This gasket seals the joint between the angle gearbox housing and its cover on a fertilizer spreader. It prevents lubricant leakage from the gearbox and keeps contaminants out of the gear mesh. A degraded gasket causes oil seepage that can lead to gearbox starvation and eventual gear failure. The gasket is cut to match the original housing face profile so that clamping force is distributed evenly across the sealing surface. On reinstallation, clean both mating surfaces and apply the specified torque to the housing bolts.