The contact owns a 2018 GMC Sierra 1500. While attempting to accelerate, the contact noticed a hard shift with the eight speed transmission. The contact thought the transmission had fallen off the vehicle. The contact felt this was a defect, especially during cold starts in the morning. Ray skillman southside Buick GMC (8424 us-31, indianapolis, in 46227, (317) 497-0711) was contacted and provided a report indicating that this was a normal occurrence. The manufacturer was not contacted. Through online research, the contact believed he had a case with the lemon law. The failure mileage was 4,768.

- Bargersville, IN, USA

The contact owns a 2018 GMC Sierra 1500. The contact stated that the transmission shifted from first to second gear while driving 15 to 20 mph. Also, when driving on the highway for a long period of time, the transmission would not downshift until the vehicle came to a stop, and would then fail to move forward. There were no warning indicators illuminated. The vehicle was taken to golling Buick GMC (1491 S lapeer rd, orion charter township, mi 48360, (248) 693-5900), but the failures could not be duplicated. On another occasion, when the vehicle was engaged in two wheel drive, the rear end failed to unlock and would jerk. The contact drove the vehicle to the same dealer where diagnostic testing was completed, but a failure could not be found. The vehicle was not repaired. The contact stated that the failure recurred three times. The manufacturer was not notified of the failures. The approximate failure mileage was 16,000.

- Ortonville, MI, USA

Truck shift into gear very roughly. Shakes when driving through all speeds. Feels as if something is falling off the truck.

- Little Rock, AR, USA

After truck has set for a while and start to take off from a stand still and it goes to shift from 1st to 2nd it will hard shift and truck will sometimes lurch forward. When accelerating slowly truck with shutter when shifting gears, almost like it can't decide to shift to the next gear. Once truck is warmed up this no longer happens.

- Owensboro, KY, USA

No transmission power regardless of the gear shifter position. I turned the engine on and off several times trying to get a solution, no luck. I returned to the vehicle 5 minutes later and did get it to move, ,,would only go 25 mph at 3000 rpms. I was in the middle of wi not near any major dealership on-star was useless saying I had a major engine problem and the computer was trying to protect the engine. I was directed me to a Chrysler dealer ship, who told they could not get me in for 2 weeks, suggested another branch which was over 45 miles away. I drove 5 miles to a friends house and was able to find a dealership in janesville, wi (fagan). When I started the vehicle to drive to janesville, the transmission did work. Fagan spent 2 hours working on it, and could not find a cause for the problems, they checked every computer, could not duplicate what happened. They reprogrammed all the computers. Then in cincinnati, oh the power steering assist went "off", while staionary. I tried restarting several times to no avail, drove the 3 miles left to the G'kids house, no power steering, trailer problem lighjt on, no RPM or mph needles moving. Called local dealership (borcharding) and they suggested I drive it to their location 12 miles away. When I started it, the power steering was back on, but the unit would not get out of 2nd gear, ran 40 mph at 2500 RPM, warning lights all on, engine light still on. Next moring I started the vehicle, everything was okay including the transmission problem, but still had the "check engine on", the dealership kept it (2) days, involved GMC engineers, could not determine the cause for all the problems, including loss of "steering assist". they drove it over 50 miles on two trips, could not duplicate what happened. They told me it was some kind of computer problem, but could not determine, they reset everything again.

- Delavan, WI, USA

Upon starting the engine the vehicle makes a clank sound and either surges forward or backwards slightly. It seems to do it more often on a light incline. Local Chevrolet ( GM) dealer has looked over twice, no suggestions made or given to me.

- Jacksonville, AR, USA

When 1st cranking truck and put in drive motors rrev up and shifts hard to second. Occasionally when I out in reverse it will sit there N not shift in. Then when it does it shifts hard. When accelerating the truck it sounds like a clattering sound under drivers side under hood. Tried different type of gasoline and nothing changes. Gmac needs to do a recall on both of these items. I am very disappointed in my GMC and gmac

- Bullard, TX, USA

Daily the transmission has a hard shift from 1st to 2nd gear. Potentially causing me to loose control of the vehicle. Ive had it in the GMC shop 3 times and GMC is unable to fix the problem. After the vehicle sits for periods of 4 hrs or more the problem reoccurs. This is a serious political saftey hazard in the 8speed transmission and needs to be recalled and fixed with a new transmission.

