Can not find any leaks so where is transmission fluid going?

It could be going is in the radiator from a ruptured transmission cooler. check the color of the anti freeze.

Use a dry very light or white cloth or washrag. run it along the end of the transmission to see if the rear seal bearing is leaking. You should get some wet oil if it is. It will leak out under driving conditions and leave droplets on the roadway. Check where the shifter linkage is also for slight leaks. Follow the trans cooler lines if you have one and where the lines are making connections for rubber seal leaks. How much fluid are you losing and over what period of time? Is the pan dry and or clean? How about the drain plug? Is it dry?