As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
TIME SINCE MAGNETO FACTORY REBUILT, 448.4 HOURS. DURING INSPECTION (500-HOURS), DISCOVERED FRONT BEARING RACE WAS LOOSE IN FRONT HOUSING. NOT APPARENT UNTIL WIPED GREASE OFF TO REPLACE WITH NEW GREASE. SUSPECT CAUSE: MAXIMUM TOLERANCE FIT WHEN ASSEMBLED AT FACTORY REBUILD.