What was found
THE LANDING GEAR DID NOT RETRACT (ALL 3) AND RECIEVED A GEAR DISAGREE WARNING MESSAGE. IAW QRH, THE GEAR HANDLE WAS PUT BACK IN THE DOWN POSITION AND THE GEAR INDICATION REMAINED, 3 GREEN. AFTER EXTENSIVE VECTORING FOR CHECKLISTS, MADE A NORMAL LANDING, TAXI TO THE GATE WAS NORMAL. PERFORMED WIRING CHECKS ON GEAR SENSOR PX37 IAW AMM 32-61-02. INSULATION CHECKS WERE GOOD, AS WELL AS CONTINUITY CHECK. FUNCTIONAL CHECK OF LANDING GEAR EXTENSION & RETRACTION SYS IAW AMM 32-30-00. AS A PRECAUTION, REMOVED & REPLACED THE LANDING GEAR CONTROL LEVER IAW AMM 32-31-01. ALL CHECKED NORMAL. NO MESSAGES NOTED AT THIS TIME. IAW AMM 32-61-05, GEAR PROXIMITY SENSORS ARE DETERMINED TO BE IN GOOD HEALTH AND RIGGED CORRECTLY.