What was found
AFTER TAKEOFF, LANDING GEAR WOULD NOT RETRACT. LANDING GEAR HANDLE WOULD NOT MOVE FROM A/C DOWN POSITION. CHECKED AIRCRAFT, FOUND NOSE STRUT NOT FULLY EXTENDED, DISASSEMBLED NOSE STRUT. REMOVED AND REPLACED STRUT ORIFICE WITH NEW. RE-SEALED AND SERVICED STRUT WITH AIR AND OIL IAW 750 CMM 32-20-02 AND IAW 750 M/M 12-10-38. COMPRESSED AND EXTENDED NOSE STRUT TO SIMULATE TAKEOFF AND LANDING. INPUT TO GEAR HANDLE PROVED SATISFACTORY. DOWN JACKED AIRCRAFT.