Hi again
Corduroy,That is a thrust bearing, and is the correct one for the machine. they are not sealed and seem happy enough to run dry....However, with my new one, on replacement, I forced some good quality bearing grease into the groove with my thumb, and it works like a dream and quiet as a church mouse.
A thrust bearing works differently to the sealed bearings on the mower, it fits into the inner clutch half
(engine side) and goes in rounded side first.

Please post some pics as you go along.
