What was found
LOUD BANG HEARD IN VICINITY OF NOSE WHEEL AREA, CLIMBING THROUGH FLIGHT LEVEL 18,000. ON FIRST LANDING GEAR EXTENSION WE HAD READ UNSAFE NOSE GEAR INDICATION. SECOND GEAR EXTENSION SHOWED 3 GREEN LIGHTS.SERVICE NOSE LANDING STRUT IAW ELECTRA MM 32-4-1. ALSO CLEANED AND LUBED NOSE LANDING GEAR IAW ELECTRA LUBE CHART 32-3 PAGE 1. ALSO PERFORMED NUMEROUS NOSE GEAR RETRACTIONS AND EXTENSIONS PER ELECTRA MM 32-0 PAGE 201. OP CHECKS GOOD.