What was found
WHILE ROTATING THE RIGHT PROPELLER TO DRESS PROPELLER BLADES AN UNUSUAL NOISE WAS HEARD. A STANDARD AERO TECHNICIAN WAS CALLED IN. THE RIGHT HAND ENGINE POWER SECTION WAS REMOVED AND DISMANTELED. FOUND ROTOR BALANCING ASSEMBLY. NR 4 BEARING P/N:3112696-03 TO HAVE BRINELLING ON THE OUTER RACE. NR 4 BEARING REPLACED WITH NEW UNIT P/N:3112696-03 S/N:FC152696. ENGINE REASSEMBLED, ENGINE GROUND RUNS COMPLETED SATISFACTORY, AIRCRAFT RETURNED TO SERVICE.