Because taking the inner primary off is a pain in the butt it is generally considered best practice to replace everything you can while you have it off.....all the seals and the belt if its getting on in years.....a mate of mine (who is a known tightwad) has had his primary off 4 times because he wouldn't listen to the Spanner......

 

Got the 1 1/8, need the other two. Definitely will check/grease swing arm bearings while I'm in there.

 

You can get small cup type freeze out plugs to plug the hole in the inner primary for about a buck each. Just put a little sealer around the edge and tap it in.
John