98 1 ton with 24V, AT, and 161k miles. I have pulled it 3 times at truck pulls (With lever in 2nd gear). Do not know the major history of the truck (bought it with 151k). It doesnt have a 5th wheel. I occassionally pull a car/car trailer with it. Never broke anything yet. Lately when driving in city limits 20-35 mph, occassionally you can feel it jump out of 2nd gear (Rpms go up), then pick it back up. It has no trouble shifting at all from stop and goes through all the gears good. It seems that when I stay at this speed constantly when second gear is being used is only when it does it. Does this mean that the 2nd gear is wearing out or just needs adjusted, or speed sensor? Thanks for the help.

 

First you should do a tranny service.. Drop pan, replace filter, inspect. How much crap is on the magnet. Adjust bands. If the threads on KD (2nd gear) do not protude beyond jamb nut, the band is WORN OUT.. I suspect the band is out of adjustment causing problem. The second (remote) potential is governor pressure solenoid. If it sticks it can cause erratic shifting.