This is a possibility. I have always thought the leak was coming from the input shaft. The older T86 transmissions don't use a seal, they have spiral groves to direct the oil back in. I have determined this is not the problem as the clutch, pressure plate and inside of the bell housing are all dry. There are only a few more possibilities. It could be leaking from the front of the case where the shaft hole is drilled. If that is the case, you would think you could see it? Perhaps the gear oil is working it's way out the side or around the case? If it continues to leak, I am going to attempt to pull the transmission back and seal the shaft hole with a gasket or sealer. I can't check the vent unless I pull the motor and transmission. That may be necessary.
I now know the best way to make sure the transmission and O/D unit are totally full. Removing both plugs and filling them from the O/D unit works best.