The dreaded K series clutch fork

[ashleyknowles]

Help!

Had my '98 Superlight R for a year now. Lovely beast. 190bhp VHPD motor, 20k miles and in nice nick. But just suffered the clutch fork problem. It bent and broke at the fulcrum pin and fell off leaving me with no clutch. Luckily the broken piece was somehow thrown out of the bellhousing without damaging anything and the fulrum pin was undamaged.

Got a new fork from the nice people at Redline and I whip out the motor and gearbox and go to fit it, but I can't get it onto the fulcrum pin when it's slotted down the gearbox input shaft. Mistakenly popped the clutch release bearing into place before trying initially and thought that was a mistake so I rived off the bearing and tried again, but still made no difference. There's just not enough wiggle room to get the fork end over the pin and sit nicely. Grrr...

Caterham lists the fulcrum pin as a spare part. It looks like a push fit. If I could take out the fulcrum pin, I could slip the fork correctly over a new one and push the pin home while aligning the fork over the input shaft.

Does anyone know if that's what you're supposed to do?

Thanks!

[ECR]

Cant recall the K setup but the crossflow and the VX both have a plastic/rubber sleeve pushed over the fulcrum pin. Removal of that does the job normaly. Replace the sleeve (its a Ford part I think ....)

[CharlesElliott]

Mmm, should all be straightforward. Can you post some pictures?

[Mankee]

Is this the dry sump belltank setup or the standard over-engineered Ford clutch arm? I have no experience with the former, but with the Ford item, I have never had a problem with a bit of wiggling. Worst case scenario, unbolt the bellhousing from the gearbox, fit the bearing and clutch arm, then refit the bellhousing with sealant/gasket/chewing gum/etc.

[ashleyknowles]

Its the dry sump belltank with the Caterham six speed box. 

I realised last night after I posted that unbolting the oil tank/bellhousing might give me a little more wiggle room and I had already removed the plastic sleeve on the fulcrum pin (with the intention of replacing it after everything was slotted together). But even with doing all that, it won't go on. The only way to do it would be to remove the fulcrum pin, slot it into the fork and push it back into the bellhousing while positioning the fork.

It very much looks like the fork is incorrectly dimensioned. Its the fabricated fork, not the pressed steel Ford (is it?) one. They must only be made in very small numbers and it wouldn't be surprising if dimensional tolerances aren't carefully controlled. No offence if the bloke who makes them is reading this!!!

I'm gonna send it back and get another one to try

How do you upload pictures on here? Let me have a go and I can illustrate the problem...

[Jonathan Kay]

How do you upload pictures on here?

Do you want to post a link to them on a server or upload them to the site?

Jonathan

[ashleyknowles]

Trying to upload now but losing the will to live...

[ashleyknowles]

[ashleyknowles]

[ashleyknowles]

There we go.

The bellhousing is removed so there's no g/box input shaft to restrict it's movement. Even witht he plastic sleeve removed the fork won't slot over the pin. 

The fork has to be the wrong size, there's no other explanation. Unless its assembled by removing the pin and slotting the fork over it and pushing the pin back in

[PROBE2]

Ashley

The install instructions state,

locate the clutch actuator fork over the plastic sleeve and fit the clutch actuator fork into the mouth of the belltank housing. To fit the fork, heat the plastic sleeve with hot water or a heat gun and remove the sleeve, position the fork with the clutch release bearing plate of the fork facing outwards and the V shaped end around the pin. Reheat the plastic sleeve and push down over the pivot pin, ensuring that the sleeve goes down between the edges of the fork, to ensure isolation.

So appears with sleeve off fork should free.

Thanks for ppictures by the way.

Cheers

Paul

[ashleyknowles]

Thanks for that Paul!

You have installation instructions? Are they in the build manual? I can't find that in the copy I have.

But there's no way I can get the damn thing to fit. Maybe if I heat the end of the arm with a blow torch or something, it will expand and allow me to slot it over the head of the fulcrum pin. Not sure I like that idea though. The other thing I can do is to remove metal at the far side of the arm. Lengthening the slot that the arm protrudes out of the bellhousing from will give me a little more room to work with. Or relieving the bellhousing casting where the thrust bearing mounting rubs against it as I'm trying to wiggle the bottom over the pin. That's not a good idea either though.

No, although the arm looks to be quite well made (the welds are nice), it's very obviously a low volume fabrication and the possibility of me having one that's out of tolerance is the most likely explanation why it won't fit.