1. The components that failed were the transmission because the vehicle was driving and continued to slow down until it came to a complete stop gradually, and had to be pushed home. And also, there was an issue with the doors unlocking on their own and all windows rolling down by themselves. 2. The safety risk was the issues that happened without any knowledge of any issues at all with the vehicle. And the vehicle could have stopped on the highway, and another vehicle could have run into it, and it could have been a very bad incident. And with the doors unlocking and the windows rolling on their own could be exposed to unsafe environments and possibly theft of the vehicle or harm to the occupants. 3. Had a scan done, which showed the issues that were going on with the vehicle 4. I haven't had a chance to have it taken to the manufacturer because it broke down, and I was waiting for some help to get these issues repaired from the manufacturer. And needed from ACC. 5. There wasn't no indicators or lights on when this happened? I was told by a coworker about the windows being down, and with further investigations, I found the doors were unlocked as well, which was done automatically without my control.

- Blytheville, AR, USA

The transmission has been shifting hard. I have had it serviced to try and address the issue. It continued to shift hard, until suddenly slamming me down and locking me into first gear. It would not shift from first gear until I found a parking lot, placed it in park, shut the truck off and restarted it. This caused me to nearly rear end the vehicle in front of me. This has not been reproduced to date because the shop cannot get to my truck for 4 weeks and I cannot be without a vehicle for that long (won-??t schedule and let me bring in the day before). There has not been an inspection done by anyone because I was able to avoid the collision, and the shop is too far out time wise. There were no prior indications/lights to warn me of a severe problem. The dealership informed me that this has been an ongoing problem with the valve body inside the transmission, but there is no warranty or recall for it. They were sure happy to take my money without telling me of the problems when I bought my truck.

- Tooele, UT, USA

I purchased my truck in December 2018 which is a 2018 Chevrolet Silverado 1500 4x4 crew cab automatic from Servco Chevrolet Dealership in Waipahu, Hawaii and making monthly payments for my truck February of 2019 truck runs good and purchased the warranty also had my oil and service changed when time is due which I always kept up. [XXX] and mileage was 40k while leaving work to go home at a stop light was red once turned green I pushed pedal to go and truck just changed noise tone started to run like rough idle, loud tapping noise coming from the engine, shaking and check engine light came on almost causing me to get into an accident. I pulled on the side and checked what was going on and heard the tapping noise from the motor. So I made an appointment with service department with Servco Chevrolet Dealership where i bought my truck from and spoke with the service tech for my truck to go in for repairs due to issue. It took 2 to 3 weeks for repairs to be complete and service tech informed me that I'm not the only person to have that issue which had to do with the lifters and camshaft with these motors but GM never came out with any recalls due to how much people has the same motors with the same issue. So luckily it was still covered under warranty but said the problem might come back and would just replace the faulty lifters and camshaft. So in August of 2023 my truck has the same issue but wasn't covered under warranty anymore and mileage is 61k and missed the warranty repairs that was for the lifters which I got it scanned cause check engine light and same issue and code was P0016. So I called Servco Chevrolet dealership in waipahu again and spoke with the service technician which he told me I just missed the coverage of the warranty repair and only way to get it fixed I would have to bring it back for them to scan and roughly would range from 4k to 8k to get it fixed. So my truck is parked in my garage and hasn't been moved but paying for truck. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT

- Haleiwa, HI, USA

10 miles from home on [XXX] after Thanksgiving with my children sleeping at [XXX] in snowy cold weather, my engine began to fail. Power was limited on hills and the check engine light would come on and go back off when on flat or downhill. The next morning I took my truck to the dealer that I purchased it from where I was told the lifters had failed and I need a new engine. 1000 miles after I replaced my engine my transmission failed completely requiring a transmission replacement. Immediately upon picking up the vehicle and going down a long hill in the area, engine breaking turned on as expected but as the truck tried to slow itself, after 2 or 3 downshifts, the transmission began making a loud grinding sound and while still going close to 50 MPH, the speedometer showed 10-15 MPH and the tach dropped to idle. The transmission was decoupled from the motor. When gas was reapplied it seemed to make the connection again and resume normal driving. I called the dealership whose techs did not believe me and told me that I could 'turn off' the engine breaking feature. The situation continued to worsen each drive and it would do it more often. This was unacceptable and they finally had a tech ride with me to experience it and immediately agreed there was an issue and reordered another transmission. The third transmission did not fix the issue and was experienced immediately. They are now guessing how to fix the issue telling me I have to replace the transfer case out of my pocket with no diagnosis, not sure what is causing it and have not fixed the problem. Videos would not fit in upload due to size. Videos show speedometer failure. [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

- Franklin, PA, USA

The contact's husband owns a 2018 Chevrolet Silverado 1500. The contact stated that while driving at various speeds, the vehicle hesitated while depressing the accelerator pedal. The vehicle was taken to an independent mechanic where the contact was informed that metal shaving were discovered in the radiator due to a defective torque converter. The manufacturer was then notified of the failure and the contact was informed that there were no recalls on the VIN. The contact was referred to the NHTSA Hotline to report the failure. The vehicle was not repaired. The failure mileage was 143,057.

