I am having some transmission troubles. I have noticed it heating up more than usual, up to 206 F, not pulling a load or up a hill. It typically runs between 180-190. I did some investigating and found that the lines going into my transmission cooler were 140 and 135, so not much cooling going on. The opposite end of the cooler was 113. Shouldn't it be hotter than this? Also, there were bubbles in the fluid. The same day, I picked up my 31' 5th wheel, drove it across town and it only got up to 201, but I had it in Tow Haul. I have read about some sort of check valve that doesn't allow fluid through the cooler. Any ideas on this, should I replace or remove it? This is my wife's vehicle during the week and she would not be cool with having to run it in neutral every time she drives it to refill the torque converter with fluid. Could the temperature increases be caused by something else?

 

Here is my vehicle info.
07 Dodge Ram, 2500 Q/C 4x4 long bed Cummins 5.9L Automatic 60k miles, Quadzilla Adrenaline