What was found
PILOT REPORTED AIRCRAFT MAKING UNUSUAL NOISE. ON INSPECTION, FOUND FORWARD BEARING RETAINING NUT ON OIL COOLER BLOWER SHAFT HAD LOST TORQUE. LOCKING WASHER WAS FULLY ENGAGED AND INTACT, ON DISASSEMBLY, FOUND AFT FACE OF BEARING INNER RACE GROOVED AND DAMAGED BEYOND LIMITS. BOARING INNER RACE HAD ROTATED ON SHAFT CAUSING WEAR ON SHAFT JOURNAL IN EXCESS OF LIMITS. REPLACED SHAFT, BEARING, NUT AND LOCKING WASHER. (X)