- Chaska, MN, USA

While driving on an Interstate the vehicle violently shook and drive shaft ce off.

- Fayetteville, NC, USA

I-??ve had to have the transmission replaced before hitting 123k miles There is a constant shake, tremble in the car that dealer mechanics cannot figure out and they relate the issue to the transmission Electrical dashboard and ac lightning fixture burnt out

- Fontana, CA, USA

Vehicle went into limp mode on I 65 in Indiana. Chevy dealer replaced tvb/ thermal bypass valve with newer version that opens at a lower temperature.Hard to get vehicle to the side of the highway. State Police arranged a tow truck to remove vehicle from highway.

- Raleigh, NC, USA

Driving on the fwy going 73mph While running Transmission stopped working and I-??m not able to accelerate to move forward and safely pull over to the shoulder. The problem was not been confirmed by the dealer or service center. The vehicle was not been inspected by anyone. There is no warning lamps Messages, or symptoms of the problem prior to the failure.

- Colton, CA, USA

The automatic transmission in my 2018 Chevrolet Silverado 1500 with the 4.3L V6 has experienced repeated failures and overheating events starting shortly after a scheduled dealer transmission flush at approximately 50,000 miles. Since then, the transmission has slipped under load, failed to shift properly, and routinely overheated-?"reaching over 270?F-?"without triggering a dashboard warning or entering limp mode. Multiple dealer visits confirmed internal transmission damage, including discolored fluid, metal shavings, and torque converter clutch failure. The entire transmission and torque converter were replaced under warranty, along with a redesigned bypass valve. Despite these efforts, the transmission failed again, showing further signs of overheating and debris in the fluid. The vehicle has been inspected and serviced multiple times by the dealership (Karl Chevrolet in Iowa) and GM warranty contractors. The issue persists even after complete transmission replacement. This condition poses a safety risk as loss of power and unexpected gear disengagement occurred during normal road use, including highway driving and towing. Transmission temperatures spiking well beyond GM-??s Dexron VI fluid thermal limits raise further concerns about systemic cooling design flaws. Warning signs included high transmission fluid temperatures (over 270?F), RPM surging, harsh downshifts, slipping, poor throttle response, and delayed engagement from park to drive. The manufacturer has been notified, and the issue has been documented with the Attorney General of Iowa. A GM case number was also opened, but no permanent fix has been offered.

- Ames, IA, USA

Transmission started shifting weard contacted dealership. They state this unit is not under recall but it is an 6L80 and it is all over you tube and the internet about failures that start with the pm valve and/or the torque converter housing that is stamped but mounting brackets are welded to it causing harded steel to meet stamped steel causing friction and wear that polutes the remainder of the transmission and causes failure before 100000 miles; usually just after 50000ish. When transmission fails it can cause loss of propulsion or collion.

- West Columbia, SC, USA

Brakes sometimes require more pressure to stop or slow down. Transmission shutters and makes a clunking noise between shifting points. Kind of a sound bad u-joints make. Air Conditioning leaked all freon out in 2024 with 70k miles just 2mos. after service at a GM Dealership. Still not repaired.

- Underwood, IN, USA

My vehicle has had transmission and engine problems that should not have been an issue until after at least 100,000 miles. At 11,577 miles I reported hard down shifting as well as a hard shift / kick when going from reverse to drive when the transmission would feel like it would slip and then kick when shifting from 1st to 2nd gear on automatic transmission. There were no codes and dealership said they couldn't duplicate problem. At 58517 miles the service 4x4 warning light came on as well as a shifting problem was continuing. A transmission valve body was replaced and a transmission service / fluid replacement was done under warranty or extended warranty. The shifting problem has continued. It has come to my understanding that Chevrolet put out a bulletin about changing the transmission fluid should solve the problem and to tell customers that some hard shift could be normal and not a problem. And I have heard about some class action lawsuits that have been filed. A second and more major issue was the 5.3 liter engine failure that occured at 62,093 miles after having a tapping noise develop and some loss of power. But this issue began earlier at 40,125 miles when I had a fuel injection clean due to it running rough. Extended warranty replaced engine with a used motor and I was still charged $1158.93 for amounts extended warranty didn't cover. My Son's 2015 Silverado 1500 which I owned previously had to have the transmission rebuilt for just under $5,000 just out of extended or manufacturer's warranty. We don't pay $60,000-$70,000 to have engines and transmission fail before 100,000 miles and before the loans on vehicles are paid off. We shouldn't have to be paying a loan on a vehicle we can't even drive because it is in the shop for an extended period of time. At 62,298 miles after getting the truck back from the engine failure, the starter then failed and was replaced under extended warranty with $133.76 cost going to me.

