My trans cooler is from a Ford 6.0L Diesel. They are kind of pricey, but I got a good deal at RockAuto Parts Catalog. It has larger 1/2" openings so I m assuming it can move quite a bit of fluid through it. It is also the stacked plate design (I think that is what it is called) instead of the less efficient tube/fin design. No fan though.

It sounds like you are using the correct thermostat etc. 230* shouldn't hurt anything, but it does sound high for being unloaded....even on a hill in high temps. I forget the temp that the fan clutch is supposed to lock at, but I think the Over Temp light comes on at 240*. From what I have heard when the fan kicks in you do hear it and the temp drops pretty fast. That could be your issue. If that is sorted out, you could re-attach the trans to the radiator and be good to go. If it is still warmer than you like you could always adjust the fan to kick on at a lower temp.

 

Thanks for the info. Keep it coming.

So is it because of the location of the trans pan that it does not get any ambient/cooler air flow over it? If there was a way to get this cooler/ambient air to flow over it would a finned pan be beneficial at all, or would the boundary layer affect make it pointless? I am just thinking about things I have done on my track car to manage brake system heat. Increasing rotor size to increase the amount of energy it can absorb prior to reaching an unsafe temp and then adding cooling ducts to bring ambient air directly over the rotors to increase the cooling capacity.

How is the quantity of fluid for a trans established? Are there mathematical calculations that are used? I would think that you would want enough fluid volume that it be able to absorb a decent amount of heat/energy without huge temperature swings, yet have a small enough amount that the trans fluid cooling system could pull enough heat/energy out of it to keep the total volume within an acceptable range. So then could you use the heat produced by the trans (which would be a range) and the ability of the trans cooling system to shed heat and then use that to figure the optimal fluid capacity? I would think it would have something to do with the amount of energy it takes to raise the temp of a certain volume of ATF a degree. Do different ATF's have the ability to absorb more energy before they increase in temp?

 

you don't need your trans coolers fan to kick on so early.i have a t-stat on mine,that forces it up to to those temps.

what type of gauge (electric or mechanical) to you have for your engines coolant temp,and where is it's sending unit?
iirc,the oem mechanical engine fan clutch still passes as "good" when it engages as high as 237F at the upper rad hose (you don't want that beast killing power until you really need it too) so run the fan test to see if it can roar somewhere under 240F.if not,replace the clutch.if it does lock up,then your just not used to diesels.hook up and pull some grades to insure it locks and keeps it cool.don't be scared of her.treat the 240F peak range as you would any other normal operating temp.
https://www.ford-trucks.com/forums/8...ml#post7461511

 

If your cooling fan is kicking in like it should you will definately know. My new one wont unlock, with serp. belt it squeals the belt at 3k. Very loud and annoying. Need to go mess with the spring but havent got around to it. I have e-fans that i pulled because the radiator is somewhat plugged inside. Also as far as that goes, the e-fans perform very nearly as well as the mechanical, (both will get hot with a good load in the summer)

 

Here are a couple of links to other forums where they discuss a procedure for adjusting the temp at which our fan clutch would engage. If you were over 230* and your didn't engage then I would think it is either bad or it should be adjusted.

DIY Fan Clutch mod | The Truck Stop

Here is one that referances the first one I listed

Fan clutch modification

I could have sworn I found one with pics before, but I don't see it now.

 

You're the expert. You must have instrumented vehicles and tested this as I have. Let's go with what you say.

 

What, you didn't know that we all did that on the weekends for entertainment?

 

I dont think i need any instruments to have a basic understanding of physics. Example A. Put 1 qt of water on the small burner of the stove, put 1qt on the big burner. which boils first? B: Time how long it takes 1qt to boil on the big burner, now time how long it takes for 2.

Simply meaning, more fluid can absorb the same amount of heat as less fluid and be cooler (deep pan). As for the fins, more surface area = more heat transfer. (why the big burner will boil faster, similarly why air cooled engines have fins). This is why pickups have big 3/4 row radiators and cars have little 2 row ones. As for the hot air under the pickup, only thing even close to that i wager is inside the exhaust pipe. Hell, the air coming through my radiator isnt even 200*

 

You may want to reread Marks statments. He naver said anything about the surface area being the issue. It was the air temp around the pan and the insulating affect of the fluid sitting on the walls of the pan.

Also, how do you know the air temp coming out of your radiator? Your coolant temp is not the air temp.

 

I am running electric gauges the sender is in the port on the drivers side near the exhaust manifold where the over temp switch sender was. My over temp switch would come on at around 140f. So my temps could be higher then this at the top rad hose.

 

So your thought experiments trump the actual vehicle testing that I did? I'll leave it to the readers to determine which path to follow. I'm sure you believe what you wrote.

 

I read them. So are you telling me that you think fluid 2" lower in the pan is going to be 90* while the same fluid circulating in the pan, 2" higher is 180*

I know the air temp coming out of the radiator is at least less than 200* as the radiator is not over 200* Now that is coming directly out of the radiator. You honestly believe the air under the vehicle is hotter?

 

1. It doesn't matter what I, or anybody else "believes". In this case it matters what the data/facts say. My first idea was that the increases surface area from a finned pan would increase the transfer of heat out of the fluid and into the air. If the air flowing over the finned pan was cooler than the fluid then this could happen. It would also required that the fluid was moving over the pan. If these factors are not present than the cooling would not happen. Mark stated that he tested, I am assuming during his time as an Auto Trans Engineer at Ford, " the air temperature near the pan when the truck is working hard and the trans needs cooling the most". He found that the air temperature was higher than the trans fluid temp. Now he could just be lying about the test, but everything he has said so far in other threads has checked out, others have corroborated that he was an Auto Trans engineer at Ford which would put him in a position to do this type of testing. For that reason I choose to believe the data he claims to have gathered.

2. When did I say that fluid in the pan was 90* and the fluid circulating the pan is 180*?

3. You Do Not know the temperature of the air coming out of your radiator, you are making an assumption which may or may not be true. Actually, you only know that temperature of the coolant at the point where you are measuring it. Depending on the location and the flow pattern of the coolant it could be lower or higher than the temp of the coolant when it is in the radiator. As the air starts to pass through the radiator it would need to be cooler than the fluid temp in the radiator in order to pull heat from the coolant. So the air temp increases as it passes through the radiator (and AC condenser and trans cooler).....how much, I do not know. However, the radiator is not the only thing increasing the air temp. Air is flowing through the radiator which heats it, over the motor which heats it, over the headers and exhaust which heats it.....and then it hits the trans. When you are working the engine hard your EGT's can be in the 1000* range. That would mean that the headers and exhaust piping could be near that temp. All of those things have the possibility of heating the air to a temp over 200*. That possibility combined with Marks statement about the data he gathered makes me think that the possibility is a reality. You also have to look at the position of the trans pan. It does not stick down very far to catch the air flowing lower under the vehicle. It also has all the heated air that is flowing through the engine compartment pushing the other cooler air away.


All of this means that it is possible that finned trans pans don't cool as I originally thought, not due to the lack of surface area but due to the lack of cool air flow over the fins and the lack of hot trans fluid contacting the pan at a fast enough rate to facilitate the heat transfer. There are 3 things needed and according to Mark's data we only have 1. Since this is exact type of information that Mark made a career out of dealing with I choose to believe him in this manner.