Rotor Bearings and Seals

Tighten with pliers, as snug as you can make it, without marring up the nut. This will ensure everything inside is seated properly.
Then back off fully, and turn nut to hand tight, wothout pliers (thats as tight as your fingers can tighten the nut). Thats it.
Insert cotter pin (stops the nut from loosening over time).
Hope it helps