I have a '93 f150 4x4 supercab with 104,000 miles on it. Bought the truck new in '93. Love it! I have changed the transmission fluid on the truck 2x. Once at 80,000 and once last week when this problem became apparent. It shifts hard into second gear, sometimes, seems to do it more often lately. Especially at low speeds. Also seems to jump a little at low RPM going up hills. Fluid has always looked good. Any Ideas short of an overhaul? Thanks.
The symptoms you describe do not sound like the manual lever position sensor to me. I've had the sensor fail a Mark VIII. It didn't do any of the symptoms you are describing. When this sensor goes bad you will get an error code. The jumping going up hills sounds like it could be the torque converter. As for the shifting hard I don't know.
As for as the shifting part goes I had tranny guy tell me he thought it was a solenoid acting up.Mines been doing that for about 65000 miles.But mine does it from second to third. I have learned to let up a little on the throttle before it shifts into second and it seems to do okay.If I don't it really hits hard.
Hope this helps.