I use a bit of gasket shellac when the outside ring of the pinion seal is bare metal. If the outside of the seal has a soft material covering, I would not. With the soft outside covering a light oil might help for a smooth installation. With all double lip seals (front crankshaft seal), pack between the two lips with grease. In any case lube the inside of any seal or its rubbing surface with some grease or oil so you do not have a "dry" break-in upon first use. The solid axle boot is a soft rubber and seals fine as long as the correct size clamps are used. Some like to use a sealer on the seam of the split boot, although not recommended by BBB.