11 replies to this topic

[simmodrz]

G'day,

So new motor, clutch etc all finally went in today after months of full rebuild and it seems I have clutch dramas... with a new clutch.

I just did heaps of searching the forum and this stepped-machining of the clutch is where I think I have been screwed...

What happens is after all being bled up it still releases ok as there is slack by the slave pin if I push it backwards but then it wont fully disengage the clutch. Even the pedal only goes down about 3/4 of the way and then stops as if something is bottoming out. Clutch is an exedy sports organic MBK-6429SO... nothing out of the ordinary. I have played with all pedal adjustment and the rod that actuates the clutch master is (and has to be) adjusted so it is pushing the master as far as possible and things still dont work as they should.

I fully cant remember as I never took notice of this step machining (even though I fitted flywheen today:))... only a light skim was taken off and I am pretty sure it wasnt step machined... but could this still be enough to screw the clutch operation?

Do I have any other options on getting around this or is it going to be gearbox out and flywheel off again? I hope not because I've been working BULK on this car lately...


Does anyone think it could be anything else the cause?

Thanks,
Simmo

[ChrisVR4]

Road Race Engineering has some info on their site about the step height, and the figures they recommend are very tight tolerance, so if the height hasn't been set properly that could be adding to the problem.

But it sounds like the main issue might be that the clutch fork is hitting the transmission casing before completely disengaging the clutch.
If thats the case, you would need to pull the box again, and shim up the clutch fork pivot ball. . . .

[BMGTZ]

Unfortunately it seems you have a worn clutch fork and pivot ball...that combined with having the flywheel machined has used all the available travel in the arc of the clutch fork.

This will mean box out and shim the pivot ball. Exedy at one stage recommended this in the fitting instruction...but Im not sure if it is still there.

basic instruction is to add shims under the pivot ball until the the release bearing touches {when the box is bolted to the engine} the fingers of the pressure plate at a point of approximately 3/8 of the total travel. I find that 3mm washers work well...but it depends on the amount of wear that is present in the clutch fork

[Gianni]

Defanatly the pivot ball. Done it many times on my cars, freinds cars and talked about it with other forum members.

A good fix is placing a washer behind pivot ball.

[simmodrz]

Hi guys,

Thanks for the replies... box is coming back out then.

Just wondering... do you think I'll be safe with just shimming the pivot ball (it is a brand new ball by the way)... or should I also be trying to find a machine shop that knows what they are doing and have the flywheel sorted out too?

I'm guessing just bite the bullet and remove the flywheel as the box will be out anyway right?

Thanks,
Simmo

[bps79]

Who built your motor if u don't mind me asking

[Gianni]

Putting a washer behind pivot ball is fine as above 3mm is ideal. That's what I used too. When doing a Mates car we didn't have any washers and it was late so stores closed so we used the cap of a sway bar link and again works fine

And I would get flywheel machines whilst it's out may aswell Get it perfect

[simmodrz]

Great thanks guys... just booked the next 2 days off work so I'm going to smash the gearbox out and back in tomorrow and then hopefully get it up and running and some "run-in" KM's on her!! Can't bloody wait

bps79 - I got my motor from a workshop in South Australia, just so happened that he had a fully built short motor in-stock as it is exactly what I was after. If you want the shop name then message me as I know some people dont want names/shops etc mentioned online... although their experience and customer service was simply A1

[bps79]

All good mate saw my first vr4 in a workshop here in Perth with a fresh motor and thought maybe it was you. Good luck with your clutch issue mate

[Evo-00x]

How did it go?
Did you check like this?

[simmodrz]

Gday,
Yeah that video would have helped beforehand but these are the things you learn with a new type of car your working on.
Turns out my clutch for was massively worn at the pivot ball area so I now have a new forrk and ball in... Seems to be working great. Just got it running this week and hope for the first drive today
Cheers for all the help

[simmodrz]

Gday,
Yeah that video would have helped beforehand but these are the things you learn with a new type of car your working on.
Turns out my clutch for was massively worn at the pivot ball area so I now have a new forrk and ball in... Seems to be working great. Just got it running this week and hope for the first drive today
Cheers for all the help