Torque converter. Me and along with 4 other people are having problems with it. Upon start up and driving it starts to get sluggish and then just comes almost to a complete stop only building RPM's accrodding to the GM dealership it's normal. With all the GMC trucks I've owned it has never done this. And is only starting to do it over the past couple of months. I've talked to a guy who just had 2 replaced in his truck and is continuing to have the problem. To avoid any vehicle damage for anyone else I'm considering if you can check and see if anyone else is having the issue. I take very good care of my truck I don't mud in it or drive it crazy(wreck less). Dealership is also pretty much refusing to look into the problem or diagnosing it considering that it's 'normal' for the truck do that. Which I strongly disagree.

- Headland, AL, USA

The contact owns a 2015 GMC Sierra 1500. The vehicle failed to shift and remained stuck in gear. Also, while driving various speeds, the vehicle accelerated without warning. The vehicle was taken four times to laroche Chevrolet Buick GMC Cadillac (900 us-290, brenham, tx 77833, (979) 836-6666) where it was diagnosed that the transmission fluid and torque converter needed to be replaced, and reprogramming was needed. The vehicle was repaired, but the failures recurred. The vehicle was taken to mac haik Chevrolet (11711 katy fwy, houston, tx 77079, (281) 497-6600) where it was diagnosed that the vehicle was working as designed. The vehicle was not diagnosed or repaired. The manufacturer was contacted, but did not assist. The failure mileage was 7,000.

- Cat Spring, TX, USA

When putting the truck into gear with the foot firmly on the brakes the truck will slam into gear causing the truck to jump forwards or backwards.

- Braintree, VT, USA

When I'm cruising highway speeds the truck get a violent vibration and makes the vehicle uncomfortable to drive.

- Huntington, IN, USA

Tcc shudder

- Grove City, OH, USA

Transmission shifted hard, delayed acceleration at times, shuddered and jerked. This was usually slowing down to turn around 30 or 40 mph as the truck was in motion. After only two years the entire transmission had to be rebuilt. The transmission was shifting poorly the moment I drove it off the lot even if it "adaptive learning" you could tell there was something wrong.

- Fayetteville, AR, USA

Brake pedal goes soft and can hit the floor on occasion. Mostly happens with in reverse. 40K miles. Also transmission shifts are erratic. RPM can shoot up between shifts.

- Saint Charles, IL, USA

When accelerating truck will sag and or hesitate. When you slow down and try to speed up the truck will hesitate for 5 or more sec. Before speed back up GM said that this is due to zero torque to me this is a safety hazard

- Creedmoor, NC, USA

Loses power when trying to accelerate, presents a problem when trying to maneuver in traffic and semi stalls for.2 seconds enough to cause a delay

- Colorado Springs, CO, USA

Called dealership about one week after purchase in August 2015 and reported vibration in vehicle at speed of 70 and above. No return call. Never had truck inspected. Vibration has increased with age of the truck. Truck has 55,000 miles on it now. Just now finding out about numerous complaints having been filed. Found information at autoguide.com. GM has issued bullet6in #pi1354C relative to this.

- West Monroe, LA, USA

Truck will not change gears and sputtering. Bad gas mileage and not wanting to start.

- Cypress, TX, USA

Steering electrical assist fightback, driving, turning resulting in no steering-deadly! this can happen at any time while driving. Very dangerous! engine must be shut off and restarted before you can get out of street. Then message reads "lower driver window then raise" before proceeding.

- Duncanville, TX, USA

Safety issue: Known issue to GM but company refuses to acknowledge as a safety issue. A large number of GMC/Chevrolet pickups have vibration issue at highway speeds causing stress and unnatural wear on vehicle components which might fail causing a crash at highway speeds. GM dealers unwilling to solve issue on majority of affected vehicles (2014-2015).

