Spring washer next to the small bearing (24-4217)
Fits the following gearboxes:
BSA M20, M21, B31 and B33 (1948-1958)
BSA A7, A10 in plunger frame (bolt-on gearbox) & C11 4-speed
BSA A7, A10, B31 & B33 with STD gearbox
BSA A50 & A65
Part number: 67-3028
