What was found
ON FLIGHT 3828 THE CREW REPORTED THAT ON TAKEOFF DURING GEAR RETRACTION RECEIVED A MESSAGE GEAR DISAGREE. THE GEAR SHOWED DOWN WHILE IT WAS UP. THE CREW DECLARED AN EMERGENCY AND RETURN TO ORD. THE WARNING MESSAGE CANCELLED WHEN THE GEAR HANDLE WAS PUT DOWN. THE AICRAFT LANDED WITHOUT INCIDENT. THE AIRCRAFT WAS REMOVED FROM SERVICE. PERFORMED PROPER ADJUSTMENT OF NOSE LANDING GEAR CENTERED PROXY SENSOR PX08 IAW CRJ AMM 32-61-05. NO PARTS REMOVED OR REPLACED. THE AIRCRAFT WAS RETURNED TO SERVICE.