As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LGA - FLT 317 - EN ROUTE LGA-ORD, AFTER TAKEOFF LANDING GEAR HANDLE WOULD NOT MOVE UP IN FLIGHT. UNABLE TO RETRACT LANDING GEAR. RETURNED LGA AND LANDED WITHOUT INCIDENT. REPLACED NOSE GEAR STRUT PISTON AND SEALS. ACCOMPLISHED GEAR SWING. SYSTEM GROUND CHECKED NORMAL OPERATION. (M)