As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING A 500 HR MAG INSPECTION, FOUND SHAFT FOR THE ROTATING MAGNET WORN BEYOND LIMITS. BELIEVE SOMEONE HAD TRIED TO CHANGE THE COUPLING AND THEN COULD NOT PULL COUPLING OFF THE SHAFT. THE NUT WAS REINSTALLED, TIGHTEN AND NEW COTTER PIN INSTALLED, BUT FAILED TO TORQUE THE NUT. THIS IN TURN DID NOT LOAD THE SPACER PROPERLY WHICH THEN WORN THE SHAFT PREMATURELY.