When I'm driving down the road on a slight uphill going anywhere from 30-55ish following someone, and i push the gas down slightly, the transmission seems to downshift out of OD for a quick second and then shift back into OD, the RPMs return to where they were before I touch the throttle, does anyone else's truck do this? '97 4.6 4R70W 4x4 3.55 My transmission fluid and filter is about 5k miles old.