The Stovebolt Site Forums The Shop Area Driveline transmission cooler for 700r4

i have seen these heat sink type tranny coolers and have wondered if anybody has used them. also wondering if a guy can get by mounting one between the running board brackets under the truck. open to any discussion on these if you have any experience or opinion. thanks MO

10 bucks cheaper direct from Jegs I'm planning on a "tube and fin" type from Derale for use with a 700R4

I'd be leery of using a cooler that's unrated [for vehicle/towing weight], especially if it's not in addition to one already built into the rad - at minimum you need to have a trans temp gauge to keep an eye out for overheating, which is the single biggest killer of automatics

Bill

The guys at performabuilt.com recommend using a tube & fin cooler instead of the in-radiator one. They furnish one with their trannies. Their reasoning is twofold.
1. The in-radiator cooler actually heats up the trans because of the high engine heat.
2. The in-radiator cooler is full of trash from the failed trans you took out.

I'd recommend adding a trans temp gauge and watching for overheating no matter what cooler you pick.

regards,
Leon

#1 is a fallacy Leon, the trans temp needs to be in a range that's about the same as coolant temp, having a cooler in the rad insures the trans doesn't run too cool as well as too hot .... the factory wouldn't put the effort into combining the cooling functions if it was a bad idea, and note that the oil cooler is located on the cold end of the rad, measurably cooler than engine thermostat temp .... for #2 if you've blown a trans and don't flush the cooling lines thoroughly you'll have a learning experience

external fluid to air coolers are primarily additions for heavier use, like towing or racing, as a standalone cooler the one mo links would appear to me inadequate

Bill

Bill,

I was paraphrasing the content from Performabilt's website. I also tend to think that the quick warm-up should help the trans and I know that, in general, liquid to liquid heat exchangers work better that liquid to air heat exchangers.

Interestly, Performabilt is the only trans company I know of that extends their normal warranty to trans used for racing. Maybe their encouragement of the use of separate coolers, and providing them, has been something that helps to reduce the number of failures they have to deal with under warranty due to dirty in-radiator coolers.

Also interesting is their opinion of heat damage to auto trans. They seem much less concerned with it than I expected to read.

IMHO, you're giving GM way too much credit for doing the right thing on purpose. Even the old GM, that designed and built our beloved Stovebolts. I'm a 33-yrs exp Avionics design engineer. My entire career has been a struggle between my desire to build the best systems I can and the company's push to build the cheapest system that meets the schedule. I know it's not the same market, but I find it hard to imagine that automotive is significantly different.

regards,
Leon

Leon - for sure the designs in the stovebolt era were 99% lowest cost, but cheapest vs best is a trade off, and sometimes may be fixed upon by accident .... Ford in 99 changed from a rad trans cooler to a separate one in at least some trucks, was it better or were they trying to save a few bucks? - in 2000 they switched back after dealing with too many fried transmissions

my understanding of the heat problem is the more rapid breakdown of the trans oil to the point of no longer lubricating properly - all the info I've seen indicates a "useful lifetime" of the oil for a range of temperatures and recommendations for changing fluid vary with observed operating temps - I've been researching this extensively, which is why I recommend a temp gauge and paying attention to it

the primary project I'm concerned with is a 4L80 in a highway coach that way predates in-rad trans coolers - it will have generous standalone cooling with thermal controls for cold bypass, which some aftermarket coolers offer and can be had separately - my concern with the linked cooler is the lack of a GVW rating, while there are a number of companies offering a similar design/size, none seem to have a rating specified - I'd consider a cooler like that as a supplement, and there are a lot of rated tube and fin coolers that are shaped appropriately for frame rail [or running board] mounting

Bill

Bill, you're giving excellent advice to someone with his mind already made up. In other words, you're packing sand down a rathole. Let him fry a few transmissions with that Mickey Mouse cooler, and the next time you offer an experienced opinion, maybe it will be more welcome. Don't count on that happening, though!
Jerry

Sounds like these things are going to be the cause of blowing many 700r4 Transmissions. I would think that the Engineering research & development on these finned coolers should have some applications & ratings? If not, why are they being sold & installed?
I read somewhere that the transmission temp. should be kept around 175 deg Fahrenheit to properly cool the fluid.
My project is strictly a cruiser,170 hp 4.3 v6 700r4, absolutely no racing involved.
Would appreciate knowing, if anyone out there is using one of these on your ride.

i guess i wont use the heat sink and stick to the cooler in my radiator. the reason i asked you guys for an opinion is i didnt know if it would work well enough to cool the trans properly. i am not a trans guy. i just liked the sink so i didnnt have to run cooler lines all the way to the front of the frame. i also agree with the problem of radiator coolers getting plugged after a burnt tranny. we always replaced the radiator along with the tranny on suggestion from the tranny shop along with flushing the lines. when we installed a rebuilt or new tranny in a customers car. just to make sure there was no problems with them. thanks for the advice. MO

A always flush the cooler before installing a rebuilt transmission. Haven't had any problems doing that.