Is this too much of a trans cooler? 4L60e, Tru-Cool 40k in Winter

R

redhat

Joined
Dec 7, 2012
Messages
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I have had a Tru-Cool 40k transmission cooler sitting on the shelf for a year now. I initially wanted to install it on my Tahoe but at the time got concerned about not having enough heat in the unit during winter months. My factory transmission cooling arrangement is Trans -> radiator -> external factoryauxiliary cooler -> back to trans.

For reference, here in Western New York (Buffalo) it is on average 25-30 degrees for a few months of the year during December to February. But then again temps do fluctuate a lot. We have also had 2-3 week long spells on -5 through -15 degrees in years past. To sum it all up, we do get some pretty cold temps on occasion.

With that said, am I correct in thinking that simply removing the factory auxiliary cooler and substituting in the Tru-Cool (still run fluid through the radiator) would still provide enough heat in the trans for OK shifts and performance? Thoughts?

Below is a pic for size comparison.

1717426351945.webp
 
redhat said:
I have had a Tru-Cool 40k transmission cooler sitting on the shelf for a year now. I initially wanted to install it on my Tahoe but at the time got concerned about not having enough heat in the unit during winter months. My factory transmission cooling arrangement is Trans -> radiator -> external factoryauxiliary cooler -> back to trans.

For reference, here in Western New York (Buffalo) it is on average 25-30 degrees for a few months of the year during December to February. But then again temps do fluctuate a lot. We have also had 2-3 week long spells on -5 through -15 degrees in years past. To sum it all up, we do get some pretty cold temps on occasion.

With that said, am I correct in thinking that simply removing the factory auxiliary cooler and substituting in the Tru-Cool (still run fluid through the radiator) would still provide enough heat in the trans for OK shifts and performance? Thoughts?

Below is a pic for size comparison.

View attachment 222957
Click to expand...

You can call Tru-Cool and ask them if this Cooler has a Bypass in it. How this works is when the trans fluid is thick or cool, the fluid bypasses the Cooler. When the Fluid gets thin and Hot the Trans Fluid goes through the Cooler.
 
Doesn’t the TruCool LPD design with wider passages at the inlet so that cold ATF flows there - then as it thins - the fluid will move into the whole cooler (part of low pressure drop tech)
 
Brian123 said:
You can call Tru-Cool and ask them if this Cooler has a Bypass in it. How this works is when the trans fluid is thick or cool, the fluid bypasses the Cooler. When the Fluid gets thin and Hot the Trans Fluid goes through the Cooler.
Click to expand...
I think it’s just variable passage TFA …
 
4WD said:
Doesn’t the TruCool LPD design with wider passages at the inlet so that cold ATF flows there - then as it thins - the fluid will move into the whole cooler (part of low pressure drop tech)
Click to expand...
Yes it does, they claim that. Which is where my confusion lies. Is that enough? The OE cooler doesn't have any bypass or LPD, so in essence this would mimic the OE cooler.

I guess what I'm curious on is, would this cooler keep the trans too cold ever?
 
redhat said:
Yes it does, they claim that. Which is where my confusion lies. Is that enough? The OE cooler doesn't have any bypass or LPD, so in essence this would mimic the OE cooler.

I guess what I'm curious on is, would this cooler keep the trans too cold ever?
Click to expand...
Is there actual thermostat available for such set up?
 
redhat said:
Yes it does, they claim that. Which is where my confusion lies. Is that enough? The OE cooler doesn't have any bypass or LPD, so in essence this would mimic the OE cooler.

I guess what I'm curious on is, would this cooler keep the trans too cold ever?
Click to expand...
Not sure what year they started the thermostat - but we elected to gut one bcs it failed and overheated the transmission …
Think Clinebarger has commented on this …
 
Last edited:
i have a 40K on my 80e. i have bypassed the radiator cooler as that is how the transmission is “heated” from factory. there is no need for a thermostat if you drive it gently until
up to temp if the radiator is bypassed.
 
on my Mitsubishi the transmission fluid runs through external cooler first, then the radiator tank cooler. so if the external cooler works too good the radiator will reheat the fluid I think. and my transmission wont lock the torque converter until it's warm

plenty of Australians have 2-3 transmission coolers and/or bypass the radiator tank cooler and have no issues, but it's not too cold in Australia

maybe Molacule or Clinebarger know how cold is too cold for an automatic transmission
 
Brian123 said:
You can call Tru-Cool and ask them if this Cooler has a Bypass in it. How this works is when the trans fluid is thick or cool, the fluid bypasses the Cooler. When the Fluid gets thin and Hot the Trans Fluid goes through the Cooler.
Click to expand...
This is how the Tru-Cools are designed. The first two rows are larger diameter and where the fluid passes easiest when it’s cold; the other rows have a smaller diameter orifice that only really flows significant volumes once the fluid has heated up and thinned out. 👍🏻
 
I put a big cooler on my old Taurus. Only thing I ever noticed was the torque converter wouldn't lock up for 20+ miles on real cold mornings because the fluid would take so long to get up to temperature.
The good thing is, the transmission never failed.
But the car still rusted in half before 100K miles.
 
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