- Clinton, MS, USA

The truck started shuttering one day it was like I was driving on the drunk bumps but I wasn't. Also it will drop gears when it shouldn't and at times it will kinda jump like it's losing power and don't want to go. I have taken it to my step dad who has been a transmission mechanic all his life and he said the transmission needs to be rebuilt but even rebuilding it won't solve the problem because it is a flaw in the way it was made so rebuilding it they use the same parts and everything so it will eventually do the same thing again it's all just a matter of when. He also had me go to another really good transmission guy and he said that we could replace the torch converter but still may need a rebuild l. I don't know if any that has to do with my passenger tire wear or my wheel bearing coming loose while driving only one bolt was holding it on when my husband checked it. The wheel bearing coming loose is pretty big safety problem. As for the transmission my step dad works at a transmission shop and he said they get probably 3 to 5 trucks a week having the same problem mine is having and I know they have been recalls on other trucks that have the same problem as mine just my one wasn't in the batch they recalled.

- Tyler, TX, USA

The contact owns a 2018 Chevrolet Silverado 1500. The contact stated that while driving at various speeds, there was an abnormal shuddering sound coming from the engine compartment. The contact stated that the stabili-trak warning light was illuminated. Additionally, on one occasion when the vehicle was started and shifted into drive(D), the vehicle failed to accelerate. The vehicle was taken to a dealer but was not yet diagnosed. The manufacturer was not notified of the failure. The failure mileage was 106,000.

- Clayton, NC, USA

Sometimes when traveling higher speeds (55-70)and braking going downhill, a hard brake will come out of nowhere. Not enough lock up the brakes or anything but enough to scare the crap out of you!!! If it would happen to a elderly person or a less experienced driver, they could probably lose control or wrack. With the power train...sometimes when accelerating(from a stop or low speed)it seems as though it gets stuck in gear or skips a gear. You won't have any power then bam... almost cerps the back tires

- Morrisdale, PA, USA

Hard shift when transmission is shifting around 70 mph and also transmission temperature keeps rising above 230 degrees. Shuddering when shifting after city driving.

- Columbus, GA, USA

The contact owns a 2018 Chevrolet Silverado 1500. The contact stated while driving at an undisclosed speed, the vehicle intermittently shuddered. No warning lights was illuminated. The vehicle was taken to a dealer where it was diagnosed and determined that the torque converter needed to be replaced. The vehicle was repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 47,000.

- Spindale, NC, USA

The contact owns a 2018 Chevrolet Silverado 1500. The contact stated while driving 30 MPH, the transmission became stuck in second gear. The contact pulled over the right side of the road and turned off the vehicle for two minutes. The vehicle was then restarted and there was an abnormal banging sound coming from the gear shifter. The vehicle was taken to the dealer where it was diagnosed and determined that the transmission needed to be replaced. The vehicle was not repaired. The Insurance Company had not yet been contacted. The manufacturer was made aware of the failure and referred the contact to the NHTSA Hotline to report the failure. The failure mileage was 141,000.

- Bayville, NJ, USA

I purchased a used 2018 Chevrolet Silverado High Country (VIN: [XXX] ) on [XXX], with 24,375 miles. On the day of pickup, the truck felt like it was driving over rumble strips. Dimmitt Chevrolet flushed the transmission and used the updated Mobil 1 HP LV fluid. This worked temporarily, but the shudder returned. CarMax then sent the truck to Burke-??s Transmission in Sarasota, where they replaced the torque converter. However, the shop declined to rebuild the transmission, citing its complexity. I later brought the truck to Cox Chevrolet in Bradenton. Despite clearly describing the shudder, harsh shifting, and driveline clunk, they told me the behavior was -??normal-?? and refused to investigate further, stating, -??We-??ll look into it once the unit fails completely.-?? The symptoms have worsened. Harsh 1-?"2, 2-?"3, and 3-?"4 shifts are back. Shifting into Drive causes a loud clunk and forward lurch. Cold starts cause bucking and sudden stopping. I-??ve replaced the tires, Bilstein 5100 rear shocks, and front suspension parts, but the problem persists. I signed on to a class action lawsuit against GM over the 8L90 transmission, but my claim was denied. This issue is well-documented and matches reports from many other owners. It affects drivability, safety, and long-term reliability. GM and its dealers have failed to properly address this known transmission defect. I urge NHTSA to investigate further. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

- Parrish, FL, USA