None of my machines have any sealed gearboxes, but there are some shafts that run in bushings, etc, and they all drip a little oil. If they don't, then I am not oiling them enough. Gotta remember, the oil that runs out is also taking dirt and contaminants out with it. The more contaminants I get rid of, the better, and cleanup is as easy as a quick wipe down with a rag. If there is any staining on the paint, a little WD-40 or diesel fuel will usually take it out.