I've got one hell of a problem

[Mahlon Osterhout]

I was out running the truck today and I lost my gears... I was going up a small incline today on my trail and all of a sudden my rpms shoot up and i come to a stop and drift backwards. I put it in park and try popping it down into drive again and nothing. I try reverse drive low 1 and low 2, nothing. Like anybody that owns and oldie I shut the truck off and let it have it's fit, while I think for a sec. I start it back up and gently drop it into drive and I didn't have any problems until about 3 or 4 miles of screwing around went by, and the same thing happened again, and I remedied it each time by shutting the truck off and starting it up again.

Then the time between restarting and losing gears got smaller and smaller... My dad had to pull me home with his truck and it's sitting down back.

I couldn't have lost a flawless tranny for no reason. The only thing I can think is that it was about 8 degrees out at the time. My dad told me that his 65 dodge acted like this, it would act fine when it was warm out but lose gears in freezing weather.

It's a Turbo 350 Tranny

Any and all help is appreciated.

EDIT: I should add that I checked all my fluids a few days ago, they're full and clean. No issues there.