As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) IN NORMAL SERVICE, THE ATTACHMENT BOLT TORQUE OF THE GEAR TO SHAFT (P/N 204-040-324-5) BECAME REDUCED RESULTING IN FRETTING CORROSION OF THE MATING SURFACES. A SURFACE CRACK WAS FOUND DURING OVERHAUL BETWEEN TWO OF THE ATTACH BOLT HOLES IN THE GEAR. SUBMITTER SUSPECTS THAT CRACK ONLY EXTENDS THROUGH THE SURFACE HARDENING.