2021 Chevrolet Tahoe: complete transmission failure

Filed Sep 1, 2026 · Engine · KY

Engine failure Transmission failure

Filed Jul 27, 2026 · Suspension, Transmission · TN

I purchased my vehicle new in 2020. It presently has around 83,000 miles. From early on, it has occasionally hesitated, then jumped when putting the car in reverse. I spoke to the dealership years ago but they said it was nothing. On July 19, 2026, my car randomly would not shift above (probably) second gear on the highway. After parking, it would not shift into reverse at all. The vehicle was towed more than 30 miles to my hometown dealership as it was inoperable. It now requires something approaching a transmission replacement costing between $2500-4500, or more. I am aware that this is a recurring problem with GM vehicles of this type and era, and it seems absurd to have so many vehicles with failing transmissions before they even reach 100,000 miles.

Filed Jul 8, 2026 · Transmission · IN

My transmission failed and it has been in a shop for 2 months. The pistons in the transmission failed not sure why but made it not go in reverse. The parts were on backorder for atleast a month. The warranty is out and my extended warranty will not pay because Chevorlet Dealership failed to flush my transmission when it was in for service. The transmission is a known problem on these models and was recalled for the diesel models but not the gas models.

Filed May 25, 2026 · Transmission · OH

Transmission failed. Only warning was check engine light on 10 minutes prior to failure. At 30 mph on city road car was suddenly coasting, engine rpms revved to 7-8k, no driving power available for approximately 30 seconds. 'Drive' reingaged but apparently in limp mode enough to get a few hundred yards more to parking lot. No reverse gear available and warning on dash 'catastrophic failure' imminent. Garage reports the transmission is 'bad' . Awaiting dealership input but 3 weeks before they will look at it .

Filed Apr 28, 2026 · Engine · TN

Urgent: Engine Failure Following Recent Service – 2021 Chevrolet Tahoe To Whom It May Concern, I am writing to formally request assistance and an investigation regarding a serious engine failure involving my 2021 Chevrolet Tahoe. In July 2025, I paid out of pocket to have the lifters and camshaft replaced on this vehicle. More recently, while traveling, the vehicle broke down and was taken to Uebelhor Chevrolet, where the valve body in the transmission was replaced. After picking the vehicle up from Uebelhor Chevrolet, the vehicle broke down again approximately one hour later while in Henderson, Kentucky. At that time, the engine began smoking, running rough, and misfiring. I checked the oil level during the incident and found it to be extremely low on the dipstick (I have photographic evidence of this condition). The vehicle had to be towed to Kate Faupel Chevrolet for further inspection. I was then informed that the engine has a dropped lifter on cylinder #8 and possible camshaft damage. Given the following factors: Recent out-of-pocket lifter and camshaft replacement (July 2025) Immediate failure shortly after leaving a Chevrolet dealership Extremely low oil level observed at the time of breakdown (with photo documentation) Diagnosis consistent with potential oil starvation and internal engine damage I am requesting that General Motors conduct a full review of this situation to determine responsibility. This raises serious concerns about a potential defect, improper prior repair, or a service-related issue that resulted in catastrophic engine damage. At this time, I am not authorizing repairs until liability is determined. I am requesting: A formal case review and investigation Assistance with repair or full engine replacement Guidance on how this situation will be resolved This incident created a significant safety concern, as the vehicle became disabled shortly after leaving a dealership during travel. Please contact me as soon as possible to discuss next steps

Filed Jan 19, 2026 · Engine, Transmission · MO

6.2l motor blew up set at dealership for 4 months no motor to fix it. finally got it back with in 10 days the torque converter need replaced in the transmission. out of service out f service for motor june 19 2025 got it back october 20 2025. transmission went out 10mdays later

