What was found
CUSTOMER NOTES: AFTER SELECTING THE GEAR DOWN, THE LEFT MAIN GEAR DID NOT GO GREEN, AND THE RED UNSAFE LIGHT STAYED ILLUMINATED. THIS HAPPENED WHILE ON APPROACH TO LAND, CREW THEN RETRACTED THE FLAPS TO DO A GO AROUND AND SHORTLY AFTER RETRACTING THE FLAPS THE LEFT GREEN DOWN AND LOCKED LIGHT ILLUMINATED. MAINTENANCE JACKED AIRCRAFT AND WAS UNABLE TO DUPLICATE THIS DISCREPANCY. IT WAS NOTED DURING THE LANDING GEAR FUNCTIONAL TEST THAT A LOUD CREAKING NOISE COMING FROM BOTH FORWARD TRUNNION ATTACH POINTS. ATTEMPTED TO GREASE THESE BEARINGS BUT THEY DID NOT ACCEPT GREASE. REMOVED LEFT AND RIGHT TRUNNIONS TO ACCESS FORWARD BEARINGS. EXTRACTED FORWARD TRUNNION BEARING PN MS21155S16 AND FLUSHED GREASE PASSAGE WITH NO BLOCKAGE NOTED. REPLACED FAILED PART NUMBER MS21155S16 BEARING ON BOTH LEFT AND RIGHT SIDE. GREASED BEARINGS. REINSTALLED TRUNNIONS AND PERFORMED A SATISFACTORY OPERATIONAL TEST OF THE LANDING GEAR RETRACT AND EXTEND. GREASED BEARINGS AGAIN AFTER OPERATIONAL TEST.