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Clutch Problem Diagnosis

Phil Megroin
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Phil Megroin Collaborator

Phil Megroin

Posted
Posted

So i was driving today along beecroft road, when all of a sudden i pushed the clutch pedal in and it felt like it snapped on me. Now changing gears is difficult, and the friction point has gone closer in towards the firewall (i.e. i bring the pedal out like half a centimetre and it feels like the cars gonna stall). The pedal's all kinda wobbly now too and much looser than it used to be.

Any ideas?

Btw its an r32 GTST with an aftermarket heavy duty clutch (not sure what type - came with the car when i bought it)

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https://www.sau.com.au/forums/topic/141697-clutch-problem-diagnosis/
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gtrchick Community Regular

gtrchick

Posted
Posted (edited)

Could be your clutch fork. I know of a person who snapped their clutch fork because he had brassy put in his car but the fork wasnt changed... im not sure if you can change the fork to one which can handle a heavy duty clutch but it could be the problem.

Edited by gtrchick
gtrchick Community Regular

gtrchick

Posted
Posted (edited)

haha yeah...im bored

So your clutch fork is what is acted upon when you put your foot on the clutch, which displaces the liquid via the clutch master cylinder, to the slave cylinder, which pushes on the fork, on the fork is your throw out bearing which is what makes contact with the pressure plate fingers.

The clutch fork is what helps changes the clutch from being engaged to disengaged.....sort of. You get the drift

hmmm then again if the pedal is wobbly.... did you check the pedal? like the pivot and all that jazz? could be something really simple...

Edited by gtrchick
FATGTS-R Experienced

FATGTS-R

Posted
Posted

I was thinking pedal box as well. My one died but it didnt snap so to speak, it slowly mangled and twisted itself into a mess.

The pedal box doesnt cost much, but it isnt a fun thing to change. Think drivers seat fully reclined, and laying upside down with head under the dash and blood rushing to your skull why you have no room and cant see sh!t!! LOL.

Its a common prob with heavy clutches, so if it is infact your problem just reinforce the new or old pedal box so it dont happen again. They are only made from thin folded tin with a scarce spot weld here and there.

kjb_r33 Experienced

kjb_r33

Posted
Posted

If it is the peddle box, get you head under the dash with a torch and look up at the peddle box while you press the clutch to the floor. If it is cracked you will see it flexing open at the crack while the clutch is being operated.

Two bolts hold the master cylinder to the firewall, they also hold the peddle box, undo the nuts from the master cylinder, take the clevis pin off clutch lever, there is one bolt that goes up to a support behind the dash, long extension on your socket can get that, it should then just come out.

Once out just get it welded and reinforced.

blind_elk Grand Master

blind_elk

Posted
Posted

If the pedal box is broken, the clutch pedal itself should be sitting closer to the floor when in "clutch out" mode.

I've actually had mine break against the standard clutch. Had a HD clutch for a while now, and it's still OK.

Removing the pedal box, there is a bolt up the top, which I found much easier to remove after I removed the instrument cluster.

HRthirtyone Rising Star

HRthirtyone

Posted
Posted

apparently the little casting in the shape of a ball inside the bell housing of the gearbox, that the clutch fork pivots on can break aswell.

i have had the clutch pedal bracket/box snap into pieces on me.. couldnt use the clutch at all. took it out and welded it back up. If it happens again, i will tig weld the seams top to bottom. but its been a year with an xtra heavy duty button xtreme clutch and its all good.

also got to watch the ram that is attached to the clutch master cylinder isnt bent or is leaking. mine has started to leak over the last week.

Wish i knew where to get one

IMPUL R33R Newbie

IMPUL R33R

Posted
Posted
apparently the little casting in the shape of a ball inside the bell housing of the gearbox, that the clutch fork pivots on can break aswell.

i have had the clutch pedal bracket/box snap into pieces on me.. couldnt use the clutch at all. took it out and welded it back up. If it happens again, i will tig weld the seams top to bottom. but its been a year with an xtra heavy duty button xtreme clutch and its all good.

also got to watch the ram that is attached to the clutch master cylinder isnt bent or is leaking. mine has started to leak over the last week.

Wish i knew where to get one

Not 100% sure on what u mean by ram attatched to master cylinder but assume you meen the actuation rod for the m/cyl which is attatched to the clutch pedal. if that is the case you need to replace the master cylinder the leak you refer to is actually brake fluid leaking out of the rear seal of the master cylinder, that can be sourced from most brake shops eg Better Brakes etc.

mad082 Grand Master

mad082

Posted
Posted

i'd say the pivot bolt. that is what the clutch fork pivots on. there are 2 places it could've broken. either at the base of the bolt, (this is usually caused by it being done up too tight) or at the head. i know of 3 r33's (mine being 1) that have done this. mine and another broke off at the base, and another snapped the head off.

you can buy a new one from www.uniqueautosports.com for about $55. i got mine repaired by an engineer mate of mine. i got a 50mm long bolt in 12.7 tensile (thats pretty strong), got my mate to machine the old pivot polt smooth at the base, drill a new hole, tap a thread in it and cut the head off the new bolt and screw it into the pivot bolt. cost me 90 cents.

it is a gearbox out job. if it has broken the thread off it isn't that hard to get out. i used a cutting disc on a dremil to score a little groove in the top and just screwed it out with a screw driver.

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