On a nice summer day, I drove my family around a scenic high-alpine lake and some mountain passes. Everything was splendid, until I glanced at my Torque Pro app and saw: Holy Cow: ATF pan was 230 degrees Fahrenheit!
Sure, we were at high elevation; the air was thinner. And very (very!) dry. And it was super-hot out (like 100 deg F hot). But still, I intend to tow and this unladen reading caused me concern.
Since I live in the Great White North, I don't need wintertime cooling. In the past (like, 1980's and 1990's) I've used thermostatic bypass units to keep external coolers from receiving oil in cold temperatures. But these days, I find you can get coolers with thermo-bypass capability built-in: at least Tru-Cool LPD, and Hayden Rapid-Cool. I want to use it from -40 to +40C.
I've used Hayden before, so I selected their Rapid-Cool 699 (largest) thermo-bypass cooler.
Many (many!) words have been written on this subject, so I'll only highlight a few aspects of what I did:
First most helpful was the cartoon-sketch by
@
zcruiser
:
https://www.toyota-4runner.org/3518282-post5.html
Summary:
I removed the entire front, and found the aluminum "crash beam" was going to be an awesome support! I bought some 4" stainless bolts, pierced the crash-beam, and basically made 1" mounting-studs out the back.
Mounting the cooler the way I did seems to be the "best" for burping air, but I also like the mechanical support.
Awesomeness:
Shout-out to Toyota for making this DIY-friendly! Here's why:
Toyota used 10mm stub of steel-tubing out of the rad-cooler, and 10mm steel tubing returning back to the transmission. Between these two 10mm tubings, they connected them with about 8 inches of hose...
To add a cooler, yank the Toyota hose, and slide the two cooler hoses onto the two steel tubings. Clamp, and you're done! 3/8" = 9.5mm which is a beautiful lightly-snug fit onto the 10mm tubing (use transmission-cooler-rated hose, please!).
The rest are in photos...