Transmission Cooler

Status
Not open for further replies.
C

cchase

Joined
Nov 3, 2009
Messages
4,021
Location
New England
So, after learning some new things about transmission coolers in a recent thread, I'm now at the stage where I'm ready to add in my external transmission cooler.

I'm adding it in series with the existing radiator transmission cooler. I've read both ways... transmission-->external cooler-->radiator cooler and transmission-->radiator cooler-->external cooler.

Is there a "significant" advantage either way? The only reason I ask is because it would be significantly easier for me to route it so that it enters the external cooler first and then goes into the radiator, but this seems to be the "less" popular way of doing things.
 
Last edited:
Originally Posted By: cchase
So, after learning some new things about transmission coolers in a recent thread, I'm now at the stage where I'm ready to add in my external transmission cooler.

I'm adding it in series with the existing radiator transmission cooler. I've read both ways... transmission-->external cooler-->radiator cooler and transmission-->radiator cooler-->external cooler.

Is there a "significant" advantage either way? The only reason I ask is because it would be significantly easier for me to route it so that it enters the external cooler first and then goes into the radiator, but this seems to be the "less" popular way of doing things.



There is a very significant advantage to routing it through the radiator cooler FIRST and then through the external cooler.

When you do it this way, the transmission oil sheds heat to the warm radiator water while the transmission oil is the hottest. Then it sheds additional heat to the coldest air coming in the front of the vehicle when it has already been cooled down as far as the radiator can cool it.

If you do it the other way, the hot transmission oil sheds its heat to the air first, and then the radiator cooler may not be able to lower its temperature much further beyond that.
 
It depends on your purpose.

Routing through the radiator last has the advantage of helping the transmission warm up quickly, and has higher total cooling for the transmission+engine since the transmission cooler will be running hotter.

Routing through the radiator first will keep the transmission cooler, albeit with much more variation. That might be useful if the transmission has an overheating problem and the engine does not have a problem.
 
Originally Posted By: 440Magnum
If you do it the other way, the hot transmission oil sheds its heat to the air first, and then the radiator cooler may not be able to lower its temperature much further beyond that.



Not sure I understand this part. Can you rephrase it?
 
Aftermarket cooler instruction always say:
trans -radiator - new cooler

In deep winter, you may want to block the airflow to the aux. cooler with a piece of cardboard/anything.
 
Okay, that's the way I just did it. The instructions did say that.

Now I just need to figure out a cleaner way of connecting the return hose from the external cooler to the return line for the transmission...

Any suggestions?
 
Clarification with a picture...

This is not staying this way. I don't do things unless they look like they could come from the factory similarly.

IMG_9742Large.jpg
 
Here's one way to use a thermostat that should make most of you happy. 180F and below it goes directly back to the trans. 180F and above it modulates the auxiliary cooler into the loop.

 
Quote:
I don't do things unless they look like they could come from the factory similarly.


In the upper right corner. Run your OEM flare fitting in one end ..another hose barb out the other.
brassppf90felbow-180x120.jpg
 
Right, this is what I want to do.

Where can I find an elbow fitting compatible with a flare fitting? This is where I have struck out so far. I can find elbows at Home Depot, for example, but not the type that can accept a flare fitting.

Also, that metal line that this fitting would go on isn't too flexible, which is my main problem. What's the "normal" solution?
 
Last edited:
It does appear that GM uses a flat thread there. I'm confused that you have the brass block with the proper thread to NPT on the rad end, but (from wherever you got it) they didn't provide the mirror piece.

Look here
 
Originally Posted By: Gary Allan
It does appear that GM uses a flat thread there. I'm confused that you have the brass block with the proper thread to NPT on the rad end, but (from wherever you got it) they didn't provide the mirror piece.

Look here



Yes... something like that but in an elbow configuration intead of a straight connection. I haven't been able to find such a thing yet but I assume it must exist...
 
Originally Posted By: cchase
I want in on your Favorites list...


lol.gif


Quote:


Thanks a ton, this should get me to where I want to be.


No problem. I've been there and done that on most of this fitting thing. I've already pounded my head against the wall in "you can't get there from here" type interconnections.
 
Originally Posted By: cchase
Clarification with a picture...

This is not staying this way. I don't do things unless they look like they could come from the factory similarly.

IMG_9742Large.jpg



Isn't that the top line the supply line. I thought you were wanting to go through the radiator cooler first and so you'd loop the aux cooler into the return line? Maybe I'm not looking at it right.
 
I can't say about other OEM applications, but I know that some GMC medium-duty trucks (school buses, etc.) use a cooler in the radiator and an external oil-to-air cooler in series. In these applications, the atf goes through the oil-to-air cooler first, then through the cooler in the radiator. And IMO, that's the preferred way to route these setups, though I'm definitely in the minority around here.

My reasoning is this: Maximum heat transfer will occur at maximum temperature differential. Therefore you will get the MOST out of your oil-to-air cooler by running the hot atf through that cooler first. This will get rid of a significant heat load before it is transferred into your engine's cooling system... so this improves overall cooling system efficiency. Plus, by running the atf through the oil-to-water cooler before returning to the transmission, you'll avoid over-cooling in the winter.
 
Originally Posted By: mechanicx
Isn't that the top line the supply line. I thought you were wanting to go through the radiator cooler first and so you'd loop the aux cooler into the return line? Maybe I'm not looking at it right.


On these trucks the top line is the return line. It's backwards from how it "should" be for some reason.
 
Status
Not open for further replies.

Similar threads

B
2001 Silverado 1500 upgrade Radiator and add Transmission Cooler
Replies
13
Views
913
Blang
R
Coolant in C6 Transmission Fluid
Replies
9
Views
512
Brons2
M
For Chrysler/Dodge Caravan/Plymouth Minivan Owners
Replies
16
Views
538
MaximumMini
9
Toyota 5S-FE (2.2L I-4) bleed cooling system
Replies
10
Views
968
lbhsbz
S
Filling a 4t65e transmission. Ran into a snag
Replies
3
Views
2K
JustN89
Back
Top Bottom