Aux Trans Cooler Question

[mclairmo]

Can a relatively small auxiliary trans cooler (about 6 inches by 12 inches) cool an automatic tranny by itself without the simultaneous use of the in radiator fluid cooler? Vehicle is light, will not tow anything and no racing around. Trans fluid will pass through cooler four times before going back to the tranny.

[lofly'a]

have seen this one used a few times on the board. 68shortstep has used it on at least 2 builds and he has had great results from hanging it on the frame under the passenger seat direct to the transmission. this is the route i plan to take. pic.......................

[lofly'a]

forgot pic...

[big_al_71]

this is what I used.....b&m front mounted

[gcburdic]

Originally Posted by big_al_71

this is what I used.....b&m front mounted

Hey Al,

I like that!!...so is it just mounted to the rad support??...Also, is it routed through the tranny cooler in the rad too??...If not, could you route it that way??...What additional plumbing will it take?

Thanks

[lofly'a]

heres another, listed as 5 x 12. summit has a multitude of coolers that are stand alone, and many that are made for towing that'll fit in a 6 x 12 space.

[gator2511]

Originally Posted by lofly'a

heres another, listed as 5 x 12. summit has a multitude of coolers that are stand alone, and many that are made for towing that'll fit in a 6 x 12 space.

I am using one similar to this one without going thru the radiator. It keeps the tranny below 160 deg. except when stalled in heavy traffic for an extended length of time or under stress trying to back my travel trailer into a tight space. I just bought a 16 pass cooler with a fan to put in series with my existing cooler. They both have fans. My trailer is 6,000 lbs. and the one cooler does fine except under the conditions listed above. They fit behind the grille. You can see it on Summit's site Part # Der-15900.







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[big_al_71]

Originally Posted by gcburdic

Hey Al,

I like that!!...so is it just mounted to the rad support??...Also, is it routed through the tranny cooler in the rad too??...If not, could you route it that way??...What additional plumbing will it take?

Thanks

Geoff It is NOT connected to the radiator at all, I ran the lines to the tranny and back to the cooler. I used high pressure hydraulic hose with anm fittings on both the cooler and the tranny. IT is bolted to the front of the radiator support and so far almost a year later no leaks or issues at all.

[hounddogs!]

Originally Posted by mclairmo

Can a relatively small auxiliary trans cooler (about 6 inches by 12 inches) cool an automatic tranny by itself without the simultaneous use of the in radiator fluid cooler? Vehicle is light, will not tow anything and no racing around. Trans fluid will pass through cooler four times before going back to the tranny.

Yep. My Grand National is set up that way. It's a 10" square supercooler ripoff with a small fan. It had to go horizontally under the pass headlights because the intercooler and the rad are taking up all the space behind the grill. The trans might get to 180* after extended stop and go driving, it's usually under 150*

[mclairmo]

Mine looks like that Summit 5x12 cooler. So, am I ok to run just the small 5x12 cooler all by itself with no small fan hooked up to it? I don't want to fry my trans fluid.

[hounddogs!]

IMO, you'd be fine without a fan if you can get the aux cooler mounted in front of the rad. The only reason the GN has a fan is b/c the cooler is tucked up behind the air dam, where it wouldn't get much natural air flow.

[kelsfine69]

Originally Posted by big_al_71

Geoff It is NOT connected to the radiator at all, I ran the lines to the tranny and back to the cooler. I used high pressure hydraulic hose with anm fittings on both the cooler and the tranny. IT is bolted to the front of the radiator support and so far almost a year later no leaks or issues at all.

So 2 bolts at the bottom, does it vibrate? is it solid? It would seem that it would need something at the top?

[WorkinLonghorn]

I would run it through the radiator after the cooler if you plan to ever tow or use your truck hard.
Also,don't just tie it up to the radiator with the supplied zip-tie things. It should be mounted securely on it's own.
There are other opinions on this I know. The above reqs come from experience as a former employee (27 years ago) of a major transmission shop chain.
edit; I just read your post again about light useage. I'd still go through the rad.

[big_al_71]

Originally Posted by kelsfine69

So 2 bolts at the bottom, does it vibrate? is it solid? It would seem that it would need something at the top?

There is Zero Vibration and it is mounted solid. My truck shakes alot because of the built motor but the cooler is there solid.

[mclairmo]

Originally Posted by WorkinLonghorn

I would run it through the radiator after the cooler if you plan to ever tow or use your truck hard.
Also,don't just tie it up to the radiator with the supplied zip-tie things. It should be mounted securely on it's own.
There are other opinions on this I know. The above reqs come from experience as a former employee (27 years ago) of a major transmission shop chain.
edit; I just read your post again about light useage. I'd still go through the rad.

I always thought that you put the trans fluid through the radiator first to cool it some and then through your auxiliary trans fluid cooler to cool it even more and then back to the trans. The oem relied on just the in radiator cooler so it must be able to cool the trans fluid at least a little right?

[lofly'a]

here's what i believe, and also others on the board have agreed based on a previous discussions and our experiences. your engine operates at 180 degrees "nominally", and flowing transmission fluid thru 180 degree water is not an added benefit unless your transmission has already overheated, then the engines radiator will cool the fluid to whatever the engines temp is at that point which is usually too late to prevent some degree of damage. a stand alone unit, and/or one with it's own cooling fan is far better than cooling tubes routed thru the engines radiator side tanks. the factory setup is fine if you are not towing or hauling much, but the design is not the best setup that your transmission can have to perform and survive, especially in my part of the country.......JMHO.

[WorkinLonghorn]

Lofly'a,yeah that makes sense and I don'tremember their rational about going through the rad after the cooler but I think that maybe it was that the trans is designed to operate at a given temp.The viscosity of the ATF is set for a certain range of temps.
During a hard pull with full throttle shifts the fluid will be leaving the trans at greater than 300 degrees.I think the plan was to knock the temp down so that it wouldn't impart too much heat to the radiator coolant,possibly contribuiting to an overheated engine.
And when you were not at the extreme heat levels,then the radiator temp would ensure that the fluid was within design temps.

[gator2511]

I would also suggest that you invest in a tranny temp. gauge. Thats the best way to see whats going on with your cooling. If I lived up north I'd run the tranny cooling lines through the radiator to help it warm up on cold days but down here its not required and lets the radiator cool the motor and the aux. cooler cool the tranny.

[lofly'a]

your insight makes a lot of sense also longhorn, sometimes i love this place and the knowledge to be gained and shared here.

[mclairmo]

My engine does run a little too warm for me. Maybe if I run the trans fluid through the auxiliary cooler only I can drop the engine temp a little? That would be awesome.

[FRENCHBLUE72]

Im throwin a small single pass aluminum one on my v-8 powered yota so thats what I tell ya to do..