| Also known as | E8181 |
| Diagram | Fig. 2 — CRANKCASE · ref 58 |
| Subsystem | engine bottom |
| Listed in parts books | 1968 |
Bolt (1¼ in. U.H.)
A 1¼ in. under-head crankcase bolt, Triumph part 70-8181 (also listed as E8181).
This is a crankcase bolt, 1¼ in. under the head, listed under Triumph part number 70-8181 (older parts books show it as E8181). It shows up in the crankcase section of the parts catalog, which is where you'd expect to find a fastener holding the crankcase halves or related crankcase fittings together.
Read more
The catalog only ties this one to a single appearance, in 1968 crankcase listings, so we don't have a broader fitment range to point to beyond that. If you're matching up hardware for a crankcase job, bring the old bolt or check your parts book against this number and the E8181 alias before ordering.
It's a plain fastener, nothing fancy, but crankcase bolts matter for keeping the cases sealed and torqued right, so make sure length and thread match what's coming out before you swap it in.
Sorry if we got something wrong here. If you think this information isn't correct, .