Vehicle has hard shift between first and second gear accelerating and deceleration. I noticed it after about a week of driving it after purchase

- Columbus, MS, USA

The vehicle does a hard shift from 1 to 2 second and has a shudder.

- Jacksonville, FL, USA

While watching the economy mileage window I noticed in the lower right side showing V6 and V4 switching back and forth. As they were switching, I noticed the engine vibrating while showing the V4 in the window. It did not vibrate while showing the V6 in the window. It did this while I was driving 65 mph(on cruise) on the expressway. I did not notice it during driving in start-stop slower traffic.this has been happening before, but did not figure out the problem until now.

- Cincinnati, OH, USA

On Friday November 6th we were on our way home coming down 1960 East when we started to hear a noise coming from the truck. We could hear it loud and clear because the A/C is also out so we have been having to leave the windows down. It sounded like an old electric fan running. Then shortly after the truck started to jerk hard it felt like we had just been in an accident. The truck would not shift gears and we were in the middle of a very busy 1960 lucky we were close to home and where able to make it there after multiple attempts to get the truck going. My husband has some knowledge of cars and realized it was the transmission. This is a fairly new vehicle. How can it have such a major problem? when doing some research apparently this is problem that GM is aware of and have done nothing to fix. As I mentioned before the A/C condenser has a major leak and this is also a problem of GM vehicles. Basically we bought a brand new lemon. I'm thankful we were not on the freeway when this happened it could have been much worse outcome. For now we are with out a vehicle and can not afford to replace the transmission.

- Humble, TX, USA

The truck loose power when key is turned off and then come back on after a few minutes also stabilatrack system is shutting off truck once on the highway at 70 mph engine runs ruff and uses oil in less than 5000 miles has use at least 3 quarts the dod system make truck run extremely bad engine has miss in it also it is becoming unsafe to drive at times and brake pedal is very hard to push

- La Fontaine, IN, USA

The vehicle first started vibrating at highway speeds while still under warranty (~15K miles) - I took it into the dealership and they said it was just out of alignment - aligned and rotated tires. This seemed to improve things for a few months until the vibration was back to the untolerable state - upon taking to another service station, they blamed the tires (uneven wear) and I paid for all new tires - only for the vibration to return after another few months. I next took it a 3rd service station and they are claiming a bend wheel that wont fully balance. After researching, I now see that this is a very common issue with a faulty drivetrain, but GMC is not acknowledging the issue"? how do I become part of a class action lawsuit in order to get this issue fixed properly"

- Tulsa, OK, USA

Vehicle slams into gear at initial take off and deceleration following an acceleration which causes a hard forward jerk. This issue has came close to causing accidents on the highway during passing and departing stalls adjacent other vehicles and/or objects.

- Silver Lake, KS, USA

Transmission shifts or jerks hard when coming to a stop, severe transmission vibration occurs when traveling at speeds of 50 to 65 mph.

- Little Rock, AR, USA

Almost collided with other cars in parking lot because the brakes weren't working right also transmission shimmies between 50 and 60 mph

- Spring Hill, FL, USA

My truck braking system is going to the floor board of my truck. Making very hard for me to stop. They call themselves fixing it but the same problem is back. Really tired of this problem and other spend $1000 on springs and the vehicle was only a 1 1/2 old was told the warranty on cover it if they were broken a lie the dealership told me.

- Houston, TX, USA

The same issue as GM service bulletin pi1513F (radiator leak) has happened on my 2017 GMC Sierra. This service bulletin currently covers 2014 - 2016 models and needs to be extended to cover 2017 models (and possibly 2018). This issue is a radiator that leaks on the passenger or drivers side on the wall between the cooling fins and the end of the radiator.

- Ravena, NY, USA

Our truck is less than three years old with approximately 69000 miles. The transmission just started slipping out of the blue while driving thru a neighborhood. While in drive it would move but once accelerating it would rev up and not change gears. This happened without warning, without an engine or warning light. We do all the necessary regular maintenance. In addition two years ago while the truck was a year old, the brakes went out while driving on the interstate. I guess it was the brake vacuum pump or whatever that didn't allow the brake peddle to be pressed which provided me with no brakes. Again with absolutely no warning! this later became recall issue but not before it had already happened to me! I understand there is a class action law suit against GMC for transmission problems and I would consider being a part of this. This is a 50;000$ and relatively new truck, this is unacceptable! the dealer now wants over 4000$ for repairs.

