Hey guys and gals, first off let me say that my mechanical aptitude is somewhat limited in the sense of anything other then swapping out parts. I own a great little 1982 Dodge Ram truck up here in Alaska, and it was running fine up till last year or so, when it would intermittently run out of transmission fluid, and require me to top it off. The symptoms were pretty cut and dry, once the transmission fluid levels would drop the truck would get 'stuck' in the low gear and not be able to shift up or down, obviously. Now here's the confusing part I need someone to help me with. The vehicle has not at any point actually LEAKED tranny fluid anywhere as far as I can tell. I'd put cardboard under it, towels, blankets and let it run for hours on end, and never once did I ever actually find a transmission leak anywhere, but the fluid is seemingly disappearing over the course of a day of driving or just idling for hours in place....I'm stumped, anyone have an idea of where I should start looking for the problem??

 

Welcome to DF
Check the yoke going into the output shaft of the transmission. There was a problem with the soft plug on the yoke. It would have a pin hole in the plug and leak, in most cases when the noise of the truck would be facing up hill.