Unless you live in a really cold climate I don't subscribe to going through the radiator either. I have done it both ways even up here in the NORTH and have seen no issues either way here, Down south I would say keeping it as cool, as possible is best

 

you dont think 100 degrees is too cold though? would it be beneficial to heat the fluid up a little bit to around 140 or so?

 

100 degrees seems a bit low. Seems like you would see too viscous of a liquid (resulting in higher pressure operation... possibly lower flow). I haven't seen anyone doing performance testing regarding fluid viscosity vs temperature so I can't comment on which way is better or not. One would assume that auto manufacturers have gone through this to prove what's best against any other option, but...

There's a GREAT long term TRUE test if a trans sponsor wants to step up to the plate.

 

haha, i'd be willing to put my trans through whatever tests necessary as long as the sponsor would help me out with a new one when the time comes

 

Running the trans fluid through the rad can remove a lot of heat as you are running the trans fluid through a liquid and not just air. Liquid will remove much more heat than air can. Just look at an air to water intercooler compared to air/air intercoolers. Also think about quenching a hot piece of metal in a bucket of water.

The rad will warm the fluid up, not a bad thing at all. Its not going to heat it warmer than the coolant. Bad things dont start happening to well over the coolant operating temps. Like over 240ºF

Not running fluid through the rad is really loosing out on some serious cooling reserve. Akin to running an A/A intercooler.
hayden continous loop styles should be avoided as they can clog and not cool at all.

There is a reason why GM PCM tuning doesnt lock TCC's until a minimum temp is reached, esp. with the always slipping ECCC TCC lockup protocol 98+. There is an operating temp to a trans. Why force the trans to operate UNDER that temp? Doesnt matter how much power you make. You arent applying that power most of the time while driving.

The GM transmissions I have run acts slightly different when cold. even in the Summer.

peace
Hog

 

Mine definitely runs differently when cold. I always thought you wanted the trans temp high enough to burn off water from condensation. I know with engine oil, if you do lots of short trips without the oil getting up to temp, the oil degrades much faster compared to normal temps. Not sure if it applies to trannies but Hog's comment about operating in the temp spec makes sense to me.