I have 1999 f250 diseal auto, when it shifts from 1st to 2nd and from 2nd to 3rd it shifts hard it more like someone pushes my track faward and i can hear bom underneat my seat, also no matter from which gear is shifting it always ****s after 2500rmps. But if i let go gas pedal before 2000rmp it will shift, Its like transmision is shifting late? Also truck dont have enoghf power till it reaches 50mph and also at 50mph transmison shifts nice in last gear you can vearlly feel it. Please some help...