Home Forums Gear Hunting Trucks and Four-Wheel Drives Need Suggestion for Tranny Oil Cooler

I am going to get an aftermarket oil cooler for my 2003 Tundra V8. I have been looking at B&M, and Hayden to name a few. I like the looks of the B&M the best so far.

Any suggestions? Anything else I might need to know?

Thanks for any help.

I went with the Hayden premium plate and fin cooler. Better cooling and a more substantial cooler. Take care when you route the hoses so it is not rubbing on anything. Good time to flush your system if it needs it.

Thanks Chris,

What size did you go with?

went with the biggest one listed at rockauto.com for my vehicle a 579 or 679

Thank you

Brand is less important than type. A stacked plate style cooler is much more efficient (for same footprint) than a tube & fin.

I went with tube/fin for a couple reasons. first, you don't have to worry about purging the air out of them like the plate style, and they are less restrictive to the airflow entering the cooling stack.

Did you guys bypass the cooler in the radiator or just add the cooler to the system?

It's usually recommended not to bypass the radiator cooler. If you do, your transmission will not have any cooling when you're backing up because no air is flowing though the cooler in that situation.

I bypassed the stock radiator cooler, but I have a fan from an H1 hummer, twin aftermarket coolers and deep transmission oil pan.

I also installed a small spin filter in the cooling circuit

I added in a spin on filter and temp gauge. Added the cooler after it comes out of the original cooler.

Make sure all the lines get routed so they are protected and not rubbing anywhere. Just has a hole rubbed through one of the lines on my suburban..
Naturally this happened while pulling a loaded trailer. I discovered the leak I. Rocksprings Wy on fri night... Great nothing open and no mechanics I just pressed on and made it to eastern neb. Without blowing the motor. Took 3 gal of oil tho...

I have the B&M #70264 on its way. I need to get it in and working before I head to moose camp in 2 1/2 weeks.

If you don't use the radiator cooler in series with an add-on cooler then the trans oil may not get warm enough in the winter to allow the trans to shift. The engine coolant warms the radiators internal trans cooler and therefore the trans oil. It happened to me.

or use THIS

but my 4L80e has never failed to function in the cold, although I do let it idle for a few minutes before moving, more for the diesel engine than the trans...

That argument holds no water. Coolant doesn't flow through the radiator until the thermostat opens. By the time the thermostat opens the tranny fluid is warm enough to negate any additional warming effects running it through the radiator would have.

holds no water... I see what you did there LOL

The only instance it does work is if it were very cold and you let the truck idle until it reached operating temperature, assuming your transmission pumped fluid in park, which many don't

I have to agree with you.

the thermostat in my link above is the cold weather cure.

Well it DOES hold water because it happened to a car I used to have. I put a big cooler in front of the radiator and didn't use the radiator cooler and the car would never shift up out of first gear in below freezing temperatures. Turbo 400 for inquiring minds. When I ran the cooler in series the trans would shift normal.