clutch release arm

[Kpcseven]

This is on a Vauxhall with a T9 5 speed and cable clutch.  In adjusting the clutch cable when I was having trouble getting into reverse, I've found that the clutch release arm is hitting the bell housing and has actually put a small notch into it where it hits.  It has to go this far in order to fully disengage the clutch, and I'm not sure that even then the clutch is fully disengaging as reverse is still a bit difficult.  Is there an adjustment that I'm missing or is this a sign that the arm has somehow bent?  Could the release bearing be causing this?  Thanks.

[shn7]

Not sure if it applies to a Vx but earlier K series dry sump release arms are known to bend. Result is as you describe.

 

Steve

[ECR]

Never heard of the standard VX clutch arm bending (its a standard Ford part). A bit preoccupied at the mo but when the clutch wears the lever moves... cant get my head round the effect just now ..... Would clutch wear make it worse or better?

[John Vine]

Would clutch wear make it worse or better?

Worse -- that is, the top of the clutch fork would have to move further towards the engine.  And I'd agree with Roger that the standard Ford clutch fork is indestructible.

As for your problem, wear in the clutch friction plate would cause this.  Also, damaged/worn diaphragm fingers in the pressure plate could also be responsible, as could a failing CRB.

Has the problem appeared gradually over time?

JV

[Kpcseven]

Thank you for the thoughts. I just bought the car so i don’t know the onset. Just noticed that reverse was a problem and then found it.  The clutch doesn’t feel worn as it engages with the pedal well down in it’s travel. I don’t think I hear noise from the CRB, but it’s a straight cut box and noisy as well as new to me so perhaps I just don’t recognize it. 

I spoke to the original owner and builder. He told me that the assembly manual called for a hydraulic clutch for a LHD, as opposed to a cable for a RHD, but he had trouble with it and put in the cable. Could it have something to do with that?  Is the pedal position supposed to be determined entirely by the cable adjustment with no stops on either end of it’s travel?  The return spring isn’t very stiff and it’s very easy to move the clutch pedal freely upwards. John, I’ve read your posts and blog about preload with an additional spring. This won’t solve my current problem but does it apply to my situation?  

The car is driveable, forward gears working fine with the arm hitting the bellhousing and reverse being a slight crunch. I’ve installed a pedal stop in the pedal box to limit full pedal down so I’ll know if it is getting worse. Thoughts on driving it like this or should it be engine out to investigate. What I can see of the arm does not look bent  

sorry for the long post and thanks again!

 

[Wrightpayne]

Could be something to do with the fulcrum pin inside the bell housing. If this is missing / broken it would have the effect you are noticing. In my build manual (1998) there are different fulcrum pins for 5 speed and 6 speed boxes. When I came to fit a 6 speed a few years ago, I was told the thinner 5sp pin would be fine.

I think at some point its engine and box out to investigate - most potential causes lie inside the bell housing.

I was speaking with a company at the Stoneleigh kit car show in May who said Ford are producing the clutch arms again using modern production techniques so they are actually better made.

Regards

Ian

[John Vine]

Well, my comments so far have been general in nature, as I know very little about VX set-up (I'm a K and Duratec person).

Presumably  the hydraulic mechanism would use the same clutch fork?  If so, I can't see how using a cable set-up could cause your problem, as the fork would still have to move through the same arc to release the clutch.

Re pedal position:  in my old K (cable clutch), I had a stop to prevent over-stressing the cable, but the pedal height was governed solely by cable adjustment (adjuster at each end).

Re pre-load:  I don't know what CRB is fitted to VX cars, but assuming it's similar to the INA/SKF one fitted to K's, a pre-load is required.

No doubt a VX expert will be along shortly.  As for driving the car, I'd be inclined to look out for any deterioration, and if it does get worse, lift the engine to investigate.

(Good point about the fulcrum pin!)

JV

[elie boone]

The fulcrum pin is only there to keep the fork in place and rattle free, the steel washer under it is the important one as it supports the fork when pressed and if that is gone then the fork will eat into the ali. of the bell housing. if the fulcrum pin would be missing you won't notice it really. It looks like you will have to pull the engine sooner or later to address the problem.

[Kpcseven]

Thank you all for the quick answers and suggestions. It sounds like that washer may be what’s missing. I’ll check with the previos owner on whether he can remember when reverse became a problem. He primarily only tracked the car so reverse wasn’t an issue that bothered him. 

[Wrightpayne]

The fulcrum pin on older cars has the washer built in - it is a machined part. Not sure about the newer stuff??

Ian

[elie boone]

On a Ford OEM bell ( cast iron or RS 2000 Alloy ) you can take the fulcrum pin out as there is a hole opposite, on a Caterham alloy bell there isn't a hole on the other side so it's extremely difficult to take the fulcrum pin out. if the steel washer would be missing you wont notice as it's only 1 mm thick.

[Kpcseven]

I spoke to the previous owner and his recollection is that reverse became difficult after things were apart to replace some worn synchros.  I’ve decided that the thing to do is to bite the bullet and pull the engine to determine what is wrong. On the slippery slope of what else should be done so the engine doesn’t have to come out again anytime soon, what else would you replace while there?  Clutch, CRB, is the rear main seal on a VX easily accessible?  Suggestions so I have the parts on hand appreciated. 

Thanks!

