As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) TACH VALVE GUIDE PIN BACKED OUT WHICH DAMAGED THE BALLHEAD RETAINER AND THE BEARING SEIZED. THE FCU COUPLING WAS ALSO DAMAGED AS A RESULT. PIN HAS PRELOAD AND IS BRAISED IN DURRING ASSY. THIS IS THE FIRST INSTANCE NOTED AND WOODWARD IS INVESTIGATING.