My Clutch Is Blown...anyone Know Why Its Worn The Other Way?

[R31 Gagz]

Hey All,

Went to the drags a couple weekends ago and on the 6th run my clutch went. What had me scratching my head is I thought when a clutch wore that the take up point became farther from the firewall, that the clutch had to be let out further before it would take up. Mine did the complete opposite, moving closer to the firewall to the stage where I couldn't get it into gear until I popped the clutch pedal rubber rest off so I could press the clutch 6mm further in.

Does this signify that I have done something else? Or is that just the way it works in R32 GTRs with blown clutches? On the 5th run, I didn't notice any clutch slip at all and on the 6th it just went once I hit 2nd gear and from then on it just slipped any time I came on full boost, to the point where I would hardly accelerate at all. Seemed very sudden, with no slow wearing.

Cheers!

Craig

PS. It's an OS Giken twin plate clutch, probably between 3-4 years old running 270awkw for most of that time and when I ran it down the strip it had been re-tuned to 323awkw a few days before.

Edited December 7, 2007 by R31 Gagz

[R31 Gagz]

Does anyone know??

Edited December 7, 2007 by R31 Gagz

[Simon-S14]

more then likely a hydralic issue, either the slave or master has a leak and has died or the clutch peddle box has broken a few welds

[R31 Gagz]

Thank you Simon,

You probably just saved me a grand on a clutch rebuild that I don't need. So is this typically the sign of a slave or master cylinder gone?

I thought that was one of the things I might have done, but still plenty of fluid in the reservoir and couldn't notice any leaks at first glance.

Haven't had much chance to play with clutches yet so I think I'll have to take it in to properly determine whats wrong.

Cheers!

Gagz

[bryyy]

Yep I've had both issues that simon mentioned, broke welds on pedal box due to heavy button clutch and lots of clutch kicking, and leaking master cyl letting air in the system. a quick bleed makes it better temporarily..

[R31 Gagz]

Yep I've had both issues that simon mentioned, broke welds on pedal box due to heavy button clutch and lots of clutch kicking, and leaking master cyl letting air in the system. a quick bleed makes it better temporarily..

Where is the pedal box located? I want to try and diagnose myself before taking it in.

Cheers!

Gagz

[Deano45]

Where is the pedal box located? I want to try and diagnose myself before taking it in.

Cheers!

Gagz

Pedal box is the plate/bracket that you brake and clutch pedals are attached to. This is then welded or bolted to the firewall. The bracket for the clutch pedal will either have some sort of tear or welds that have come undone.

[R31 Gagz]

Pedal box is the plate/bracket that you brake and clutch pedals are attached to. This is then welded or bolted to the firewall. The bracket for the clutch pedal will either have some sort of tear or welds that have come undone.

Oh well im pretty certain its not that then as Ive been under the dash trying to adjust the pedal and it all looks fine to me....I guess that leaves the slave or master cylinder...anyone got a tech article on checking/replacing or bleeding the system?

Cheers!

Gagz

[R31 Gagz]

Talked to a mate whos a mechanic and he said it sounds like I've busted the diaphram. Will be taking it in next week to look at it with him and know for certain what I've done.

Thanks all that helped.

Cheers!

Gagz

[MBS206]

To check for broken welds, at the point it normally snaps, is best done with the dash partly out.

Pull the stereo surround out. Then remove the speedo/tacho cluster.

You'll be able to see the top of the fire wall now.

Sit in the drivers seat and put your foot on the clutch.

Did anything visible through the top just move?

If it did, that's most likely the broken part, as it normally doesn't move up there...

I snapped mine 3 weeks ago and had to reweld it.

[R31 Gagz]

To check for broken welds, at the point it normally snaps, is best done with the dash partly out.

Pull the stereo surround out. Then remove the speedo/tacho cluster.

You'll be able to see the top of the fire wall now.

Sit in the drivers seat and put your foot on the clutch.

Did anything visible through the top just move?

If it did, that's most likely the broken part, as it normally doesn't move up there...

I snapped mine 3 weeks ago and had to reweld it.

Would you actually notice the flex simply by watching the bracket looking up from the footwell while pressing the clutch??....the clutch pedal still feels solid and I imagine that it would have to flex a fair bit to affect the actual clutch this much which surely would be easily noticeable right?

Cheers!

Gagz

[Simon-S14]

its very unlikely that the pressureplate (diaphram) will be busted mate.. i still suggest a hydralic issue