Filed Jan 3, 2026 · Fuel system, Transmission · FL

This vehicle has experienced multiple substantial defects, several of which directly endangered my family, including an infant, and rendered the vehicle unsafe and inoperable for extended periods despite warranty repairs. Summary of defects and failures: 1.Electronic door locking failure The vehicle experienced an electronic malfunction that caused the doors to randomly lock, resulting in my infant being locked inside the vehicle when we exited. This wiring defect was later repaired under warranty but represents a serious safety failure. 2.Fuel pump recall and highway breakdown While driving my family of six on a major highway over an hour from home, the recalled fuel pump failed while in motion, leaving us stranded on the side of the highway. We were forced to arrange an Uber for transportation. This incident placed my family in a dangerous situation and constitutes a major safety-related defect. 3.Transmission failure and extended inoperability The vehicle suffered a transmission failure that rendered it unsafe and inoperable. The dealership required over one week to schedule service and more than two additional weeks before the vehicle was inspected and repaired. The vehicle was out of safe driving condition for approximately one month. Upon return, the vehicle experienced additional failures, including a dead battery. 4.Known poor design defect – rear entertainment screens The rear entertainment system screens cracked due to a widely known poor design and placement issue, unrelated to misuse. 5.Rear headrest internal mechanism failure The internal mechanism of a rear headrest failed and requires replacement, further demonstrating ongoing quality and safety concerns. Due to the number, severity, and safety-related nature of these defects—combined with cumulative downtime exceeding 30 days—I have lost all confidence in this vehicle. I no longer consider it safe or reliable for transporting my family.

Filed Aug 30, 2025 · Electrical, Engine · FL

The affected components are the electrical system, engine, and power train. In March 2025, my 2021 Chevrolet Tahoe displayed multiple warning lamps across the dash, including traction control and check engine lights. The vehicle shifted erratically and sometimes entered limp mode. I brought the vehicle to AutoNation Chevrolet South Clearwater for inspection. The dealer replaced the battery, dismissed my concerns, and stated that a test drive was performed, but the mileage in and out on the invoice was identical, showing it never actually occurred. Diagnostic trouble codes (P0700, P0717, P2714, P2716, P0706, and multiple U-codes) were present but were not fully investigated. A GM Technical Service Bulletin (21-NA-149, December 2022) covers these exact symptoms (caused by engine wiring harness chafing), but it was never referenced or applied. Because the problem was not addressed, the condition worsened. By July 2025, the vehicle suffered a complete transmission failure. At that point, the dealer confirmed the issue, documenting transmission slipping, shuddering, noise, and additional codes (P0700, P077C, P17F6, P17FB, P1872). GM increased its goodwill contribution from 15% to 40% of the $9,925 repair cost, while AutoNation offered only $500 despite their role in the missed diagnosis. Safety Risk: My family and I were at risk each time the vehicle stalled, lost power, or shifted erratically while driving, including at highway speeds. These failures created a significant risk of collision. The drivability problem was not properly confirmed in March 2025 despite multiple codes being present. By July 2025, the dealer acknowledged and confirmed the transmission failure. The vehicle remains available for inspection, and I have retained all invoices, diagnostic reports, and communications with GM and the dealership.

Filed Aug 30, 2025 · Electrical, Engine · FL

The affected systems are the power train, engine, and electrical. My 2021 Chevrolet Tahoe experienced failures consistent with GM Technical Service Bulletin 21-NA-149 (engine wiring harness chafing) and the conditions outlined in Recall N232404190 (valve body failure, November 2024). Beginning in March 2025, the vehicle displayed warning lights and messages including Check Engine, Traction Control, Service Transmission, and limp mode (Reduced Acceleration – Drive with Care). The vehicle shifted erratically, lost power, and occasionally failed to accelerate, creating a serious safety hazard at highway speeds. These problems were documented at AutoNation Chevrolet South Clearwater, where multiple diagnostic trouble codes (P0700, P0717, P2714, P2716, P0706, and U-codes) were recorded but not properly investigated. No test drive was performed despite being claimed by the service technician, and the applicable TSB was not referenced. By July 2025, the condition worsened into a complete transmission failure, with additional codes (P0700, P077C, P17F6, P17FB, P1872). The dealer’s estimate required a full transmission replacement at nearly $10,000. GM reviewed the case through its internal Policy Evaluation Tool and increased goodwill assistance from 15% to 40%, while AutoNation contributed only $500. GM’s partial contribution confirms the defect is recognized, yet this VIN remains excluded from the official recall. This issue placed my family and other motorists at significant risk, as sudden loss of power and shifting failures occurred during normal driving conditions. Dealer records, GM documentation, and photographs of warning messages are available. I request that the federal safety agency expand Recall N232404190 to include affected VINs such as mine, since the symptoms, diagnostic codes, and confirmed failures match exactly what GM has already identified as a known safety issue.

