Best way to warm up/cool down transmission fluid?

[snonut12]

On cold day when starting the truck to let it warm up, would it make a difference if I apply parking brake on and then shift the transmission into NEUTRAL help the fluid circulate better so it could warm up the fluid better before I hit the road? Or do it have the same result as letting the truck warm up with transmission in PARK?

The same question apply to when I am done plowing. I usually let my truck sit and run for 15 minutes, sometime 30 minutes to help cool down the transmission fluid. Again, which would be better and faster method to cool down the fluid?

[Alan]

Unless you're going to start working it as soon as you start the truck I wouldn't worry about it. If you drive a mile or two before you put a load on, or quit working it, I can't believe that isn't enough.

As the engine coolant warms it will transfer heat into the tranny fluid until they are equal temperatures. Same thing on shut down, the transmission will give up heat to the engine coolant as long it is warmer. But I don't think that transfer would last more than a mile or two in either direction.

You can idle it all day and the temperature will not go above or below engine temperature by any appreciable amount.