As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING 1500 HOUR ENGINE INSPECTION FOUND RETAINING RING P/N 9745008005 LOOSE IN MOUNT GROOVE IN COUPLING. REPLACED RING WITH NEW RING WITH NO CHANGE (RING SHOULD BE TIGHT WITHIN GROOVE WITH NO MOVEMENT). DETERMINED COUPLING TO BE WORN AT RING GROOVE. TO BE SENT TO VENDOR.