How do I know if my flywheel has been machined too much?

ToyRX · Post by **ToyRX** » Mon Oct 17, 2005 5:32 am

WRX flywheel in EJ20T Rally car, pulled apart to replace clutch as it was out of adjustment, ie very hard downshifts (2 hands + crunch) and slipping when on boost.
Was expecting to pull it appart and see a clutch plate "down to the rivits" but it was less than half worn!! Preasure plate looks fine as well so I am thinking the flywheel has been machined several times and now the preasure plate runs out of "travel" early.

But how do i tell? is there a standard thickness etc I should be measuring?

Outback bloke · Post by **Outback bloke** » Mon Oct 17, 2005 6:07 am

With the fly wheel being flat I can't see how machining it too much
would create any problems. If you have plenty of pad left on the clutch
plate you may find the pressure plate is faulty or the fly wheel and
pressure plate are not flat or very shiny. In any case, take it all to
a performance clutch shop and have it looked at.

grytvikken · Post by **grytvikken** » Mon Oct 17, 2005 7:47 pm

when you can see thru it........?

ToyRX · Post by **ToyRX** » Tue Oct 18, 2005 9:30 am

Took the clutch etc down to a specialist clutch place and engaged the wisdom of the resident 60+ year old expert - Les.

It seems that when the adaption was made for the cable clutch a short (~4cm) extension was added to the end of the fork. This was to allow a bit more purchace above the pivot point and also to allow the cable to clear the bell housing to attach to another bracket. In effect this lengthining of the fork caused a shortining of the release stroke at the thrust bearing end by an estimated 2mm or so.
This lead to the clutch being adjusted (so it did not slip) so that the thrust bearing always was on the preasiure plate so that when the clutch was disengaged (foot on pedal) the clutch plate still slightly touched the preasure plate. This resulted in premature wearing of the clutch plate and hotspots on the preasure plate.

Solution? New clutch kit and machined p-plate for a start. And, a 2.0mm thick spacer between the crank and the flywheel. Ite idea being that it moves the whole clutch assembly 2mm toward the thrust bearing. This will then mean I can move the cable end of the fork ~4-5mm further forward before the preasure plate is engaged and also therefore allow a 4-5mm longer stroke at the top and thereby increasing the release stroke by ~2mm

Result - hopefully everthing is back in "normal" alignment

Ill let you know how it goes

soobygus · Post by **soobygus** » Sun Oct 23, 2005 3:59 pm

Had it for a fang yet shaun?? how does it go?

you're doing better than me, i just pulled the 'dog' box (auto) out today, got your gearbox all lined up to poke in after i have put in the front lift kit- i figured it will be easier to put the gearbox in once there is more space between the mounts and the body. was a bit of fun getting the auto out of under the car- i had to employ the forklift, one of the perks of some decent gear at work i guess....

catch ya,
Gus.