I had to leave my 2019 GMC Canyon in the shop for 94 consecutive days. I recently got it back just prior to Christmas of 2019. I provided a list of 15 different issues, one of which, is the "slamming into gear" scenario I am experiencing, even more so now.

Also, while my truck is either stationary at a stoplight, stop sign, or in my own driveway, it has a shake that I constant and rather annoying. From what I have researched online, the shake may be triggered by a possible transmission (8-speed) issue that I may have.

My truck was put in the dealership shop just prior to the GM strike of 2019. I had no clue they were on strike until after the first week my truck was being inspected for the listed issues I presented. After all of those days, 94 to be exact, the dealership technicians could not recreate the problem. Well, I found out they only put 22 miles on it. I drive 300 miles a week, 60 miles daily. I can recreate the problem just by driving out my driveway and stopping at the first stop sign that is at the end of the street. Once I stop and apply minimal pressure on the accelerator, my truck doesn't move instantly. It is as if it pauses itself and then bam!, the first gear finds its position. It feels like I am getting hit by a car from the rear.

I have reached out to the service manager again via e-mail. I have explained that the "shaking" effect is now getting worse to the point a freshly opened soda in a can splashes out. Sometimes, it feels as if the truck will just shut off. Once I get a reply from the service manager at a local GM dealership and hopefully get the truck serviced for the issue, I will return to post the findings/results.

Reported transmission shifting problem to dealer at 1000 miles - was told everything was normal. Problem worsened until the vehicle was almost impossible to drive at which point dealer acknowledged that GMC needed to replace the torque converter and change fluid to a different specification. That happened around 2000 miles. Vehicle now has 7000 miles and the shuddering problem is starting to happen again. Apparently it has to get much worse before dealer will acknowledge it.

Update from Aug 7, 2019: Dealer finally acknowledged the problem at 8000 miles and claimed that GMC had changed the transmission fluid specs. Fluid has been replaced again and the shuddering problem has gone away but the low speed up and down shifting is still jerky. We shall see how long this fluid lasts.