I am once again having transmission problems:baby: The truck will shift find through all the gears when I am driving around town. Once I am at WOT the truck will not shift from 2 to 3, 3 to 4, and 4 to 5. Once I lift off the throttle, and get back into then it will shift into the next gear. There are no DTCs, and the fluid is full. Is it the clutches slipping?