburban. The contact stated that while operating the vehicle, the engine was idling rough, the Check Engine warning light was illuminated, and the vehicle failed to properly accelerate. The vehicle was driven to the local dealer who diagnosed the vehicle and determined that the engine rods were bent, causing internal damage to the engine. The contact was informed that the engine needed to be replaced. The vehicle was not yet repaired. The manufacturer was notified of the failure, but no assistance was provided. The contact was informed that the VIN was not included in NHTSA Campaign Number: 25V274000 (ENGINE AND ENGINE COOLING). The contact stated that the vehicle had experienced the failure listed in the recall. The failure mileage was 99,000.

POWER TRAIN — Filed 06/01/2026

2021 Chevy Suburban started to have harsh shifting particularly on acceleration and shuddering at higher rates of speed (feeling like you are driving over a rumble strip). I took it to the dealer, and they confirmed the torque converter was in the process of failing. It's currently in the shop getting a new torque converter. No warning messages/lights had yet appeared. Technician at dealer stated that this was a common failure with this model.

EXTERIOR LIGHTING — Filed 03/12/2026

The front headlight leaks water which pools inside the led front headlight bezel causing the headlamp to blow/fail. This is a known GM issue and TSB's have been initiated. Concern was confirmed by the dealership who reported that the seal on the headlamp had failed causing the water leak and full replacement of the headlamp/headlight bezel needed to be replaced.

POWER TRAIN — Filed 06/03/2026

The failure involved the transmission valve body control valve within the automatic transmission system of the 2021 Chevrolet Suburban, a critical component responsible for regulating hydraulic pressure and controlling gear shifting. The malfunction caused erratic and unreliable shifting behavior, including hesitation, harsh engagement, and loss of proper acceleration; the failed component is in the custody of Northside Chevy in San Antonio, TX. This issue created a significant safety risk, as the unpredictable transmission response impacted the driver’s ability to accelerate when necessary (merging onto high traffic roads) and increased the likelihood of dangerous situations like rear-end collisions or loss of control. The problem was confirmed by an authorized Chevrolet dealer, where diagnostic testing identified faults in the transmission control system and verified the failure through performance testing and fault codes. The vehicle has been inspected by the dealership service department, though it has not been directly examined by the manufacturer, law enforcement, or insurance representatives; however, documentation of the diagnosis is being withheld by the dealership. Prior to the failure there were no warning signs present. Only after failure did the check engine light illuminate, transmission-related warning messages, and noticeable symptoms such as hard shifting, delayed engagement, and slipping, which appeared shortly before the complete failure and significantly worsened over the three-mile drive to the dealership.

ENGINE,FUEL/PROPULSION SYSTEM — Filed 05/31/2026

Vehicle stalled during routine driving. Code P129F. I was stranded in 95 degree weather with three small children. Please correct and advise ASAP. Had to be towed home. Vehicle inoperable.

POWER TRAIN — Filed 06/05/2025

transmission failed high speed jerking shifting ruined a set of tires yes has been confirmed by dealer but our vin is not covered under the recall no yes error codes appeared before we took the vehicle in for service 6-5-2025 we have had the vehicle in to 2 separate dealerships a total of 4 times for repair now that powertrain warranty is expired they are calling for a transmission replacement