On a 727, which is the in and which is the out?

[Paul]

I'm supposed to have the tranny fluid go from the tranny to the auxillary cooler to the radiator then back to the tranny, but I can't remember which fitting on the transmission is "in" and which is "out." Anybody know?

[Cliff]

It does not matter. The cooler works regardless of which direction the fluid flows.

[scotty]

i would eliminate the radiator from the equasion. it keeps the trnny from ever runing cooler than the coolant,and tho unlikely,it is possible to leak tranny fluid into the radiator and/or coolant into the tranny :eek:

when i ran an auto i had it hooked to my old a/c condensor for a cooler,and a remote filter. it used to run 100-125*,and i dont think i ever saw it get above 150

[JeepJerk]

It's best to run the accessory cooler before the radiator cooler. It removes quite a bit of the heat before it reaches the radiator; thus by easing the job of the rad. Trans fluid that is overcooled is not as bad as transfuid that is too hot, but its still not good. AutoTrans are designed to operate at certain temp parameters; overcooled is not better. This seems to be more of an issue with more modern trans as opposed to the older 3speeds. Can effect shift points and shifting speed. Classic Auto restorer mag had a long running debate about this in their tech forum for months.I agree that running through the radiator increases the possibilty of mixing fluid in the event of a crack developing or seam letting go. Have had good luck with the few autos I have and our work truck autos by going through the cooler first and then into the radiator. Had one or two times that fluid co-mingled but caught it in time. Seemingly no damage. My two cents.Spend as you see fit.