Datsun Roadster & Fairlady Rear Axle Bearing - NISSAN
New style sealed rear axle bearings. Seal simply pops out to repack when necessary. The advantage of this bearing, over the stock unit, is it's protection from a failing inner axle seal,(see part#1569), thus permitting gear oil from the 3rd member traveling along the axle and entering the bearing fouling the packed in grease. Since this bearing is not meant to run on gear oil bearing failure will occur. Periodically check the bearing and the seal. Install the bearing so the seal it faces the differential 3rd member.
NOTE:This bearing is the correct Koyo automotive bearing, NOT, to be confused with the Koyo industrial version that has a smaller inner ID.