2023 GMC Sierra 1500: harsh or hard shifting

Filed Sep 9, 2026 · Engine · 12,998 miles · TX

The contact owns a 2023 GMC Sierra 1500. The contact stated that while driving 65 MPH, the engine made a clunking, knocking, and tapping sound. The engine was driving on seven of the eight cylinders. The contact slowed down and pulled over. The engine warning light was illuminated. The vehicle was taken to the local dealer and was diagnosed with a detached valve. The vehicle was repaired under an extended warranty. The dealer informed the contact that the failure might recur. The failure mileage was approximately 12,998.

Filed Aug 28, 2026 · Engine, Transmission · SC

Truck went into limo mode while driving and required valve in transmission to be replaced. Went from driving normal speed to only being able to go about 15 miles and hour. Was repaired got the truck back and the next day was on the interstate in the fast lane and the truck again had speed issue reduced speed and had to coast off interstate. This time entire valve body had to be replaced. Have gotten truck back and still have hard shifting in the transmission at times. Engine was checked for recall and now I have to pay a much higher oil change price due to a GM issue. This was not a known cost when purchasing this truck.

Filed Mar 17, 2026 · Driver assistance, Engine · MA

My 2023 GMC Sierra has 60,571 miles for a while now while driving the transmission slips and slams into gears. Recently driving with my kids in the car on highway going 70mph the back brakes locked up multiple times, so scary and dangerous while driving. I now currently have a code P-0747 in the system.

Filed Feb 2, 2026 · Acceleration, Engine · 8,496 miles · LA

The contact owns a 2023 GMC Sierra 1500. The contact stated that while driving at an undisclosed speed, the vehicle shuddered while in first gear. The contact stated that the transmission sounded strained and shifted rough before slamming into gear. The vehicle was taken to the dealer; however, no cause for the failure was found. The dealer diagnosed the vehicle and determined that the vehicle was oversteering while turning to the right. The dealer replaced the valve and torque converter. On another occasion, while driving at an undisclosed speed, the vehicle accelerated independently. Most recently, a burned transmission fluid odor was coming from the front of the vehicle and entered the cabin through the A/C vents. There oil stains found on the ground on several occasions. The vehicle was taken back to the dealer and the valve body was replaced, the fluid levels were checked, and the transmission filter was replaced; however, the failure persisted. The contact called the dealer, and the dealer towed the vehicle. The dealer determined that the oil cap was loose. The vehicle remained at the dealer unrepaired. The manufacturer was made aware of the failure, and a case was opened. The failure mileage was 8,496.

Filed Apr 4, 2025 · Transmission · CO

The system that is not working properly is the transmission. It is available for inspection upon request. The safety of the vehicle, and myself, was put at risk because the transmission (once warmed up / at least 30-60 minutes of driving takes place) downshifts hard, making a clunking noise, and has at worst given the vehicle a rough nudge/jolt forward upon downshifting particularly from 2nd to 1st gear (it is a 10 speed transmission). This issue, when it occurs, will require me (the driver) to apply extra force to the brake pedal due to the rough downshift / jolt upon shift. The issue is exacerbated when quickly stopping the vehicle causing the transmission to downshift more rapidly. The vehicle's transmission flaws, of which this happens to be one of them, were being looked into at a certified repair facility (dealership). After the vehicle was in their possession 3 days, they informed me that they could not replicated or reproduce the issue. I informed and reminded the following: (1) the vehicle has to be warm and operated for I would state at least 30-60 minutes of driving before the issue arises (2) I have recorded videos of the problematic sounds of the transmission. (3) I am willing to go for a test drive to try to replicate the issue with dealership staff, but the issue is infrequent and the vehicle must be warmed-up and/or driven more than the typical "test drive" for the issue to be observed. The vehicle component has been inspected by a certified repair facility (dealership), but not directly by a manufacturer's direct representative, police, insurance representatives, or others. The transmission is also problematic in another way (rattling at low rpm's during upshift), but pertaining to safety the downshift is most concerning as described above. There were/are no warning lamps or messages. The symptoms of the problem pertaining to the transmission began occurring around 11,800-12,000 miles in my estimation.

Filed Mar 27, 2025 · Transmission, Wheels · ID

I was driving at approximately 25-30 MPH, accelerating from a stop light and I felt a clunk, heard a grinding noise and my back wheels locked up. It was snowy/icy conditions so the back end of my pick-up slid out to the right a little bit before the wheels unlocked and I was able to regain control. I could have slid off the road or into another vehicle had the wheels remained locked. The computer system then alerted me to a transmission issue and to reduce speed immediately and call for service. The pickup was then unable to shift out of 1st gear. The vehicle has been towed to a dealer and I have been informed the valve body in the transmission has to be replaced which is 8-12 weeks backorder.

Filed Feb 23, 2025 · Transmission · AZ

Valve Body. While driving the vehicle, hard shifts occurred; the vehicle check engine light came on and stayed on while the vehicle went into limp mode. I was able to link to the GMC dealer. The dealer was not and would not inspect the vehicle at that time. I was told I needed to leave or return in two for inspection. The left vehicle was inspected the next day and determined as a value body. The GMC dealer found the part in another state and has the part shipped. I installed the part, had the GMC dealer search it, and performed a recall update.

Filed Sep 9, 2023 · Suspension · NY

There is a clunking and popping noise on the rear suspension or spring leaf when going between 5-20 mph, there is no active recalls for this but there is a lot of people complaining about this problem and the dealer does not wants to take responsibility for this issue need help. They are forums online all over the country complaining about this issue.