Problems After Twin Plate Re-install

[silman]

I recently wore out my OS Giken STR2CD twin plate clutch in my R33 GTS-T gearbox. I had a shop remove the clutch, and send it to a well known clutch shop here in Brisbane. This clutch, (purchased new direct from Japan) only lasted me 15,000km's. I pretty much killed it with bumper to bumper starts/stops in early morning traffic, before i changed shifts to later on in the morning.

The clutch shop said that the plates can be remade with pads measuring 7.5mm thickness (from pad surface to pad surface), rather than the 6mm or so thickness it comes with from factory to give a lot more life to the unit, and allow for more power holding capability. Only thing is though, is that a spacer ring (approx 3-4mm) is needed to be placed on the top of the assembly so that the main (red coloured) clutch cover is appropriately spaced up, due to the thicker pads. Sounded fine. (they said they do this with all there rebuilds of os giken's successfully).

Clutch shop refurbishes (if that's the appropriate word) the clutch for one day, and sends it back to the installer. The installer isn't able to select any gears once it is installed though. The clutch adjustment rod underneath the clutch pedal use to have a pickup point of close to the floor (maybe 3cm's or so out from the floor. To set that pickup point, the clutch adjustment rod behind the clutch pedal use to be turned to the point where there a few more turns and there wouldn't be any more thread left, going towards the seat (away from the firewall).

After this refurbishment, the box would not change into gear, until the rod was turned all the way completely back towards the firewall (away from the driver's seat). This is some 2.5cm's of turning the adjustment rod, a pretty huge difference.

Currently I am unable to turn the adjustment rod any further, or else it will pop out of the bracket. The car is changing gears in first and second fine. In third and 4th though, i can feel it being very notchy, and slightly grinds, unless i clutch it into neutral, and then clutch it into gear.

I've now driven 400km's and it hasn't gotten any better. I thought it may have something to do with the new redline lightweight shock gear oil (smurf's blood) needing some time to work in, but it hasn't gotten any better. The clutch seems to have been bled properly. Now the key thing is that I have always had a Nismo oversized slave cylinder installed. The installer said that the rod wasn't long enough for the newly rebuilt clutch, and so they replaced the rod with a longer one? I was on the understanding that the difference between the nismo big slave cylinder was that the bore was larger internally as opposed to the stock item, therefore allowing for less pedal pressure to be required to change gears.

I've seen quite a few members on here with twin plates so there has to be some people on here who at some stage has had there twin plates rebuilt (perhaps the same os giken twin plate like mine) who have had thicker than factory clutch pads put on. Has anyone run into this problem before? Did you end up needing a longer slave rod, and a longer clutch adjustment rod behind the pedal? It feels like if I could get a couple more turns out of clutch adjustment the rod (say 2 or 3 more threads for example), it would probably change a bit better. I don't really want to take the option of burning out the clutch a bit so that I can adjust the rod back towards me.

Edited May 5, 2008 by silman

[MFP]

Recently upgraded from a STR2CD to a TS2CD (BNR32) and had the same symptoms.

I found my my bearing release sleeve needed changing from 22mm to 15mm. Seems 7mm makes a big differance. There are 5 sizes 32-15mm.

Also had to get 4mm machined off the front cover. As I bought from Otomoto they helped me out with the info.

[silman]

Thanks mfp. just to clarify, it sounds like you mean that you wore out your old clutch, and instead of refurbishing it, you purchased a different os giken clutch?

When i purchased my STR2CD it came with the OS Giken throwout bearing. Actually come to think of it, i did buy my clutch through otomoto originally too (car was built for a while, before going on the road - too long ago).

What is this sleeve that you refer to? is that a stock nissan part? From what i remember, there were instructions that came with the clutch originally, saying to cut off 5mm i think from the shaft. This was done by the shop originally as per the instructions. not sure if this is what you're referring to.

[MFP]

Yep burnt the STR2CD out. Not rated for drag racing.

Throwout bearing = bearing release sleeve. Not a stock Nissan part but OS Giken.

Bearing release sleeve may still need changing, due to increased thickness of plates. Would check with installer/otomoto.

Sounds like the same mod has been carried out to the front cover/shaft as mine.

[silman]

Ok got you. I remember that instruction sheet. Unfortunately I don't have that anymore, but I do recall the "general warning" section about cutting 4mm to avoid contact. This was done when mine was installed. (a once off thing)

The clutch shop didn't say anything about requiring a change of the throwout bearing but I'll call them back to ask tomorrow. The guy did say that they had to put the spacer on underneath the cover, as the "diaphram alignment point" needed to be adjusted (by using the spacer) to compensate for the thicker clutch pads. I'm not sure how long the R33 GTS-T bearing is, I can't see it on your GTR sheet attached, but will let you know tomorrow what they say. Thanks.

[sic200]

i know which clutch place your talking about.. simply from the red colour they spray stuff and the spacer they want to put between the pressure plate and the plates. don't take it there, i've used rebuilt os clutches from them, and there nothing but a piece of rubbish, if your gonna take it anywhere, take it to jim berry, atleast he'll do a good job that will last.

[silman]

Ok i spoke to the clutch shop today, and they have asked me to bring it in to look at first thing tomorrow morning and they will see what the issue is, and correct it for free. That sounds like good service to me.

Just by talking on the phone, they think it may have something to do with a pivot ball, but since they didn't change the slave rod themself, they won't know if that's the problem until they see it. (more than fair enough).

Just to clear up sic200 - the os giken plate cover is red from factory and if i'm not mistaken, all twin plates have a floating plate between the clutch plates themself. This isn't a thread about bagging any shop whatsoever, so let's not take this thread in that direction. Will update tomorrow.

[sic200]

Ok i spoke to the clutch shop today, and they have asked me to bring it in to look at first thing tomorrow morning and they will see what the issue is, and correct it for free. That sounds like good service to me.

Just by talking on the phone, they think it may have something to do with a pivot ball, but since they didn't change the slave rod themself, they won't know if that's the problem until they see it. (more than fair enough).

Just to clear up sic200 - the os giken plate cover is red from factory and if i'm not mistaken, all twin plates have a floating plate between the clutch plates themself. This isn't a thread about bagging any shop whatsoever, so let's not take this thread in that direction. Will update tomorrow.

no probs, just thought i'd save you the trouble, i know twin/tripple/quads have plates inbetween, the place that i've seen mod them puts a spacer in between the pressure plate and where it bolts to the flywheel to space it out. has never worked for me. goodluck thou.