Adding Trans aux cooler need advice

1989GMCSIERRA said:

I always completely bypassed the radiator cooler when I install coolers. And I put a inline filter On the cooling system

I use the cooler from a 6.0 Ford on every automatic trans truck I own. My GMC is gonna get one also. I just get the 32 row coolers. I swapped out my 7.3 factory cooler to a 6.0 cooler back in 2004. 180,000 miles on a 4R100 and not one issue. I did replace the TC but other than that no issues.

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Could you be able to show me how you have the cooler set up

Well I only did the one on my 7.3. That was a bolt in deal. Pull the 7.3 cooler and instal the 6.0 cooler. The 6.0 cooler is literally 3x the size of the factory 7”3 cooler.

I happened to have the grille off on my GMC when I was swapping the coolers on my Ford and I just put the 6.0 cooler up against the AC condenser. I was gonna use some special threaded rivets called rivnuts riveted to the core support and some threaded rod or bolt with some tubing for spacers . The 6.0 and 7.3 coolers have these built in long metal tabs that mount to the radiator support. The 6.0 cooler is absolutely humongous. It may keep the trans too cool since it’s so large. I’m actually thinking of using a 7.3 cooler as it’s smaller but still very large for a 1/2 ton old truck. Right now I’m using a old Hayden cooler which in its day was considered large.

I’ve been so busy I’ve stopped the project on my gmc. Just haven’t had the time.

I’ll see if 8 can get some pics nex5 weekend or over thanksgiving as 8 have a few days off

The alum radiator I put in the 91 didn't have transmission cooler so I just run a Trucool 40K out front.
Here in the south east it doesn't get all that cold. But even if it's 50* in the morning my transmission fluid wouldn't even get to 100* by the time I make it to work 25 miles away.

But during the summer runnin it hard, temps would stay sane so works good.

What I do in the winter is make a plastic block off for the cooler. I been messing with it for awhile and now I have made one that covers the whole cooler and even a inch extra on each side. Temps get up to 135 or so on a 40* morning so not too bad. Evening time when it's in the mid 60s the temps only get up to 150 on the ride home.

Engine temps stay the same even with half of the radiator blocked off too.

Sent from my HiDiNg PlAcE

L31MaxExpress said:

I have seen it time and time again on Nissan midsize SUVs and Trucks but not on GM vehicles. Hot fluid from the trans should enter at the top of the in radiator cooler, the lower fitting should be the outlet into the external cooler, finally the external cooler outlet is the return to the transmission. I ended up adding a thermostat on my Express van to automatically bypass the external cooler when it was not needed. In 40*F weather at highway speeds my trans was only running 120°F.

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The Nissan's do that because if the oil filter/cooler housing, only a damn 0 ring seperating trans fluid and coolant. Replaced quite a few trans because if it, there is a board in there that once contaminated, it fails. Stupid design ND I've never seen it on a GM truck either.

Here's my trans and engine oil cooler setup. I made my own lines. The trans feed line goes to the bottom of the radiator then another line from the top of the radiator to the bottom of the auxiliary cooler then the return from the top of the cooler back to the trans.

RDF1 said:

The alum radiator I put in the 91 didn't have transmission cooler so I just run a Trucool 40K out front.
Here in the south east it doesn't get all that cold. But even if it's 50* in the morning my transmission fluid wouldn't even get to 100* by the time I make it to work 25 miles away.

But during the summer runnin it hard, temps would stay sane so works good.

What I do in the winter is make a plastic block off for the cooler. I been messing with it for awhile and now I have made one that covers the whole cooler and even a inch extra on each side. Temps get up to 135 or so on a 40* morning so not too bad. Evening time when it's in the mid 60s the temps only get up to 150 on the ride home.

Engine temps stay the same even with half of the radiator blocked off too.

Sent from my HiDiNg PlAcE

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Could you be able to show me how you made it fit

Derick said:

You must be registered for see images attach

Here's my trans and engine oil cooler setup. I made my own lines. The trans feed line goes to the bottom of the radiator then another line from the top of the radiator to the bottom of the auxiliary cooler then the return from the top of the cooler back to the trans.

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Looks cool what type of coolers are those

Dannothemanno said:

Could you be able to show me how you made it fit

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Made the cooler fit?

Sent from my HiDiNg PlAcE

Dannothemanno said:

Looks cool what type of coolers are those

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Just universal oil coolers on Ebay

Dannothemanno said:

So im trying to add an oil cooler to my truck since I just got my transmission rebuilt and I was wondering if it would be a great Idea to just bypass the cooler in the radiator or just connect it to it. And what would be a good cooler to add I was planning on adding this one but I'm not sure what all I'd need to do to make it fit

https://www.oregonperformancetransm...1uRqQXfnGDr1yDjAmiPVAuG0qfoNwUZRoCdJ4QAvD_BwE

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Never, never, never bypass the "in radiator" factory cooler. Talk to any good trans shop and they'll tell you the same thing unless they're stupid. Water draws heat off much faster than air. Adding an external cooler, (and inline filter), is a good mod but run through the stock cooler first.