Symptoms: Routine VA surveys identified an inner raceway frequency for the CP01 tail pulley. The condition had been evident for some time in the VElocity domain and was highlighted to be changed out at the next opportunity. The amplitude of the primary fault frequency at 24.15Hz was 0.4mm/sec RMS with impacting at 0.2g in the waveform. Levels were similar on both sides. a
Other Maintenance/Operational Information: The pulley was flagged as a high risk defect and site informed to plan for it to be replaced.
Actions Taken at Time: Pulley changed out during maintenance
Post Repair Details: Bearings were removed for pulley and send to NES for analysis. Spalling to both inner races was found as well as damage to rolling elements and early stage spalling of the outer race.
Vibration data collected from the replacement pulley indicated no bearing problems.
Likey causes are inadequate lubricant to seal housing and possible failed internal seal preventing adequate lubricant getting to the bearing