I didn't see a whole lot of installation tips or info out on the web (maybe I use bad search words). So, here's my experience with installing this clutch and pull-to-push adapter.

After bolting on the flywheel to the counterweight (using tightening sequence and loctite), you'll need to insert the new pilot bearing and oil seal.

I made a "bearing driver SST" out of one of the tranny bellhousing bolts and a nut (14mm head size).

Thread the bolt through the top side of the nut (opposite from the lipped side).
Now you'll have a flat cylinderical surface to use against the pilot bearing and oil seal and the bolt head for the hammer.

 

Make sure you test fit the washer on the pilot bearing to ensure it covers the outer radius of the bearing. You don't want to crush or damage the bearing.

I put the SST against the pilot bearing which is positioned on the eccentric shaft outlet. Tap the bolt head of the SST lightly until the bearing starts to seat in the outlet.

Lightly tap it into place inside the e-shaft.

 

Repeat the above steps with the oil seal.

Very light taps.


Tap it in... tap tap tap it in...
Are you too good for your home, ball???

 

Here's a snapshot of the engine side OS Giken hardware.
Some bolts, plastic bushing, clutch plates (marked and keyed in order of installation), clutch alignment tool, "ghetto driver SST," and a chair.

 

Here is a snapshot of the push-type adapter w/ throw out bearing, slave cylinder spacer, and tranny front cover (pipe or sleeve).

 

A close up of the slave cylinder side of the spacer shows the milled out sections for the allen head bolt clearance.

Three bolts for the spacer to the bellhousing.
Two holes tapped for the slave cylinder.
One hole with a tapered double sided bolt fastens the spacer to the push-adapter.

 

I bought my OS Giken clutch pre-assembled from the previous owner. I double checked the sequence with another FD owner who posted the info online.

I used a sharpie to mark the side and location for each disc during disassembly.
The number 1 disc has a slightly smaller outer metal radius. The flared side up or towards the tranny.

Dual sided friction plate is installed.

The number 2 disc goes on with the flared side towards the tranny.

The single sided friction plate is installed.

 

The clutch cover is bolted on.

Balancing the discs on the alignment tool was fun.

I basically sandwiched the discs together with the friction plate loosely hanging in the middle. Then push the alignment tool w/ discs intol position. Apply some pressure to re-adjust the discs.

It's easier if you have the engine facing downwards (i.e. engine stand).
But this milk crate will do for now.

 

BTW, I lost some of the clutch cover bolts during the last photo. Fortunately, there's a big hardware store nearby where I found the rest of the bolts.

Now the tranny side of the hardware needs to be installed.

I replaced the stock tranny front cover with the OS Giken front cover.
It serves as a guide for the throw out bearing just the same as stock except the inner diameter of the throw out bearing is different than the stock and it has a U-shaped hinge for the push arm linkage.

 

With the help of a forum member (LetsGO7), I believe the plastic bushing is used to support the arm linkage inside the hinge on the front cover.

Here is a picture of the front cover and adapter in place.

 

I should note that you don't want to tighten all the bolts down except for the front cover bolts. Leave the adapter in place, but a little loose from the bolts (and peg guides).

If you haven't removed the starter and slave cylinder, you may want to do so now.
Remember to unplug the negative battery cable so you don't accidently short anything when tampering with the starter.

Here is a picture showing the differences between the spacer and stock adapter.

The double sided tapered bolt is fastened on one end (spacer) with a locking nut and the other end is the push adapter with a nut.
You'll see the nut in this spacer comparison pic.

 

Mount the spacer to the transmission bellhousing with the tapered bolt going towards the front of the car and the milled side towards the tranny.
You can only correctly fit it in one direction anyhow since you have to mount the slave cylinder to it.

I fastened the spacer down with the three metric allen bolts. You may need to wiggle the spacer as there is a little spacing tolerance with the plate.

 

Oops. I forgot to throw in the "before" picture so you can see the work area.

 

Fasten the nut on the tapered bolt on the engine bay side.

You'll see it right under where the slave cylinder tip would be positioned.
There is a very small amount of tolerance for the nut to spin down on the bolt since the lever arm is right above it.

I used a 12mm open ended wrench to fasten it down a bit.

 

Then you can install the stock slave cylinder in place.

It's best if the tip is retracted pretty far back until you can get one bolt to bite into threading. Thread it down enough so you can insert the second bolt.
Evenly torque down the bolts (alternating bolts every 1/4 turn or what not).

 

Pull-type is now push-type.

 

Good stuff! Almost makes you wonder why Mazda didn't use a push-type clutch to begin with.

Dale

 

lol...it's such a beautiful thing seeing another FD get the push-type treatment

 

Because you can get higher clamping force with less pedal pressure when using a pull type diaphram spring.

 

AP Racing says pull-type clutches can be up to 30% more efficient than conventional push-type clutches as well as being lighter and simpler in construction, all of which may be true. However, I've also heard that they were developed because they're not serviceable and the consumer has to buy a new assembly each time.

The Camaro and Firebird as well as the Corvette all use push-type clutches behind the LS1, whereas the LT1 had a pull-type. The reliance on a clutch fork, however, as well as the need for an external slave cylinder, makes them somewhat less reliable. I switched to an LS1-style hydraulic throw-out bearing and push-type twin disc clutch assembly for my car for this reason, and to free up some space for exhaust on the driver's side of the transmission tunnel...

 

AJatx, how does feel, and what did you have installed previously?

 

i have been debating between the OS twin, and the exedy twin for some time now. the push conversion didnt sound so zesty to me...why mess with somehting that already works well. plus the exedy twin plate is sprung (one set of springs for both plates) which should make it more streetable. im leaning toward exedy at this point... why did you choose OS? -heath

 

Klar, I had the RPS Kevlar clutch and stock flywheel. The previous owner dragged the car with that set-up.

Rotormotor, I originally wanted to get the triple plate Exedy clutch from Steve Kan, but I couldn't pass up a good deal on the OS Giken twin plate clutch I got from a forum member. It was a REALLY good deal.

As far as conversion, it's very straight forward and you can refer to this thread in case you get stuck. If you can change out the clutch, then you can easily convert.
Furthermore, I know I will take the engine out a few times in the life of the car so it's much easier with a push type clutch set-up. The FD isn't my daily driver and it's going to be built as a (street legal?) track car.

How does it feel? Well, I've only pulled the car into the garage after my friends and I brought up the engine after rebuild. Still troubleshooting idle issues (leak somewhere), so I didn't get to drive the car around. It felt great pulling into the garage.

I think it's streetable, but I can't really stand behind that statement until I drive in traffic.
However, it didn't bite like my old 6-puck ACT on my FC. That was fun driving in traffic.

J

 

Just drove the FD around the block. Pulling out of the driveway required a few reverse and 1st since I had a couple cars to avoid.

Anyhow, the engagement window is a bit smaller than stock, but the pressure feels nice (not too harsh so far on the calf muscle). It's a lot more streetable than an ACT 6 puck set-up.

So far, very streetable... but still no traffic yet. Still fixing stuff in the engine bay.

J

 

You'll find the OS Twin to be streetable in stop and go traffic. Mine has the same pedal feel and engagement window yours does it seems.

OS Twin is definitely much more streetable than any of the high torque holding ACT clutches and the pull/push adapter = cool.