400 mile tow • trans temp gauge • etc

[Cobra]

Has anyone in the colder climate thought of putting a switch in to switch the fluid flow so we can have it stand alone in the summer and in line in the winter (wonder if it's even worth the effort for our 1 month summer lol)
Edit:oh... those solenoid operated hydraulic valves aren't cheap... anyone know how many GPM pass through our tranny coolers?

[LaGrasta]

I leave for a week's camping vacation (Yosemite National Park) tomorrow morning at 5am. Hmmm, dare I go and reconfigure it today, just prior to leaving?

[astrozam]

Take lots of pics for us. Are you going to check out half-dome?

[LaGrasta]

yeah, we'll check it out, but from the base.

[Meterpig]

This topic has come up a lot on Yotatech in regards to cutting off the radiator completely. Nobody, and I mean nobody has reported any problems with cutting out the radiator. I imagine that if you lived in a climate that routinely saw sustained temps of freezing or below, this might be an issue-and I say might. ATF is a super thin oil living inside of a machine that generates a lot of heat.

Just do it and if you don't like the results-hook it all back up.

[brokenwrench]

So you advise bypassing the rad cooler to lower the trans temps? I do understand being in SoCal, we really don't need to heat the trans fluid like other climates.

Anyone else have any advise on this?

Several problems with this flow of logic. The engine thermostat prevents the radiator from warming up the transmission fluid until it opens. If you are driving, the transmission has warmed itself up and "gone through the gears" so to say long before the engine is up to operating temperature. The optimal operating temperature for an automatic transmission is 165 to 175 degrees farenheit. This is theoretical as the temperature varies all through the transmission depending on what it is doing. The ideal temperature has to do with seal performance, nothing else. The mechanicals of the transmission are lubricated at any operating temperature. An automatic transmission operating below the idea temperature range may shift awkward but that is all. Some modern engines have a temperature sensor to prevent shifting into overdrive until engine operating temperature is reached.

The optimal arrangement is a isolated cooler (not inline with engine) with a fan and thermostatic switch. I have never seen an automatic overheat with any remote cooler stuck in front of the radiator, fan, thermostat or not. Nor have I ever seen an automatic operate at too low a temperature. If you want to get creative, take the thermostatic valve from a sandwich oil adapter and put it inline with you cooler. They start to open at 165 degrees.

Where I live in Canada it is routinely minus 20 degrees and certainly there are minus 30 days and the occassional minus 40 days. We bypass all in-radiator transmission coolers and I have heard of no mishaps.

If you want both your engine and transmission to live longer, take out the 195 degree engine coolant thermostat and put in a 165 degree one. You will also get about 3 or 4 miles to the gallon better mileage. Put on the biggest steel pan on your transmission that you can (Derail), put an inline filter on the out line on your transmission, you can use remote oil filters or transmission specific ones. Don't waste money on an aluminum pan. Upgrade the accumulator servo piston (outside the case), many use Corvette pistons but better after market ones are available and are cheaper. Install a "tow and go" shift kit. When you put on your deeper transmission pan, if you buy the filter extension it puts your filter intake back on the bottom of the pan where are the fallout accumulates. It is better to make a little suspension cage from gas welding rod and keep the pickup off the bottom of the pan.

I rebuild transmissions and engine for a living, about 50 each per year, no imports,

[LaGrasta]

An update: Still running through both the radiator and extra tranny cooler. Temps still rise uncomfortably when towing, climbing hills, severe stop and go, etc. But with all said, still original tranny and not showing any real signs of damage, 174k…