Running only a trans cooler?

[Z34Phoenix]

I have a nice sized trany cooler on the car right now and I am wondering if I still should have the fluid run thru the factory cooler built into the radiator? My issue right now is that the trany is going and will slip at around 4-5k from 1-2 only when above 185* My thinking is that the heat from the rad is waking up the fluid in he trans. Which I'm sure normally is a good thing. But right now it is causing me to have to drive very slow until I can get to 2nd gear. The rest of the gears the trany is solid! And when the trany is cold it is solid. So I figure if I can run the fluid thru just the cooler I have that I will stay cooler longer. I don't normally go on long trips so what input do you all have? And yes I am planning for a replacement trany. Actually planing an entire engine trany swap. Yes I know i have a 4t60e but this I feel has more benefit to the sub forum and don't want to put it in both.

 

[FordMan77]

Yes you can run it just through an external cooler. Most of the nicer B&M coolers come with a thermostat built in that will bypass it through the cooler until it gets up to operating temp. I've run both my other cars this way and never have temp issues and the trans. are still happy.

The "cooler" in the radiator is more of a heat exchanger than a cooler since it is in contact w/ the rad. It does cool it some, but not as much as a true cooler would.

A cooler will not help keep the trans from slipping when warm, only a rebuild will as you stated.

 

[Z34Phoenix]

K Great info too. i got replys on other forums as well so seems this is what most do. yeah i know it isnt really a fix for the trany slipping but since the trany is solid when cold. i figure the longer i can keep it cool the better off i am!