I use a 5/16" drill in a drill press and a 5/16" bolt with a Nylok
nut. I've not had a failure in any of the street or race cars. The
hole must be positioned so the nut misses the two bolts holding the
cover plate for the layshaft. Remember, for this bolt to fail, it has
to shear the bolt off -- pretty unlikely, especially if you use a
grade 5 or 8 bolt. That darned stock pin has two problems - the dowel
shaped portion ends at a cut thread, which is a natural stress riser,
right at the point where the shaft and fork intersect. If I were
given the assignment to design it so it would break by fatigue
failure, this is the way I'd design it. Also, it is made of dead soft
steel. Good grief.
At 07:46 PM 9/8/2005, Don Malling wrote:
>Nelson argues that unless the bolt is a press fit, it is too sloppy
>and does not share the load of the fork pin. First the fork pin
>snaps and then the load is carried by the bolt. He makes the same
>case for the roll pin because it's a spring.
>
>I take it you guys believe it doesn't matter in actual practice?
>Seems like a reasonable line of logic to me. Maybe the bolt is tight
>enough in actual practice -- it assumes I drill a nice straight hole
>-- free hand. Seems like the reamer would clean up any sloppiness in
>the hole I drill.
>
>Don Malling
>
>
>
>
>Randall wrote:
>>>Hmmmm.... Maybe adding a taper pin is not as hard as I thought.
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