i had my truck in to have my trans rebuilt. it worked great except intially with my camper behind it it overheated with OD off. finished the trip no problem. Truck then began overheating. after replacing water pump, radiator cap, ac condenser, ac compressor it stopped overheating. Then the trans started overheating. OD would kick off and trans temp light would come on. Torque converter was not locking up properly. after going through wiring and replacing ignition switch, trans worked fine, now engine is overheating again. WTF. Fan was not kicking on when it overheated. after i turned the truck on again no problem with overheating. i have a problem somewhere but short of replacing everything i am getting frustrated. the dealership was no help whatsoever. said my motor was bad when i took it in for trans overheating. motor runs great. HELP!!!

 

Sounds like your fan could not be turning on or you might have restricted airflow through your radiator. I beleive that their is also a check vavle that can stick in your trans cooler line. Have you checked/changed trans fluid? Was the old torque convertor reused or replaced? A slipping torque convertor builds a lot of heat.