Unfortunately one of my decks hit a stump yesterday and broke a tooth off in one of the right angle gear boxes. That deck was one that was only used a few hours this summer because it is on an older 16hp machine. When I opened the gearbox I found it totally out of oil as well as the other two deck gear boxes. None had leaked out since hitting the stump, so the deck must have been dry for some time. I had noticed that the deck was seeming louder, but I wasn't sure. I don't usually check unless I see evidence of oil leaking into a blade cup. It seems that only the bearing on the bottom of the gear box with the damaged gear has a problem. I will go ahead and change the seals in both of the righ angle boxes to try to make sure the oil doesn't leak. Anyone else had a gearbox run dry for a while without damaging it? Note I didn't find hardly any metal filings. I thought I would find metal everywhere.