Whist the bearing is on the inlet side of the motor the bearings...

Whist the bearing is on the inlet side of the motor the bearings are typically "white metal" for larger electric motors - similar to those in the crankshafts of your car engines. These types of bearings require scraping prior to installation which is usually a repetitive process of scraping, installing, checking for surface contact with the shaft and if contact isn't sufficient disassembly and more scraping. This process isn't as straight forward as may might think and as such many issues can arise, such as; oil groove clogging, delamination of the white metal, insufficient bearing area with the shaft, incorrect assembly, alignment and excessive vibration.
I'd agree that the motor bearing problem isn't as concerning as would a pump bearing problem in this specialist application.