Im looking at a bunch of these auxiliary trans coolers and one question keeps popping up in my head. Is it enough or not.

Im looking at the Series 9000 Derale trans coolers, and there is one that is a 5 row cooler that states 14,000 GVW rated. This is going on a old F150 truck with a C6 trans and my goal is to have the transmission cooler line go from transmission to the cooler built in the radiator and then out of the radiator cooler into this auxiliary cooler then back to the transmission.

So do I need to go bigger than I think or can I go with something like the 5 row cooler rated at 14,000 GVW? Truck is rated at 5,250 GVW, I don't know what the GCVW is for this old truck. I want to say 10,000 GCVW which would effectively be a 5,000 lb tow capacity. In my eyes a 14,000 GVW rated 5 row cooler sounds like it would be well over enough for cooling my old C6.

Am I thinking this out logically or am I missing something?

I understand bigger is better, but my truck has a dealer installed AC so it makes it hard trying to fit something next to the condenser as I don't want the trans cooler mounted to or infront of the condenser itself. I found a NOS cooler for my truck its a 24 plate cooler and I thought about this but I think I want to go with an aluminum aftermarket one for more efficiency since im using it after the factory radiator cooler and not using this as a stand alone cooler.

Im also looking at the Derale 9000 series 13 row cooler which it says that one is rated at 20,500 GVW. I could probably fit this one as well but I hate to go with something excessively over kill especially if I have a GCVW of 10,000 lbs then a 14,000 lbs seems more logical at least to me.

 

That is the correct routing method. You want the OEM system, in this case, the radiator, to cool as designed. Then your auxiliary cooler will provide additional cooling.

There are charts you can look up online. There are different types of coolers. Tube & fin, plate & fin, stacked plate. Modern transmissions use a cooler bypass to help the transmission come up to proper temperature and to prevent "over-cooling".

I selected a cooler with a fan. Most of those designs set the fan to come on at 180 Fahrenheit. If you think about it, your fluid should be well below 180 after it passes the OEM system. If fluid in the return line going back to the transmission, after it has already been cooled, is still at 180, your transmission's internal temperature must be 50 - 100 degrees higher. I bypassed the thermostatic switch on a fan and installed a fin probe for the fan to turn on at 140. That's 140 degree fluid exiting the OEM cooling system. On my car, the ScanGauge II will show about 200- 220, before the fluid exiting the OEM system and entering the auxiliary reaches 140 degrees to turn on the fan. Once that fan turns on, the temperature begins to drop, which tells me that it works.

You don't have to think too hard. Any additional cooling after the OEM system is better than just the OEM system. You should also consider installing a temperature gauge so that you can actually see your pan temperature.

 

I was with you until you posted that last chart. That chart was probably somewhat accurate in the 1960's but is WAY out of date with today's modern materials. New transmissions have thermostats that keep them warmed up to 200-225°F. It would do the world a great service if everyone would delete that chart.

Edit: The offending chart was removed. Thank you.

 

Interesting. Did not know it was that old, and no longer relevant. Thanks!