Does anyone know if the built in auto tranny cooler uses all of the factory rad or just a section of it?
I bought a hayden 404 tranny cooler and would like to install it, by-passing the factory in rad one.
Is this a good idea, or should I install the Hayden one in-line with the factory one?
Oh yeah, was checking out the auxillary cooler install in the tech section and noticed it was being installed in a 3.4L vehichle. Is the return line to the tranny on my 85 Runner on the passenger side as well?
Thanks,

Tye

All the A/T cooler consists of is a few loops of small copper tubing inside the lower radiator tank.

Perfect, thanks Roger!
So there really isn't a problem with by-passing the stock cooler if you are going to be replacing it with a larger one.
Inlet on the drivers side and outlet on the passenger side though right?

Tye

Couldn't you use both, and have the added capacity?

You sure could but put the aftermarket cooler on the discharge of the radiator cooler. The aftermarket cooler is going to cool the fluid more then the radiator cooler will, so you do not want to send the fluid into the radiator to be heated up.

I have the Auto as well, and I have been wondering what the little radiator is coming from the tranny. It is maybe 4 x 6 inches and on teh passnger side of the tranny. Is that a seperate cooler for the transfer case?

Radiators and I do not get along very well, or at least in my 86 5 spd. One summer I went through 3 rads and I cannot imagine the tranny working very well with coolant in there. So I want to eliminate that possibility and bypass the stock system all togeather.
The 4Runner that I am building is quite a bit larger than my truck was, so mabey it will not be a problem any more.
Thanks all,

Tye

Yup, tcase cooler.

I broke an old Taurus radiator apart one day just to see the AFT cooler. It was a tube heat exchanger about 2" diameter and 12" long (the coolant flows though the middle and surrounds the outside). It looked like it could quickly cool the ATF down to the coolant temp. Only thing is the coolant temp may be 190F (a cooler t-stat would help that).

I was considering removing mine from the loop (I'm adding these right now pics ) But I'm thinking in cold weather the radiator loop may actually help warm the ATF to keep it from over cooling and resricting flow. If you do remove it (or even if you don't) I'd use one or two of these self regulating coolers: http://www.importperformancetrans.com/coolers.shtml especially in a cold climate.

Hayden 679HD install

I also used the 679 cooler and routed "out" line from radiator to the Hayden and then back to tranny. If you were looking to bypass radiator I wouldn't be concerned if you step to the nearly sq. ft. 679.

I also installed a coolant sensor on OUT line of transmission so I can see the high temp fluid reaches in transmission... rest assured, the 679 does the job intended (imagine 22RE motorhome climbing mountains in summer).