External Transmission Cooler - how does that work in cold weather?

[farmerjon]

I live in an area that get's quite cold in the winters (as much as -40F!), as well as very hot (100F+) in the summers, and was wondering what downsides I would have to installing an external transmission cooler? (Especially in COLD weather)

My 4Runner is at 98K miles and I'm thinking I should replace the radiator and/OR add an external transmission cooler to avoid the dreaded milkshake issue in automatic transmission 4Runners...

Thoughts? Replace the radiator AND add an external cooler? or just the latter? Add a bypass for colder temps?

Also, if I go with an external cooler, does that mean that my built in temperature gauge is useless?

Thanks!

 

[t4r4life]

you can just run the External Transmission Cooler inline with the radiator, at 98k the radiator should in in pretty good shape unless there are rust issues. most milk shake happen when the tranny gets too hot, so adding an another cooler will deff make your chance of getting the milk shake almost to 0 especially in cold weather. hope that helps

 

[98Base4R]

I have bypassed my radiator with a trans cooler. I am not sure how many of the total population of T4R suffer from pink milkshake. But it seems to occur often enough to be a weakness. And I decided to remove the possibility of the coolant and ATF mixing.

I am not sure if the external cooler has as much total heat removal capacity as a water to fluid radiator heat exchanger. So 100 degree plus weather may be an issue. The only way to know is to install an ATF fluid gauge, so you can monitor.

Remember that worst case ATF is at -40 when you first get rolling, regardless of if you have bypassed. It takes a long time for the coolant to warm up in cold temps. So the ATF must flow at cold temps in either case. You could always run synthetic if you're worried about it. I have been skiing and snowmobiling on negative degree days, and haven't had any issues. The AT seems pretty bullet proof overall.

The best overall solution seems to be new radiator, trans cooler and trans temp gauge.

 

[Nunyabiz]

Not sure about regular ATF but Synthetic ATF (Amsoil) has a cold pour point of minus -63 degrees F.

So I am sure synthetic would help.

Also in that cold a temp you would probably have more problem with the radiator itself I would think and might have to put one of those blankets in front of the grille.

 

[rjaudi]

You need to get a tranny cooler with a bypass built in. My trucool has this and when the fluid is cold it only goes through a couple of fins. As the fluid gets warmer the fluid is allowed to got through the whole cooler.

 

[LittleCaesar]

Look for a cooler that has a built in LPD device and you will be good to go (the LPD prevents the ATF from circulating in the cooler until a given temp such as 170 or 180).

 

[farmerjon]

For my T4R, I think I'll add an external cooler in series for now and then replace the radiator when I'm further down the road (in terms of mileage - currently at 98K)...

Will this suffice to keep the ATF cool enough during the summers of 100+ heat? It cools MORE if it is in series than if it was JUST the radiator or the external transmission cooler, right?

 

[farmerjon]

Also, I'm really confused on a couple of points...

When we say that a B&M (or other cooler) has a bypass for cold weather, what exactly does this mean? Does it mean the same as bypassing the radiator entirely?

When we DON'T bypass, does that mean we're running the external cooler in series or what?

Also, I'm confused about the LSD things... where it doesn't let the coolant mix somewhere until operating temps? How does this work? Does it work in conjunction with the radiator AND the external cooler?

Thanks, I really want to get things right and make the right purchase/decision for my T4R...

Appreciate all the help thus far!

 

[t4r4life]

For my T4R, I think I'll add an external cooler in series for now and then replace the radiator when I'm further down the road (in terms of mileage - currently at 98K)...

Will this suffice to keep the ATF cool enough during the summers of 100+ heat? It cools MORE if it is in series than if it was JUST the radiator or the external transmission cooler, right?

in series is always cooler, which first doesnt matter

 

[t4r4life]

Also, I'm really confused on a couple of points...

When we say that a B&M (or other cooler) has a bypass for cold weather, what exactly does this mean? Does it mean the same as bypassing the radiator entirely?

When we DON'T bypass, does that mean we're running the external cooler in series or what?

Also, I'm confused about the LSD things... where it doesn't let the coolant mix somewhere until operating temps? How does this work? Does it work in conjunction with the radiator AND the external cooler?

Thanks, I really want to get things right and make the right purchase/decision for my T4R...

Appreciate all the help thus far!

no need for bypass, atf will ever freeze its way too flammable, thats your thermastat it doest let the coolant enter the clock untill it hits 130 degrees, then it fully opens at 195

 

[farmerjon]

no need for bypass, atf will ever freeze its way too flammable, thats your thermastat it doest let the coolant enter the clock untill it hits 130 degrees, then it fully opens at 195

you mean it never freezes?

Don't understand quite about the thermostat, do you mean the LSD doesn't let the coolant enter the "clock" (what is the'clock'??) and why fully opens?

Thanks for the replies man. appreciate it

 

[t4r4life]

you mean it never freezes?

Don't understand quite about the thermostat, do you mean the LSD doesn't let the coolant enter the "clock" (what is the'clock'??) and why fully opens?

Thanks for the replies man. appreciate it

its as flammable as gasoline and when was the last time you saw gas freeze.
please explain what LSD stand for, because only LSD i know is limited slip differential and lucy in the sky with diamonds lol

 

[farmerjon]

its as flammable as gasoline and when was the last time you saw gas freeze.
please explain what LSD stand for, because only LSD i know is limited slip differential and lucy in the sky with diamonds lol

That's what I thought thanks for the patience, I can be slow at times

LPD! lol I knew I had that wrong...

 

[t4r4life]

That's what I thought thanks for the patience, I can be slow at times

LPD! lol I knew I had that wrong...

dont worry about that, all you need to know is that running inline tranny cooler is fine , and as long as there is 50/50 mix of coolant and distilled water your coolant wont freeze, in hotter weather people run 30/70 coolant to water rato for more cooling, since water is what actually cools the engine.

 

[shootmymime]

bringing the dead back to life.
so [MENTION=81047]farmerjon[/MENTION] im moving back to idaho and will be pulling a 6x12 trailer with me in jan of 2014. should i get the larger 70264 or the smaller one 70268?

 

[farmerjon]

bringing the dead back to lift.
so [MENTION=81047]farmerjon[/MENTION] im moving back to idaho and will be pulling a 6x12 trailer with me in jan of 2014. should i get the larger 70264 or the smaller one 70268?

I have the 268, I believe, but I still have not installed it. Oh, we've swapped places haha, I'm now in IN!

 

[xcmtb83]

in series is always cooler, which first doesnt matter

For those reading this over a decade later, this is wrong. If running in series, it is best practice to run the external trans cooler after the radiator.

 

[Hungryhawk]

I think 5th gen have needs for warming and cooling trannys. So the factory set up cools the ATF in hot weather when workng the truck.

And the factory set up also warms the tranny in cold weather.
I notice my shift points are different when cold.