Bratton offers a fiber thrust washer that goes at the front of the shaft next to the commutator Page 70 part # 15790 price $1.85 . Snyders offers a rear thrust washer in two thickness .030 & .060 . These parts are on page A-149. These type washer-shims can be used on starters or generators. Rear thrust is most important on starters and don't make all that much difference on a generator. I have used them on both to take up end play. use steel on the starter rear thrust and fiber at the commutator end.