As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
NR 1 ENGINE TREND DATA SHOWS A SUDDEN INCREASE IN LOW PRESSURE ROTOR VIBRATION LEVELS. DATA SCATTER INDICATES HARDWARE INSPECTION AND FAN LUBE REQUIRED. ACCOMPLISHED FAN BLADE LUBE PER T/C 78472002. FOUND FAN BLADE SHIM COATING WORN. REPLACED 24 EA FAN BLADE SHIMS P/N 340 252 307 0 PER T/C 78472002.