Either do the hand test (possibly dangerous) or get a laser thermometer. The cooler one is going to be the return line.

 

Yea I was gonna do that if nobody knew.

 

I cannot seem to pinpoint which is the outlet

 

I can't remember but easy enough to pull one hose off and check the flow direction quickly. Obviously be armed/ready with something to catch the fluid, towel of some sort or whatever. After just check the level and top up if needed. Not really risky IMO, when changing the fluid I remember doing that briefly to empty the torque converter/trans - it's not like you'll be there with it running for a long time till dry. Also better to do this when the car is cold of course.

 

I imagine that the outlet would be the lower line, similar to the radiator.

 

Yes that's what I was thinking. Try following the pipes to its cooler, the uppermost one is most likely outbound from trans.

 

Crawl under the radiator and see if you can identify the two transmission lines that connect to the back side at the bottom of the radiator. One line is on the drivers side of the radiator and the other line is on the passenger side of the radiator. The flow of fluid comes into the transmission cooler through the drivers side line, travels through the cooler and exits out the passenger side line back to the transmission. If you follow both lines up about 10 inches or so you will see that they both join up into a harness as they travel together back to connect to the transmission. The passenger side line comes out of the radiator with a metal tube that connects to a rubber transmission line. Ideally, we should use that one to drain the fluid since we could flush the transmission cooler. But the metal line connects to the rubber transmission hose too high up to comfortably disconnect the rubber transmission line from the metal line so I used the drivers side line.