Small drive gear uses a flanged shaft.

For engines with CPL#s 2237, 2475, 2691, 2693, 2694, 2695, 2946, 2964, 2995, 2996, 2997, 8056, 8145, 8146, 8151, 8152, 8153, 8185, 8222, 8292 , 8307, 8380, 8388

Small drive gear uses a shaft with a holding washer.

For engines with CPL#s 400, 401, 422, 424, 906, 915, 1096,1286, 1404, 1632, 1738, 1754, 1793, 2722, 3093, 3144,3169, 3175, 3212, 3301, 3517, 3518, 3519, 3600, 3663, 3664, 3665, 3735, 3823, 4524, 4525, 4526, 8017, 8159, 8220, 8221, 8389, 8419, 8430, 8458, 8478, 8537, 8538, 8548, 8627, 8630, 8636, 8639, 8641, 8647, 8648, 8650, 8692, 8693, 8695,8697, 8698, 8703.8728, 8730, 8746, 8780 & 8792