Hi dynodave,
Well put! a good explanation
This is my understanding of the references as well,
I know needle roller bearings are more critical on fit than large ball/roller bearings
Waaaay back when I had and worked on loads of BMC mini's the transfer gear bearings were needle roller bearings
In normal service they were quite reliable, then there seemed to be a rash of failures???
Guys and garages started adding STP or similar additives to the oil!!!
This closed up the bearing clearance and they failed in short order
Cheers
John O R