Which parts fail
Components named in complaints (automatic and manual transmissions, CVT, axles, driveshaft, 4WD/AWD).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2018 GMC Terrain owners, lightly cleaned up (personal details are redacted by NHTSA).
My husband and son were involved in an almost fatal accident on 07/08/23 in our 2018 Terrain. My husband described that the vehicle spontaneously veered to the right uncontrollably, he was unable to steer to correct the vehicle, unable to brake, they went airborne, hit several poles and a transformer, rolled and flipped several times. All the airbags deployed.After the accident, I found a recall notice from back in 2017, I believe, regarding the drive train. My husband was extricated from the vehicle. My son wasble to cut the seatbelt and crawl out the window. From what my husband explained (he was the driver), this sounds like what they experienced during the collision. I never received a recall letter from GM as this is something I would of taken care of and have got repaired. Please see the photos and the recall I found. …
The contact owns a 2018 GMC Terrain. The contact stated that while driving at various speeds, there was an abnormal grinding sound coming from the vehicle while transitioning to 4WD. The contact continued driving and the driving sound became more frequent while shifting into 4WD. Upon inspecting the vehicle, the contact discovered that the driveshaft had detached and was hanging down from the suspension. An independent mechanic was contacted, and the contact was informed about NHTSA Campaign Number: 17V516000 (Power Train); which the mechanic associated to the failure. The contact called two local dealers and was informed that the VIN was not included in the recall. The manufacturer was notified of the failure, and the contact was referred to the NHTSA Hotline to report the failure. The vehicle was not repaired. The failure mileage was approximately 160,000.
The contact owns a 2018 GMC Terrain. The contact stated that the transmission was shifting gear erratically. The contact stated that the doors were locking and unlocking independently, and the instrument cluster was blank. There was an abnormal beeping sound coming from the vehicle. Additionally, the contact stated that while at a traffic light, the Auto START/STOP feature delayed to respond. OnStar was alerted, but the contact declined to perform the service. The contact was in contact with the independent mechanic who sold the vehicle, but no assistance was provided. The local dealer was contacted. The vehicle was not diagnosed or repaired. The manufacturer was contacted, but no assistance was provided. The failure mileage was approximately 130,000. The VIN was not available.
The contact owns a 2018 GMC Terrain. While attempting to shift to reverse(R) out of a parking spot, the message "Transmission Unable to Shift" was displayed on the instrument panel, and the transmission was unable to shift into reverse(R). The contact called for tow truck assistance. The vehicle was unable to shift into neutral (N). The contact stated that prior to the transmission failure, the "Service Transmission Soon" message was displayed. The vehicle was towed to a local dealer to be diagnosed, and it was determined that the transmission had failed and needed to be replaced. The vehicle was not repaired. The manufacturer was not informed of the failure. The failure mileage was approximately 245,000.
The contact owns a 2018 GMC Terrain. The contact stated that while driving at an undisclosed speed, the unintendedly decelerated and failed to properly accelerate. The vehicle was taken to the local dealer, who diagnosed the vehicle with transmission failure. The contact was informed that the transmission needed to be replaced. The transmission was replaced with a used transmission, but the failure reoccurred. The vehicle was taken back to the local dealer who diagnosed and determined that the replacement transmission had failed and needed to be replaced. The vehicle was not yet repaired. The manufacturer was not notified of the failure. The failure mileage was 53,000. The VIN was not available.
The contact owns a 2018 GMC Terrain. The contact stated while driving at various speeds, the brakes became inoperable. While the vehicle was in park(P), the gear shifter inadvertently shifted into an unintended gear. The brake assist warning light was flashing. The vehicle was taken to the local dealer where it was diagnosed that the vacuum pump and brake booster needed to be replaced. The vehicle was repaired four times but the failure persisted. The manufacturer was contacted and informed the contact to take the vehicle to a local dealer if the failure recurred. There was no additional assistance provided. The approximate failure mileage was 131,000.
