Os giken twin won't disengage

[goodine17]

As the title says I have a a os giken grand touring clutch it worked fine for the first week but now when I push the clutch in it grinds every gear and I can't get it into any of the gears . I used the upgraded throw out bearing and machined the shaft 4 mills like the manual says and a nismo clutch pivot . Iv bleed all the lines .its also now a brand new transmission in the car too. I manually moved the clutch fork all the way back to disengage the clutch while someone was trying to put it in gear thinking it was my slave but still got no disengagement .

Iv got a dyno tune on Thursday and drags on Friday and well was suppose to be painted today but I couldn't drive it out to our body shop


Can someone please help iv tried everything

[mptjimmy]

does the transmission shift withthe car off? if so the trans is probably good. what's the pedal pressure feel like for the clutch. try bleeding the clutch, and visually inspect the movement of the slave cylinder, if all that seams good pull the trans and check the clutch. probably just needs to be bled. use some good fluid too motul rbf600 or so.

[goodine17]

Yes I works fine when off plus transmission is brand new . Slave and lines have been bled ill try running a thicker clutch fluid . I'm pretty sure it's clutch that's messed but not sure why or what happened

[xcye]

I had the same problem after using the first batch of GT2CD after a year and an half. The problem with mine was that the metal ring between the leaf spring and the pressure plate was shattered into pieces. I think it was a design or material flaw of the GT2CD. I heard that they had fixed the problem in later batches. Anyway, in the end, I decided to switch back to an old style clutch of theirs.

Yes I works fine when off plus transmission is brand new . Slave and lines have been bled ill try running a thicker clutch fluid . I'm pretty sure it's clutch that's messed but not sure why or what happened

[goodine17]

Okay thanks for the info guys I'm going to drop the trams again today and check that plate . Can u buy those parts seperate ?

[xcye]

If that was your problem, OS Giken would replace the whole pressure plate assembly for free. When they do that, let them know if you want the old style or the GT style pressure plate.

Okay thanks for the info guys I'm going to drop the trams again today and check that plate . Can u buy those parts seperate ?

[goodine17]

Okay thanks alot yea I'm a little pissed I don't even have 3000 k on it thanks for the help ill let ya know tomorrow what's wrong with her

[tryingtobebest]

Before you do that, THINK, if that plate was broken you would hear EXTREME amount of noise from transmission and especially when clutch pedal is pressed!
I would recommend getting or trying a NISMO slave cylinder, it has a longer walk/working distance for fork to walk more and thus it might help with disengaging the clutch fully. The only downside to this - it will be much heavier on the pedal!
Think of that before dropping the tranny!

Anton

[mikes_ca]

Hold on. I'm trying to work out why my new transmission isn't as smooth as I believe it should be, and have been examining different possibilities. I have an ORC twin plate, not sure on the exact model unfortunately. I installed a Nismo clutch slave at the same time as the trans, but have just found this:

When a person upgrades their clutch for the vehicle, the feeling of the clutch pedal will become much heavier, thus the driver must put more force when depressing the clutch pedal. The solution to this problem will be the Nismo Clutch Slave Cylinder. The bigger cylinder diameter (20.54mm) will enable you to control the clutch pedal easier over than the stock (19.05mm) slave cylinder.

Application: R32 4wd w/ RB20DET, R32 GTR w/ RB26DETT, Skyline R33 2wd with RB25DET, R33 4wd w/ RB25DET, R34 4wd w/ RB25DE

Important* The following Nismo RB Clutch Slave Cylinder will not operate using a Twin Plate Clutch.

http://www.thenismoshop.com/Nismo-JDM-Clutch-Slave-Cylinder-30620-RS580--Nissan-Skyline-GT-R-RB-Engine_p_84.html

So I'm thinking this could be part of my problem, and I wouldn't install a Nismo slave with your twin plate. The travel of the Nismo is only 8 mm as opposed to 11 mm for the stock unit.

Mike

[goodine17]

Okay thanks guys I moved the fork manually and the clutch still won't disengage so the slave is still good . Ps I used a big ratchet to move the clutch fork back u can't do it by hand .

[Frankyy]

still going to the dyno eh? did you figure out the turbo situation???

[Dragon Humper]

I have a Nismo slave on my twin, works just fine.




Jon.

[goodine17]

Pressure plate snapped in like ten pieces

[Skym]

Similar problem another GTRC forum member had and I think he found out it was due to using the wrong release bearing, sleeve, etc and the answer to the problem is here (including part numbers) -

http://forums.gtrcanada.com/gt-r-tech/58148-os-giken-bdp-440-what-release-bearing-use.html

Nismo slave is designed to work with one of the types of Nismo single plate sports clutches (I think was with a solid centre clutch disc).

[goodine17]

Yes I grabbed a set of used n1s off a buddy . But won't make the dyno now cuz of the clutch