99 dodge ram 1500
Ok so i have a 99 dodge ram 1500 5.9L 4x4. when i drive it, it wont shift im thinking into 3rd or 4th. Also when i reaches 40 mph it wont go any faster, and when you give it more gas to down shiftg and maybe pick up, it will just get stuck inbetween 35 and 40 and not pick up or go any faster. i did a tune up on the tranny but no luck. does anyone know what this means? Thanks