> From: Mitchel Seff [mailto:ms6453@optonline.net]
> Sent: Thursday, May 16, 2002 6:45 AM
>
> ...are there any suggestions on a replacement for
> the original in an upgraded quality.
Hi Mitch,
>From a post I saved a long time ago made by an extremely knowledgeable TR
mechanic, Brian Schlorff:
<< start of Brian's post >>
The fundamental engineering problem with the clutch fork is simply this:
The pin is tapered.
The cross-shaft has a tapered hole to accept the tapered pin.
The partially threaded bore in the fork IS NOT TAPERED!!!
What this means is that contact is made on only one side of the fork pin.
(the side
nearest the threaded portion just below the head) All the force is
concentrated at
that spot and the pin will ALWAYS break at this spot - never anywhere else.
The best,
albeit not so easy, solution is to ream the hole in the cross-shaft to the
same
diameter as the bore in the deepest part of the fork. Then fabricate a new
pin, one
with a straight shank of corresponding diameter + .001" for an interference
fit that
will tightly engage both sides of the fork. No modifications are made to
the fork,
but now the shear force is divided equally between the top and bottom of the
new pin,
which is also slightly larger in diameter than the original tapered pin.
The real benefit comes from the fact that the topmost portion of the pin
extends
directly up into the right-hand finger of the fork, thus there is no chance
of
overstressing or cracking the base of the fork around the shaft. I know it
is not
exactly a do-it-yourself prospect to make such a set up, but we feel this is
the best
way to insure never having to do that job twice! :-)
Regards,
Brian Schlorff '61 TR-4 '64 TR-4 '72 TR-6 '79 Spit
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Power British Check out Power British
371 E. Main St. on the 'net!
Norristown, PA 19401
(610) 270-0505 http://www.powerbritish.com/~britcars
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<< end of Brian's post >>
Peter Zaborski -- CF58310 UO
(I used the second bolt method myself, no problems so far - 15k miles)
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