[ECR]

If the engine is out and the clutch and flywheel removed, the crank seal is accessible. It can. Be prized out. However I have had difficulty pressing a new one in because it tends to extrude back out. If there is no sign of oil leak behind the flywheel I'd leave the seal alone. Use new bolts to refit the flywheel.cable operation for the clutch is in my opinion the best solution, I have had problems with leaking clutch hydraulics and replacing a cable is very easy. The crb will be on an alloy carrier probably and it might be that a spacer has to be added.to give sufficient clearance to allow for clutch wear. Iirc you can assemble engine and bellhousing outside the car, attach the clutch cable at both ends ( I think its long enough) and check clearances before putting the engine back in

[Kpcseven]

Thanks for the tips!  I’m definitely NOT an experienced mechanic, although I’ll hopefully have good help, but now that you point it out not being able to press the new seal in properly does sound like a very real possibility. It’s LHD so there should be plenty of space to check the cable action before putting it back in. Thanks!

[ECR]

Thinking further on this, when I changed from the oe caterham hydraulic clutch I fitted a standard non hydraulic bellhousing and that needed the alloy crb holder to correct clearances. I guess this is what has been done to your car ....

an external hydraulic system exists for the clutch, perhaps this is what your car previously had?

im just flagging up possibilities here....

[Kpcseven]

Are you saying that there is a different CRB holder that I should be looking for?

i checked with the original owner and his recollection, 24 years now, is that he had trouble during the original build with figuring out the hydraulic and exchanged those parts for the cable set up. He doesn’t recall exactly what was sent but not a different bellhousing. 

Is there anyplace where I could find a diagram or parts list on what the cable set up should be?  In case it’s not obvious, I really have zero experience with this repair!

[Wrightpayne]

Just take plenty of pictures on dis-assembly and we’ll all help. Specifically, arm, bellhousing, fulcrum point and bearing/carrier.

Unless you need a quick turn around!

 

Moving the fulcrum point forwards will have the same effect as spacing the bearing carrier. As mentioned Caterham made two different thickness fulcums - 3mm height for the 5 speed and 9mm height for 6 speed. This is in the 12/1/1998 build amendments and when I enquired about 4 years ago the 6 speed version no longer available.

For the caterham k series bellhousing, the fulcrum pin consists of a 20mm (approx) diameter disc either 3mm or 9mm thick with a plain 6mm (approx) pin one side which pushes into the bellhousing and a barbed pin the other side on which pushes a bit of screen wash tube to stop the fork rattling.

Regards

Ian

[Wrightpayne]

Just done some more googling and believe the VX bellhousing is different and does not use the same fulcrum arrangement as the K series.

Ian

[ECR]

If your car was originally fitted with a caterham hydraulic clutch which is a piston surrounding the output shaft from the gearbox which is supported in a bearing in the end of the crankshaft then there is insufficient space in that setup to use the ford clutch arm that you have and it would then be have fitted with a bellhousing to suit.

if your clutch pack remained standard overall thickness then I think that the standard ford crb was used which clips onto the clutch arm.

if an uprated clutch was fitted with a smaller overall thickness then it is normal to buy an aftermarket allow crb carrier and modify that to suit

when the engine is removed you will see that the clutch arm setup is very simple. The only head scratcher for me was how to remove the clutch arm from off the gearbox shaft. This is easily done if you remove the plastic sleeve from the fulcrum pin with a pair of pliers ( probably a good idea to use a new one when refitting

the ford crb carrier has tags on it to secure it to the arm which are prised off with a small screwdriver. An alloy carrier doesn't make use of the tabs

[John Vine]

...a caterham hydraulic clutch which is a piston surrounding the output shaft from the gearbox...

Ah, so it's a concentric jobbie (like the Sigma and Duratec cars) and not an external one (like the K VVC).  Thanks, Roger, I've learnt something useful there!

JV

[Kpcseven]

Thank you again for the continued comments. I’ll do a detailed search of all of the parts receipts which I got with the car to see if that reveals anything about replacement parts. Might take me awhile to get to the pulling engine point with work and other responsibilities getting in the way but will absolutely take pictures and seek more advice as this is way over my abilities. 

[ECR]

ill try to add some pics to help identification

Aftermarket hydraulic clutch in caterham wet sump bellhousing

Caterham hydraulic clutch in caterham dry sump bellhousing

Aftermarket alloy crb carrier

Clutch arm with alloy crb carrier (you can see the rubber/plastic sleeve over the fulcrum pin at the far end)

 

 

[Kpcseven]

Thank you so much for the pictures!  Extremely helpful.  It is much clearer to me now that if there is a washer missing from the fulcrum pin or the CRB is not the correct height by just a bit that the movement of the end of the arm would have to be much further, creating my issue with the arm hitting the opening in the bellhousing.  I'm wondering now if the CRB on my car isn't the correct one.  Would it be the same CRB for a hydraulic clutch as for a cable operated clutch?  Suggested source for the correct CRB for a cable operated clutch?  

Does anyone know or have speculation on why Caterham would spec a RHD Vauxhall with a cable clutch and a LHD one with a hydraulic clutch?  Perhaps the parts that were swapped out in the initial build to make it a cable operated clutch weren't all of the correct ones?

Great help on here - Thanks again!

[elie boone]

In order to use the same bell housing a LHD has a hydraulic clutch because the steering is on the other side of the release arm, https://caterhamparts.co.uk/clutch-parts/89-clutch-release-bearing.html should be the correct one

[John Vine]

Excellent photos, Roger!

That CRB looks like the SKF unit, as currently sold by CC for cable-clutch cars (and linked to in post #24).  

Out of interest, does it have a number on it (possibly FRA174C?), and was it ever originally the INA unit (as used on the Sierra), with p/n F202994?

JV