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Transmission and drivetrainPart report

2026 GMC Terrain Transmission and drivetrain Problems

Complaints
5about this part
Share
15%of 33 total for the year
Median mileage
3,250miles
Trend
Too newThis model year is less than 4 years old, so a trend is not meaningful yet.

NHTSA recorded 5 complaints about the transmission and drivetrain of the 2026 GMC Terrain, 15% of the 33 complaints for this model year. Where a mileage was given, the median is 3,250 miles.

Fewer than 15 complaints name this part, so treat the figures as a rough indication only.

Example complaints

Selected from NHTSA records; personal details are removed. They are consumer reports, not findings.

“The contact owns a 2026 GMC Terrain. The contact stated that while attempting to depress the accelerator pedal after coming from a complete stop, the vehicle started wobbling. A dealer was contacted. The vehicle was taken to the dealer to be diagnosed; however, the diagnostic result was unknown. The vehicle was not repaired. The contact associated the failure with Technical Service Bulletin: PIT6466 (Shimmy, Shake or Wobble When Leaving a Stop); however, the VIN was not included in the bulletin. …”

NHTSA complaint #11734525, filed 2026-04, 5,200 miles

“This vehicle was bought new and is a NEW 2026 GMC TERRAIN DENALI with less than 5,000 miles at this time. It is a continuous event and not a specific failure date, but began soon after purchasing. The specific parts are UNKNOWN. It could be tires, wheels, steering parts (CV JOINTS, CONTROL ARMS ETC) or possibly transmission. I took it initially to the purchasing dealership and they took it for a ride and just dismissed the problem without investigating. …”

NHTSA complaint #11748269, filed 2026-07

“The car has always had an issue where it would just get stuck in a low gear and RPMs would go high. Does this every single day. But recently it also started acting like it was put into neutral for a few seconds and then back into drive.”

NHTSA complaint #11737215, filed 2026-05

“Avis Rental. Vehicle simply shut down while driving and would not re-start. Vehicle could NOT be put into neutral to move from roadway. Emergency services vehicles had to remain on site awaiting tow vehicle. Very dangerous situation.”

NHTSA complaint #11763641, filed 2026-09

“The contact owns a 2026 GMC Terrain. While driving at 28 MPH, the RPM became elevated to over 3,000 RPM. There was no warning light illuminated. The contact immediately pulled over and then resumed normal operation after the failure. The vehicle was taken to the dealer to be diagnosed; however, no cause for the failure was found. The contact was advised to bring the vehicle back to the dealer if the failure reoccurred. Approximately one week after the initial failure, while driving approximately 30 MPH, the transmission unexpectedly downshifted to L2. There was no warning light illuminated. …”

NHTSA complaint #11714905, filed 2026-02, 1,300 miles

Transmission and drivetrain: other model years

YearComplaintsShare of year
2026515%
2025431%
20242343%
2023820%
2022813%
2021822%
20202814%
20195328%
20184219%
20172418%
2016117%
2015217%
20143311%
20134412%
20123710%
20117620%
20105118%

Other parts of the 2026 GMC Terrain

Other or unknown
9 complaints
Forward collision avoidance
6 complaints
Electrical system
5 complaints
Suspension
5 complaints
Brakes
4 complaints
Wheels
4 complaints
Steering
3 complaints
Lane departure
2 complaints
Body and structure
2 complaints
Back-over prevention (rear camera)
1 complaints
Engine
1 complaints
Latches, locks and linkages
1 complaints

← All problems reported for the 2026 GMC Terrain

About this data. Data from NHTSA (ODI) complaints, recalls, TSBs and investigations, updated Oct 30, 2026. Complaints are unverified consumer reports and may be duplicated or inaccurate.

To check a specific vehicle for open recalls, use its VIN at nhtsa.gov/recalls. Methodology