What was found
ON FINAL APPROACH TO DAL AT 600 FEET 3 GREEN AND 3 RED GEAR LIGHTS ILLUMINATED, AT 500 FEET "TOO LOW GEAR" WARNING SOUNDED. INITIATED A GO-AROUND LOWERED GEAR, NORMAL INDICATIONS. INSPECTED FOUND LANDING GEAR SELECTOR HANDLE INNER SHAFT STICKING, CLEANED AND LUBED PER MM.