The clutch basket spins between the space created by the spacer than the 2 thrust washers. 2 things cause this space to become smaller than the width of the basket and clutch drag occurs and neutral hard to find. Gets worse when things heat up and everything expands. The back side of the basket gear wears and becomes rough, adding to the baskets total width. Search this topic out and read; there are alot of how to's and pictures. You are not really removing material, more polishing the roughed out back of the gear. As for the spacer and thrust washers. The thrust washers wear, but you can flip them over and use both sides before they need replacement. The spacer appears to be made of a harder material than the washers and I did not measure any wear; thus nor needed to be replaced.