The other day I replaced the sector shaft seal on my '47 3100. When refilling the gear box I noticed a small hole in the fill plug (about an 1/8"), drilled vertically from the top to the bottom. This seems like an easy route for moisture to enter the gear box. It doesn't look like it would have come from the factory this way and likely is the handy work of a PO. There's no mention of a vent in the shop manual either. Are these steering gear boxes supposed to be vented? I may get a new plug and drill a 90 degree or tee vent hole configuration, if needed.
Thanks,
