Clutch disc to shaft spline tolerance

[rob07]

I bought a new 9 1/2" single plate clutch disc for my Ferrari 308 but when I placed it onto the splined shaft of the transfer gear it is what I would describe as a loose fit. The shaft has no wear or defects as the car has only done 16,000 miles.
Should the disc be a tight fit,snug fit, good fit or a bit loose. It is certainly more loose than my original. My gut feeling is that there should be no noticeable movement but the disc should be able to slide along the splines.

[stevieturbo]

does it measure to spec ? Are the splines formed correctly etc ? Is the input shaft ok, not worn ?

It should absolutely not be tight, the disc needs to be able to "float" or move.

But yes, it should not be very loose. That said, I've had discs over the years that seemed looser than they should, but never had a problem. If it is tight, it will almost always be a problem.

Assuming it's a single disc, it likely has plenty of depth too, so decent contact area ?

[rob07]

I've found out that it should have 0.2 mm across the shaft diameter/clutch disc center boss, and 0.5 degrees rotational tolerance.

[wildoliver]

If it feels sloppy on the splines (rotational or rocking movement) then it's not right. But it should slide freely back and forth on the splines. If there's slop it will just rip the splines out on a hard acceleration.

This is somewhere you might need someone who works on cars to look at it and say it's normal or not.

[richhead]

If it has a course spline then yes a bit of play is normal, and alows for expansion, better abit loose than sticking causing drag, expecialy in those gearboxes