| Also known as | E1335 |
| Diagram | Fig. 16 — FRAME · ref 11 |
| Subsystem | engine top |
| Listed in parts books | 1960–1974, 1976–1980, 1983, 1985 |
COPPER SEALING WASHER 3/8X5/8 - ROCKER SHAFT TWINS/TRIPLES
Copper sealing washer, 3/8 x 5/8, used at rocker shaft and other oil feed joints on Triumph twins and triples.
This is a copper sealing washer, 3/8 x 5/8, used on the rocker shaft oil feed. Copper washers like this one crush slightly when torqued, giving you a flat, reliable seal at a joint that's carrying engine oil under pressure, so they're not meant to be reused indefinitely once they've been compressed.
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The catalog shows this washer turning up across a wide spread of figures - cylinder block and head assemblies on 3TA, T90, T100S, T100C, T100R, and T100T, plus timing cover, chaincase, gearbox inner cover, frame, motor unit fitting, and oil tank listings. That range tells you it's a small standard part used at more than one oil-feed joint on the twins and triples rather than one dedicated to a single spot, so make sure you know which joint you're sealing before you order.
Older parts books may list this one under 60-4184, which the factory superseded with 70-1335 - also shown as E1335 in some references. If you're working from an older book and see that number, it's the same physical washer under a different number.
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