The GMC Sierra pickup truck is one of GMC’s best-selling models in the United States, with a record 348,222 models sold in 2025. Despite its popularity, the GMC Sierra has become associated with ongoing transmission problems, with class action lawsuits alleging serious defects in the 8-speed and 10-speed transmissions.
Owners of 2021–2026 GMC Sierra trucks have reported the following transmission issues:
- Transmission shudder
- Vehicle vibration
- Harsh shifting
- Torque converter problems
- Transmission control valve issues
- Jerking when accelerating
- Harsh gear engagement
- Transmission failure
If your GMC Sierra has experienced ongoing transmission issues that affect its use, value or safety, and these issues have not been resolved by your local dealership within a reasonable number of repair attempts, your pickup truck may qualify as defective under California law.
However, California Lemon Law typically applies to newer vehicles that are still covered by the manufacturer’s original warranty. In most cases, this means 2021 or newer GMC Sierra trucks purchased or leased new (or as Certified Pre-Owned).
To illustrate how these issues present in real-world conditions, below is a sample of complaints submitted by GMC Sierra owners to the National Highway Traffic Safety Administration (NHTSA).
GMC Sierra Transmission Types (2021–2026)
Many newer GMC Sierra trucks are equipped with 10-speed automatic transmissions, which have been associated with issues such as harsh shifting, hesitation, shuddering, erratic gear changes, and occasional loss of power.
Some GMC Sierra models may still be equipped with earlier transmission designs, including 6-speed or 8-speed transmissions, depending on the engine and configuration.
Some 2021 GMC Sierras feature the now-phased out 6L80 transmission. Some GMC Sierra trucks may still be equipped with 8-speed transmissions such as the 8L90 transmissions, which have been linked to drivability concerns such as vibration, rough shifting, torque converter-related issues and the infamous Chevy Shake.
2021–2026 GMC Sierra Transmission Complaints
In their submitted complaints, GMC Sierra owners frequently report erratic shifting, shuddering, vibration, and loss of control, issues that dealerships often struggle to replicate during repair attempts.
2021 GMC Sierra
Transmission shifting is at times confused causing the vehicle to jump forward shifting to first gear. It pushes your vehicle 2-5 miles an hr faster when slowing down. The transmission also does the opposite when letting off the accelerator, shifting fast to a lower gear slowing the vehicle down quickly in a jerking motion at times. I have an 8 speed transmission. GMC dealer is replacing my torque converter, stating this may fix the issue, but it is a safety concern.
2021 GMC Sierra
Transmission shifts hard when shifting up and when downshifting. Vehicle jerks when going speeds less than 40 after coming off highway at highway speeds above 70.
2022 GMC Sierra
The transmission became inoperable and a message appeared on the display ‘Engine Power Is Reduced’ in area of the highway where the speed limit is 55 and then the transmission failed completely and left the engine revving at high rpm and not moving the vehicle forward and we rolled to the side of the road to a stop. This was a very dangerous situation as traffic was flying past us and had to move out of the way of our coasting vehicle. It was towed to a GMC dealership about 8 miles away as it is still under warranty. I’ve read many stories in GM forums about problems with this GM 10 speed transmission in this pickup truck. This needs to be looked into as a potential recall as this problem left us stranded on the side of the road as we had to wait for a ride because we had a dog with wife and I. Currently there is not a transmission recall listed for this vehicle. We were lucky to be in an area where we had cell phone service and relatively close to home, within 10 miles.
2023 GMC Sierra
The contact owns a 2023 GMC Sierra 1500. The contact stated while driving at an undisclosed speed, the vehicle started to shake abnormally with the check engine warning light illuminated. The contact stated that after arriving at a parking structure, the transmission warning light illuminated. The vehicle was towed to the local dealer where it was diagnosed with transmission failure. The vehicle was not repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 15,000.
The transmission made a loud noise, resulting in a sudden decrease in speed while driving in traffic. Felt similar to being rear ended in a collision. The lights came on in my dashboard including the check engine light. Tried driving the vehicle and it would shift erratically rendering it un-drivable. Had to be towed to my GMC dealership for service. The initial diagnosis is an issue with the "valve body.” A quick search on the internet presented several other users with this issue in this model truck with this transmission. The service department also seemed to be aware of the issue. If it is so widely known, why would there not be a recall placed on these vehicles? I'm glad I had already dropped my son off at school and that I was not on a Main Street where I could safely pull over and wait for the AAA driver.
Intermittent shudder at 25-55 mph under light throttle (rumble-strip feel); 5-6 dealer attempts failed due to non-duplication; GMC corporate refused escalation. Safety risk: Distracts from road, potential loss of control. TSB 22-NA-182 is a known issue and the dealer says they can’t repair it without duplication.
The vehicle has a vibration and stuttering feel during highway driving. Cruise between 70-75 has off and on again vibration is the seat, steering wheel, and center console. The issue feels more pronounced between 60-65 and exhibits more of a hum, much like a washing machine drum that is out of balance. I have had the truck at 2 different dealerships and they have insisted it was a whee balance issue. I have also had the truck balanced at Costco. None of these issues have been alleviated with wheel balance. The dealership, where the truck was purchased, refused to test the truck at highway speeds and would only drive it for a short period at speeds up to 55mph. I have also reached out to GMC customer service, and they simply regurgitated what the dealer indicated about balance and testing at 55 mph or less in town. There seems to be a number of TSBs out on this issue. Most related to torque converter issues, but none of the dealers have indicated that my truck is impacted by any of the current TSBs, even though it exhibits all the symptoms. Not sure of the safety replications, but I am disappointed in the fact that the truck has had this issue for around 1,000 miles, and it seems like the dealer service departments are just ignoring it and refusing to do a thorough evaluation of the issue unless a code triggers or until a major failure occurs.
Earlier GMC Sierra models (particularly mid-2010s trucks equipped with 8-speed transmissions) were widely reported to experience torque converter shudder, rough shifting, and transmission failure. While those issues are well-documented, older, high-mileage vehicles are generally less likely to qualify under California Lemon Law.
If your GMC Sierra has experienced similar issues, particularly in a 2021 or newer model that remains under warranty, you may have legal options.
Have A GMC Sierra Lemon? Here’s What To Do
If your GMC Sierra has ongoing transmission problems that have not been resolved despite multiple dealership visits, your vehicle may be a lemon. Vehicle owners in California may recover restitution under the California Lemon Law if their vehicles have warrantable problems that have not been repaired within a reasonable number of attempts.
Learn more about the Chevy Shake and other issues facing GMC vehicles or get a free consultation with our lemon law attorneys to better understand your California lemon law rights. If you would like more information, complete the form below to request a free consultation.
