Auxuliary transmission cooler

[Grieke]

When 4 wheeling in low gears or even heavy towing in the mountains, my trans temp goes up more than I like.

Has anybody tried the Mopar trans cooler offered in my 2004 Dodge accessories brochure?

Is there an even better one out there (OEM fit)?

 

[Texasrattler]

You already have two transmission coolers. These trannys require a certain fluid flow rate and if you add a third cooler in series you can do more harm than good. If you correctly add a cooler in parallel you may improve cooling.



Pete

 

[Grieke]

I was under the impression that a larger cooler would replace the original one. No third cooler should be installed, or am I wrong. I just need more cooling, so it seems.

 

[Matt400]

Check out the last few posts on this thread:

https://www.turbodieselregister.com/forums/showthread.php?t=129688&page=2&pp=15

 

[Tim]

I was under the impression that a larger cooler would replace the original one. No third cooler should be installed, or am I wrong. I just need more cooling, so it seems.

How hot does it get? You do realize that you can over-cool an automatic trans, right?

 

[BHolm]

Over cool the trans????? Not likely, in fact that is virtually impossible unless you can find a way to get the fluid down below freezing or something.



I would be interested to hear what temps you are seeing and where you are taking the readings from. Maybe we should determine if the actually is a problem first?

 

[Grieke]

The temp has reached 220 or in one case 230. That is in 4x low first gear, crawling up a steep forest service dirt road.

I also experience similar temps pulling my travel trailer up a 12% grade in the moutains from zero in first gear.

What I don't understand is, why shoud it be so difficult to increase the size of the cooler by replacing it. Has anybody ever done this? Why does Mopar have an aux trans cooler in their offering if there is no need for it?

 

[macdaddy]

The temp has reached 220 or in one case 230. That is in 4x low first gear, crawling up a steep forest service dirt road.

I also experience similar temps pulling my travel trailer up a 12% grade in the moutains from zero in first gear.

What I don't understand is, why shoud it be so difficult to increase the size of the cooler by replacing it. Has anybody ever done this? Why does Mopar have an aux trans cooler in their offering if there is no need for it?[/QUOT



Wether using 4wd for rock crawling, or towing loads. If you allow the torque converter to remain in fluid coupling mode (unlocked) while under load the trans will rise to those temps every time, especially when there is little to no air flow through the front radiator. This will also put extra load on the engines cooling system as well. All that being said those temperatures are normal for the driving conditions mentioned above.



Mac

 

[BHolm]

220-230* is getting up there, I would also be a little concerned. Macdaddy is right though, it is un-avoidable in a low speed situation. The convertor is slipping like crazy which produces the heat you see.



I don't see any reason why you couldn't swap out the external cooler for a larger capacity model. If you search RV sites you should be able to find one with a dedicated thermostat controlled fan. That would provided better airflow and cooling at low speeds when you need it.



The temps you are seeing also require that you strictly adhere to the fluid change interval. If you do have a failure, you will want the documentation that you did the service on time. That and the fluid will need changing after seeing those temps for any amount of time.

 

[TCDiesel]

The 3gen"s have a complex trans cooling system ,The main cooler (water cooler & the auxiliary air to air that has a internal thermostat that is serviceable) the auxiliary coolers thermostat is set to running temp I think it is about 120* any temp below this the auxiliary air to air cooler is bypassed. Some option you have are you could install a 5. 9 gas auxiliary cooler but this would be a plumbing nightmare since the gas cooler is bigger but the lines enter on the rider side, the gas cooler dose not have the water cooler. A fan override switch this would rob you of some hp. I would install a electronic operated fan with a manual switch 140* to 180* and mount it on the condenser. Also you could remove the thermostat 3. 7 and 4. 7 engine do not use the thermostat it is removed, this would cause a problem in cold weather and would effect the shift patterns.

 

[Grieke]

OK, but the key question still remains. Does anybody have any experience with the Mopar aux cooler offered in the accessory catalog?