Filed Jul 25, 2025 · Engine · TX

I’m reporting a transmission failure that occurred unexpectedly on my 2021 Chevy Tahoe/the diesel version has been recalled so I don’t know why all the other 2021 Tahoe have not been recalled for this issue . The vehicle began shifting roughly and slipping between gears, followed by a warning message and eventual inability to shift properly. I had it inspected by a family friend who owns a body shop , and I was told the transmission needs to be replaced at a cost of nearly $7,000. I am no longer under powertrain warranty, but this failure feels premature and unsafe for such a new vehicle. I’ve seen many other 2021 Tahoe owners report similar issues online including transmission failure, harsh shifting, valve body problems, and complete breakdowns . This seems like a pattern, and I believe it may warrant investigation. I’m asking the federal safety agency to investigate whether this is part of a broader transmission defect that poses a safety or reliability concern. Sudden shifting issues and inability to accelerate or reverse are dangerous for drivers and passengers. Thank you for your time and attention to this matter.

Filed Jul 23, 2025 · Transmission · CT

In May 2025, my 2021 Chevy Tahoe experienced transmission failure related to the valve body. The vehicle has now been at the dealership (Richard Chevrolet in Cheshire, CT) for over 2 months with no timeline for repair due to a national backorder on the part. This issue is widely reported among 2021 Tahoes and other GM vehicles, and appears to be a systemic transmission defect. I was never notified of any recall or service bulletin, and I’m still making monthly payments on a vehicle that is inoperable. The rental provided does not suit my family’s needs, and GM has been unable to offer a resolution or clear update. This type of critical drivability failure should be classified as a safety concern, especially considering the volume of similar complaints and the absence of repair parts. I am requesting the federal safety agency investigate this issue further and take action if warranted.

Filed Jul 16, 2025 · Electrical, Engine · FL

On 01/03/24, the vehicle stalled and smoked on the Suncoast Parkway. All dashboard warning lights and messages illuminated, and the vehicle entered emergency park mode. OnStar was contacted and the vehicle was towed to Jenkins Chevrolet in Homosassa, FL. The failure was linked to a broken pulley and belt system that damaged the ECM and wiring harness. No DTCs were pulled, and mileage in/out was 80042/80043—no test drive performed. On 08/06/24, the vehicle returned to Jenkins for a roaring noise. A pulley bearing was replaced, possibly related to the earlier failure. Again, no drivability evaluation or codes recorded. On 03/09/25, the same full system warning lights/messages appeared again. The vehicle experienced harsh shifting and delayed acceleration. It was taken to AutoNation Chevrolet South Clearwater on 03/10/25. DTCs (P0700, P0717, P2714, P2716, P0706, and U-codes) were found but dismissed. Only the battery was replaced. Mileage in/out was 99494—no test drive performed despite claims one occurred. On 07/08/25, the vehicle again showed full dashboard warnings. Brought back to AutoNation on 07/09/25. On 07/14/25, customer received a $9,177.85 estimate including full transmission replacement. Safety was at risk due to repeated stalling, loss of acceleration, and emergency parking mode while driving or merging. These failures could have led to accidents or left the vehicle disabled in traffic. Driver and children were present during each incident. The vehicle is enrolled in OnStar and the MyChevy app, which provide monthly health reports. Despite these incidents, no faults or warnings were ever shown in the reports. Vehicle remains available for inspection. A case is open with GM. Across 4 service visits, GM-certified dealerships failed to follow proper protocols, including code checks, drivability assessments, and test drives—contributing to delayed diagnosis of transmission failure.