On the A4LD transmission the lower line on the transmission is the OUT to cooler, upper is IN from cooler.
On the radiator trans cooler there is no IN or OUT, no internal valves or flow direction.
So these can be hooked up either way.
If trans cooler is on the side of the radiator instead of the bottom most hook up the OUT from trans to upper fitting on rad, although not required.
If you want any automatic to last longer then add a second transmission cooler to either of these hoses
For pictures Google: ford ranger transmission cooler lines images
