Date:         Mon, 22 Aug 2005 20:55:17 EDT
Reply-To:     THX0001@AOL.COM
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         George Goff <THX0001@AOL.COM>
Subject:      Re: WTB: woodruff key
Comments: To: conradk@MAC.COM
Content-Type: text/plain; charset="US-ASCII"

In a message dated 8/22/05 5:26:35 PM, conradk@MAC.COM writes:

<< I'm concerned that without a woodruff key, that there would be some
movement that would cause wear, etc. >>

As you well should be.

In a message dated 8/22/05 11:54:28 AM, dhaynes@OPTONLINE.NET writes:

<< they stopped using the woodruff key. I guess they figure that the pulley
being driven will further tighten the pulley nut if it should slip. >>

Of course, unless it slips in the opposite (righty tighty, lefty loosey)
direction whenever you snatch a downshift.

Dispencing with the key does not make sense to me.  A nut alone fixing a hub
relative to a straight shaft cannot be depended on to maintain the
relationship of the two components.  The shaft and the bore of the hub have a sliding
fit.  If only the clamping force of the nut is locating the pulley relative to
the shaft, then it is really the coefficient of friction of the sides of the
pulley hub which is generating the force opposing independent rotation.

A key may not be needed for a shrink fit or an interference fit, but it is
necessary for this application.  Even some taper fits use keys.  Unkeyed the
to-and-fro inertial tug-of-war between the alternator and the crankshaft would
act to loosen the nut as well as to tighten it.

If the hub of the pulley is broached with a keyway and the shaft has a
Woodruff keyseat cut into it, then I think the Woodruff key itself simply fell out
of the shipping box somewhere along the way.

George