85_Ranger4x4
Well-known member
Since part of the OEM tranny cooler runs through the radiator, it picks up the engine heat and transfers it to the tranny...which is why I'm swapping to the massive 6.0 powerstroke tranny cooler and by passing the radiator completly.
The flipside is on a cold climate it helps the transmission warm up faster.
And liquid to liquid transfers heat much more efficiently than liquid to air as far as cooling the transmission.
IMO the only problem with the in radiator coolers is when they start mixing fluids which is pretty uncommon, I wouldn't bother deleting one altogether (add bigger remote cooler(s))