- Ogden, UT, USA

At 40mph loud bang felt like we were rear ended, sounded like we were rear ended, huge jolt forward nearly causing accident, possible back injury, seats jolted, looked behind us and nothing there. Was driving at 30-35mph and just accelerated slightly to pass a car when this happened. City street 3 lanes. Dealer turned us away because could not duplicate for them. GMC said case was accelerated no call back as of yet.

- Elk Grove, CA, USA

Transmission has shudder and now wont downshift properly while driving

- Lewis Center, OH, USA

Document id 4605342 #16-na-361 : information on transmission harsh 1-2 shift upon first start up/shift of the day under light throttle this GM bulletin was issued Jul 21, 2017 on numerous vehicles and according to this bulletin the problem does not have a resolution. The bulletin clearly states changing the entire transmission will not solve this issue. This is affecting my GMC with the 8 speed transmission. GM has known about this issue but has none the less sold the vehicles to consumers without disclosure. Neither GM or darrel waltrip GMC in franklin tn disclosed this issue prior to the sale. The service dept at the dealer admitted the issue cannot be repaired and told me GM is unwilling to do a trade assistance or buyback. GM claims nothing is wrong with my car yet has a clear document that says otherwise.

- Murfreesboro, TN, USA

While the truck is in motion and when accelerating around 15-20 mph the transmission will sometimes "hunt" for a gear causing the truck to not accelerate. This results in a mild jerking of the truck when it is trying to accelerate and feels like the transmission is slipping/skipping. This is more apparent when going up a grade versus on a flat surface. So I have to push harder on the gas pedal waiting for the truck to shift. This is a safety issue since when not properly accelerating into traffic, an accident is more likely to occur. I see that this issue has already been reported in another incident on your website. I have had this issue since I bought the truck on 02/2018 and the reason I have waited to report is due to the dealer stating to allow the computer to update/learn your driving habits. I have 11,000 miles on the truck now and still experiencing the issue.

- Stevensville, MD, USA

Extremely hard shifting on lower gears. When slowing when it goes from 2nd to 1st it feels like I got rear-ended. Not all the time but once a day at least. It also shudders when slowly accelerating in traffic, sometimes the RPM goes way high and it lurches forward when it upshifts.

- Fort Walton Beach, FL, USA

Brand new 2018 Sierra 1500 Z71. When driving the truck for the first time after sitting for a number of hours (6+hrs) the truck experiences a "hard" 1-2 shift. This occurs 100% of the time when I leave for work in the morning. Sometimes it feels like the transmission slipped, this is the hard shift feeling. Other times the truck loses acceleration, cuts out, feels like the truck has ran out of fuel. Only happens when the truck has been sitting for a long period. When I took the truck in to have this looked into I was told this is a known issue without a resolution. Ive attached a scan'd copy of the document they gave me #16-na-361.

- Gilbert, AZ, USA

Since day 1 of purchasing new, to current date, there is vibration at idle. There is vibration at highway speeds of 60 mph plus. It has been to the dealer 5 times for testing. This is a known problem with thousands of vehicles. GM says it meets their specifications. The dealer balanced the tires 3 times, no luck. The dealer replaced the tires, same issue. I am told the vibration at idle is normal. This problem is distracting when driving. I have been dealing with GM and the dealer for 7 months with no resolve. Https://www.kshb.com/news/local-news/investigations/general-motors-customers-frustrated-over-shaking-in-pickup-trucks this link of a news clip shows what is happening to my vehicle. This happens every day, so ignore the date I entered below. I have videos but the file is too large to download.

- Mansfield, MA, USA