Transmission shudders, slips or shifts hard

What got replaced

Owners who name the part that was replaced mention the torque converter (8 reports) and the transmission (3 reports).

Recalls and investigations

No recall on the transmission and drivetrain covers the 2018 model year as of Sep 9, 2026.

What owners paid

5 of the 67 reports quote a price. Each dot is one quote. The middle half runs $618 to $6,000.

When it happens

The middle half of failures fell between 10,000 and 50,000 miles, from the 42 reports that gave a mileage.

What owners wrote

“I'm experiencing constant transmission shuddering at constant speed between 25 and 40 mph. This is a know issue, General Motors known issue, with the 8 speed transmission installed in this vehicle. TSB 18-NA-355 was issued in August of 2019 for this issue, but general motors refuses to recall all affected vehicles. Something needs to be done about this!”

Filed Jul 5, 2025

“Vehicle jumps when shifting gears. When coming to a stop it jumps Forward. Hard shifting.”

Filed Feb 5, 2025

“Engine AFM has failed. No engine light was present at the time. A loud ticking noise was noted from the engine bay. Was taken to get diagnosed, and the AFM was replaced. The problem was then resolved. Transmission has been jerking and hard shifting through the period of owning the vehicle. No diagnosis has been made”

Filed Oct 2, 2024

“2018 gmc Seirra 1500 8 speed transmission. Making unsafe conditions while driving transmission tends to make hard shifts, jerks, hesitation when moved into gear, gets worse when stopping momentarily at stop lights and then trying to accelerate vehicle will not move. Makes hard shift and jerks then will accelerate in an unsafe manner.”

Filed May 6, 2024

Other problems on this car

• Brakes grind, pulse or wear early 44 reports