It is the DE bearing that is wearing on the housing. The bearings and housings are now long gone as I suspected, so I can not provide any pictures unless it happens again.
I am trying to retrieve the bearings but seem to have been discard of as soon as they were changed, I have uploaded a photo of the most recent fan tat has had this issue.
I hope to have some more information on this issues later...
Over the last few months I have witnessed a large number of bearing being changed during routine maintenance, for wear appearing on the outside, of the outer race and bearing housing caps. Upon inspecting the bearing and cap, it would appear that the bearing has been rotating in the housing and...