with all the overheating issues many 3rd gens have, wouldn't it be better to remove the added heat that the trans fluid adds to the radiator, by running only a external trans cooler? would this add any un forseen problems?

 

Only thing may be over cooling the trans fluid. Why do some cars overheat and some don't? What have the "overheaters" done to their cars? I like the idea (and look) of louvered hoods to let the hot air do what it wants to do. Go up, and out.

 

I read on here somewhere that ventilating the hood keeps the radiator air deflector from doing its job. ever hear that one?

 

Non-sense...

 

Some guys have done it, mainly to keep from burning up the transmission in case they lose a head gasket, or something similar to where you dump all the water out of the radiator. Me, I installed a cooler and plumbed it in the return line to further drop the temperature of the fluid. If you were to use it as the sole cooler for your transmission, I'd get the largest cooler that will fit.

 

my working theory is; if there is no heat being imparted to the radiator from the trans.the coolant SHOULD run cooler.and yes, I will buy the most efficient cooler I can get. BUT can a trans run too cool?

 

Like most mechanisms I think an auto is designed to run in an optimum temperature range so maybe it can be too cold even though too hot is the usual problem. Auto experts?

 

As for hood vents I can't think of any way they would reduce the effectiveness of the deflector. I removed the rubber sealing strip from the rear of my hood when running auto-x in near 100 degree temps. You could feel the hot air pouring up and out of the gap with the car sitting still and the fan not even running. Hot air really wants to go up not back down under the car.

 

Hi Rusty ,

Yes , a transmission can run too cool , and your more expensive trans. fluid coolers will have a thermostat bypass to help regulate the fluid's temperature . Just like engine oil , trans, fluid must reach the proper operating temp to both lubricate properly and to boil off any atmospheric condensation that may have formed during the last warm up / cool down cycle . (that tiny vent at the top of the trans. case can pull in a small bit of humidity after parking it on a damp muggy day)

 

My advice is sort out the cooling/over heating issues.

My experience with not running through the radiator cost me two TH400 rebuilds in the late 70's.
We had put a 454/TH400 combo in my '57 Chevy PU, used a radiator out of a MH...just wanting to keep the engine cool..I had to have the tanks cut down and sorta "V'eed" together, the tranny cooler had to be removed.

So I ran just an external cooler.

After the same shop went through the tranny the 2nd time, they asked me how I could be destroying it so quicky...we started talking about it, and that's when I found out (as OrangeBird says) my set up was a big no no.

 

In the grand scheme of things the amount of heat transfered TO the engine coolant FROM the transmission fluid is negligible. The flow rate of the ATF is tiny compared to coolant, and seeing as how the ATF should never be much hotter than the engine coolant so it shouldn't be an issue at all from a heat transfer standpoint.

If your overheating fix the problem instead of trying to put a band-aid on it and making a lot of extra work & trouble for yourself. Do you have the factory air deflector installed?

 

I did that, and removed the hood insulation, not because of coolant temperatures though. My intake temps were about 25 degrees above ambient, and after I did that they dropped to about 10 degrees above ambient. Yes, technically you can have your trans fluid too cool, but I'm fairly sure that it would take a really big cooler to do that. Basically from the factory, the thought process was to have your transmission help heat up your coolant, and then once it's up to temperature, the engine coolant helps keep your transmission temps in check. Now, if you're still stock, then you have other issues you need to address first. Hoses, water pump, airflow (I cooked a 305 because the space between the condenser and the radiator was half full of leaves), heater core, etc. A good tune up will help as well, and don't forget to burp out any air that might be in the system. If you aren't stock, and things changed after your last mod, look more carefully into what you changed.

 

it was more of a theoretical question. my car runs as it should. I was thinking about the trans vs coolant ,maybe being a problem for others

 

Gotcha.