[Old Cowboy]

Way off topic,

Been cold up here the last week, REALLY cold like well below zero. I'm not used to running automatic transmissions but I bought a good used pickup last spring with one, a guy told me the other day that in cold weather you should let the pickup warm up with the transmission in "neutral" rather than in "park" so the oil in the transmission will circulate and warm up before you drive. Hadn't heard that before, anything to it?

 

[CalvinMD]

No..pump runs in park too..only difference is a pawl holds output shaft locked so car don't roll...synthetic tranny fluid is always a good idea though

 

[grntitan]

What Calvin said.


Since the transmission fluid is normally(there are exceptions) run through the radiator to cool the fluid, just warming the vehicle up in park will do fine. As soon as the radiator fluid/coolant starts to warm up from the engine heat, so will the tranny fluid. That said, unless you have constant daily temps of -20 below zero, you really don't need to warm your vehicle up more than a few to 5 minutes. Any longer, and you are really just wasting fuel.

 

[ric3677]

Therein lies the problem Matt. John had lots of days below that.

Stay warm my friend.

Rick in Windy Great Falls

 

[Catpower]

What everybody else says, but on my wife's F250 it has a transmission temp gauge, I never drove it until we got the 5th wheel and it is now the tow vehicle, but I was surprised the transmission warms up faster than the engine, a lot faster, didn't know they put out that much heat, and it does it whether we are towing of just normal driving

I like to be able to monitor the tranny temp, it has never gotten warm, but it is a little piece of mind when you are pulling a good sized load up a long hill/mountain

 

[motordoctor]

In the really cold weather synthetic fluid is recommended in the trans, engine and rear axle. It was designed to work in those cold temps and then will work great in the regular weather also. Motordoc

 

[Brian in Oregon]

This is the reason why the auto trans fluid is run through the radiator. It not only helps cool it a bit in the summer, but it keeps it warm in the winter.

If you live where it is hot or warm most of the year, you can get away with bypassing the radiator connection when adding an external trans cooler.

If you live where it gets below freezing, and especially where it gets to zero, it's a good idea to run the output of the external cooler into the radiator. This will keep the fluid up to temp.

There are automatic shunts made that will divert to one or the other, and I've seen manual valves installed to do this as well.