What was found
AFTER TAKEOFF, A STEERING INOPERATIVE CAUTION MESSAGE DISPLAYED. A VIBRATION FELT IN NOSE. AFTER APPROXIMATELY 20 SECONDS, A GEAR DISAGREE WARNING MESSAGE. FOLLOWED QRH. VIBRATION FELT UNTIL GEAR HANDLE WAS PUT DOWN & HYD PUMP 3B TURNED ON VIA QRH CHECKLIST. NOSE GEAR CONTINUED TO CYCLE, MAINS CYCLED BETWEEN UP AND TRANSITION, NOSE GEAR NEVER RETRACTED. NOTED NLG STRUT FLAT, SERVICED NLG STRUT IAW 900-12-710-700. THE MLG EXTENDED FOUR TIMES IAW 32-30-00. OPS OK.