Clutch issues - ARRRRGGGHHH!!!!!!!

[Uncle Arthur]

Public Holiday in NSW today...........

Not like they deserve it - beaten in the AFL and didn't even have a team in the NRL

How's that for getting the big spoon in

[AJ]

day of mourning UA

[Uncle Arthur]

Can you get Jen to do the pedal work whilst you bleed?

Jules

Fortunately I have a bleed kit so I can do it solo.

[jules]

Are you sure it's working?

Jules

[Uncle Arthur]

Are you sure it's working?

Jules

Yep - did a set of brakes on the weekend and it worked fine - and the way I do it it couldn't be not working (I keep the discharge end in clean brake fluid and it is certainly pumping it through).....

I'm more 'sketchy' on getting the setting right at the pedal end - given that I wasn't sure where the takeup point should ideally be and how far is too far to push it.....

[JBT]

IIRC, Rogue had a problem because the OEM hydraulic system could not cope with the release pressure needed for the heavy duty (competition?) clutch kit he fitted. I remember he was looking at a slave with a different bore size to get the pressure needed at the release lever. He could barely get the clutch to release.

It seems to me that you have:

a. internal bypass or leak happening in the master cylinder; or
b. a leak in the slave cylinder; or
c. ballooning of the flexible line in the clutch hydraulic system; or
d. air in the system; or
e. free play mis-adjustment; or
f. a bit of all the above.

There is a worse case though - wrong clutch components.

[r0gue]

Argh I feel your pain mate.

I replaced the slave with one that had a longer extention and more pressure, a new Master with a bigger bore for more pressure again and still had the same problem.

I just couldn't get the clutch to fully disengage. With the car in 1st and the clutch all the way to the floor the car would drive off and build up speed. The symptom is like the clutch material is too thick and the pressure plate just won't separate enough to fully disengage.

I assume you have adjusted the push rod (on the firewall) all the way to the end of the thread? Also there is a stopper on the pedal you can remove to get an extra few mm of travel when pushing the pedal in.

Basically I had to do this for about 2,000 km until the clutch compressed and wore down enough to allow me to slowly adjust it back.

The problem with the above is you'll be riding on the throw out bearing and as is the case with mine now it has crapped itself.

So the cause of my problem is still unknown and even now, if I give it some stick the clutch will play up and quite often changing gears doesn't work (eg take it to 7200 rpm in 1st and try to throw into 2nd and all of a sudden the disengagement point is in a different place *smash* and I can't get 2nd without double clutching ... not good at 7200 rpm)

My job was done by JAK and I had the following replaced:

- Hardened Lightned flywheel
- PWR pressure plate
- Heavy duty clutch
- Rear main
- Throw out bearing
- some other bearing.

UA - good luck in sourcing the problem as I still have no idea and until I pull it all apart again I'm not sure I will

[sabretooth]

Are you sure it's working?

Jules

I have the same bleeder kit - my clutch is working beautifully.

[jules]

This doesn't make for pleasant reading. I've still got cuts on my hands from that friggin gearbox!


Jules

[JBT]

I'm just wondering if the clutch disc being supplied as the MX-5 part is too thick or the pressure plate is wrong

[r0gue]

I got my pressure plate from Ryan - and it worked fine in his car. It was reconditioned so maybe something changed there ??

I thought maybe my flywheel was from a 1.8L but apparently they are interchangable. The whole time I must admit I have suspected the pressure plate or perhaps the alignment of the parts as it is the most complex part.

[jules]

The pressure plate is correct. It fitted the flywheel dowels properly. The clutch plate looked correct as well. There was plenty of meat left on the plate. Everything lined up nicely.

If is was parts related and not hydraulics, then it would be either too heavy a pressure plate, or an over machined flywheel.

But how do you buy an MX-5 cluch kit that is too heavy duty for the cars hydraulics. Surely you would be told if you needed to upgrade the hydraulics as well?

Jules

[r0gue]

It won't be the hydraulics.

Although the reason I upgraded mine was because the place I got the parts from said that they see it as a common problem in performance cars where the clutch is too heavy for the hydraulics.

I did verify however that the clutch fork (or whatever the fork that pushes on the TOB is called) was being fully extended by the slave. There was absolutely no room against the boot.

Actually Mikey that is one check you can do. Have someone fully depress the clutch while you are under the car and see if there is any room left to move on the clutch fork. If not ... welcome back to the start again.

[ampz]

umm...

would the clutch plate be the right way around?

I mean, with the pedal out the plate mates to the pressure plate right?
With the pedal in, it should be somewhere between the pressure plate and flywheel.
What if (i have done it with a holden before), you have the clutch plate back to front, and there is no play between the flywheel and pressure plate (because the metal spliney bit in the middle is making contact with the craksahft bolts)...

I do hope i am wrong (cause the mx5 gearboxes are a pain to take out).

[jules]

The plate was marked clearly \"Gearbox Side\". I showed it to Mikey when he bolted on the pressure plate. Surely if you got it back to front it woud make a racket on the flywheel or spigot?

Jules