Gear box may have a fill/check plug on side of it. If so, remove plug and top off with 80W-90 oil until it comes out the plug.My old Snapper has a right-angle gear box at the rear of the deck with no apparent way to lubricate it. Whereas the three sindles for the blades have grease fittings. Just wondering why no provision for a component that drives the whole shebang.