| Diagram | Fig. 5 — GEAR CLUSTER · ref 3 |
| Subsystem | gearbox |
| Listed in parts books | 1969–1972 |
BSA Lockwasher, final drive sprocket
Lockwasher for the final drive sprocket nut on the gearbox output shaft.
This is the lockwasher that sits under the final drive sprocket nut on the gearbox output shaft. Its job is simple but important — it keeps the retaining nut from working itself loose once the sprocket is torqued up, since that nut takes a beating from chain pull and engine vibration every time the bike is ridden.
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It shows up across gearbox figures in our books covering the gear cluster and camshaft area, alongside the oil pump and gearbox sprocket parts, in catalog entries running from 1969 to 1972. If you're pulling the gearbox sprocket for a chain or sprocket swap, this is a part worth replacing rather than reusing — a tired lockwasher won't hold the nut the way a fresh one will.
We don't have more detail on this one beyond the catalog listing, so if you're not sure this is the exact washer your gearbox needs, give us a call and we'll confirm fitment before you order.
We've never carried this one. Tell us what you're after and we'll go looking — you'll get a price and photos before you commit to anything.
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