As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) THE FLIGHT CREW REPORTED: GEAR UP DISAGREEMENT (NOSE) ON TAKEOFF. QRH PROCEDURE WERE COMPLIED WITH (PRECAUTIONARY LANDING). AIRCRAFT RETURNED TO DEPARTING AIRPORT. MAINTENANCE FOUND NOSE STRUT IMPROPERLY SERVICED (RE-SERVICED NOSE GEAR STRUT ASSEMBLY) AND GEAR RETRACTION CARRIED OUT.