As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) ON A COMBINING GEAR BOX REMOVAL, AME NOTICED A LARGE AMOUNT OF BLACK FRETTING MATERIAL BETWEEN THE C BOX AND BLOWER JOINT FLANGE. ONCE CLEANED UP THE AME WAS ABLE TO SEE THAT THE OUTER RACE OF THE BEARING ON THE BLOWER WAS ROTATING IN THE BLOWER CASTING. BLOWER WAS R & R WITH SERVICEABLE UNIT.