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Should I bypass the radiator to my transmission cooler. I have rebuilt the transmissio, put in a shift kit, a larger transmission cooler and a large Derale cooling transmission pan, Well this was to make a fission towing with my 1994 F250 with a 7.3 IDI.
Should I bypass the radiator to my transmission cooler or not?
The water transfers heat away from the ATF much better than air can.An auxiliary air cooler alone doesn't work well at idle and driving slow.
There's actually no such thing as a cooling trans pan as explained by Mark,as he states the surrounding outer layer of ATF keeps airflow from effecting the fluid and therefore doesn't aid in cooling at all.
I suppose even if they did work you wouldn't want one because you couldn't regulate it via a thermostat like you can put inline,in front of an aux cooler.
With 175F trans temps being ideal,a much larger pan isn't ideal either because now it takes longer to reach ideal temps.The one good thing about adding more capacity is you can extend your fluid changes a bit more.The down side is,it's going to cost more when you do change it though lol.
What you said makes sense. I'm going to weld a coupling in the stock pan for the temp sensor and put that on. I have been having an issue shifting from 2nd to 3rd unless it has warmed up for a while
thanks
Instead of putting the sensor in the pan you'd get a much better reading putting it in the test port on the side of the trans. And you don't need to weld anything to do that.
I got under the truck and looked. I thought what you show in the photo wass the test port, but was sure. I was going to send a photo to confirm, but you beat me to it.
Thank you very much for all your help, it is much appreciated.
You can check my sig for the part number I installed in my truck. It came with metal brackets that can be bent to mount the cooler, and various fittings. I chose to just run rubber hose from the radiator output, and the transmission input line where it ends behind the bumper.
Others have also installed coolers that came stock on 6.0L diesel Superduty's. Replacements can be found on Rockauto for pretty cheap.
Thank you both for your input. I purchased the Tru Cool 4588 24 plate cooler. That doubles my transmission cooling capability as I already have the factory plate cooler.
I just got back from a 1400 mile trip and the transmission temp never got above 165 deg.. The second half of the trip my GVW was 15k. I had two passes to go over and the temp came up about 10-15 deg. and then went right back down. After the sun set and the outside temps dropped off the trans. temp stayed right around 150deg.
Does anyone know what size and thread pitch the bypass fittings are? I just rebuilt my bypass valve and it looks like I’ve buggered the trans case threads on the front port. The front fitting mics out at .518 and 13mm is .512. The rear fitting mics out at .650 which is 16.5mm. My thread gauge says they’re 1.5 thread pitch, but I want to make sure before I cause more damage.
Thank you both for your input. I purchased the Tru Cool 4588 24 plate cooler. That doubles my transmission cooling capability as I already have the factory plate cooler.
I just got back from a 1400 mile trip and the transmission temp never got above 165 deg.. The second half of the trip my GVW was 15k. I had two passes to go over and the temp came up about 10-15 deg. and then went right back down. After the sun set and the outside temps dropped off the trans. temp stayed right around 150deg.
You only want 1 aux cooler so you don't get too much pressure drop.The small factory aux cooler should be taken out so you have;
Out from trans - Into radiator - Out from radiator - Into aux tru-cool - Return to trans.
It also sounds like you might want to install the tru-cool thermal bypass (you can buy them separately). Though 150F @ the test port is acceptable,that's really the minimum temp you want to see.Seeing how you saw the minimum while at 15k gross,it's more than probable that you wont see minimum operating temps when running solo and when cold weather comes.
In a perfect world,your trans temp gauge would read 175F @ the test port when you turn the key on and when you turn the key off,regardless of the outside temps and regardless of gross weight (although 150F - 225F is acceptable and a safe range).
With the LPD4739 40k tru-cool and thermal bypasses on my trucks,I hang right around 180F 99% of the time.
(after about 20 mins to a 1/2 hr of driving)
