Transmission cooler questions

[Cubey]

If that is the same one I have, it has an internal thermal bypass so it won't run too cold. It's supposed to bypass until the temperature gets hot. That's one of the reasons I picked the one I did.

No, the bypass one costs about twice as much (over $100) This one was about $55.

But for your location, that makes sense to have. Not so much for me.

 

[Cubey]

Leave the radiator in the cooling circuit. Specially with a C6.
This is the primary cooler, it does most of cooling in slow speed and reverse.

Don't bother with a bypass valve unless you are in extreme cold. You will not need it.

As for dark fluid, one or more clutch packs are failing. Clutch material will make the fluid dark.

Ok. I'll just ask the trans shop to flush the trans cooler in the radiator with fresh ATF, in case that's not something they'd normally do. I can't imagine they wouldn't though, with a failing transmission pumping contaminated fluid through it. I doubt they want transmissions coming back for warranty work because they didn't take 5 minutes flush the cooler. I'm guessing they have equipment for that type of thing, a simple pump to push clean transmission fluid through it until it comes out clean.