General Motors filed paperwork with the National Highway Traffic Safety Administration to launch an investigation into reported problems with the eight-speed dual-clutch transmission found in the C8 Corvette Stingray.
Some C8 Corvette Stingray owners have experienced gasket failures with their vehicle’s Tremec TR-9080 transmission, resulting in leaks, while others have observed error messages telling them to put the vehicle in park and take it in for servicing. Paperwork filed previously with the NHTSA indicates some problems could be traced back to “debris on the park position sensor magnet causing an incorrect position reading to the (transmission control module).”
After widespread complaints to GM and online, the automaker decided to launch an official investigation into the matter to see what’s really going on. The automaker sent out a letter to dealerships requesting technicians remove the transmission fluid filter when a 2020 or 2021 model-year Corvette comes in for its first scheduled maintenance at 7,500 miles. Technicians are instructed to carefully remove the filter, place it into a plastic bag without letting the fluid drain out of it and mark it with the associated vehicle’s mileage and VIN. The filters will then be returned to the warranty parts center and later inspected by GM engineers.
A poster on Corvetteforum.com previously shared communication from GM that indicated the transmission pan and gasket had been redesigned at some point during the 2021 model year. The older pan design, according to the poster, was made of steel and was connected via two studs and 13 bolts, whereas the new pan is cast aluminum and features 17 bolts. The new pan also does away with two reinforcement plates used in the original design and has a new machined groove at its leading edge to help properly seat the gasket.
GM Authority will provide an update on the C8 Corvette transmission investigation once more info becomes available. As we exclusively reported earlier this month, production of the Corvette’s eight-speed transmission will begin at GM’s St. Catharines plant in Ontario in the second quarter of 2022.