As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
STL INFLIGHT T1642/12JUN - NOSE WHEEL VIBRATION AFTER ROTATION. BEFORE DURING AND AFTER RETRACTION VIBRATION EXTREME. RETURNED TO STL AND LANDED WITHOUT INCIDENT. REPLACED LOWER STRUT PISTON ASSEMBLY AND LEFT STEERING CYLINDER AND LEFT AND RIGHT NOSE TIRES. SYSTEM GROUND CHECKED NORMAL OPERATION.