There’s a class action lawsuit against General Motors for their 8-speed automatic transmission

Back in July 2018, I bought a new GMC Canyon as my first personal vehicle. I was very fortunate that I was able to get the exact vehicle that I wanted, as I perceived the GMC Canyon as essentially the best-in-class vehicle that fit my exact needs. I took my enjoyment of the vehicle to the next level and also added on a handful of modifications.

This isn’t quite the best photo, but it’s the only one I have handy that hasn’t been posted on my blog before (but you can find more pictures in other blog posts):

Making a stop at the Grewal Business Center in Baker, CA after driving through the Mojave Desert from Las Vegas in a rainstorm

Unfortunately, a few months after purchasing the truck, I started having some problems with the transmission. At the time, I didn’t really know what was wrong, but I new something was definitely abnormal, because I had driven a lot of vehicles before, especially considering that I’ve done enough car rentals for work to earn myself elite status with Enterprise Rent-A-Car. In my half-year owner’s review, I mentioned this problem; here’s an excerpt from that blog post:

The transmission is slow and lurches the vehicle when the fluids are still cold. There’s an option to display transmission fluid temperature in the gauge cluster, and whenever it’s below ~100°F, the transmission takes longer to shift to different gears. This is particularly noticeable when you’re just starting up the vehicle and making your first stop of the day. If you do not come to a complete stop then wait a few seconds (and instead just slow down and roll through a stop sign), the vehicle will hiccup and lurch when you ease your foot off the brake and begin accelerating again.

When I took it into the dealership, they did no work on it and sent it right back to me with the commentary, “Performed complete vehicle DTC scan. No codes or service bulletins found. Could not duplicate concern. Vehicle is operating as designed.” At that point, I wasn’t sure if the mechanic had someone else warm up the vehicle and transmission fluid so much that the problem went away, he was just incompetent and didn’t recognize the problem, or he was intentionally ignoring the blatantly obvious problem.

Yesterday when I got back from hiking, I was browsing the Internet while recovering and came across a class action lawsuit against General Motors, the manufacturer of the GMC Canyon. I got curious and looked into it, seeing as I am a General Motors customer, and got extremely intrigued when I saw that it was regarding a defect in the 8L90 and 8L45 8-speed automatic transmissions. Apparently, the vehicles affected were:

  • Chevrolet Colorado, Chevrolet Silverado, Chevrolet Camaro, Chevrolet Corvette
  • GMC Canyon, GMC Sierra, GMC Yukon
  • Cadillac ATS, Cadillac CTS, Cadillac CT6, Cadillac Escalade

At this point, figurative red and blue lights were flashing in my brain as I began digging through my vehicle’s purchase paperwork. Lo and behold, my 2018 GMC Canyon had an 8L45 transmission and was an affected vehicle for this class action lawsuit. According to the “GM facing class action lawsuit over transmission problem” page on, the problems that others are having are the same as mine:

“When a driver accelerates or decelerates, the cars will reportedly hesitate and then shudder, jerk, clunk, or ‘hard shift’ when the automatic transmission switches gears. This may also occur when the vehicles are accelerating in a single gear and not necessarily switching gears.”

I got in touch with one of the class action lawyers, and I’m in talks with them right now providing relevant information, so hopefully this ends up doing something for me. Even though the transmission sucks, I still really like the truck, and I’ve already put in a good chunk of money modifying it to my desires, so it’s not like I want to completely bail out and get rid of the truck. Ideally, I just want to avoid a situation where I ding 60,001 miles, my powertrain warranty ends, and my transmission proceeds to immediately implode.