As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PILOT REPORTED GRINDING NOISE FROM ENGINE COMPARTMENT WHEN STARTER WAS ENGAGED. STARTER WAS REMOVED ARMATURE WAS FOUND WITH 2 SPLINES SHEARED OFF. INTERMEDIATE GEAR WAS MISSING 2 TEETH. CAUSE UNKNOWN. THIS IS THE THIRD ARMATURE IN THE PAST 6 MONTHS WITH THE SAME DEFECT. (K)