In radiators with built in transmission coolers, does it make a difference which direction the flow is? On radiators that have the cooler lines connect into the side of the radiator, I've always understood that the upper is the in or hot, and the lower is out or cool. If flow is flipped, would it cause any problem?
Transmission cooler flow direction?
- Thread starter Johnny248
- Start date
Counter flow should increase both output temps compared to flow in the same direction.
In my experience, one cooler hose was longer than the other, so I always knew which goes where on the radiator cooler. Are you making some sort of modification, like a bigger radiator or separate external cooler ???
counter flow increases temps?
there would be a difference, but not enough to make a fuss about. it is very small oil to water heat exchanger
I think you have it reversed. Lower side is in (from transmission), upper is return to transmission.
The cooled oil line is typically the one that goes into transmission the furthest away from the torque converter.
Yes, it is the log mean temperature difference…greater in countercurrent flow.
CleanSump
Site Donor 2026
in the bottom, out the top so air gets pushed out rather than trapped.
