s10 tranny trouble

I bought a 96 s10 with a 4 speed overdrive tranny behind a 4.3 with 107000 miles. Today I left my last job and 1/4 mile later with a cold engine the tranny started revving up like it was in neutral. I pulled over and went through the gears and it sometimes helped but normally it acted like it was in neutral or slipping. I checked the fluid and it is full and although dirty it is not burnt. I pulled over on side of road again and this time shut off engine and restarted and this time I got gears. i managed to drive 50 miles to dealership all the while it hunted from od to 3rd on steady gas on level road. i picked up a neutral safety switch at dealer remembering that there was alot of problems with them. I replaced when i got home and thought it fixed problem. But 5 blocks later on a test drive I lost "pull" sitting at road construction and barely made it home. I had no reverse or forward gears. occasionally pulling over and running through gears or killing engine and restarting got me something so i could get going. This is a very bizarre problem cause it doesn't seem consistent. Sometimes it works other times it doesn't. I have read many troubles about shift solenoids under pan. If I lost 1st and 4th due to a solenoid would that keep me from taking off from a dead stop or would it default to 2nd to get me going? I can't tell if I lost all gears or not EXCEPT I do know when it has acted up reverse has also been dead. Can someone help please? I just paid 3300 cash for this a week ago from a car lot and Now I am feeling the noose. i am suspecting head gaskets leaking too so I am not too thrilled. In addition to a new blower motor, battery, and rusted leaky fuel lines, all replaced this week, this is getting to be too much.

It also seems to not make a difference whether I try low 1 or low 2 as well as d and od. And when it starts working again reverse is back. I still think this is electrical just doesn't fit other peoples issues. Weird.

I bought a 96 s10 with a 4 speed overdrive tranny behind a 4.3 with 107000 miles. Today I left my last job and 1/4 mile later with a cold engine the tranny started revving up like it was in neutral. I pulled over and went through the gears and it sometimes helped but normally it acted like it was in neutral or slipping. I checked the fluid and it is full and although dirty it is not burnt. I pulled over on side of road again and this time shut off engine and restarted and this time I got gears. i managed to drive 50 miles to dealership all the while it hunted from od to 3rd on steady gas on level road. i picked up a neutral safety switch at dealer remembering that there was alot of problems with them. I replaced when i got home and thought it fixed problem. But 5 blocks later on a test drive I lost "pull" sitting at road construction and barely made it home. I had no reverse or forward gears. occasionally pulling over and running through gears or killing engine and restarting got me something so i could get going. This is a very bizarre problem cause it doesn't seem consistent. Sometimes it works other times it doesn't. I have read many troubles about shift solenoids under pan. If I lost 1st and 4th due to a solenoid would that keep me from taking off from a dead stop or would it default to 2nd to get me going? I can't tell if I lost all gears or not EXCEPT I do know when it has acted up reverse has also been dead. Can someone help please? I just paid 3300 cash for this a week ago from a car lot and Now I am feeling the noose. i am suspecting head gaskets leaking too so I am not too thrilled. In addition to a new blower motor, battery, and rusted leaky fuel lines, all replaced this week, this is getting to be too much.

Reverse is not electrical.
No reverse is internal or filter problems.

Pull pan and check filter and pickup and shift linkage.
May have wrong filter in it.

Any transmission codes?