1995 E-150 V6 shifting problems, high shifting?

my 1995 E-150 V6 shifts perfect except after it is really warmed up, and usually does it on a hot day(somedays it won't do it at all) mainly if i get off the highway from over 65, starting back out from a stop it doesn't seem to want to go into 2nd or 3rd easily or shifts at high rpm or when i let off the gas it will shift, when i manually shift it it works fine, could it be shift solenoids? or is there a manual shift lever or sensor or maybe the linkage? any help would be greatly appriciated, I can do simpler work like that myself just would like to diagnose the problem or start out with the cheaper possible fixes first, also how hard is it to buy the tranny rebuild kit and a manual and just do the work myself, thanks, Will

Actuallly the shift modulaltor is probably bad. It is a diaprhagm on the right hand side of the granny as you are looking towards the front of the engine. Has it been using a lot of tranny fluid lately? The shift modulator diaphragm could be bad causing tranny fluid to be suicked into the engine. Check the vacuum hose to the modulator first. If it checks out the modulator is probably bad.

I had the same symptoms, and around Xmas last year I took it to the shop and got the dreaded "tranny needs overhaul". So I made the $ 2,000 Xmas present to the shop owner.

Sometime after the re-build, the symptoms returned. This time, I actually ran the diagnostic test myself, and it pointed me out to the Vehicle Speed Sensor (mounted on the differential). Changed for Sensor ($ 22). Did not need fix things, ran the diagnostic test again, same code again. Went and checked the wires and found a crushed wire. Fixed the wire, end of the problem.

You should run diagnostics first and see what you will get.