factory trans cooler/trans heater

["Top Fuel" Bender]

working on my cummins swap project with the auto
the factory has a mess of plumbing going on here
line comes out of the trans
goes to an exchanger mounted near the block with coolant lines going thru it
then to the radiator support for a very small trans cooler

anybody pull this off and install a larger front mount unit ?
any issues not running thru the coolant filled canister?

some of the cummins guys I've talked with swear to leave it all alone
they feel the Chrysler trans fluid needs to come up to temp quickly to make the trans live and work right

any thoughts

[dixiedodge7369]

i have a 06 cummins but its manual... the factory set up runs through the non heavy duty equipped trans cooler in the rad. but then adds a additional one after the coolant to obviously cool the fluid more. but as far as trans fluid if you have a HUGE trans cooler or not a trans makes more then enough heat to warm it self up, and get to a good running temp.
The key to long life in a auto is keeping things cool. personally i feel the cooler the better. none of my fast cars are auto. but my cruiser boat mopars are auto and they all have alum deep sump pans, inline spin on oil filters and the biggest thickest trans cooler that would fit. I dont know what your swap project is or what your putting the cummins in but, i would say bypass all factory anything go get the largest trans cooler that will fit and call it a day.

[Evilancer]

If you are going to be running it in the winter in a northern climate, you want to KEEP the block mounted heat exchanger that has engine coolant circulated through it, without this the trans fluid temp would never get up to an acceptable level in the winter time.
Now, what you do NOT want is the check valve mounted in the transmission line up near the cooler that is mounted behind the grill. They have been known to stick and cause the fluid to overheat badly. Not all trucks have them, mine never did.

I've got a built auto in my truck, with an efficient triple disc converter and a double deep pan and I run the factory cooler setup and my temps usually run 140-160* in everyday driving, which is about where you want it.

What burns up the fluid on these trucks isn't the factory trans cooler, it's the crap factory torque converter that slips like crazy when it isn't locked up, it generates a ton of heat.