tranny neutrals out in od when cold outside
 

ok so had problems with tranny neutraling out in overdrive only when cold weather. eventually it would only go down the road in 2nd (auto tranny) still cold outside. no chance for weather warm up. so anyway pulled tranny had a total rebuild, very respectable rebuild. tried to go down the road again, still cold outside, and did the same thing. so I contacted rebuilder and he said let it run for a while and then drive it hot. so I let it run for about an hour and truck did excellent! ok so then I drove it to work and after work got in the damn thing and went down the road again and it did it again! any thoughts?

I would say you need to do a couple of more transmission fluid changes w/filter. Sounds like the valve body is sticking and needs a good flush.
Drain the fluid while tranni is at opporating temperature (Drain it Hot)

tranny completely rebuilt

tranny is completely rebuilt

please help im stupid!
 

any other suggestions?

Something's wrong with the trans - take it back. Check for DTCs stored in the trans control module. Maybe it's just a bad solenoid.

what is DTC's

My tranny (not rebuilt) did that once.....I put some Lucas tranny fix in it, has never done it again....knock wood

DTC stands for Diagnostic Trouble Code. So basically see if there's any codes in the computer for any solenoid problems or if there is any transmission slippage codes.