I bought this car used and had only had it about a month when I was driving to work and was in slow traffic on the freeway when my car slowed to a stop despite the fact that I had my foot on the gas pedal. It turns out it was a transmission failure. My safety and the safety of the drivers around me were put at risk because I was unable to move my car over to the shoulder and out of the lane of traffic. Traffic was slow but was still moving. My vehicle is available for inspection but I've already had it repaired so I no longer have the faulty transmission. The problem was confirmed by an independent service center where I had it repaired. The vehicle was inspected by the dealer and the independent service center. The dealer had it for 12 days but was unable to diagnose it so I took it to an independent service center. …
April 2025, Vacuum Pump went out meaning lost breaks going 60 miles per hour down the road after engine light came on. Left me and two children stranded 2 hours from home with no way to get back except a tow. Now September 2025 Cam Shafts are out as well as Vacuum Pump. Stranded boyfriend and I two hours away again. Now metal in oil and warranty is not willing to cover it due to the vacuum pump going out. Made a post on Facebook and got lots of feedback on how their newer terrains have done the same things. Work in insurance and have people car pertaining to their terrains wondering if we cover engine replacements. There is major issues with these vehicle. Mine only has 107,000 miles on it and I have 12,000 left to pay. The motor is shot and dealership wants to "flush" the metal out of the engine. …
Hello. As I come to a complete stop the car will go into auto-stop. After releasing the brake pedal the car will jerk forward . As I press the gas pedal the car Jerks and shakes . The rpm jumps way up and the mph say low.. there's been times I try to accelerate and the car with jerk and put itself into park.. in the middle of traffic.. heart pounding to say the lease. I also notice theres alot of black liquid dripping for the front right side under the front bumper. There were no problems with the car or lamp indicating there were before this. I went to where I brought the car and they told me my warranty expired and that I will need to pay $265 just to diagnose the issue. I didnt have that money. I do have a car code reader and I did my best to find a solution. Codes P0700, P171D, And P187D all appear on my device. I then looked up recalls and my VIN wasn't confirmed.. …
When driving the car at low speeds, or right after having been stopped for a few moments. Upon, acceleration, the car will sometimes go into a limp mode. On the DIC, will be displayed a warning about how the car will have the speed reduced after 175 miles and to check the emissions system. The speed has already been reduced at that point. Also displayed maybe a warning about how the power has been reduced. USUALLY, if I turn off the car and wait about a minute, I can restart the car and drive at a normal highway speed again. But not always. The warning on the DIC, will usually turn off if the car does return to normal speeds after about 5 - 10 miles. However, the check engine light may still stay on for several days. This problem can be a daily occurrence. I've had the car in the shop several times, and they have been unable to fix the problem. …
Related recalls
Power train › Automatic transmission
General Motors LLC (GM) is recalling certain 2018-2019 Chevrolet Cruze and Buick LaCrosse, 2018-2020 Chevrolet Equinox, Chevrolet Traverse and GMC Terrain, 2018 Chevrolet Malibu, 2019-2020 Buick Encore, Buick Enclave, Cadillac XT4, Chevrolet Blazer and GMC Acadia, and 2020 Cadillac XT6 vehicles.
Remedy: GM will notify owners, and dealers will inspect the start-stop transmission accumulator and replace it if any bolts are missing, free of charge. The recall began December 15, 2020.
Power train › Driveline › Driveshaft
General Motors LLC (GM) is recalling certain 2018 Chevrolet Equinox and GMC Terrain vehicles and 2017-2018 GMC Acadia vehicles. The right front intermediate driveshaft may fracture and separate while driving.
Remedy: GM will notify owners, and dealers will replace the right front intermediate drive shaft assembly, free of charge. The recall began August 25, 2017.
Transmission complaints in other Terrain years
Frequently asked questions
How common are transmission problems on the 2018 GMC Terrain?
NHTSA has 42 complaints about the transmission & drivetrain of the 2018 GMC Terrain, 19% of the model year's 225 complaints. The component named most often is clutch assembly (1 mentions).
Is there a recall for 2018 GMC Terrain transmission problems?
Yes — NHTSA recall 20V-668 (automatic transmission, Oct 29, 2020); NHTSA recall 17V-516 (driveshaft, Aug 22, 2017). Recall repairs are free at authorized dealers.
At what mileage do 2018 GMC Terrain transmission problems start?
Half of the complaints with a recorded mileage happened before about 10,000 miles, and 61% before 25,000 miles.
Is it dangerous?
Owners linked 2 crashes, 0 fires and 2 injuries to transmission & drivetrain problems on this model year. If you notice symptoms, have the car checked before driving further.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.