Abstract: An oil seal for a locking differential mechanism. The seal assembly includes a generally flat plate with a first generally circular oil seal adjacent an outer margin of the flat plate, a circular inner margin defining an opening in the flat plate with a second oil seal surrounding the inner margin, an oil outlet opening lying in an otherwise imperforate area between the first and second margins, and a cover for the flat plate with the cover and plate defining between them a passage for oil extending from a point radially outside the first seal to at least a point adjacent the oil outlet. The seal takes in a supply of oil from the differential sump and supplies it through the oil outlet to a multi-plate clutch which is activated only when the two axles undergo rotation relative to each other and thereby actuate a Gerotor type oil pump.