What was found
AFTER TAKEOFF, HAD A WARNING GEAR DISAGREE. THE NOSEWHEEL DID NOT RETRACT. DIVERTED. PERFORMED TORQUE OF NLG AFT DOOR DRIVE BRACKET HARDWARE IAW JC 900-32-710-900. VERIFIED RIGGING OF PX37 IAW AMM 32-61-05 FOR NOSE GEAR CENTER SENSOR. ALL CHECKED NORMAL. EXTENSION & RETRACTION OF ALL GEARS GOOD IAW AMM 32-30-00. COULD NOT DUPLICATE. REMOVED & REPLACED THE PROXIMITY SENSOR HARNESS ASSEMBLY PX 37 IAW AMM 32-61-05. PERFORMED OPS TEST OF THE PROXIMITY SENSOR SYSTEM IAW 32-61-05. ALL CHECKED GOOD. ACFT OK FOR SERVICE.