Installing a trany cooler.

I was just wondering what you guys thought about trany cooler's and how to hook them up. Any time I have run a trany cooler before I went from the trany to the after market cooler then thru the radiator and back to the trany. I just had a bullet proof trany built for my Suburban and they told me to run my trany lines to the after market cooler and back to the trany, and not to the radiator at all. It get's pretty cool out here in the winter, below 30 at times. I would think that the trany would have to get some heat from the radiator to help keep the temp in operating range for the cold months. Now in the summer it gets to 120 at times, so I go from one extreme to another extreme.
I bought a big cooler because I tow with this from time to time, and I am on my 3rd trany now in this vehical.
How would you guys run your trany lines or set up your cooler for your trany's???
Thanks Kurt

Here's what I had done to the trany and it comes with a 5 year or 1000,000 mile warrenty.
And I bought a 21in.X10.5 in.X 1.5 in. cooler from Summit.
Purchased a 4160E rebuilt transmission Level 3.
All mods of a Level 2 plus all sonnax updates to valve body bore valve body & install over sized updated valves, Beast sun-shield, Corvette servo, shift kit, heavy duty springs, kevlar band.

the fluid temp returning to the trans should be warm just like the coolant flowing back to the engine-----that's why the OEM set them up like that !!!!!!!!!

Thanks Jerry.
Kurt

Fluid should flow through the cooler, then the radiator.

That way the fluid doesn't get too cold.

The biggest reason for the heat exchangers in the radiators is to heat the fluid in the winter like you're needing and describing. The other main reason is a secondary heat transfer in case there is a lack of air flow. LIke a traffic jamb. The biggest issue with a transmission during towing is heat. If you utilize the heat exchanger in the radiator, your trans fluid will always be the temp of your engine coolant and then ran through your external cooler and on some vehicles the temp coming out of the external cooler still exceeds what some trans builders want. I know people's opinion on here varies on this, but we've built and worked on many, many high performance diesel trucks that haul a lot and we've installed a lot of transmissions. We've never had any come back with the heat exchangers removed. The best thing that works for trucks in both climates, is putting a junction valve in the cooler lines so you can shut off the heat exchanger in the summer. It is a little more work but it gets the trans fluid temp down to where builders want it. Most of the major builders in the diesel world never want to see your trans fluid above 180*.

For cars I like to go through the auxiliary cooler then the OEM back into the trans...

For trucks that are towing I like the opposite, OEM then the aux. into the trans. works for me!