Magnaflux the balancer hub to check for cracks. It's not uncommon for a hairline crack to develop along the edge of the woodruff key slot which allows the press fit to go away. Otherwise, it's probably a matter of slight motion between the crank snout and the hub that wears both items a little. The fix is to drill and tap the crank for a bolt and machine a step into the hand crank lugs for a flat washer to bear against. Use red Loctite on the pulley hub to take up the clearance.
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!