What was found
RT MAIN LDG GEAR WOULD NOT RETRACT ON FIRST ATTEMPT. SLOWED TO <230KIAS AND RECYCLED GEAR. 2ND RETRACT ATTEMPT WAS SUCCESSFUL. AS CREW BRIEF, DID NOT SEE SECONDARY MAIN LANDING GEAR INDICATION WHEN HAD NOT RETRACT. ALSO THEY COULD NOT FEEL ACTUAL DRAG. PERFORMED EXTERNAL VISUAL CK, FOUND NO DAMAGE AND NEED MORE T/S. FOUND CLEARANCE ON RT LANDING GEAR UP AND LOCK SENSOR OF 3.577MM (OUT OF LIMIT). REMOVED AND REPLACED RT LANDING GEAR UP AND LOCK SENSOR PER MM 32-61-15-4 AND ADJUSTED CLEARANCE PER MM 32-61-15-5. RT LANDING GEAR UP AND LOCK SENSOR R-T-S PASSED. A/C OK FOR SERVICE.