2015 GMC Sierra 1500: harsh or hard shifting

Filed Mar 23, 2026 · Body, Suspension · WI

Truck started to make loud clunking noise when driving taken it to two shops and wrong parts were installed as stated below. Bought from a used car dealership and they sold it as is now with the wrong parts.

Filed Feb 18, 2026 · Transmission · WA

During day to day driving when the truck is accelerating from a stopped position there's a massive clunk or hard shift from either 1st to 2nd gear. have also heard similar complaints from other 2015 sierra 1500 owners saying the transmission is having a hard shift on acceleration from a stop. Have seen possible issues with the TCCM

Filed Oct 18, 2025 · Electrical, Transmission · MA

The temperature sensor in the transmission is faulty leading to hard/delayed shifting, shuttering, and vibration

Filed Oct 31, 2023 · Transmission · 100,000 miles · NM

The contact owns a 2015 GMC Sierra 1500. The contact stated that there was an abnormal clunking sound coming from the vehicle with the check engine warning light illuminated. The vehicle was taken to Quality Buick GMC, INC. (7901 Lomas Blvd NE, Albuquerque, NM 87110) and Pitre Buick GMC- (9737 Eagle Ranch Rd NW, Albuquerque, NM 87114) and the contact was informed that the failure was related to the transmission and the contact was provided an estimate for the repair. The manufacturer was not notified of the failure. The vehicle was not repaired. The failure mileage was approximately 100,000.

Filed May 9, 2023 · Transmission · MO

Vehicle has a history of hard shifting and jumping forward under certain conditions. In April 2019, while on the highway traveling about 65 mph, the vehicle slipped out of gear and do no longer be driven. No warnings were displayed prior to the incident. The dealer replaced the torque converter and repaired a broken transmission shaft under warranty. Hard shifting and jumping continued to occur, but the vehicle went without incident for another 4 years. Yesterday, 5/8/2023, the transmission went out again while driving around 35 mph. Vehicle is currently at dealer. My research has shown there is a class action lawsuit in 26 States for transmission issues for GMC vehicles between 2015-2019. the federal safety agency needs to take action and issue a recall. Losing a transmission while driving is dangerous.

Filed Apr 21, 2023 · Transmission · 30,000 miles · IL

The contact owns a 2015 GMC Sierra 1500. The contact stated that while shifting from drive (D) to park(P), the contact heard a loud clunking sound. Additionally, while driving and downshifting the contact heard the loud clunking sound. The contact also stated that while driving at an undisclosed speed, the transmission slipped while shifting from 1st to 2nd gear, and the vehicle failed to immediately accelerate. The contact stated that the failure occurred more during the winter months. The vehicle was taken to the local dealer who reprogrammed the TCM however, the failure persisted. The manufacturer was notified of the failure. The failure mileage was approximately 30,000.

Filed Jun 23, 2022 · Engine · CA

bad lifters causing hesitation and and hard shifting.

Filed Jun 20, 2022 · Transmission · NC

The 8-speed transmission in 2 and 3 gear exhibits a hard shift...no slippage. When slowing down to a stop you hear what sounds like two steel barbell weights slamming together. You feel like the transmission will break and leave you in the middle of an intersection. I have visited the dealer and they state this is normal. My vehicle only has 41000 miles on it. This has been an issue for me for the last 3 years.

Filed Nov 9, 2021 · Transmission · VA

I bought my 2015 gmc sierra 1500 certified and since then it has had vibrations when driving and hard shifts. The dealer has looked it over many times and said it's normal. Last month they said they sent gmc the readings and I haven't heard back. They have lied to me before about other vehicles and I'm tired of dealing with them not fixing it.

Filed Jun 17, 2020 · Transmission · 71,122 miles · IA

My 2015 gmc sierra has the 8 speed transmission which has been an issue since I have owned the vehicle. I bought the vehicle used in the fall of 2018 and the truck/tranny ran good for about 10 months. Then in late summer and early fall of 2019, the truck jerking hard shifts started to appear. In october of 2019 I brought my truck into my dealer to have them look at my tranny due to the really hard shifts from 1st to 2nd or 2nd to 3rd and vice versa 3rd to 2nd and 2nd to 1st. I had to pay a $80 diagnosis fee and they reprogrammed my tranny and the ecu to smooth out the shifts and not make the shifts so hard. In all the software reprogram did get rid of the hard shifts, but in return now my vehicle drove like it has a 6 speed transmission instead of an 8 speed. In june of 2020 I brought my truck back into my dealer to look at my tranny again! Now my tranny felt like it was always "hunting" for a different gear. When driving on the interstate at 75 MPH 1600 RPM, if there was a little bit of head wind or I started to drive up a hill, the tranny would downshift and RPM's jump up to 2200 RPM to make up for the difference in road grade, same as when driving in town up a hillat 35mph. A 8 speed transmission should not be doing that! At interstate speeds (75 MPH) my passenger side seat will sit there and just wiggle and shake back and forth. I have changed out ball joints and struts with brand new ones thinking that was the problem and the seat still wiggles back and forth. When driving my vehicle it feels like I am driving with a 6 speed transmission than an 8 speed. I have read that this seems to be a common problem in these model year gm vehicles and I feel gm needs to finally address this issue once and for all and keep their gm customers satisfied. I didn't plan on buying a 3 year old used vehicle for it to have the issues it has had since I have owned it.

Filed Jun 30, 2019 · Transmission · 18,000 miles · VT

When putting the truck into gear with the foot firmly on the brakes the truck will slam into gear causing the truck to jump forwards or backwards.

Filed Feb 21, 2017 · Transmission · 15,000 miles · OH

Significant clunking in rear end indicative of improper alignment or lash is rear differential. Excessive vibration at speeds over 65 MPH when the driveline is under load. Vehicle has been to the gmc dealership where it was purchased three times with no resolution to date. Current mileage is 18,000.