3d Oil Plug DF 200

[Photogimp]

ON the starboard side I have 3 oil plugs. I know the ones for the gear oil change, but near the one marked "Oil Level" is another one marked "Oil".
Upon removing, there was no oil dripping out.

Anyone know what that port is for? Is it normal for there to be no oil drip from it? How is it serviced?

[pniksnut]

both the top plugs are ventilation plugs. there are 2 chambers in the gearhousing . to be certain that both chambers are filled with oil you have to unscrew the 2 top plugs and fill it up from the bottom plug until oil come's out of the one marked "oil level" . put in the top 2 plugs , remove the oil filler or tube from the bottom plug and put this plug in also . otherwise one chamber wont be filled with oil and you can wait until bearing damage wil occur.