Hello Guys and Gals ,, I have a 2001 dodge 3x4 2500 Diesel 2500 with Ram air and 4 inch exhaust.
I had trans rebuilt before going on a trip pulling a 13,000 5th wheel camper... Made it to Ark , and part way home and clutches were SMOKED ..... Had it rebuilt There and came back to chicago... when I got here new trans Clutches were smoked . ????? I have no Idea if any other work was done on my 5.9 24 valve

 

Sounds like there is not enough line pressure to keep the clutches applied properly.
The other possibility is that the rebuilder did not check the clearances properly and you dragged the clutches when they weren't applied.

But since it was "fixed" twice... get a manometer and check the line pressure according to the factory service manual. Do this while driving, maybe you have a drop when going into a certain gear, this can help you find the leak path.

 

^^exactly^^
Another factor of low line pressure is low RPM. Do not load your drive line at any engine rpm less than 1500. 1700 is safer. This is the usual cause of our stock tranny failure. Mine was not abused before I bought it, it had no issues. Took one trip to Mexico with Lance camper, still no problems. Bought a bigger boat and decided that max load requires a better transmission. I use this truck mainly for long vacation trips and it has been flawless for 16 years with the ATS transmission.