What was found
PILOT REPORTED NORMAL MAG CHECK PRIOR TO 10-MINUTE FLIGHT. AFTER LANDING NOTICED OIL DRIPPING FROM COWL. FOUND LT MAGNETO WITH LOWER MOUNTING EAR BROKEN OFF AND MAG PULLED AWAY FROM ACCESSORY CASE. THE MAGNETO CASE WAS GAPPED OPEN AND ONLY 2 SCREWS REMAINED HOLDING IT TOGETHER. REMOVED MOUNTING NUTS AND FOUND A SMALL PIECE BROKEN FROM UPPER MOUNTING EAR. LW12706 ADAPTER BROKEN IN SEVERAL PIECES AND LOWER MOUNTING STUD BENT. MAG DISSASSEMBLY FOUND DRIVE END BEARING DESTROYED, SHAFT BENT, AND DISTRIBUTOR GEAR BROKEN. ELECTROSYSTEMS BELIEVES BEARING FAILURE MAY HAVE BEEN INITIAL CAUSE OF FAILURE. COMPONENT P/N S4LN-2110-51360-37.