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RE: Flywheel Bolts and Locknuts

To: "Triumph List" <triumphs@autox.team.net>
Subject: RE: Flywheel Bolts and Locknuts
From: "The Brooks'" <TR3A@worldnet.att.net>
Date: Mon, 14 Aug 2000 22:34:31 -0400charset="iso-8859-1"
Importance: Normal
The one item missed in this locktab discussion is why locktabs are scorned
in racing circles.  It is because the locktabs are typically a softer
material than your bolt or what you are bolting to.  Think about how easy
it is to bend the tabs up.  Now you take the time to find really good
strong bolts to attach the flywheel to your crank, or to bolt up the big
end of the con-rod, etc., etc. and then you put a soft piece of steel in
between the bolt head and the steel.  If you have vibration at your
flywheel, i.e., if you didn't check the runout of the flywheel on the end
of the crank (did you check it, right?) the flywheel has the potential to
rock ever so slightly on the end of the crank.  Eventually, it'll deform
the soft locktab sandwiched under the bolt head and the vibration gets
worse, maybe bad enough to shear the flywheel bolts before you figure out
what it is.  I've seen it and it isn't pretty or fun.

For street use locktabs should be fine, (although I wouldn't use them on my
flywheel) but in my street/AutoX TR3 engine you won't find a single
locktab, but you will find lots of locktite.  There is that one locktab the
bottom of the steering box though.....

BTW - I think I took about 4 threads off the original flywheel bolts (then
checked for clearance) before I was happy with the length of the flywheel
bolts.  I will be changing the shortened original bolts out for Grade 8
hardware next time I have the tranny out of the car, since seeing a
flywheel that had sheared it's bolts.

Regards,

Jack Brooks
Hillsdale, NJ
1960 TR3A
1980 TR8
1974 Norton 850 Commando Roadster


>  On Mon, 14 Aug 2000, Michael Singleton wrote:
>
>  > For a final word on the fastening of flywheels to crankshafts, I would
>  > recommend Carroll Smith's book "Nuts, Bolts, Fasteners and Plumbing
>  > Handbook," Page 93 and Page 116 on the use of locktabs. To
>  summarize, He
>  > doesn't like locktabs, won't allow their use, and if one must
>  use them,
>  > never, never re-use them. Safety wire, on the other hand is
>  your friend,
>  > learn to use it, and then use it frequently and everywhere.
>
>  Folks - this is good advice. Listen, learn and live.
>
>  > Naturally, this information moves from the recommended to the
>  critical list
>  > if you are racing!!!!!
>
>  What he said.
>
>  > Good luck,
>  > Michael Singleton
>
>  Later,
>  rml
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