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

Extreme lag/delay- harsh engagement when shifting from park to reverse. Its like you are backing into something? when cruising 28-32 mph and releasing accelerator(as if you were coasting into a turn) when slowing the vehicle seems to shift up and lunge entering the turn. Clunks and shifts hard when cruising normally when you have to release the gas pedal and slightly reaccelerate, causing the driver to hesitate. Vehicle shutters and hard accel 10X worse when towing a 7000 # trailer (truck is rated over 12,000 lbs. Towing).

- Sequim, WA, USA

The contact owns a 2015 GMC Sierra 1500. While driving various speeds, the transmission vibrated and caused a hesitation when the gears shifted without warning. The vehicle was taken to the dealer and repaired; however, the failure recurred several times. The manufacturer was made aware of the failure. The failure mileage was 50.

- Spokane, WA, USA

First of all the headlights are very dim and at night cannot see nothing.dealer said it is what is.very bad !! also my Sierra on window sticker states comes with all terrain tires it does not have all terrain tires. They are 265/65/R18 Goodyear Wrangler sra.I worked for Goodyear and those tires are all season !!! not all terrain as specified on window sticker !! I talked to dealer and called customer service at GM they never call back and they said those are the right tires.they are not according to my attorney who states the window sticker is totally incorrect and is fraudulent check your tires and window stickers and compare and look on goodyears website you will see.also my transmission clunks and knocks and shifts incorrectly dealer states its normal I spend 40K on a new truck and all I have are problems and GM does nothing. It downshifts horrible what can I do"?"

- Los Angeles, CA, USA

Delayed engagement in drive, transmission clunks, RPM flares and truck quits moving unexpectedly. Shudder at 3- 50 mph, vibrates steering wheel and leaves an uneasy feeling the truck is going to quit moving.

- Montgomery, AL, USA

Purchased vehicle with just over 9,000 miles on it. Noticed excessive vibration at highway speeds. At just over 12,000 miles driveshaft suffered catastrophic failure at low speed in a residential area. Failure occurred on a wet road under moderate acceleration at around 10-15 mph. Driveshaft literally ripped into two pieces.

- Castle Rock, CO, USA

The contact owns a 2015 GMC Sierra 1500. While driving 60 mph, the vehicle began to decelerate and the engine warning light illuminated. The vehicle was towed to a dealer where it was diagnosed that a gear cylinder fractured. The vehicle was repaired, but was unable to be driven. The manufacturer was not notified of the failure. The failure mileage was approximately 4,000.

- Fenton, MO, USA

Brought in my 2015 GMC 1500 Sierra truck in for vibrations issues at high speed of 70-75 mph. After 4 attempts GMC Corp refuses to admit that there is a safety issues in driving this vehicle at a normal rate. They continue to remove and replace the tires. I have never owned a vehicle before that such vibration is felt in the cabin of the truck, passenger seat, foot petal, etc.that is so uncomfortable, that my wife refuse to drive in the truck due to its safety. GMC will not acknowledge any of these complaints but will say everything is of specs. Like others this is the worse vehicle I have ever purchased. Found more complaints like this has been filed, but same result, GMC will do nothing.

- Waveland, MS, USA

Truck starts to vibrate at 60 mph and gets worse the faster you go.

- El Monte, CA, USA

On two separate occasions my truck has acted like it is in neutral while driving. The drive system disengages and the engine just revs. Once this happened while driving down the road, the other when the truck was stuck in snow. When it was stuck it disabled the 4WD system completely, rendering the vehicle stranded.

- Elkview, WV, USA

Headlights are very poor (when wet road or in town) cannot tell they burning...I have 20/20 vision......on slow down does not down shift....cannot accelerate....the starter hangs up on start as if does not fire or no fuel pump

- Rocky Mount, NC, USA

The transmission seems to slip or hesitate at takeoff. The running lights are too dim to see down the road.

- Vancleave, MS, USA