Who has gone around the heat exchanger , trans

[JFaughn]

With the weather warming up & the post count going up on hot tranies I thought I run this up the flag pole .
Or just thought about , the exchanger helps to warm up the trans is cold weather , but seems to get it hotter in summer , swapping heat with eng.
So thought about eliminating the heat exchanger , next how much is it needed in cold weather , if needed , then having a valve to reroute for hot & cold seasons .

 

[LMcCary]

Who has gone around the heat exchanger

Yes, on a 1978 D200 crew with 98 5. 9 auto. I took two 18 X18 coolers stacked with an electric fan and mounted under the bed like some of the 1993's came w/heavy duty towing package. Can't remembe who, summit, jegs etc, has a similar cooler ready made.

LMcCary

 

[rweis]

WAY BACK several years ago I asked Bill K about taking the heat exchanger out for summer operation. He said NO, emphatically NO!



His reasoning as I recall was the transmission fluid does need to be at an operating temperature. There is a cooler (and some of us have added additional coolers) to help cool the fluid, but the fluid does need to be at operating temperature for the transmission to function properly.



Mine runs about 150* locked up. Just be sure it NEVER goes over about 225* and if it does, change it as soon as possible.



I also asked him about transmission spin on filters. Again NO! He wants the owner to open up the pan and look inside every 12k miles to see how things are going. Change the filter, adjust the bands, clean out the inside of the pan. Generally know what is happening inside the transmission.



Bob Weis

 

[JFaughn]

Most all of that sounds right , except the heat exchanger , almost every other light truck / car does not have one , and almost all have an auto trans . , if in some cases , winter - can not wait to warm up , everything els warms up ,
could put a valve in with a choke cable , watch gauge - on / off .
But I was looking for info for making decessions , not some one said , I do not mean to dump on your comment , its just the way I work , gather info / facts , understand how / why some thing works or not , fixing things means under standing how they work ,
Its my opinion the dodge detuned the eng & added stuff like this because they were too cheap to put a trans that was up to the job , my intension is to put in a Georand trans , so the need for micky mouse is less .
Thanks

 

[rweis]

"But I was looking for info for making decessions" sometimes that knowledge comes from those you consider to be experts in the area you are gathering knowledge ie Bill K in this case.



I often go beyond the available body of knowledge (VP44 fuel temperature, mechanical fuel level sensors that report back to the DC canbus are examples) and discover it myself generally through experimentation.



However, I would suggest if you do not like the information provided by someone with your open ended question disregard the sender and move on.



"I do not mean to dump on your comment" either!



Report back and let us know what you ultimately did and how that worked with your setup. That way you can add to the available body of knowledge.



Notice the DTT 89%? I agree the dodge transmission would not stand up to the task I use it for - RV towing.



Have you asked Georand? What did they say?



Bob Weis

 

[Lightman]

Most automobiles with automatics do indeed have a heat exchanger. They are just in a different place. The transmission coolers that are in the radiator tank are a heat exchanger. The cooler is submersed in coolant which transfers heat either from the coolant to the transmission fluid in cold weather or transfers heat from the transmission fluid to the coolant when hot. Dodge has just gone a different route with theirs that is actually more dependable and more exspensive to boot. The heat exchanger accomplishes the same function.

 

[tlgdiesel]

Most automobiles with automatics do indeed have a heat exchanger. They are just in a different place. The transmission coolers that are in the radiator tank are a heat exchanger. The cooler is submersed in coolant which transfers heat either from the coolant to the transmission fluid in cold weather or transfers heat from the transmission fluid to the coolant when hot. Dodge has just gone a different route with theirs that is actually more dependable and more exspensive to boot. The heat exchanger accomplishes the same function.

Perfectly Said

 

[Bandit1]

i was told by a DTT installer when i took mine off that it wasnt needed. that he had taken his off and installed a second cooler, bc cooler is better. ever notice why a trans shifts firmer and more positive when the fluid is cooler bc itis thicker. i am sure if it is to cool than that is not good, so may have to take it easy for a while in winter.

 

[JFaughn]

A combination of being out of the repair buis for a number of yrs & memory getting old , I forgot about the trany cooler in rad .
An issue may be that like having a gauge that normal opp. range is in the middle , then almost any reference I've ever seen just showed high temps being an issue , all those references leveeing out the bottom end [ needs some temp ] so what would the min. temp needed for good trans life ?
thanks guys

 

[Mhannink]

this is just fromt what ive gleaned over the years but i would think 100 to 200 degres would be best for long transmission life

 

[rweis]

I think there is some kind of a thermostat inside the transmission for the fluid. Mine warms up to 150* (hot line) and then stays there summer and winter (florida) unless there is a lot of unlocked driving. When locked it stays at 150* when empty (ie not loaded). The pan temperature sits pretty much at 150* as well.



Bob Weis

 

[Fishin Guide]

I simply relocated mine when the twins went in. But I kept it. After running without and on a passive radiator setup, the difference was night and day.



If it was a track vehicle, it would have been chucked for weight and simplicity sake.



The heat exchanger helps keep the fluids warm in the very cold climates your truck may or may not see. And, it is a very effecient worry free cooler.



Do you NEED it? Maybe not. But it's nice to know you can drive from AZ in 80+ degree temps up to Canada in the 0 degree temps without worrying about bolting a part on and off the truck.



Just my . 02



Dave