FRETTING DAMAGE DUE TO VIBRATION
The damage illustrated is fretting damage in the bore as distinct from fretting damage elsewhere. Bearing operating surfaces may suffer fretting damage while the shaft is at rest due to vibrations transmitted to the machine from external sources, etc. 

JOURNAL BEARINGS 
Fig. 38 - Surface damage caused by external vibration while journal was not rotating. 

RECOMMENDED ACTION 
Eliminate transmission of vibration from external sources if feasible by spring or rubber -mounting affected machine. If damage occurs in transit, clamp journal to prevent vibration during shipment, or fit dummy wooden bearings during transportation.