- Dickinson, TX, USA

I have been experiencing the hard up shift and down shift problems that has affected almost all GMC Sierra pickups with the GM 8L90 and 8L45 transmissions since 2015. The dealership told me that there was no repair for the problem and reset the transmission computer on 5 separate occasions which did absolutely nothing to remedy the problem. My vehicle is now out of warranty and the dealership wants to charge me $2800 to replace the valve body in the transmission. What is the NHTSA going to do about this issue and why hasn't GMC been forced to recall these vehicles.

- Navarre, FL, USA

The contact owns a 2017 GMC Sierra 1500. On several occasions, the accelerator pedal was depressed; however, the vehicle failed to respond. On one occasion, the gear shift lever was placed in reverse and the accelerator pedal was depressed; however, the rpms revved without the vehicle responding. The vehicle was taken to greg lair Buick GMC (16200 canyon dr, canyon, tx 79015, (806) 553-5706) on two separate occasions; however, the transmission technician was not available to diagnose the vehicle. The vehicle was not repaired. The manufacturer was not notified of the failure. The approximate failure mileage was 33,042.

- White Deer, TX, USA

The 8 speed transmission shifts hard going from 1st to 2nd. It cant decide what gear it wants at speeds around 40mph. It has revved up and then slammed into gear going into garage and has even done it going into a parking spot. Thank god no one was in front of me! the truck has done this since new. Dealer has reprogrammed the software per GM, changed the transmission fluid to no avail. Dealer has been great in trying to find and repair issue but all they tell me is GM is aware of issue but does not know what to do. The only thing they are allowed is to reprogram the software and send it home. The dealer has even told me they have several customers with this issue in only the 8 speed transmission. I know how to fix it, replace the transmissions with the new 10 speed. GM has even said that is why they came our with it because the 8 speed has issues. I know GM will say it is not a safety issue but if a vehicle jumps into gear and hits a pedestrian, who will be to blame! my truck has 46,000 miles and it has done this since it was new.

- Wichita, KS, USA

The contact owns a 2017 GMC Sierra 1500. While driving at low speeds, the vehicle violently downshifted from first into second gear. There were no warning indicators illuminated. The vehicle was taken four times to demarois Buick GMC Mercedes-Benz (3115 w broadway St, missoula, mt 59808, (406) 721-4000) where it was diagnosed that the transmission needed to be reprogrammed. The vehicle was repaired, but the failure recurred. The manufacturer was contacted and provided case number: 9-526--2561452. The failure mileage was 20,000.

- Salmon, ID, USA

The truck lurches forward as if the accelerator is being depressed while coming to a stop obviously while depressing the brake. This causes dangerous situations every day in traffic. I have not found any solutions to the problem online. Reprogramming computer and replacing other speed control modules has not solve the problem for other drivers.

- La Grange, NC, USA

8 speed transmission is dangerous. Under light throttle, the vehicle will make a loud popping noise and lurch forwrward. Like stopping at a stop light, driving through a drive-thru. My truck will shake violentlly.. dealer says its the transmission. When I try to enter my garage the truck will sort of jump forward. Delear says its torque converter sutter. Transmission has been worked on 3 time. It seems to get worse. Delears says the 8 speed transmission has many issues but GM does not have a fix. These 8 speed transmissions will end up killing folk.. this stuff happens on a daily basis

- High Point, NC, USA

My truck shifts very hard between gears, especially 1st to 2nd. Feels like getting rear ended sometimes. It also hesitates daily when backing out of my driveway and putting it from reverse to drive. You don't know when it will actually engage making it dangerous when pulling out into the street. Its definitely an issue with the transmission but no fixes offered from dealer yet.

- Morton, IL, USA

"have taken my 2017 GMC Sierra into the dealership twice for transmission issues, the last time was a month ago. Both times I was told that there wasn't anything wrong but that the transmission software was 're-flashed' and that the transmission would have to 're-learn my driving habits'. my truck is still having problems. While upshifting from 1st to 2nd gear, the transmission sometimes hesitates before it engages and then causes the truck to lunge forward with a huge slam. While downshifting from 2nd to 1st gear, the transmission will make a very noticeable 'clunk'. I'm about to take it back a 3rd time. This is extremely frustrating my bought my truck less than 2 years ago and it only has 25,000 miles."

- Bossier City, LA, USA