As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
UPON CHECKING AILERON TRIM FOR PROPER RIGGING, THE INDICATOR WAS NOT MOVING AS AILERON TRIM WHEEL WAS TURNED. FURTHER INVESTIGATION FOUND THE GEAR ASSY FOR THE INDICATOR HAD MOST OF THE TEETH STRIPPED OFF. THE AILERON TRIM TABS WERE MOVING OK. THE GEAR WAS REPLACED AND TRIM SYSTEM WORKED NORMALLY.