Purchased GMC Canyon 5/24/18. Felt shuddering and loud noise at fifty mph on 5/20/19. Took truck to GMC service dept. 2995 miles. Tech said no problem after they kept truck five hours. On 5/24/19 same problem, went to service manager, took test drive and he said there is a bulletin on the transmission fluid. We will flush the fluid and put new hydraulic fluid in the transmission and torque converter. The new fluid will not do the job right. It is a song and dance story cover. They should replace the transmission and torque converter.

After paying near 40k for this Canyon the transmission is shuttering most of the time. With less than 6000 miles on it and finding out many other people are having the same problem with this 8 speed tranny as I am. And to make matters worse I now have to face leaving my truck at a GMC dealer for over a week. For them to do a temporary fix on it that some say lasts less than 1000 miles. I'm ready to join a suit against gm. If enough of us that are having the same problem join together we may make the story into the news. Which could hopefully get GM off their dead asses and do something about this

Bought a 2018 Canyon SLT. 2500 miles into ownership the shudder/vibration issues started. System was flushed/re-synched and torque converter replaced (at 5000 miles). Issue is back at approx 8000 miles. GMC has no fix but says the issue is under investigation with results expected first qtr of 2019. I’m left holding a piece of crap GMC product and looking to lose a bundle if I get rid of it.. also, reality set in and I realized that the dealership never mentioned there was an issue with the 8 speed transmission when I was buying the truck.... so, buyer beware and do your homework before buying a GM product!

Update from Jan 6, 2019: Also, I’ve been trying to get in touch with the GM customer service folks to discuss my issue. Called, got a case number. Issue with my phone number so had to give them that again. Still waiting for a call back. I think they know they have a big problem looking them square in the face and they’re not wanting to deal with it. The is BS!

Update from May 6, 2019: Received a call from GMC service dept Said they had the trans fluid required to fix my transmission issue. Call was in late Feb 2019 so GM had the fix, tools, instructions out when they said they would. Took the truck in, explained when the issue would start each time. Usually after the truck had been driven 15-20 mins and trans temp got up around 115 degrees. So, this fix requires a check using an analyzer to measure vibration. Tech took vehicle out for a short drive to check for the issue with analyzer installed. Obviously didn’t drive it very long because they initially came back with no issues detected. Fortunately for me, the service rep that took my car in listened to me about when the issue occurred. They drove it again and let it warm up this time. Damn, issue came up and they saw it on the analyzer as expected. So fluid was drained, flushed and refilled with the newer/heavier weight fluid. I have approx 2100 miles on the truck since this procedure was performed. So far, so good. No shudder detected. Still holding out to say the issue is resolved since issue seemed to reappear about 2500 miles after previous attempts at resolution. Word of advice to all. Be specific on when the issue occurs if you are experiencing the same and go to take it in. Note the speed at which it happens and how long you’ve been driving when you notice it. Don’t let the dealerships blow you off and tell you there’s nothing wrong. Ride with the tech or have them ride with you for as long as it takes.

Purchased this 2018 Canyon to replace a 2016 Canyon that GM refused to fix by say it was running "as designed". Within 4 days of purchasing this 2018 Canyon, I noticed a "shuddering" in the transmission upon acceleration at about 55 mph and took it back to the dealer (Lee Buick GMC). They told me it was the torque convertor and that they would order one to replace the one in my Canyon. After waiting 15 days for it to come in, I took the truck in to the dealer for the repairs. At that time, I was told that they found a service bulletin that required them to change and flush the transmission fluid and that "should" repair the problems. For the next 4000 miles all seemed good but that was short lived. Now, after doing as they required, the truck is doing the same thing again. Again, they (the dealerships service department) say that they have to replace the torque convertor. This should have been done the first time since it was a new vehicle when the problem started. It is apparent that GM does not want to stand by their vehicles or properly repair them.