transmission temp in winter

[mpaulson]

I'm hoping that someone can give me a answer as to if I should be concerned about transmission temperatures in the winter with the set up that I have. This summer I added an auxillary transmission cooler under the truck just behind the transfer case up between the frame rails and it has a 12" x 12" or so core and a fan on it that comes on at 170 degrees. My concern is that will I be running to cold for the transmission when the temperature drops? averages between 30f to -20f (0c to -30c). Should I be going throught the hassle of bypassing it for winter? or just leave it? Does anyone else live in the freezer that has a set up like this? What have you done?

What is a safe minimum temperature on the return line side?

 

[RobertHiltz]

A trans temp gauge would be a good investment. I doubt that you will have a problem if ambients never drop beyond -20. Anything colder than that could be. How it is plumbed (in relation to trans fluid flow) will make a difference too. Maybe a bypass for the cooler can be installed.

 

[mpaulson]

I have it plumbed into the return line from the factory cooler. I have tought about adding a bypass. I'm just lazy and would rather not add more fittings for restrictions in the flow. I have a temp guage but I used the wrong line back when I installed it and it is on the return line. The current temps on the return line are around 80 degree while the temp out side is around 30f/0c. What is a safe minimum temp for trannys to operate at???

 

[Midnite]

I wouldn't give it a second thought. transmission fluid at 80 deg. F works just beautifully and certainly isn't a threat to the transmission's health. If you run into extreme cold, like -40 F then just baby it and don't give it heavy throttle until the fluid warms up to the point it'll flow well.

I'm no transmission authority by any means, but I think if the fluid can flow then it's warm enough. You can't cool the fluid enough with auxiliary coolers at an ambient temp of 30 F to cause a problem, and I've never had any problems down to -30 F here in Alaska. I haven't seen colder temps than that though, personally.

 

[WDaniels]

Having lived in Fairbanks AK where it does get to -40, -50, -60 and more, your transmission cooler in -20 or lower will be affected. The colder, the more you need to keep that fluid warm. Fords route their transmission cooler through their radiator and during the extreme cold, I've seen dozens of them(Fords) along the road with their transmission trashed because the fluid got so cold that it ate up the xmission. Just my 2 cents worth.

WD