Have had 2018 GMC Sierra into the dealership prior to 30,000 miles (twice) complaining of hard shifting and truck "shaking" while driving. Dealership dismissed secondary to vehicle did not hard shift or "shake" during test drive and could not identify the problem or did not acknowledge a known issue with the transmission at that time. Vehicle has continued to have this problem off and on over past 18 months but never at a time when it was brought in to diagnosis the issue.

Driving vehicle yesterday and vehicle starting "somewhat violently" shaking while changing gears while driving locally. Very hard shifting as vehicle accelerated. Did research online and it has been a known problem with thousands of complaints from customers with same issue calling it the "Chevy shake." Recommended to have transmission fluid changed and flushed since has resolved the issue in some vehicles. Had that done in which repair shop expectantly found metal shavings in the pan which they said was very unusual and would not be expected for a vehicle with that low of miles and year.

I also noticed that there was a missing bolt never attached on the pan which would not have been able to release on its own. On the test drive, after 2 miles, the vehicle violently shook. The technician was extremely surprised and was not expecting that extent of an issue since it had not been driven before the transmission fluid change. They did diagnostics attempting to do a 'factory reset' if able with that vehicle (that option was not available with the GMC Sierra) and could not do that. Technician recommended an immediate replacement of the transmission since it was not related to the torque converter. Stated vehicle should not be driven any distance due to the possibility of the transmission shifting into neutral unexpectedly and vehicle becoming undriveable.

I received a quote for transmission replacement for a 2018 GMC Sierra with 64,000 miles and I'm not happy about it. Will be going to dealership to speak to management regarding GMC being responsible for the cost of the transmission replacement, secondary to it having been a known problem with these vehicles. GMC is dismissing that it is their responsibility due to it is a defect in the part, not the vehicle while class action lawsuits are pending that they were aware of this part defect when agreeing to use the part for the transmissions in certain vehicle lines.

Buyers beware and stay away from GMC and their $60,000 2018 Sierra 1500 8 SPD automatic transmissions. They have huge manufacture defects and GMC won't fix them. I've had my truck in the shop 3 times since I purchased it new and GMC has said they don't have a solution to fix the problem. But they do and they won't take responsibility for their problems. They don't have issues with the 10 SPD but stay away from the 8SPD. Now I'm considering trading in my Junk Truck and losing thousands of dollars for a defective transmission.

GMC Sierra 1500 SLT, V8. GMC needs to find a solution for the following situation.

Transmission hard shift, at low speed, going 1st to 2nd gear when cold. Now at 7,000 miles still has same problem consistently, disengages and engage very hard. Dealer transmission technician produced a document #16-NA-361 stating not to fix. Condition due to initial clutch fill time (C4) clutch. Latest revision date 5-21-2018.

I find this unacceptable. This is my first and last GM vehicle. I

Too bad, truck has great features, and I really like everything else about the truck.

GMC Sierra 1500 SLT, Really like the truck, specially the gas mileage.

GMC could find a solution for the following situation.

- Front suspension, when you turn to left, makes noise. (problem resolved by the dealer, had to go twice) - transmission hard shift, at low speed, reverse going to 1st gear. now at 17,000 miles started the same hard shift in reverse, disengage and engage very hard. ( Dealer does not have a transmission technician available ) - Engine at 15,000 miles stated to show rattling noise " like if there is loose chain in the engine" (Dealer couldn't identified the noise, keep my truck for 2 days and described a idle noise) - Cooling seats, vibrates at maximum speed. (dealer try to fix, but is back)

I am a contractor, hard to find time to be involved with this situation.

Too bad, truck has great features.