What was found
MAGNETO DISASSEMBLED FOR 500-HOUR MAINTENANCE, BALL BEARINGS, PN 1081806 AND PN 2202, FROM ROTATING MAGNET ASSY WERE OBSERVED TO HAVE A SMOKY-BLUE CAST. ROTOR WAS RE-ASSEMBLED IN CASE HALVES TO FACILITATE SHAFT END PLAY CHECK WITH DIAL INDICATOR. PER SERVICE MANUAL, 30 POUNDS OF FORCE WAS EXERTED ON ROTOR SHAFT IN EACH DIRECTION - NO PERCEPTIBLE NEEDLE REFLECTION RESULTED. SM SPECIFIES INITIAL ROTOR SHAFT END PLAY SHOULD BE FROM 0.0005 INCH TO 0.0015 INCH LOOSE TO OBTAIN PROPER BEARING PRELOAD. BY REMOVING SHIMS AND RE-CHECKING END PLAY, IT WAS DETERMINED ROTOR BEARINGS WERE UNDER A COMPRESSION LOAD OF APPROXIMATELY 0.003 INCHES. (X)