I just installed a class A motorhome size trans cooler into my 4.6 F150 (it's huge but from what I have been told by trans rebuilders is that cooler is better for transmissions). My question is this: because I had a issue with a broken hard line on the pump side that goes to the radiator trans cooler, I have the hot fluid run first through the external cooler then it goes through the factory in-radiator cooler then back into the trans. Does it really matter that I am not running the fluid through the radiator cooler first per the instructions that came with the external one? Some might think that doing this will re heat the fluid but I think the fluid is hotter then what the coolant in the radiator is anyways. Whats your thoughts? Worst comes to worst I can probably switch it out to the correct path but this was the easiest route at the time.

 

"5.4 killer"? Not unless you have a supercharger?

 

i dont think it will hurt anything. worst case scenerio, your fluid will be the temp that the factory intended but under harder use.