| Diagram | Fig. 2 — CRANKCASE · ref 43 |
| Subsystem | engine bottom |
| Listed in parts books | 1970–1971, 1974, 1976–1980, 1983, 1985 |
Bolt, rear - crankcase halves
Rear crankcase bolt, 3/8-16 UNC x 4 inches, for joining the crankcase halves on a Triumph engine.
This is the rear crankcase bolt for a Triumph engine, part number 14-6242, one of the bolts that clamps the two crankcase halves together at the back of the bottom end. The catalog appearances show it appearing across a long run of years in the CRANKCASE figures, so this is a bolt that stuck around in Triumph's parts books for a good while without change.
Read more
By spec it's a 3/8-16 UNC hex head bolt, four inches long. That's a coarse-thread bolt doing a structural job, holding the case halves true to each other so the crank spins in proper alignment and the case doesn't leak or flex under load.
If you're splitting cases for a rebuild, it's worth checking this bolt for stretch or damaged threads before it goes back in - a crankcase bolt that's been over-torqued in the past is not one to reuse blind. Give the shop a call if you want to confirm which position on the case this one goes in for your particular engine.
Sorry if we got something wrong here. If you think this information isn't correct, .