Towing, Tranny Temps, and Coolers

[PNW yota]

Yea, you guessed wrong. Better luck next time.

ound:

If you weren't so sensitive, you would have seem I did give you helpful advice.

Not sensitive. I actually laughed when I read your post. I've come to expect rude posts and was surprised this thread made it 3 pages without one... Way to step-up and be "that guy."

As for the other thread. Thanks for the link. I read through it and there is plenty of debate on the issue. Sounds like you're a self claimed expert on all things 4runner cooling. Good points made by all (well most) posters.

Call me Old Fashioned but I'm gonna stick with the bypass for now. Like I said before if I change the rad out I'll consider hooking it back up.

 

[19963.4lsr5]

The trans cooler is on the cold side of the rad. And the 3.4 runs at or around 185. So the rad is not cooling to or heating to 200 degrees. My Saturn had the trans cooler on the hot side of the rad. And it took a 105 degree day in heave traffic in Hershey PA to see 205 for the trans temp. And once I got back to the open road temps were back down to the mid 180's within 3 miles.

 

[Drcoffee]

I think properly sized and executed, the stand alone cooler will be more than enough to properly cool the transmission.
in fact, I believe it would work better, as you aren't adding 200°+ temps to the already hot transmission fluid.

the trans cooler is placed within the radiator to help the transmission fluid to WARM up when cold.

Apparently you don't understand how the radiator works. Let me help here. Your engine is running at about 190*-210* and thats the temp of coolant exiting the engine. That coolant then poors into the top of the radiator where it passes thru the coolng grid where the ambient air removes some heat. By the time the coolant reaches the bottom, it has been cooled to about 160* give or take. Your transmission is creating heat and a lot of it. It passes thru the radiator where its efficiently cooled by the water/air heat transfer. Where the benefit of an external cooler comes in, it will then reduce the ATF fluid an additional 20* from there. Without the radiator, the ATF doesn't get cooled effectively. So the radiator down at the bottom where internal cooler is located is actually cooler than the engine temp. You are not adding heat to the ATF.

So you bypass the radiator and you use an air cooled cooler. Most of the heat issues come at low speeds. Your external cooler needs a shit load of air pulled across it to pull the heat off. Where is that air volume coming from in your application? The engine fan? Its good but not good enough. Air will flow thru the path of least resistance. A proper external setup would require independant puller fans and plenty of surface area to be effective at the most demanding times. You can make a budget setup work on the highway but add a trailer, hilly roads and other stressors, and your budget cooler will cook your transmission.

But you will pay the repair bill, so you make the call. Is your cooler capable of functioning at the extremes.