Quote Originally Posted by dbextreme View Post
^^^ Hmm.... I have a 180* stat AND tuned for it. Even in stop and go traffic or pulling my mountain behind a slow paranoid driver my temp gauge has never gotten above quarter way on my gauge so IMO and based on my experience with my car it's working properly and keeping my motor around 180 - 190 degrees. If mine hits 200 or 210 I'd be concerned after what I've done to keep it cool.

NOW if you drop your tstat temp and NOT tuned for it then you will have more erratic temperature movement according to your gauge (in stop and go traffic). If you are in stop and go traffic, your coolant temp can get to 200* because while your car is not moving your fans will not start to circulate air over your radiator until you have hit your factory temp settings. By this point, your motor will probaly be running hotter because your stat will be open more frequently not allowing your coolant to sit and absorb the heat from the motor as it's suppose to... It is ideal to have your stat and fans working hand in hand.

Your trans pump is constantly working so really your trans fluid does not "sit" in your radiator and cool as your coolant does. When I have my trans built, I (personally) will run an external trans cooler large enough to bypass my radiator one. I will also have an electric fan attached to it on the front pushing air through.

This is just my $.02 and maybe wrong, but seems legit.. LOL
The actual reason the transmission oil is routed through the radiator, is to help warm it up on cold days. As you said, the radiator doesn't work very well to help cool it off, once it's above the T-stat rating.