masho95:
I wonder if somehow the 9-puck fibertuff disc has a looser tolerance around the splines where it seats on the input shaft which causes the rattling noise. But from what everyone has said the noise is just an annoyance and not something that will cause damage. But from my point of view it's not something that should occur from a $175 disc. I'm not sure how much Josh has heard about this rattling noise, but I'll be sure to point it out to him, because as the number of people that are using this disc, so are the number of people that are noticing the noise. Thanks.
I'll have my manufacturer look into it. He had the hub inserts specially made for him, and they seem fairly close toleranced from what I've seen, though I have not been comparing different discs on an input shaft for that purpose ...
One thing to consider is that the spline insert (that engages the splines and transmits the torque to the sprung hub and thus the marcel spring and linings themselves) is an all-metal unit on these 9-pucks, which is unique in the SHO clutch world (remember that this is a custom-made disc for the SHO, and not a re-lined Valeo.) Most other discs are based on the Valeo disc, which has a composite metal/plastic/metal spline insert.
Now, recall that the disc is firmly clamped between the pressure plate the flywheel when the clutch is out. Thus I would not be surprised that if the disc were clamped in place, say, a couple thou off centre from the input shaft (which is reasonable, given the slip-fit nature of the hub over the splines, especially if the splines are worn at all), that the all-metal construction of the spline insert may transmit any contact noise of a slightly off-centre spline insert through the sprung hub into the input shaft, into the tranny, into the engine block, through your reinforced (stiff) mounts, through your solid aluminum subframe bushings, and into the cabin.
If it does not go through the input shaft, then through the disc that is tightly clamped by the pressure plate, to the flywheel, to the engine, and then the HD mounts, solid bushing and again into the cabin ...
As I browse the sigs, I see aluminum subframe bushings and HD mounts in nearly all of them. Thus a noise that may otherwise be absorbed by a composite plastic/metal spline insert would then trickle into the cabin that is not insulated by rubber bushings
It's a theory.
One other theory is that the tranny shaft bearings are shimmed loose from the factory, not to mention that the service shim is even thinner than most factory shims. Loose bearings mean that the shafts can move around more than they do, leading to more gear rattle.
Maybe select-fitting the shaft bearing shims like the diff shim is an answer. I don't know.
If someone wants to pull out their 9-puck and try a Valeo based disc with a composite spline insert to see if it goes away, I can supply one.
However, in the end, I'd rather have a rattling, but strong spline insert in my blower car. I've never liked the idea that plastic was (I run the 9-puck in there now) used to transmit the torque I make.
BTW, I don't consider $175 to be particuarly expensive for a custom-made disc wink
