Hi Murf, yes it should be re-staked to stop it comming undone, I used an ajustable pin key for an angle grinder which also worked for the head bearing nut. From meemory, the book states a torque setting? I will try and double check later, useful to clean and add a small amount of copper grease to the threads, I did screw back and forth for a while to make sure the ring went on smoothly so as not to `fool you` into thinking it was tighter than you thought.