Raise the rear of the vehicle and support the axle housing securely on jackstands, then remove the wheel and brake drum. Clean off all the dirt from around the differential housing cover, progressively loosen the cover bolts, and allow the lubricant to drain until the oil has stopped flowing out, at which point the cover can be removed. Turn the differential case for access to the lock screw, then remove the lock screw and pinion shaft. Push the axleshaft in and remove the C-washer from the inner end of the shaft, then carefully remove the axleshaft from the housing without damaging the shaft bearing. Inspect the axleshaft for galling, pitting, and hard spots; if any of these conditions are present, replace the axleshaft and the bearing. Use the inner end of the axleshaft to pry the oil seal from the end of the axle housing, noting that a new one must be used during installation. To remove the bearing, it may be necessary to use a slide hammer. When installing the axleshaft, ensure all parts are clean, then press in the bearing while applying pressure to the outer race only, making sure it goes in squarely. Install the oil seal and lubricate the lips with differential oil, ensuring the lips face inward. Complete the installation by reversing the removal steps, ensuring the housing cover and differential gasket flange are clean, applying ATV-type sealant to the cover, and refilling the differential with oil.