What was found
(CAN) GEAR DISAGREE ON R MAIN GEAR DURING APPROACH. ABOUT 45 SECONDS LATER A THUD WAS HEARD, THE MESSAGE CLEARED, AND WE RECEIVED A DOWN AND LOCKED INDICATION. CONTINUED FOR A NORMAL LANDING AFTER GO-AROUND. CORRECTIVE ACTION: JACKED AIRCRAFT IN REFERENCE TO AMM 07-11-02. OPERATED LANDING GEAR AT LEAST 10 TIMES AND COULD NOT DUPLICATE. REMOVED AND REPLACED MLG SELECTOR VALVE IN REFERENCE TO AMM 32-32-10. PERFORMED OPERATIONAL CHECK IN REFERENCE TO AMM 32-32-30. SWUNG GEAR 10 MORE TIME AND PERFORMED 2 FREE FALLS. OPS CHECK GOOD, NO LEAKS NOTED AT MLG SELECTOR VALVE. LOWERED AIRCRAFT IN REFERENCE TO AMM 07-11-00. (TC# 20190612014)