Originally Posted by blufeb95
I don't see where a bigger pan helps unless you're only using the truck to pull in short bursts, more fluid will take longer to come up to temperature but will just heat soak the same as with a smaller pan when towing a distance.
I agree;
On a related note, folks have talked about the degradation of the ATF when it gets hot - and the notion, then, of changing it more frequently to compensate... fair enough. But what of the elastomers inside of the transmissions... specifically in the valve body. They suffer from heat. So the bottom line is to cool the ATF properly, plumbing the aux. ATF cooler into the OUTLET of the in-rad cooler.
The best arrangement would be with block valves and bypass valve so that in wintertime the whole aux. cooler could be bypassed. I know that, yes, some folks tow in winter, too... That'd be a judgement call. The ATF temp should, of course, be measured with a bung on the side of the pan. It is bulk ATF temp you want... not the temp OUT to the cooler(s), or the temp back from the cooler(s).
I think A/T's generally like to run at 175F... and excursions once in a while, say, up a sustained hill, to 190F probably are not a 'real issue.