As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING ROUTINE LUBRICATION SCHEDULE OF 600 HRS, REMOVED AIR CONDITIONER QUILL SHAFT PULLEY AND HAD BALL BEARING FALL OUT. FOUND BEARING HAD COME APART. BALLS HAD FLAT SPOTS. QUILL SHAFT WAS ALSO KNIFE EDGED AS WELL AS THE PULLEY. THIS CONDITION DID NOT EXIST LAST TIME LUBED. SUBMITTER STATED HAVE NO SUGGESTIONS AS TO CAUSE OR PREVENTION.