After reading a copious amount of posts on here over the past year and learning a lot thanks to all of you! I must start a new thread in hopes I can stop pulling my hair out.
2001 Dodge Ram 1500 Van, 5.2L with 46re trans 91k miles

The first occurrence about a year ago with my issue was traveling at highway speeds, around 65-75 (Arizona here) uphill and downhill mid to high ambient temps. My overdrive light will turn on to indicate od is off (which i can easily tell that it has happened) and if continued driving my trans temp light. Pulling over right away I let it cool and continue. After doing a bunch of work, which i will list, it still has the same problem. Engine temp is good city or highway, trans temp is slightly high (told by technician recently) and obviously higher when od turns off from what i read as safety feature. I also notice it has power loss and hard to climb slight hills at higher speeds after trans starts getting hot in overdrive. No problems occur if i keep it 55 or under it seems but trans still is higher than should as told by tech.

The only problem Amoco could see is a 3-4 flare which i can feel and doesn't happen that often. However when im locked up in od going 55+, there is no slipping that i can feel and over all the whole vehicle runs great. So im not sure how that would explain my overheating issues being just a 3-4 flare unless im mistaken?
Slight engine oil leak from what seems to be rear main seal or just oil pan gasket (not fixed yet)

As far as the work iv done from recent to longest;
-Checked exhaust back pressure before cat
-Fuel pressure on fuel rail
-Changed trans fluid/filter
-Pulled valve body, cleaned and checked all valves, upgraded tcc lock plate with bigger orifice
-Flushed trans oil cooler radiator (seemed okay but i should have replaced)
-Adjusted TV cable
-Replaced spark plugs
-Clean distributor cap
-Changed trans fluid/filter
-Replaced all solenoids, governor or whatever else and accumulator spring (which was of course broken)
-Changed engine oil/filter
-Greased zerks
-Flushed radiator
-Pulley replaced (forgot which one, was squealing)
-Water pump, fan clutch, thermostat
Previous known work before me
-Trans cooler line check valve was taken off
-ECU/PCM was replaced (unknown reason)

From collecting all the info i could from here and what is happening. I can only conclude it its possibly my torque converter causing over heating?
Or even something as simple as my trans oil cooler being slighting clogged still and at higher speeds not enough circulation occurs, especially in this heat and up hills.
Would any of this also cause power loss when my trans gets hotter?
No codes put out ever

I am stumped! Any and all input on this situation would be more than appreciated after having a headache for a year.
Thanks in advanced

 

Might try adding an aux cooler to the system, see if that helps at all. Beyond that, I might try replacing the governor pressure sensor and solenoid. See if that makes any difference.

 

Checked visually? I've seen crushed and kinked lines that restrict the flow of tranny fluid just enough to cause overheating issues but not drivability issues. If the lines are good the next step might be to replace the radiator in case the tranny cooler is restricted.