A transmission flush, for those who aren’t mechanically inclined, is a process that replaces old, dirty transmission fluid with fresh fluid. Depending on the shop (and the technician), a visual inspection will be performed to look for leaks or potential problems. The filter is typically replaced, too.

It’s an important part of maintaining the vehicle. Keeping all fluids fresh is critical to keeping a vehicle healthy and improving longevity. This is exactly what Joel Coeler, was thinking when he took his 2021 Chevy Silverado to a dealership to maintain his truck.

Coeler paid the shop to rotate and balance the tires and perform a transmission flush. A visit that cost him $400. But, like all good truck owners, it was worth the cost. However, his feelings changed as soon as he drove away.

“Got transmission ‘flush’ done at the dealership because I thought that was best to do at this mileage, along with tires. Honestly, it had kind of a slight clunk before but nothing out of the ordinary,” Coeler wrote on the 2019-2025 Chevy Silverado & GMC Sierra Owners Facebook group.

“But now it’s like missing shifts between first and second when accelerating, especially in turns—like pulling away from a stop. I am upset because I spent $400 for it to be worse than before.”

He wasn’t the only Chevy owner with similar issues

Another owner, Will Crosby, noted that his 2019 Chevy Silverado had almost the same thing to happen. The solution to his problem was expensive, though.

“My 2019 8-speed had similar issues at 50k miles and ended up needing a new transmission. The transmission fluid was replaced at 22k when they did a torque converter,” wrote Crosby.

“Mine started acting up when it was cold, then it got better, but it continued. After four days, I had it looked at.”

Crosby, Coeler, and a few other owners noted their transmissions were acting funny as the ambient temperatures began to drop. Others suggested checking the fluid level while warm, as that’s a more accurate way to check the level and quality.

Thankfully, Chevy is aware of the transmission issues and issues a technical service bulletin on that model year. If your truck is exhibiting the same issue, it may be worth taking it to a dealership to ask about it.