Some questions and a few observations that might be of interest to the list.
I came back from the beach and decided to tackle the slipping clutch
before the summer is gone entirely.
Everything came apart easily. The clutch was worn out, the taper pin
was broken, the TOB was rough, the diaphragm fingers were worn, as
were the little trunnions on the release fork. Finding all those
problems made it worth pulling the interior and the gearbox.
Surprisingly, the clutch had been working fine until it started to
slip a few months ago.
It appears that the clutch has been replaced before (the car has done
56k miles according to the odometer). The flywheel had been ground
before and the release fork had been drilled to remove a previous
broken taper pin (which made it very easy to remove the current pin).
I am getting the flywheel reground and the Laycock clutch refurbished
with a new TOB fitted to the carrier/sleeve. I could not get a new
Laycock locally and the supplier told me that the Laycock was
inherently smoother than the Borg and Beck and the Quentin Hazel that
are available new.
[The clutch specialists made an interesting observation about the
weight of the TR6 clutch. The wear on the diaphragm was about 10 mm
from the ends of the fingers. They believe that the clutch was
designed for a smaller diameter TOB that would press closer to ends
of the fingers. This would reduce the actuating force. However, the
size of the gearbox input shaft precludes the use of a smaller TOB.]
The replacement taper pin is another matter. The replacement pin
that I purchased is supposed to be of higher strength than the
original. It is copper plated and probably of Moss USA origin (based
on the source of most parts from this particular vendor). The
problem is that it does not fit. Even after a light file to remove
any rough edges, it will not go in far enough to engage the threads.
The only way to make it fit would be to machine it to size.
Now come the questions:
1. Has anyone else had problems with oversize taper pins? Is there
only one size? Is one supplier better than another?
2. Has anyone replaced the little trunnions on the release forks?
They are available separately and appear be replaceable.
3. Why do these trunnions wear so much? The rotation of the TOB
carrier is constrained by a pin and the trunnions move up and down in
the carrier only slightly as the shaft and release fork rotate. Is
that enough to cause the wear?
4. How long should a TR6 clutch last? I thought 56k miles was
reasonable but now I know that it is at least the second clutch.
Regards, Trevor Jordan
74 TR6 CF29281U
Melbourne, Australia
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