| Also known as | T1842 |
| Diagram | Fig. 7 — GEARBOX SHAFTS, BEARINGS AND INNER COVER · ref 16 |
| Subsystem | gearbox |
| Listed in parts books | 1966–1970 |
Layshaft third gear (21T)
Layshaft third gear (21 tooth) for the gearbox cluster, also listed under the older T1842 number.
57-1842 is the layshaft third gear, a 21 tooth gear that lives inside the gearbox on the layshaft, part of the cluster that gives you third. It shows up in the parts book under the GEARBOX SHAFTS, BEARINGS AND INNER COVER figure, so it's a component you'd only be pulling if you're into the box for shaft or bearing work, not something you get to from the outside.
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Older parts books list this one as T1842, same physical gear under the earlier number. Our records show it across catalog entries running 1966 through 1970, so if your bike falls in that stretch this is the number to check against your parts book or the gear you're pulling out.
When you're in there, it's worth looking at the rest of the cluster and the layshaft itself while you have things apart, since wear on one gear in that stack often means it's a good time to check its mates too. Confirm your gearbox casing and shaft match up before ordering, and give us a call if anything doesn't look like a clean match.
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