Thanks JB, the manual is indeed as clear as mud, but I'm starting to get the idea.
I have not changed the output shaft bearings, therefore the spacers have not
been disturbed and the old O rings are already in place.
Looking at the manual, I was thinking some O rings went on before screwing in the
locking nut/bearing which caused the confusion.
It maybe a good idea to take the spacers off and replace the O rings anyway. Do the spacers
lever off the splines reasonably easily or would I need to pull the bearing off to free them?