What was found
FLT 3517 - AIRCRAFT RETURNED TO FIELD AFTER CREW WAS ALERTED TO MLG NOT UP AND LOCKED INDICATION. AIRCRAFT LANDED COS WITHOUT FURTHER INCIDENT. COS MAINTENANCE CLEANED AND LUBRICATED BOTH LT AND RT MLG UPLOCK ROLLERS, AND RELEASED AIRCRAFT FOR FUNCTION TEST FLIGHT. TEST FLIGHT RESULTS NOT SATISFACTORY. COS MAINTENANCE REPLACED BOTH LT AND RT MLG UPLOCK ASSEMBLIES IAW AMM TR 32-167 (SB 328-32-183). GROUND OPERATIONAL CHECK OF LANDING GEAR 'GOOD'. AIRCRAFT RETURNED TO SERVICE. (X)