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Help with my cooler idea?


AZFX4

Well-Known Member
U.S. Military - Veteran
Joined
Feb 7, 2011
Messages
198
City
Arizona
Vehicle Year
1990
Transmission
Automatic
So I was planning (possibly foolishly) To replace my stock tranny cooler with a B&M Super cooler and an electric fan. In the process of doing my 4.0 swap I jacked up all the damn hard lines going to the tranny cooler so I figured oh well ill just put in a remote cooler and fan and ill be good. Is this a bad idea? Everyone is telling me now that a remote cooler should be used IN ADDITION to a stock cooler not in place of it. I dont see why since the stock cooler was a POS compared to this thing. Anyway im going to buy a new radiator and it will probably come with a cooler in it so should I run some hoses up there and use it or am I safe with the remote cooler only? I do live in AZ...
 
The cooler in the radiator works by exchanging the heat with your coolant. This does two things:

1. Warms your tranny fluid when it's colder than the engine coolant
2. Cools your tranny when it's warmer than the engine coolant

For standard driving #2 is generally going to be sufficient for your cooling needs. When it's not you add an auxiliary cooler after the radiator cooler to get rid of extra heat. By bypassing your radiator cooler you eliminate #1, which means it takes longer for the transmission fluid to warm up and can cause additional wear on your transmission unless you get one that has a bypass. You also negate the advantages of #2, which always cools the transmission fluid even if you're not moving; an auxiliary cooler only works when you're moving unless you devise a fan assembly for it. From what I've read, if you insist on bypassing your radiator cooler you're supposed to really oversize the auxiliary cooler in order to compensate.
 
The cooler in the radiator works by exchanging the heat with your coolant. This does two things:

1. Warms your tranny fluid when it's colder than the engine coolant
2. Cools your tranny when it's warmer than the engine coolant

For standard driving #2 is generally going to be sufficient for your cooling needs. When it's not you add an auxiliary cooler after the radiator cooler to get rid of extra heat. By bypassing your radiator cooler you eliminate #1, which means it takes longer for the transmission fluid to warm up and can cause additional wear on your transmission unless you get one that has a bypass. You also negate the advantages of #2, which always cools the transmission fluid even if you're not moving; an auxiliary cooler only works when you're moving unless you devise a fan assembly for it. From what I've read, if you insist on bypassing your radiator cooler you're supposed to really oversize the auxiliary cooler in order to compensate.

Well theres something confusing about what you said there. 1 - The stock trans cooler that came with both the A4LD that was behind my 2.9 and the A4LD that came with my 4.0 were NOT inside the radiator in the first place. They were simply small coolers placed in front of the radiator the same way that an aftermarket cooler is. 2 - The kit I bought does have a bypass and a fan with and inline thermostat and it measures 11" by 7" by 3/4" which is about twice the size of the cooler that came with both trannys that I have. Im by no means arguing that one cooler is better than two but it seems like this would be sufficient.
 
Not saying you're wrong, but I've never seen that before. Every auto I've seen, GM, Ford, Import, whatever, has used at least the radiator cooler. I looked up your BII on EBSCO's repair manual and it says that the Auto Tranny's had coolers running to the radiator. I suppose someone could've bypassed them for whatever reason (had a MT radiator lying around), but there isn't any need to, and my understanding is that it's detrimental in the long run.

The key to remember is that oil to water is quicker and more efficient than oil to air. And your radiator and engine cooling system is much bigger than any auxiliary cooler you can buy.
 
Yeah Im sure these were not put on by someone thats how they came from the factory. They have the exact same lines and they are the exact same coolers.

you can see the cooler in the bottom of this pic.
picture.php
 
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My 93 ranger has lines that go to the radiator and then to the separate cooler in front of the radiator. Every vehicle I have seen runs through the radiator cooler first, and then to the auxillary cooler second. Maybe someone lunched the original radiator and installed a manual radiator. Just a thought, but it might have happened. I have heard the stock secondary coolers are not as efficient as an aftermarket, but I plan to insatll another tranny cooler in place of the stocker shortly. Thermostat controlled and fan cooled should be better than stock.
 
mine has both.. cooler on the outside of the radiator and the one inside the radiator. and honestly, it needs both...

remote cooler? idk.. i'd just put the stock stuff on there and call it a day. unless you need MORE.. junkyard it... get the hard lines. no biggie.
 
AZFX4...

the cooler in front of your rad. can always be upgraded.


im using a cooler from a 10,000lbs+ RV/ motorhome (16 pass), and i live in heavy snow conditions (for SoCal ) and i have the cooler after the rad. cooler, the trans doesent over hear or over cool.
 
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The fact that yours was not running through a pre cooler is prolly what killed your transmission to start with. The fact that the donor was set up the same way makes that transmission also suspect.

I was just looking at my Dually (had to go on a rescue mission to get my mom and my blazer from the side of the road) and even my Powerstroke/E4OD combo has a pre-cooler in the radiator and a frackin huge monster sized auxiliary cooler (looks suspiciously like the cooler from a 6.0L powerstroke).

neither an auxiliary cooler or the radiator pre-cooler is sufficient by themselves. they have to work together to do the job (I don't care what summit racing says, RV life and Heavy Haulin both agree with me, so does the tech article I read in Muscle Mustangs and Fast Fords)...... although your choice in auxiliary cooler is most excellent.
 
The fact that yours was not running through a pre cooler is prolly what killed your transmission to start with. The fact that the donor was set up the same way makes that transmission also suspect.

Killed my tranny? There is nothing wrong with either tranny, I have never had a single problem with either one. But it sounds like I need to run it through the rad. cooler first for the best cooling. Im not sure If I want to go back and mess with the hard lines though. I may just run hose all the way.
 
what ....... my bad, you doing a 4.0L swap then?
 
Yes...well its almost done, in the process of hooking things back up. Hence the cooler question.
 

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