I bought a new 2024 Sierra in May 2024. 5.3L 10 speed transmission. Last Friday, no reverse and wouldn’t go above 2nd gear. Towed to dealership. Was told it needed a new valve body. The service advisor said she ordered a new VB and a new transmission. Which ever one comes in first, she will have installed. Sad—- the truck only has 9000 miles. Driving a loaner Malibu. Life long GM buyer, but rethinking that now.