BugDuckley,
If you look at a cutaway of that bearing, you will see it is a semi-typical thrust bearing with massive upper and lower races to handle the tough chore it was designed to do.
Although it certainly isn't a high speed precision bearing, I will bet its first rate.
My guess is that the formed steel dust shield is
rubbing slightly on one of the race OD's.
Finding that piece as a separate item could be a chore. Personally, I would run it, but as my dear old dad often said, "take my advice and suit yourself".
Good luck.
Stuart