- Portage, MI, USA

My truck suffers from vibration problems, the same thing that 10,837 other posts from other people suffering the same problem are talking about on this forum. www.GM-trucks.com/forums/topic/153186-shake-or-vibration-issues/page-723 this forum has been viewed over 1.5 million times which means a ton of people are having this issue. This is absolutely a risk to motor vechicle safety and absolutely exists in a group of vechicles of the same design or manufacture. The problems this shake presents that pose a danger are vibrations so significant that it can cause driver distraction, fatigue on long trips, potential loss of control, not to mention long term health effects from vibration exposure. The health effects defined are as follows: "the effects of whole body vibration (wbv) have been studied extensively in occupational medicine. In particular, it has been shown that when the body undergoes chronically to whole body vibrations spinal degeneration is likely to be one of the deleterious outcomes. Low back pain has been shown to be the leading major cause of industrial disability in the population under the age of 45 years and has been linked to whole body vibration exposure encountered in some industrial settings. Whole body vibration has been recently purposed as an exercise intervention suggesting its effectiveness in increasing force-generating capacity in lower limbs and low back. It has also been reported to be an effective non-pharmacological intervention for patients with low back pain. Relatively short exposure to whole body vibration has been also shown to increase the serum levels of testosterone and growth hormone. The combined effects on the neuromuscular system and endocrine system seem to suggest its effectiveness as a therapeutic approach for sarcopenia and possibly osteoporosis."

- Lackawanna, NY, USA

The GMC Sierra has a terrible vibration from 70 - 80 mph. It has been in the shop 7 times over the last year, 9 new tires, and the vibration still continues. I have attempted to resolve the issue with GM but there has been no resolution. The truck feels unstable and like something is going to break on the highway which is a safety concern. This vehicle has issues and it needs addressed.

- Topeka, KS, USA

The GMC Sierra has a terrible vibration from 70 - 80 mph. It has been in the shop 7 times over the last year, 9 new tires, and the vibration still continues. I have attempted to resolve the issue with GM but there has been no resolution. The truck feels unstable and like something is going to break on the highway which is a safety concern. This vehicle has issues and it needs addressed.

- Topeka, KS, USA

I bought the vehicle new in 9/2015. I reported a vibration between 75-80mph to the nearby GM dealer (twice). The dealer kept the truck for a few days and stated they could not correct the problem. I took the truck back to the original dealer where I bought it, they did a road force balance on the tires and reported the problem fixed. I took the truck back to the original dealer at 13K miles, they kept the truck for a few days and reported the tires needed to be replaced. They replaced the tires and stated the vibration has been resolved. I drove the truck for another 3K miles and noticed that the vibration was starting up again. At 18K miles, I returned the truck to the original dealer and they are going to try and resolve the problem a 5th time.

- Canton, GA, USA

Significant clunking in rear end indicative of improper alignment or lash is rear differential. Excessive vibration at speeds over 65 mph when the driveline is under load. Vehicle has been to the GMC dealership where it was purchased three times with no resolution to date. Current mileage is 18,000.

- Cincnnati, OH, USA

The automatic transmission has a hard shift when going from park to reverse or park to 1st gear. The vehicle shudders when at interstate speeds causing a shake similar to running over interstate road bumpers/ lines. This has been brought up to the dealership several times and they reset the "learning transmission" fixing the problem temporarily for a day or two.

- Raleigh, NC, USA

I purchased my first new vehicle in Oct of 2015. I've owned 4 vehicles since I've had my license, 2 Dodge and 2 bmws. I chose a truck I've dreamed of having since I was 16. I'm currently 28. I chose the Sierra denali. Not only was this my first new vehicle but this was my first truck and my first GM product of my life. Now I'm teetering on it being my last. Through the 14 months I've owned the vehicle (since 4 miles) I've had numerous issues. My front differential has been rebuilt not once but twice. My truck has 45K on it. It has never towed hauled or other wise performed a task requiring it's power other than normal driving. It has been babied. Cleaned washed oil changed tires rotated and 93 octane fill ups. Amongst other issues were the infotainment center freezing. Cvs axle shafts performing erratic along with bucking slamming and noises through the power train. A random leak in the lower oil pan that the dealer said was a manufacturer defect they were aware of. A airbag software safety recall and a shifting driver seat that tends to move a bit during cornering. Now to top all of those issues off in those 14 months I now have a leak the extends out from the edge about 5 inches from the rear windshield all the way from the driver side to passenger side. I'm not in bumper to bumper warranty. I was told 100 dollars and it will be fixed. It shouldn't have to be fixed. None of it should have. I have had less issues in all 4 of my last vehicles put together than this 1 vehicle I have owned for 14 months and I bought it new. This has been a big let down. A disappointment 12 years in the making apparently. One that has more than ruined my day. I honestly don't want this truck. It's scarred for life. That's obvious and not reversible. But now I'm under water on a loan for a truck that's not worth its weight in scrap metal. That's neither right nor fair.

- Danvers, MA, USA