Bypass radiator/tranny cooler combo?

Gdetrailer wrote:

LarryJM wrote:
I'm not going to try and debate the point, but based on what I have read from both real auto tranny engineers and auto cooling system engineers the OTW cooler in the radiator does nothing to warm the tranny. This is because of basic PHYSICS the smaller mass, less fluid and the basic "FURNACE" that is called the tranny torque converter will outpace warming the tranny up over the considerable cooler bottom area of the radiator (IIRC there is somewhere around a 20 to 50/60 deg delta between the top and bottom of the radiator) and just the mass of the intially cold engine, larger coolant capacity and the heat being generated by basically friction only in the engine just lags the tranny too much to do any warming even in extreme cold weather.

With that being said IMO you can run a tranny too cold since for efficiency reasons trannys in general are designed to run somewhere in the 170 to 180 range so again IMO simply trying the slap on extra coolers is not recommended in general w/o serious consideration of the particulars of the vehicle being modified.

Larry

Actually, the "mass" of radiator "coolant" will PREVENT the transmission oil from getting COLDER in extreme cold weather, even with a COLD just started engine.

Consider this, if you live in the north, your transmission WILL be better off having the fluid routed through the radiator.

I have seen winter cold temperatures even in PA make radiator antifreeze turn to slush the moment the fan starts pulling cold air through the radiator. Imagine what will happen with your transmission fluid going through an aux transmission cooler that is placed in front of the radiator..

Personally, the OP is being way over the top scared for no reason.. Auto manufacturers have been routing the transmission fluid through a radiator loop since automatic transmissions came to being.. Perhaps as early as the 1950s..

What the OP is fussing over is a MANUFACTURER DEFECT in the radiator on a FEW MODELS or MODEL YEARS of one vehicle manufacturer.

If the OP is scared that they possibly may have a defective radiator, perhaps they should just consider replacing the radiator with an AFTERMARKET radiator and call it a day.

As I said I'm not going to try and debate this, but HERE is a post Mark made on this subject back on 09/02/10 10:44pm and neither you or I will win any arguements with Mark on tranny matters.

The in tank cooler will NOT warm the trans fluid in cold weather. In cold weather the coolant in the tank where the trans cooler is located will be near ambient. If it's 0°F out the coolant in this part of the radiator will be about 10°F or cooler!. This is from actual testing I did as a transmission cooling engineer. After extensive testing on many different vehicles in temperatures as cold as -40°F I never found a condition where the in tank cooler warmed the trans fluid at all.

Putting the radiator cooler after the air to oil cooler will result in warmer transmission temperatures when you need to cool the trans. The system is more efficient going from the trans to the in tank cooler to the air to oil cooler and back to the trans. That's the way all the manufacturers route the fluid because they have people that can calculate this is the right way to do it, and an extensive test program to prove it, too.

Mark

Former Ford Automatic Transmission Engineer, 1988-2007

SORRY, but I'm going to go with what Mark says;)

Larry