> The TR250-6 did not come with the threaded fork lever
> nor spring -- it is not adjustable.
That's right, it was "self-adjusting", so no need for the adjustment.
> One of the TR experts (might have been
> N. Riedel) wrote that he thought that the bearing on the TR250-6 was meant
> to stay in contact with the driven plate, thus continuing to spin, but he
> wasn't sure.
Nelson may have said that at one point, but his "Reliable clutch" article states
unequivocally (and correctly) that "The TR250/TR6 is designed to have the
release bearing held against the pressure
plate at all times." FWIW, my 1980 Chevy used a similar design (with a cable
and ratchet rather than hydraulics), as I believe all GM cars (with manual
clutches) do.
Also, Nelson wrote that he found the KOYO bearing Not Satisfactory, because it
doesn't hit the B&B pressure plate in the right place.
> If the bearing is in contact with the driven plate, and hence always
> spinning, then it had better be perfectly coaxial with the driven plate,
> otherwise you can imagine that the rotation of the bearing could become
> slightly eccentric and that can't be good.
Personally, I do not believe this is a concern. Any eccentricity would be
amplified with the clutch released (meaning a large load on the bearing) ... not
enough to hurt anything with the bearing not loaded.
> This may be why it seems to be a
> really big deal on the 6-cylinder cars to line up the gearbox perfectly with
> those dowl pins -- to ensure that the bearing and the driven plate are
> coaxial.
The dowels are present on all cars (although not always as dowel bolts) because
it is important for both clutch and gearbox operation that the gearbox input
shaft be perfectly in-line with the crankshaft.
> I ordered the clutch shaft "kit" from TRF, RFK1249, which comes with the
> cross shaft, shaft bushes, pin, and lever. It is listed as the part for
> T46, so is for 4A-6. I looked up the part number you gave, it lists it as
> applying T23.
As we've discussed before, those numbers are intended only as a rough guide.
They are not always accurate and this is a perfect example. 57193 is the number
given in the factory Spare Parts Catalogue, which is more definitive than the
TRF price list.
> All of the parts
> suppliers list the same clutch for 4A-6, but the 4A actually had a different
> B&B clutch that had less spring pressure.
I think you can blame that on B&B, not the suppliers. The 4A clutch was
superceded by the TR6 clutch ... possibly even by the factory (but I don't have
my factory supercession list handy to check). And the clutch being supplied
today isn't even "right" for the TR6, it's a later "rationalization" apparently
done by B&B.
> Well, I'll give the Koyo a go and hope it all works well. Would hate to
> have to pull that gearbox again...
Good luck.
Randall
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