Tranny cooler hookup quick question.

[garr]

What’s the best way to tie in the cooler hose?

1. Cut into the return side soft line, use 3/8" double barbed fittings on each side to connect up the cooler hose?
2. Cut into the hard return line, slip the 3/8" hose over it & double clamp it?
3. Disconnect the soft line (On the return side) & slip the 3/8" hose over the flare on the hard line, Double clamp it & then use a double barbed fitting on the hose side? (Cutting the quick connect off the hose).

What do you guys recommend?

And should I use the constant pressure hose clamps or the standard screw on stainless band clamps, what is better?

Thanks in advance!!!!!!!!

 

[kastein]

Use constant pressure clamps or fuel injection clamps - the standard band clamps pop off of things and don't apply pressure all the way around. I also like to use two clamps.

1 would work.
2 would also work - deburr/smooth the ends of the line and flare them lightly, bubble flare if possible.
3 works if you push the hose all the way over the flared ridge and put the hose clamp on the far side of it. It would take an act of Congress to get the hose to come off with that setup. You may have to use a heat gun to warm the hose up a bit to get it to slide over that flare though.

 

[DieselSJ]

Not into the return - splice into the feed side. Proper path for trans cooler is trans to external cooler to stock cooler back to trans.

 

[Starboard M]

Not into the return - splice into the feed side. Proper path for trans cooler is trans to external cooler to stock cooler back to trans.

The path seems to be a heavily debated topic. However most do:
1 Trans-Cooler-stock radiator/trans cooler-return to trans
2 Trans-Cooler-return to trans

I would be curious as to how people are mounting the hookup as well since hopefully I will be installing a cooler this summer.

 

[kastein]

Where you put the cooler in the line is a religious debate I do not feel I should comment on :spin1:

Choose whatever makes sense to you and run with it.

 

[garr]

Where you put the cooler in the line is a religious debate I do not feel I should comment on :spin1:

Choose whatever makes sense to you and run with it.

I feel there is nothing to debate,
Every vehicle I have seen that had a factory towing package installed had the tranny cooler installed in such a way that the fluid went through the radiator first, then through the addidtional tranny cooler, then back to the tranny.
This is good enough reason for me to install my cooler this way.

 

[kj139]

I'm doing the same with the cooler after the radiator. It doesn't get that cold out here, but it gets super hot, so I need as much cooling as I can get. Question: How do you get the factory spring clip attachments off? I have tried using the x-shaped tool that is supposed to release them, but I can't get them off without destroying them. Any tricks?

 

[garr]

I'm doing the same with the cooler after the radiator. It doesn't get that cold out here, but it gets super hot, so I need as much cooling as I can get. Question: How do you get the factory spring clip attachments off? I have tried using the x-shaped tool that is supposed to release them, but I can't get them off without destroying them. Any tricks?

The B&M cooler I am installing has an internal thermostatic bypass that will divert the fluid out of the cooler without cooling it if it is too cold.

Spray all the gunk/dirt out of them with carb/brake cleaner before attempting to disassemble them.

 

[Sillyputty]

It would seem to me that routing the trans fluid through the radiator first would cool it to the temperature of the coolant, then through the tranny cooler to further cool the fluid makes more sense. My logic for this is due to the fact that the radiator is more or less a fixed temperature due to the thermostat regulating the coolant temperature, and the tranny cooler is independent and can further cool the fluid more. Just my 2cents. I may be wrong...

 

[DieselSJ]

It would seem to me that routing the trans fluid through the radiator first would cool it to the temperature of the coolant, then through the tranny cooler to further cool the fluid makes more sense. My logic for this is due to the fact that the radiator is more or less a fixed temperature due to the thermostat regulating the coolant temperature, and the tranny cooler is independent and can further cool the fluid more. Just my 2cents. I may be wrong...

Why would you want to put all that heat back into the cold side of your radiator?

