[chiphead]

I run mine through a B&M stack plate cooler mounted in front of the radiator, not using the radiator cooler. I've got an autometer tranny temp gauge mounted on the trans output line going to the cooler. Once the car warms up, it registers 130-150F, engine temps 160-180 in 70F weather.

[SRR]

Originally Posted by chiphead

I run mine through a B&M stack plate cooler mounted in front of the radiator, not using the radiator cooler. I've got an autometer tranny temp gauge mounted on the trans output line going to the cooler. Once the car warms up, it registers 130-150F, engine temps 160-180 in 70F weather.

My 455 powered TH400 Buick has a Derale tubed pan on it with an external cooler not run though the radiator. My trans temp gage never goes over 140-150 degrees. I can't see a reason to heat the trans fluid to engine temp. A good look at that posted chart will tell you why.

[Cobrabill]

Originally Posted by SRR

My 455 powered TH400 Buick has a Derale tubed pan on it with an external cooler not run though the radiator. My trans temp gage never goes over 140-150 degrees. I can't see a reason to heat the trans fluid to engine temp. A good look at that posted chart will tell you why.

Then why did the factory engineers want the fluid returning to the trans at engine temp?

[Pontirag]

Originally Posted by Cobrabill

Then why did the factory engineers want the fluid returning to the trans at engine temp?

because at engine operating temperture, its still lower than the spike temps some tranny's experience under extream use. and operating tranny's at that higher temp for even a short period of time will cause internal damage and shorter life down the road.

and the factory does not want tranny fluid returning to the tranny at engine temperture per se. they want it to be cooled down to engine operating temperture when it is operated in a fashion that will raise its temp above opertaing temps to a point where it may cause internal damage. All party's concerned agree that if the tranny could operate at a cooler temp than engine temp it would be better still. Even the largest external cooler operating in winter time does not cool the temp much below 160 degrees which is an ideal temp for hd/towing use.

(not drag racing though!) Drag racing bearly raises the temp enough to be of concern so most racers remove the cooler and lines all together and just run the fluid right back into the tranny.

the radiator cooler is a comprimise in effectiveness and cost for a majority of users. those others that stress thier tranny's are either lucky, living on short time or have an external cooler. the radiator cooler is not effective in these small % of users.

You asked what temp is my T stat...180. I currently have a smog 400 and a manual tranny in my car and a 4 core ac cooling system so its not relevent. running without a t stat it ran so cool it did not even register on the guage

But I have 2 1957 GMC trucks with hydromatics and niether of them have any type of tranny cooler. but for 1 ton and above a cooler is standard and it runs through the radiator. as for mine. I cant even hook up a cooler if I wanted other than some sort of finned pan.

I have also owned corvairs/pg's with no cooler at all either. even some of the cheapest PG cars came from GM with out coolers of any kind.