ATF Temperature Management Advice?

[UTEP]

Howdy

I know this has probably been beat to death but I'm on the road now and search function not working too well on my iPhone app

So this is my first summer with a 4runner. Did a Death Valley/ panamints run and ATF was reading up to 240 degrees on the long fwy grades coming out of Laughlin et al. Ambient temperature about 80 at worst. Would cool down to 160 if I let up and crawled up at 55 mph.

This using an iPhone app and wifi dongle.

I am running ATF through the radiator and a medium B&M Supercooler.

I'll be doing much more of this soon with 100 degree runs off road perhaps.

Any advice on how to manage this would be great.

Thx

Utep

 

[the great him]

get a second cooler and ditch the factory radiator cooling... the factory radiator will actually heat up the atf, as your coolant is regulated to around 190*, so at its coldest you will see probably 180*(if your lucky) in the radiator. i run dual coolers and one of those coolers has an electric fan on it that has a thermo switch running off the return line(after both coolers) that will come on at 180* and wont shut off until 160*. i have had that fan come on several times, even in the winter on snow runs. the factory cooling system is a joke, its not a cooling system, its a temperature regulating system thats marginal at best and meant for "normal" driving or commuting. id go with two of the larger B&M coolers like the 70264s if you want to really have a cooling system. they have the by-pass if temps fall too low(they wont trust me), i have a temp gauge on my trans and with both of my coolers and the middle of a snow and ice storm drive 50mph on the freeway i was still seeing temps of 130+. thats plenty warm. -if your trans will shift into overdrive then the fluid is warm enough.

 

[Drcoffee]

Your are probably climbing the mountains in Overdrive. Shift into D and the temps should come down. Its a matter of having the trans locked or unlocked. In overdrive the trans is unlocked and creating a lot of heat.

An external cooler should be able to drop your current temp by 20*. If you need more cooling, add a bigger cooler or a second cooler. You can over cool the fluid as well. Keeping it connected to the radiator helps regulate the temps no matter if you are in AZ or AK.

Is your cooler mounted to the condensor or somewhere else?

 

[BrianSD_42]

2nd'd on taking the overdrive off

 

[19963.4lsr5]

When the trans shifts to overdrive does the lockup clutch engage at about 48-50mph.

If the TC is locked up there is minimal heat created even going up hills.

 

[jgue467]

That's what i thought about the lockup tc

now you guys have me worried. i've got a bm 15k btu cooler (replaced fac cooler to avoid milkshake thing), but i don't really know its operating temp. I'm planning on a mid-summer trip from texas to cali then colo and back, starting to wonder if i'll need more cooling on all those hills along the way?

Another question, does everyone run synth fluids in trans and diffs?

 

[LittleCaesar]

Make sure the cooler is mounted in front of the fan.

Consider an external spin on ATF filter:
B&M 80277 Universal Remote Transmission Filter Kit : Amazon.com : Automotive

 

[19963.4lsr5]

If he is running up a steep grade and the PCM unlocked the Torque Converter because of the load I can see that type if heat.

 

[UTEP]

Thanks. Yep OD off have me 151 degrees on the same type grades with 70 ambient T. Cruising at 2400 rpm through PHX has me at constant 151 degrees. Oddly the engine T seems inversely related some how. If ATF went up engine went down. If engine T up ATF T down ???

I'll break this down later when of the road.

Thanks as always!

Utep