Crankshaft pulley locknut

Any topics pertaining to the BMC A-Series engine.

Crankshaft pulley locknut

Postby johnmcguire » Mon Jan 27, 2014 8:06 pm

The locknut from Moss is different than the one from VB. Neither has a prong that fits into the groove for the Woodruff Key. My new one is from Moss and is concave. Do I tighten it down with the concave or convex side toward the pulley? Do I bend oven the rim even though it is not really fixed in place?
Thanks, John McGuire
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Re: Crankshaft pulley locknut

Postby Sprite33 » Mon Jan 27, 2014 8:44 pm

Are you talking about the lock tab washer? If so, it has to lock onto the crank some way or bending it over on the crank bolt head will do nothing to keep it from rotating.

I gave up using the tab lock washers because they are soft and can relax on a highly stressed race engine and lose clamp up on the pulley/dampener. I had bolts made with longer threads and Loctite them. I have to use an impact wrench to get them off but I don't have a problem with them backing off and having a loose pulley.
61 Sprite 1098
Set up for full prep racing in SCCA
2004, 2005 & 2006 Southern Pacific Divisional GP Champion
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Re: Crankshaft pulley locknut

Postby trevor » Mon Jan 27, 2014 10:20 pm

In theory it is supposed to lock into the divot in the pulley that is locked to the crank with a key, and then lock to the head of the bolt. That is what I do. Well that and loc-tite.
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