As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
#2 ENGINE TREND DATA SHOWS A SUDDEN INCREASE IN LOW PRESSURE ROTOR VIBRATION LEVELS AFTER LAST SCHEDULED FAN LUBE. FAN TRIM BALANCE WAS ACCOMPLISHED ON 3-17 WITH NO RECOVERY IN VIBRATION LEVELS. GROUNDED - YES. DURING DISSASSMBLEY, FAN BLADE SPACERS DIFFICULT TO REMOVE (8 AND 22). REMOVED AND REPLACED ALL FAN BLADE SPACERS REF. TSR704973 AND TASKCARD: 78472010.