| Also known as | S1878 |
| Diagram | Fig. 11 — CHAINCASE AND CHAINS · ref 30 |
| Subsystem | primary |
| Listed in parts books | 1969–1971, 1974 |
Screw (2 3/4 in. U.H.)
A 2 3/4 inch cover screw used on the chaincase and gearbox outer cover, part number 21-1878 (also S1878).
This is a 2 3/4 inch long screw, part number 21-1878, also listed as S1878 in the older letter-prefix numbering. It shows up in the chaincase and chains area and in the gearbox outer cover figure, so it's one of the fasteners used to hold those covers in place over the primary and gearbox area.
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The catalog record spans appearances from 1969 through 1974, and it turns up five times across those years' parts books, so it's not a one-off fastener - it gets used in more than one spot on the cover work in this area.
If you're chasing one of these to fill a hole in a chaincase or gearbox cover, have your old one on hand to compare length and head style before you order, since covers can use a mix of fastener types.
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