As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RIGHT ENG VIBRATION, 3.1 TO 3.2, DURING CRUISE. THE FLIGHT DECLARED AN EMER & RETURNED WITHOUT FURTHER INCIDENT. ACFT WAS TAKEN OUT OF SERVICE. INSTALLED RT ENG CHOCKING PADS ON LP FAN BLADES, NR 4 & 16 IAW MCM 72-94-01. ACCOMPLISHED FAN TRIM BALANCE IAW MCM 71-95-25. ALL INDICATIONS WERE NORMAL.