Contrary to popular belief you actually can run a trans too cold. 170-180 should be your target temp. The theory for remote cooler first (as it was explained to me by some old transmission guy named Art C.) is that you use the big aftermarket cooler to pull as much heat out as you can. Then when it runs through the cooler in the radiator one of two things will happen - 1) if the trans oil is still too hot, then it will pull out additional heat without putting large amounts of heat into your coolant, or 2) if the trans oil is too cold, then it will put some heat back into it.

 

[iwannadie]

I feel there is nothing to debate,
Every vehicle I have seen that had a factory towing package installed had the tranny cooler installed in such a way that the fluid went through the radiator first, then through the addidtional tranny cooler, then back to the tranny.
This is good enough reason for me to install my cooler this way.

So with this logic we should have no worry about a fog light rewire to use a relay. After all fog lights came from the factory with all the power going directly to the cabin switch, that must be the correct way?

I am in the camp of not wanting to over cool the fluid.

 

[garr]

So with this logic we should have no worry about a fog light rewire to use a relay. After all fog lights came from the factory with all the power going directly to the cabin switch, that must be the correct way?

I am in the camp of not wanting to over cool the fluid.

What does trying to power HUGE aftermarket fog lights from the same circuit as the TINY Jeep oem units have to do with tranny coolers?

Every Mfg GM, Ford, Toyota, Chrysler, Nissan, MB, BMW, Volvo, etc... All run the tranny cooler after the rad. Why? Because it works.

I guess they must all have gotten it wrong all these decades, Legions of engineers who get paid big bucks to figure these things out are all wrong.
Because Bubba from the tranny shop says to run it the opposite way so he must be right!!!!!

 

[DieselSJ]

What does trying to power HUGE aftermarket fog lights from the same circuit as the TINY Jeep oem units have to do with tranny coolers?

Every Mfg GM, Ford, Toyota, Chrysler, Nissan, MB, BMW, Volvo, etc... All run the tranny cooler after the rad. Why? Because it works.

I guess they must all have gotten it wrong all these decades, Legions of engineers who get paid big bucks to figure these things out are all wrong.
Because Bubba from the tranny shop says to run it the opposite way so he must be right!!!!!

The factory setup on my F150 goes through the remote cooler first. And the guy that told me to do it that way was some dude named Art Carr.

 

[iwannadie]

What does trying to power HUGE aftermarket fog lights from the same circuit as the TINY Jeep oem units have to do with tranny coolers?

Every Mfg GM, Ford, Toyota, Chrysler, Nissan, MB, BMW, Volvo, etc... All run the tranny cooler after the rad. Why? Because it works.

I guess they must all have gotten it wrong all these decades, Legions of engineers who get paid big bucks to figure these things out are all wrong.
Because Bubba from the tranny shop says to run it the opposite way so he must be right!!!!!

Nothing to do with after market lights, my stock switch melted with stock lights. Just because the factory did it a certain way doesn't mean it is the best way. The engineers get paid mega bucks to find the cheapest/quickest way to do things, not the -best- way.

My line of thought is still why choose to over cool the fluid? It has nothing to do with being told by 'bubba', it just makes sense to me to have the fluid at a correct temperature.

Running through the cooler last will ensure that the fluid is as cool as possible. However, running the fluid through the radiator last will ensure it is close to the correct operating temperature. So, explain to me why ensuring the transmission fluid being as cold as possible is better than being at/near a proper operating temperature? What is the gain by running the cooler last other than thats the factory does?

 

[garr]

First I am sorry if I pissed anyone off.
Here is some good info my Brother in law tells me, His name is not Bubba :flipoff: , He has been in the tranny business for 30+ years, (It’s a family business) he owns 5 transmission shops.
ATF (Especially the AW4s old tech Dex3) is rated to last about 100K miles @ 175oF. For every 20oF increase in operating temp the ATFs life is cut in half. (It will last 50K @ 195oF, 25K at 215oF etc...), once operating temps get in the 225-240oF range Dex3 has had it, It will oxidize turn brown & will wreck your tranny really fast. So it is best to keep Dex3 at about 175-180oF.
The cooler in the rad does very little to cool the fluid, it will help warm it up when it is very cold outside.
He stated that most tranny coolers do have some kind of temp bypass that will prevent overcooling. The B&M cooler I am installing does have the low fluid temperature bypass, so there is little chance of overcooling the fluid. ​

 

[NEWYXJ]

Why would you want to put all that heat back into the cold side of your radiator?

