Transmission Temp - did I make a mistake?

[mikez71]

SUPER writeup, links and all!
Thanks swathdiver!

 

[Geotrash]

My model didn’t come with a cooler, so I mounted one to the passenger side of the radiator.

Wait… did you plumb this cooler in series with the oil to water cooler built into the radiator end tank or did you take that out of the loop? The temps you’re describing are typically what you’ll get without the radiator’s cooler in the loop. Needs to be plumbed in series with it and after it in the circuit.

Do you suspect the heat coming off the cooler/slightly blocking the radiator impacted the performance of the radiator and led to higher trans temps?

That was my experience with a Trucool 40k mounted in front of the radiator when towing. I mounted a Derale 13960 with its own fan below the front bumper and it made all the difference.

 

[Jhwhite05]

Maybe, do you have a photo of the installation? If it's a big 40K cooler, when they are mounted in the stock location in front of the radiator, they wind up increasing the coolant temperature which in turn heats up the transmission fluid as it first passes through the radiator.

They guys on here have learned to mount them a little lower down, so their shed heat will not heat up the coolant in the radiator.

I mounted the Derale 13960 passenger side of the radiator, as far left as I could get it. Here’s a picture.

Maybe that’s the culprit. Maybe I should have mounted it on lower bumper?!

 

[Marky Dissod]

... mounted the Derale 13960 passenger side of the radiator, as far left as I could get it. Here’s a picture.
Maybe that’s the culprit. Maybe I should have mounted it on lower bumper?!

For better results, mount it behind the lower grille that's under the bumper.

 

[swathdiver]

I mounted the Derale 13960 passenger side of the radiator, as far left as I could get it. Here’s a picture.

Maybe that’s the culprit. Maybe I should have mounted it on lower bumper?! View attachment 402084

Is that cooler covered with a shroud and fed by a fan? That may be the issue right there. Are your baffles around the radiator still intact?

For better results, mount it behind the lower grille that's under the bumper.

5.3s don't have an opening like that originally. His grill looks aftermarket so he might have it open down there.

 

[Geotrash]

I mounted the Derale 13960 passenger side of the radiator, as far left as I could get it. Here’s a picture.

Maybe that’s the culprit. Maybe I should have mounted it on lower bumper?! View attachment 402084

Yes, but you missed my most important question: did you plumb it in series with the cooler in the radiator end tank?

 

[Jhwhite05]

Wait… did you plumb this cooler in series with the oil to water cooler built into the radiator end tank or did you take that out of the loop?

This is the key question! Thank you for teasing it out. This is what I asked of my mechanic: that the Derale be “plumbed in series after the fluid-to-fluid cooler in the radiator” after having read about that on this forum.

….that said, I never visually confirmed this was done correctly after picking up the vehicle. That’s on me - I need to research and find a cooling diagram to understand what to look for to confirm it was done correctly.

Is this video representative of what it means to plumb the cooler in series with the oil to water cooler built into the radiator end tank?

 

[Geotrash]

This is the key question! Thank you for teasing it out. This is what I asked of my mechanic: that the Derale be “plumbed in series after the fluid-to-fluid cooler in the radiator” after having read about that on this forum.

….that said, I never visually confirmed this was done correctly after picking up the vehicle. That’s on me - I need to research and find a cooling diagram to understand what to look for to confirm it was done correctly.

Is this video representative of what it means to plumb the cooler in series with the oil to water cooler built into the radiator end tank?

Gotta mark that video as public or the rest of us can’t see it.

It’s pretty easy to tell visually. There are two parallel metal lines that come forward of the engine at the bottom toward the radiator on the passenger side of the truck. The line on the left as you’re facing the front of the truck should run directly to the bottom of the radiator end tank on the passenger side. The line on the top of the end tank should then go to the external Derale cooler. Then there should be a line that exits the Derale cooler and connects into the other metal line going back toward the transmission.

 

[Fless]

Gotta mark that video as public or the rest of us can’t see it.

It’s pretty easy to tell visually. There are two parallel metal lines that come forward of the engine at the bottom toward the radiator on the passenger side of the truck. The line on the left as you’re facing the front of the truck should run directly to the bottom of the radiator end tank on the passenger side. The line on the top of the end tank should then go to the external Derale cooler. Then there should be a line that exits the Derale cooler and connects into the other metal line going back toward the transmission.

Click on the "Watch on YouTube" link.

 

[Geotrash]

Click on the "Watch on YouTube" link.

Thanks! As far as I can tell, he plumbed it in series with the radiator end tank cooler AFTER the Derale. And therein lies. the problem and why he's seeing the temperature spikes. Per the revised version of the upfitters manual, it needs to be plumbed in series with the end tank cooler BEFORE the Derale. I made the same mistake when I first plumbed mine in and had similar results.

@Jhwhite05, change the order of the cooler in series and you won't have any more problems. The reason is that the radiator’s cooler is much more efficient at heat transfer, so when the fluid coming off the torque converter is hotter than the coolant (the fluid there is probably 20° hotter than is shown on the gauge because the gauge reads the pan temperature), it takes a big chunk of that heat out and does a great job of setting up the Derale for success in cooling the fluid even further before returning it to the pan. Similarly, in cold weather the radiator serves to warm the fluid.