This overhaul kit for the rear axle bearings fits Datsun 510 1600 and 180B rear trailing arms. Contains 2 axle bearings, axle seal, spacer and is the only Datsun bearing kit that includes a new rear axle lock nut. The lock nut is a heavy duty type and unlike the original Nissan part is threaded to the flange face. The extra thread is good security if the end of the axle is damaged during removal.