bought a dodge ram w/ a 318 that needed a transmission. replaced with a smaller transmission out of a Durango w/a 318 engine. Drove it for a month w/ no problems. It suddenly quit working. Symptons: start engine, put it in drive, it shifts perfectly will move ab ougt 100 ft, starts slipping and will not pull anymore. Thought tranny was bad put in another transmission just like the one AI put in, drove it for 4=5 hours and its doing the same thing. You can kill enjoy and let it set a minute, restart engine...it will go 100 ft or so and stawrt slipping...and then won't go. Any one have any ideas?

 

Just throwing horseshoes now, but did you use the same torque converter with both swaps?

EDIT: After further thought, another horseshoe: a clogged or kinked tranny line could possibly manifest itself this way. When you let it sit, the fluid trickles through, and pools on the other side of the clog/kink, this could be why it will go 100ft or so without problem.

 

i had the transmission changed. how would the torque converter act it its the problem?

 

another thought is did you clean out the tranny lines and tranny cooler on the radiator or if it has an inline cooler before you put the new tranny in....a bad tranny usually means a bunch of clutch/metal/crap may have been flowing in the tranny fluid and got in those parts to...depending on the filter...just a thought im just guessing though

 

That's a biggie, right there. What almost always takes these things out is insufficient lube flow. Always flush coolers every time the lines are open, and always replace the anti-drainback check valve with a remote filter.

Used transmissions are always a bad idea in these trucks, as are used torque converters even if it's the one the factory installed.