So what you're saying is that with a tranny cooler in the circuit ... at -30 something ambient ... even with the radiator after the cooler ... if the ATF gels in the cooler ... (now we're getting to the scarey part) there's a very good chance that the gel will block the line so there's going to be no flow no where no how ... no cooling of the tranny interior and we've got "burnt toast"???

So when it gets really cold put a "snuggy" (winterfront) on your front end if you have an auxillary cooler ..... ???? Now THAT'S SCAREY!! Lots of ticking time bombs running around out there in the north country.

After my worst overheating experience I had a good opportunity and switched to synthetic Mercon. I trust that a synthetic will fare better in this scenario?

 

Its not that bad. Dexron III/Mercon (essentially equivalent) generally has a pour point between -50*F to -65*F depending on maker.

Under pressure, it will still flow. But thats why I said, at the point where it actually does gel, the engine didnt start.

Im surprised that you didnt find that the moisture always present in ATF didnt crystalize at extreme temps and block flow?

 

I live in the south and I have never considered the possibility of transmission fluid being so cold it wont flow, that's amazing!

If I ever have a problem with "frozen" oil I think I'll move. Thats just too cold for me.

 

Yes, it will. A cold weather front will help, too.