2018 GMC Canyon transmission problems

Filed Jul 30, 2026 · Steering, Transmission · CA

On many occasions, over several years of ownership, ''NEW in 2018, the trans has had violent shift Problems. I could only find 1, ONE instance where a person was "injured'' by ANY of the GM 8L transmissions. My neck is hurting Now. I'm compelled to do this for Others who been Scammed by GM as they still sell a 8 speed rewrapped. I can't believe this has been protected against being called a SAFETY ISSUE By any Gov. agency. I got my truck in Retirement and Know I can't and won't Tow a Trailer or Boat Like I planned to. If I cause a wreck, Knowing the Defect, I will be held Responsible, Not GM LLC. It just did something new on 7/23/26. it stuck I a mid range gear and wouldn't shift, I Bumped it into Neutral to slow down and Recover proper control. I've said enough, be safe if you Have an 8 Speed from GM, or a 10 speed too.Read UP.

Filed Feb 21, 2026 · Transmission · GA

This is a known problem with GMC and Chevy trucks, known as the Rumble. At approximately 45mph and up, the truck feels like it’s going over rumble strip and the back end is slipping. This causes the steering wheel and truck to shake. It could result in the loss of control if it gets too bad. I took it in for diagnostic testing, which confirmed that it was the transmission. They recommended a triple flush and replacement of the transmission fluid, as well as a computer upgrade. I had them complete the recommended service. As of right now it seems to have helped. But if it returns the next steps is to replace the torque converter. There were no warning lights, nor messages indicating an issue.

Filed Feb 2, 2026 · Transmission · 40,000 miles · CO

The contact owns a 2018 GMC Canyon. The contact stated that while driving in the snow, the 4WD function became inoperable, and the vehicle lost traction and started skidding. The "Service 4WD" message was displayed. The vehicle was taken to a dealer where it was determined that a chip inside of the casing of the 4WD feature was inoperable. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was approximately 40,000.

Filed Nov 12, 2025 · Transmission · 34,929 miles · NH

The contact owns a 2018 GMC Canyon. The contact stated that while driving at an undisclosed speed, there was an abnormal knocking sound coming from the engine compartment. No warning lights were illuminated. The vehicle was taken to the dealer, who diagnosed a failure with the transmission. The contact was informed that the transmission needed to be replaced. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was 34,929.

Filed Jan 20, 2025 · Transmission · TX

The transmission is sluggish and jerky resulting in unpredictable and inconsistent speed control. The vehicle is available for inspection, if requested. The inconsistent speed control is a potential hazard during acceleration and deceleration. The issue is known to the manufacturer. No warning lamps or messages have been observed. The symptoms began to appear soon after the vehicle was purchased on 12/28/2024.

Filed Jun 6, 2024 · Body, Fuel system · NV

Major potential for deadly fire or explosion. Fuel tank strapped failed after forward strap bolt fell out of threaded cross member where fastened in frame. The failure led to the fuel tank hanging inches off the ground on the freeway stressing fuel pump lines to forward upper tank. Metal grinding noises heard to prompt roadside inspection confirming hanging, unsecured tank full of 26gal of diesel. The tank wedged the fuel tank strap between plastic tank and drive shaft (propeller shaft) with heat and potentially spark as the the metal strap ground into the drive shaft marring and striating the durable metal. Heat and plastic melts, heat and spark with diesel combusts..in addition to risking of dragging tank at highway speed rupturing tank. Upon service at the dealer, mechanic observed the rear bolt to fuel strap was also loose and needed to be secured. GMC Protection Plan denied compensation for coverage as they do not cover "bolts, fuel straps, or manufacturer defects" under advertised "Bumper to Bumper" GMC Protection Plan marketed by GMC dealerships as protection for all non-wearable parts. No warning indicators appeared. My dog was in the truck bed in a camper shell directly above the potentially massive fire or explosion, this could have been catastrophic if it had been ignored. Additionally I was in northern California and southern Oregon when issue presented- potentially causing a major forest fire incident. While my outcome was fortunate in terms of safety, this could claim lives and even massive incidental loss of property. Vehicle has been inspected by local dealer and GM notified, hoping to receive coverage for damaged parts. Interestingly, there was previously a GM recall involving forward fuel strap dislodging and wearing into drive shaft on previous years of GM vehicles. No notable corrosion observed, bolts in question are high on frame secured to protected cross members, occurred at approximately 75K miles. I have photos on another device, if needed.

Filed Mar 10, 2024 · Transmission · ID · crash

Vehicle switched out of four wheel drive while travelling up hill in snow. Resulted in a loss of traction and sliding downhill until it collided with a tree, resulting in$9,000 worth of damage. I have heard of the AWD/4WD actuator failing in other GMC trucks. The vehicle is currently in for repairs.

Filed Jan 6, 2024 · Transmission · VA

Transmission developed shutter/shimmy when shifting gears especially at lower speeds. Took truck to dealer and they diagnosed that the torque converter had failed. There are numerous reports and complaints online regarding this issue with GMC Canyons.

Filed Jun 17, 2023 · Brakes, Steering · CA

Transmission shifting really hard, has problem shifting from low gear shaking when brakes are applied makes loud noises when you go reverse to park and park to any gear Driving home lost power Steering and had to pull of freeway This truck has already been in the dealer for 7 other warranty issues This will be the 4th issue with the transmission!!!! It has already been fixed once before on the transmission now again 2 Top Ends already now more transmission issues again We have been waiting for a new transmission for my 2018 sierra for over 3 months I have lost Complete faith that GMC really cares about the safety of people I have 2 LEMONS in my driveway just sitting The contact stated GM has not resolved the issue and there are no brakes which is a huge safety issue.

Filed Jun 8, 2023 · Acceleration, Engine · NM

“Engine power reduced” service message “Stabilitrack” service message “4x4” service message Vehicle is available for inspection Vehicle jerks and loses power while driving at highway speeds causing 18-wheelers and other drivers to swerve around me, vehicle accelerates very slowly while in city traffic. Intersections and traffic lights are difficult to navigate due to reduced engine power endangering myself and family, also other drivers. Vehicle erases all stored messages after a certain period of non-use. Dealer service center hasn’t reproduced symptoms. Service center technicians say nothing is wrong and releases the vehicle back to me. I have invoices of the vehicle taken in 3 times. Vehicle is currently in the service center as of 10 June 2023, for the same problems indicated above. Problem is unpredictable and occurs at random. Vehicle hasn’t been inspected by manufacturer, police or insurance representatives. Warning lamps, messages and symptoms started prior to September 23, 2022 can’t remember actual date. I have the first invoice vehicle was taken in to be serviced.