Whats normal operaring temp supposed to be running 75 pulling a 20 ft enclosed bumper pull trailer outside temp is 78 with strong wind my tranny is runnin around 240-260 degrees .

 

Pulling a 37 ft 5th wheel, truck and trailer total weight, a biscuit short of 30K. I will see about 50-75 degrees above ambient temps. temps will kill this tranny just like an auto. I added a 40K Trucool cooler and a Fastcool housing. this plus good synthetic oil will help alot. After adding all this I've never seen max temp over 175. Another benefit, it you let your truck sit and idle after a long 8hrs of pulling. temps will drop to outside temps in less than 10 min.

Barney

 

I figured the temp mines running was too hot but gotta get home before I can do anything with it.