I have been researching this topic on the web and am still not sure which train of thought to believe.

I just bought a Hayden 30,000 (radiator-style) cooler, per my tranny builder's recommendation, and he told me to bypass the cooler in the radiator, running only from the Hayden.
Then somewhere along the line I read that you can overcool a transmission and that you should run the fluid to the hayden, THEN to the radiator so that it stays "warm"...THEN I read that you should put it to the rad first and THEN the hayden!! Hayden's own site says that you cannot overcool the trans...some other sites mentioned that only for winter driving should you use the rad...

At this point I am tending to agree that I should just bypass the SOB and run JUST the hayden...but I wanted some opinions/expiriences first.

Thanks guys

 

I'm also running a large Hayden with a 2400 lockup converter. Believe me you won't over cool the transmission.

Main idea behind running the factory cooler then to the aftermarket is to use the engine coolant to warm up the transmission fluid for cold starts. Course that should only be a concern if you drive in the winter.

Mine bypassed the factory cooler allowing me to install a GM 31x19 radiator. I do no driving in the winter. Trans still gets plenty warm.. 160ish all the way up to 200+ degrees at times.

 

Totally agree. by-pass the radiator and run tranny cooler independantly. The convertor will build up enough of it's own heat you dont need the engine to help, and it works both ways, once the fluid gets hot you dont need the residule heat from the tranny fluid saoking into the coolant system.

"Optimum" transmission temps are 160* for getting the proper vicosity, but if/when you install a tranny temp gauge you'll find it's not to hard to reach that and exceed that temp goal.

Same here crusing around town and driving the interstate I'm 120* but when I stand on it or at the race track it'll shoot to 160-180* real quick.

 

Thanks for the replies guys...one more quick question: the HOT line, out from trans-into cooler, is the bottom, correct? That is where I want the temp sensor?

 

I would say put it in the return line. I've heard if you put them in the feed line to the cooler it can cause jumpy temperature readings from the converter spinning then locking up.