As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
REPLACED MAIN ROTOR MAST CONE PN 407-010-104-109 FOR HUB SHIFT/MAST NUT TORQUE STABILIZATION PROBLEM. ORDERED NEW CONE P/N 407-010-104-109 FROM MFG. NEW PART WAS RECEIVED WITH A WEAR GROOVE IN CENTER OF CONE FACE (APPEARED USED). REORDERED ANOTHER NEW CONE AND INSTALLED. INSTALLED MAST NUT AND STABILIZED TORQUE.