This is the thrust bearing which replaces the plastic pad used in the stock item. Its a 7.5mm diameter steel shim and is 1.5mm thick. These are used for adjusting valve clearances on a motorcycle engine and are easily obtainable. (lots of different thickness's) I've polished one ready to use. The steel on steel contact with the spindle, is only possible because its running in oil. This modification is common on Thorens decks which have a similar plastic thrust pad. From personal experience I can vouch that they do run quieter this way, so why not on the Technics?