Help me identify this clutch!!! Twin Disc?
 

Hey FC gurus!
I'm slowly restoring a modified Turbo II and reverting it from drag car to drivable status.
I knew it had a very expensive, heavy clutch... but I wasn't sure what kind. The transmission was leaking and the clutch was making a ton of noise with the pedal down. Today I pulled the transmission to replace the shifter bushings, seals and throwout bearing. Here is what I found:


The only markings I could see are a B-D and what looks like a stylized "MS" (or "SW" depending on how you turn your head). Mazdaspeed clutch? Any help is greatly appreciated.

https://lh4.googleusercontent.com/-r...o/IMG_0632.JPG

https://lh3.googleusercontent.com/-v...o/IMG_0633.JPG

OS Giken?

OS Giken is the brand for sure. Not sure which model.

It's OS's basic twin disc. It's the "street" version of their crazy multi plate clutches.

I know because I have one lol

Also, the throw out bearing is a pull type (the OS clutches only come in "push" type but their throw out bearings connect to the inside of the pressure plate springs). Just get a new one

Don't remove any of the center bolts unless you want to buy a new pressure plate. Just take off the alan headed ones to inspect the plates. New should spec out to 3.4 mm I think

Awesome! I bought the car for a grand, so if feels good to know the clutch alone is worth that
=P

ok, I'm a little unclear on the throwout bearing situation and push vs. pull.

Only FDs need the push to pull converter, right? My S4 Turbo doesn't have one.
Can I use an OEM Mazda TOB without any issues? The TOB in there now seems to be ok but I'm going to replace it anyways.
Is excessive noise and chatter normal with OS Giken twin discs? With the clutch disengaged it is ridiculously noisy and annoying. If I'm at a stop I have to immediately put it in neutral so I can let the pedal up and stop the noise.

Just want the noise to go away!

Taken from another thread: "I'm comparing the position where the stock throwout bearing contacts the fingers on the stock pressure plate (PP) vs. the OS Giken unit. It looks like the OS bearing would need to be 1/2" smaller than stock to contact the same way the stock bearing contacts the stock PP."

You can't use a OEM throw out. You have to her a new one from OS Giken. Also your fc will be fine in terms of push/pull.

As for the noise, twin disk are going to be noisy. If it is making too much noise you may have worn out disk and they need to be replaced ($500 I think) the TOB is like $100 or $200) spec out the parts and look for excessive wear.

These clutches are awesome but for the price to repair one you can get much cheaper options that will work just as good.

PM if you have any questions