I have been putting this job off for a year or two. But during the lock down I considered this an ideal opportunity to service and clean my old 1970s Xpelair ceiling kitchen extractor fan. I serviced it in 2016 and today, the only times that I can guarantee that it has been serviced. I cleaned off all of the cobwebs and cooking grease from the motor and fan blades. WD40 is a good grease dissolver for cleaning purposes, then hot water and detergent to get the WD40 off the cover and blades. The bearings are sintered bush type bearings and allow oil through them. I used a synthetic light oil that can run at high temperatures and will not gum up like mineral oils. This video shows how its done.
https://www.youtube.com/watch?v=-LOY-c6QE9Y
Let's have a competition. Who has the oldest working extractor fan? Both metal and plastic can be entered into the competition.
Z.