[s-cars] question about 993tt rotors

Kenneth Keith auditude at gmail.com
Mon Apr 24 23:45:18 EDT 2006

Hi Sean,

Thanks for the reply.  My rotor part numbers are 99335104610 and
99335104510.  My fasteners are tight in the hats too, both distinctly
different groups.

Here's a pic of the two fasteners.



On 4/24/06, Sean Douglas <quattro20v at telus.net> wrote:
> Ken:
> I just swapped over billzcat1 custom hats and did not notice any
> difference between left and right, seemed to be the exact same. Also, no
> gasket either. Are you sure both rotors are for the 993tt?
> I did notice however, that the "t-lock" fasteners you describe were a
> very tight fit in the hats and I had to carefully press these in.
> BTW, the torque value on the bolts is very low, 8 ft-lbs, IIRC.
> Cheers,
> Sean
> > -----Original Message-----
> > From: s-car-list-bounces at audifans.com
> >
> > Some of you may be running brakes using 993tt rotor rings and
> > custom hats, and able to help with my question.  I have a
> > Billzcat1 Turn 9 setup for my 200q20v, which has custom hats
> > and brackets to mount 996tt "big bloc" calipers and 993tt
> > rotor rings, and I've got a question about the hardware that
> > holds the rings to the hats, which consist of "t-lock"
> > fasteners and bolts.  I bought the kit with unused rotors
> > from a lister and am sorting things out to install them.
> >
> > The t-lock fasteners (sort of a sleeved nut) that attaches
> > the rotor rings to the factory hats (which need to be removed
> > and replaced with the custom ones, re-using the hardware) are
> > different from left to right.  These t-lock fasteners have an
> > internally threaded tube that runs through both hat and
> > rotor, and the bolt goes through that from inboard.
> >
> > One set/side (can't remember left or right) has longer
> > fasteners that bottom out against the bolt before the rotors
> > are clamped tightly against the hats, leaving the rotor able
> > to float away from the hat slightly, and the other set/side
> > has a stepped fastener that is quite a bit shorter and when
> > bolted up will put the hat in tight contact with the rotor
> > ring with no play.
> >
> > The diameter of the holes in one rotor is about 5.0mm and the
> > other is 5.5mm, as far as I can tell.  Both t-lock fasteners
> > are 5.5mm towad the "head," as are the slots in the billzcat1
> > hats, and the "shorter" set of t-locks has stepped down to go
> > into the 5.0mm holes.
> >
> > I think the 5.5mm sections of the shorter ones might be the
> > correct length to bolt up to the hat leaving some float, but
> > cinch up against the rotor firmly, while the other t-locks
> > are different and would leave both rotor and hat able to
> > potentially float along the whole fastener (instead of just
> > on the thicker part that goes inside the hat, being solidly
> > attached to the thinner part between the bolt and "shoulder"
> > created by the 5.5mm-to-5.0mm reduction.  I don't think more
> > words will help in describing this, so that's it for now. =)
> >
> > In addition to this difference between left and right rotors,
> > I also found that one of the rotors had a thin black gasket
> > between the factor hat and rotor ring, but the other side
> > didn't have any such gasket.  The gasket is way thinner than
> > the difference in t-lock length (depth really, as the overall
> > length of the fasteners are the same, but the "shorter" ones
> > have a much thicker "head" area).
> >
> > I haven't gotten a chance to take pics yet, but I will do
> > that.  My basic question is whether there should be a
> > difference between how the left and right rotors are attached
> > to the hats.  If one is better than the other, such as the
> > shorter ones that bolt up tighter, then should I shorten the
> > longer ones?  Right now, if I bolt it all up without worrying
> > about it, one rotor/hat combo is completely tight and the
> > other has play where the fasteners can slide back and forth
> > (or the hat pulled away from the rotor slightly).
> >
> > Thanks,
> >
> > Ken

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