What was found
ORD - FLT 4045 - AFTER TAKEOFF WHEN CREW WENT TO LIFT LANDING GEAR HANDLE, HANDLE WOULD NOT GO UP. THEREFORE, GEAR WOULD NOT RETRACT. AIRCRAFT RETURNED TO ORD AND NO FURTHER INCIDENT WAS REPORTED. REPLACED LANDING GEAR HANDLE, PERFORMED GEAR SWING. OPS CHECK GOOD. RETURNED AIRCRAFT TO SERVICE. (X)