Hi Dick,
I would trust your judgment in this more than my own. I am only passing
along the information I have.
Joachim Gunst was not concerned about the "graininess", and stated it
was not uncommon. If memory serves, he used words to the affect that
"they were all somewhat like that -- more or less". He said it would
pass after the bearing was in use, and suggested if we were concerned,
we should run it for about 1.5 hours on a lathe, and recheck it. My
understanding is that it was run for about 10 min., not on a lathe, but
in some way with an electric motor. I was not there. After the 10 min or
so, the bearing was reported to be less "grainy" but a few drops of oil
came out during the test, and there was still a "thump" in the bearing.
Joachim seemed to be mostly concerned that the bearing yielded a few
drops of oil. He also stated that the manufacturer said the preload was
critical, and therefore his instructions to us to run it on a lathe may
not have been correct. He would replace the bearing regardless.
It's my understanding that this particular bearing was discussed with
Nelson and that Nelson was also aware that some bearings were reported
to be grainy.
I will run this past Joachim for a clarification.
Don Malling
Sally or Dick Taylor wrote:
>
> Stephen---When the spring is connected to both the strap and the bottom
> hole in the clutch operating arm, it should have 15 lb. of pull when
> extended 1/2". This is a good quality extension spring with hooks at
> both ends. The instruction sheet should show this. If you don't have
> it, I can check the overall length and wire diameter with one I now have
> in operation.
>
> Don---Any bearing to be found "grainy" is not worth installing. I'm
> surprised that anyone at Gunst would say that such a bearing may need to
> be broke in.
>
> One of the features in any throwout bearing that is preloaded would be
> that it turns at the same speed as the clutch. This would mean wear at
> the fingers should be at a minumum, since the bearing doesn't have to go
> from Zero up to X,000 rpm during gear changes. This also reduces the
> amount of metal dust flying around that has the potential to get into
> the bearing balls, thereby reducing bearing life. Only a quality
> bearing can withstand running full time over many miles. I feel that
> it's also the main reason why the tech guys at TRF do not recommend that
> any of their bearings be preloaded. I was also told that the crank
> thrust washers may not hold up under a preload. While worth watching, so
> far I have not found any of these to be an issue with this setup.
>
> Dick Taylor
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