Help 03 ram transmission

[Eddyj]

I recently bought an 03 ram 3500 quad can drw. I have 3 others same year. They are work trucks. This one had some issues but it was cheap and like I said I'm familiar with that year. I have all my dodge transmissions rebuilt by Aamco in rolla mo. The manager of shop is a straight forward guy who has a general knowledge of transmissions and diesel pickups, and gives me a 3 year nation wide warranty.
On to the problem I believe the 03 have a re47 but when he rebuilds them be uses 48 parts. I just had a complete rebuild with billet TC. When I picked it up it drives fine. Same as when I test drove it. But hook up a trailer in it goes to ****. I pull at 55-60 with overdrive off. This truck when trans warms up (45 miles into trip, only when loaded) the "halo" disappears around the D and "overdrive off" light goes off. To me it feels like TC unlocks and it will cycle regular to ( what I would call this limp mode). No codes popped up.
Now another Aamco can't get it to do it. Because they won't take time to hook up a trailer and drive it. They said its ready to go, but haven't done anything to it. If I get it I will burn up the trans and they will have to fix it, but that's just more time with me not having my truck.
Any suggestions? ???

 

[Rohlingoffroad]

So when u are towing u are putting the truck in tow haul (overdrive off) ? Are u getting funny shifts when u start and stop like the Trans is not shifting down to 1st gear ?

 

[Eddyj]

Yeah I tow with the overdrive off. The 03 has overdrive on/off, not a tow/haul mode. It drives perfect until halo disappears, then goes to **** and usually will not act right until trans cools down. Leave it sit overnight.

 

[Rohlingoffroad]

It sounds like it's in the electronics to me the transducer is what senses the Trans fluid temp that problay needs replacing if they didn't replace it when they built it but sounds like u need to get it hot and take it by for them to look at it then

 

[twiztedzuki]

yeah mine sumtimes will not shift like it stays in 3rd gear. I can shut it off and restart it and it shifts through gears fine. it an 05 cummins with twin turbos came from down Tn. I wondering what makes transmission do that

 

[Rohlingoffroad]

When ever they don't shift down below 3rd it can be the transducer or governor pressure solenoid I always replace both of them while I have the pan off and it always fixes the problem they cost around $80 for both of them and when u buy them get the Borg warner governor pressure solenoid for a GM they have bigger magnets and are a lot better