If anything has been changed (bearings, spacers, shims, etc.) the manufacturing tolerances can require some tweaking of the spacer to establish the right preload on the bearings. Rarely, if ever, can parts be swapped around without making some slight changes in the spacing of things.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!