Contrary to popular belief you actually can run a trans too cold. 170-180 should be your target temp. The theory for remote cooler first (as it was explained to me by some old transmission guy named Art C.) is that you use the big aftermarket cooler to pull as much heat out as you can. Then when it runs through the cooler in the radiator one of two things will happen - 1) if the trans oil is still too hot, then it will pull out additional heat without putting large amounts of heat into your coolant, or 2) if the trans oil is too cold, then it will put some heat back into it.

I agree! See my post #29 at www.naxja.org/forum/showthread.php?t=953485&page=2

 

[kastein]

First I am sorry if I pissed anyone off.
Here is some good info my Brother in law tells me, His name is not Bubba :flipoff: , He has been in the tranny business for 30+ years, (It’s a family business) he owns 5 transmission shops.
ATF (Especially the AW4s old tech Dex3) is rated to last about 100K miles @ 175oF. For every 20oF increase in operating temp the ATFs life is cut in half. (It will last 50K @ 195oF, 25K at 215oF etc...), once operating temps get in the 225-240oF range Dex3 has had it, It will oxidize turn brown & will wreck your tranny really fast. So it is best to keep Dex3 at about 175-180oF.
The cooler in the rad does very little to cool the fluid, it will help warm it up when it is very cold outside.
He stated that most tranny coolers do have some kind of temp bypass that will prevent overcooling. The B&M cooler I am installing does have the low fluid temperature bypass, so there is little chance of overcooling the fluid. ​

Now THIS is some info I have been looking for - hard numbers. I looked all over the AW-4 service manual I have and could not find them anywhere, never thought to look at the ratings for the fluid! Since XJs run at around 210, this makes me think it would be beneficial on an XJ to put the cooler after the radiator to (hopefully) bring the ATF down about 30 degrees after it leaves the radiator. Bringing it down a bit further than that might even be better because that would keep the fluid temp in the right range even after it's heated by use in the transmission.

 

[RCP Phx]

Now THIS is some info I have been looking for - hard numbers. I looked all over the AW-4 service manual I have and could not find them anywhere, never thought to look at the ratings for the fluid! Since XJs run at around 210, this makes me think it would be beneficial on an XJ to put the cooler after the radiator to (hopefully) bring the ATF down about 30 degrees after it leaves the radiator. Bringing it down a bit further than that might even be better because that would keep the fluid temp in the right range even after it's heated by use in the transmission.

Except that the 210* is engine temp not radiator temp!

 

[garr]

Except that the 210* is engine temp not radiator temp!

On a fully up to operating temp 2001 XJ (Running 65-70mph on the Highway for 40+ miles @ 65oF ambient), Using a calibrated heat gun, I read about 190-195oF on the tranny fluid return line right where it leaves the rad.
Keep in mind that this is all new condition nice red colored fluid, as I just completed 6 poor mans flushes with pep boys Dex3.

I have not checked but I can assume that when I drive the jeep hard in the sand that temp will be about 10-15oF higher as that is about how much hotter the radiator temp gauge rises at that time, So with a good condition cooling system under hard conditions (But not severe conditions like Towing a trailer or Climbing steep hills on a hot day) the AW4's tranny fluid probably reaches 210-215oF.
After I get the cooler installed I will take some more temperature readings & post results.

 

[kastein]

wake up... THEN post. I need to remember that.

Still, I'd prefer to stay on the low side temp wise rather than ending up at a higher temp then I wanted.