451138 seal Fits NationalOne New Aftermarket Replacement 451138 Oil Seal National This National (Federal Mogul) oil seal is a radial shaft seal designed to retain lubricants and exclude contaminants in rotating shaft applications found on construction equipment, agricultural machinery, industrial equipment, and related machinery. The seal seats in the housing bore and rides on the shaft to prevent oil leakage from axles, transmissions, differentials, and other rotating