4l60e cooler line flow

[Jason7121]

What direction is everyone running there 4l60e lines to the radiatior. I was told bottom line on trans is discharge and goes to top of radiatior and top line on trans is return and goes to bottom of radiatior. Curious how everyone is doing theres

[87Skier]

It doesn't matter, but I put the hot side (being pumped out of transmission to cooler) on the higher port of the cooler, and the return side on the low side. The thinking here is that it doesn't need to be completely full for fluid to get back to the transmission if the cooler isn't completely full.

Really it shouldn't matter though, since having a empty cooler would mean that the ATF isn't being cooled, but I would rather the transmission has enough fluid to operate than to worry about it being low on fluid and the fluid being too hot.

[Jason7121]

Ok I figured if hot out is pumped to top of cooler it would return easier on bottom of cooler back to trans

[54Caddy]

Lower line on trans to lower on radiator, upper from radiator to inlet on external cooler, then outlet to upper line on trans. If no external cooler than upper from radiator to upper on trans. Routing it opposite way could cause aeration in fluid. And we all know that’s not good for your transmission

[Jason7121]

Monster transmission told me opposite of that lower line at trans is hot out and goes to upper on radiatior.

[ga-stepside]

The upper transmission fitting is the return from the cooler into the tranny.
The lower transmission fitting is the outlet from the tranny to the cooler.
So- OUT the bottom, IN the top.

[Jason7121]

In the top of radiatior correct

[davepl]

It varies by transmission and it does matter, I'm told. TH400 is backwards from 200-4R, for example. 4L60E return is on the top. 4L80E is on the lower. And so on...

Any blanket statements about which way it goes without being specific to your model of transmission has about a 50/50 shot of being right.

USUALLY though, and this is a gross generalization, I've noticed that they're typically laid out so that the lower port goes to the lower port on the radiator. That might not be 100% though!

[Jason7121]

Yeah it shows return port is top fitting on trans which means it goes to bottom of radiatior is how I take it

[Bigdav160]

The top of the radiator is the hottest and the bottom the coolest.

In newer car tech, they use hot transmission oil from the converter to warm the radiator up faster to control exhaust emission sooner.

In my truck the hot oil from the transmission goes into the top fitting on the radiator.

[54Caddy]

Originally Posted by Jason7121

Yeah it shows return port is top fitting on trans which means it goes to bottom of radiatior is how I take it

Look at your crew cabs lines and route the same way. I’ve always routed the way I’ve stated with no issues.

[Jason7121]

Everyone says different things I did find this image and think I'll route them this way.

[VetteVet]

Here's another diagram.





It shows the hot from the trans to the bottom of the radiator,then to the bottom of the cooler and out the top of the cooler and back to the top of the trans.

The hot fluid from the trans is going to the cooler port on the radiator and then out the top of the radiator through the external cooler back to the transmission.

[Bigdav160]

Just confuse this topic further I have this quote from an automotive manual I have:

If installing an additional transmission cooler onto a vehicle, the lines should be set up so the fluid flows from the converter to the add-on transmission cooler in front of the radiator. From the add-on cooler, it should flow to the factory heat exchanger in the radiator before returning to the transmission. This arrangement allows the fluid to warm up in cold operating conditions to prevent excessive transmission wear and harsh shifting.

[ga-stepside]

Another thing I found when I installed the coolers in my cars and the truck.
Orientation as follows:

[LH Lead-Foot]

I always found it was interesting that 200+ degree coolant is cooler than a transmission. Unless you are pulling, towing or hitting the metal under the pedal, it is a good idea to have a cooler. Since the top of the radiator get the engine hot coolant, make sense to run the red juice into the top of the radiator's internal plate cooler, to the bottom, where cooler coolant lives, out to cooler, then back to the transmission. For those of us who live on the North side of global warming (We called it weather when I was younger), I think I have seen a bi-metal valve that helps to keep the fluid from getting to cold...or is that even possible unless your cooler is the size of an old A/C condenser. Thoughts?