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green96v4
V4 Mad

Canada
737 Posts

Posted - 11 May 2016 :  15:46:49 Show Profile Reply with Quote
finally the weather has bucked up in Canada for me to get out on the roads (takes them a while here to clean up the salt/sand mix that ends up in the road gutters)

HOWEVER, I have a problem with the clutch slipping (a new Highgate friction plate and pressure plate, bought back in 2003/4 and was just installed into the housing whilst the rest of the car was being finished, so has just sat for a decade unused) I've read somewhere there was trouble with these Highgate units...?

Pedal pressure is good and the arm adjusting screw doesn't make any difference (unwound fully and I can't get a gear, presumably the friction plate/lever hasn't disengaged enough, and my understanding is this is needed when there's wear to the friction plate, but mine is brand new)

any suggestions would be welcome before having to pull the engine/gearbox for closer diagnosis (sigh....)

Wheelspin
V4 Beginner

Denmark
99 Posts

Posted - 12 May 2016 :  07:14:09 Show Profile Reply with Quote
I think it might be the springs sticking. Try to get some WD40 (or similar) on them. It should be possible by removing the "vent grille/louvre" on the clutch housing.
I had the same problem when I bought my V4 years back, so I installed a new clutch. Had I known what the problem was I could easily have used the old one (which I still keep on the shelf as spare)
Regards, Mads
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green96v4
V4 Mad

Canada
737 Posts

Posted - 12 May 2016 :  11:43:56 Show Profile Reply with Quote
Thanks Mads, I'll give that a try!
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green96v4
V4 Mad

Canada
737 Posts

Posted - 17 May 2016 :  01:34:48 Show Profile Reply with Quote
Just tried a road test again after shoving a bunch of WD40 down the bell housing access panel - nope still slipping, any other ideas?
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john-saab
Administrator

United Kingdom
2679 Posts

Posted - 17 May 2016 :  07:43:08 Show Profile Reply with Quote
IIRC the Highgate clutch is a VW item and needed slight adaptation of the clutch slave to work. I'm sure others will know more about what was needed.

'73 96 (Vernon),'74 95 (Veronica)plus 4 other 95's and 2 96's
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john wyatt
V4 Guru

United Kingdom
1031 Posts

Posted - 17 May 2016 :  08:04:28 Show Profile Reply with Quote
Is there any free play at all in the pedal? I.e. Could the clutch be being held on?

Is it right that younhave 2 problems, clutch is slipping and it won't "clear" to engage gears?

I installed a Highgate clutch couple of years back and ended up ditching as I coulnt make my combination of bits work to create a properly functioning clutch, after pulling engine for 2nd time I installed a Sachs, as John has suggested will be others on here who can shed more light
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green96v4
V4 Mad

Canada
737 Posts

Posted - 17 May 2016 :  11:47:27 Show Profile Reply with Quote
Hi John

There is (as per what the Haynes Manual references) the play in the pedal before it engages

It does clear to engage gears, not had any problems selecting gears and even tried the freewheel and was doing clutchless changes (fond memories of that from when the car was on the road)

Everything seems to be pointing to the fact it's a Highgate unit, would love to know if anyone found a solution to making it work without having to pull the engine/gearbox. Are the problems with the Highgate unit in relation to it sticking on the shaft?
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Derek
V4 Guru

United Kingdom
2187 Posts

Posted - 17 May 2016 :  12:25:58 Show Profile Reply with Quote
Doesn't the flywheel have to be reground to suit the VW clutch? I believe that the working surface is recessed and if this is resurfaced the outer ring has to be taken down to compensate as the clutch cover is bolted to this. There is a set depth for the step. 0.43 comes to mind, probably cm. I haven't seen this discussed lately.
Didn't the Highgate kit come as a clutch/flywheel package?
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James Ranaldi
V4 Guru

United Kingdom
1475 Posts

Posted - 17 May 2016 :  12:59:42 Show Profile Reply with Quote
Good Call Derek,

It is a long time since I fitted the Highgate Clutch but it did indeed come as a Flywheel / Clutch assembly and the old flywheel was returned on an exchange basis.

Cheers



1968 V4, LHD
1984 99 GL
1992 900i Convertible
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green96v4
V4 Mad

Canada
737 Posts

Posted - 17 May 2016 :  15:15:33 Show Profile Reply with Quote
Hi Derek, thanks for the info, I didn't get a flywheel with the Highgate clutch, just the pressure plate, friction plate and release bearing (didn't even get the clips as Highgate had run out, so ended up ordering those from Scandix - not cheap!)

so this all leans towards me pulling the engine and seeing what's what!! I'm assuming if the flywheel has to be reground I should see wear on the friction plate at just the outer edge? (am I interpreting your instructions correctly?)

Damn...and you buy this stuff from "Specialist" in the faith that it should work.....
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Derek
V4 Guru

United Kingdom
2187 Posts

Posted - 18 May 2016 :  13:06:58 Show Profile Reply with Quote
If the recess in the flywheel is too deep the spring pressure on the drive plate will be too low. ergo clutch slip. The step has to be correct for the clutch so the outer has to be ground to correct this. Even with a standard clutch, if the drive surface is refaced, the outer ring has to be ground a corresponding amount to give the correct step depth. Maybe the diaphragm clutch needs to have the flywheel ground completely flat with no step?
There maybe a difference in the step depths for the two different types of clutches. If anyone has a few flywheels lying around or has them accessible on engines please measure the step depth. Small chance, but if you know it was last used with a diaphragm clutch please include that info.
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green96v4
V4 Mad

Canada
737 Posts

Posted - 18 May 2016 :  13:55:26 Show Profile Reply with Quote
Thanks Derek, having reread your last comment I realize I was asking the wrong question (my relative lack of experience on clutches...)

So my next question - If I have my flywheel machined, is there a way of checking the spring pressure or measuring the accuracy of the recess before it goes back in the car?
Or, as you've already alluded, is there a standard amount a flywheel should be machined?
If I simply purchased a new clutch and pressure plate (one that should be correct, Scandix list one as well as some US sites) will I be in the same position of still needing the flywheel machining?

I'm thinking that I've been sold the wrong clutch kit by Highgate or wasn't aware their clutch kits required additional work to make them...well, work - but I'm not sure if flywheels need machining regardless of what kit you fit and always require a mating process

Mine isn't a diaphragm clutch - guess I'll start taking the engine out and figure out which way to go....

Let me know in my questions if you don't mind
much appreciated!
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Derek
V4 Guru

United Kingdom
2187 Posts

Posted - 19 May 2016 :  12:26:44 Show Profile Reply with Quote
I've no hands on experience of this and am relying on posted knowledge. I thought that the Highgate clutch conversion was based on a VW diaphragm clutch. (VW Bus?) As said, the step maybe different for the two types of clutch. I was hoping that someone who has fitted a Highgate or has had their flywheel machined/reground would have piped up by now.
Stories of cover plates being spaced off the flywheel with washers have been posted when the step has been too small (?) and then the cover plate can hit the release arm. Obviously standard is best or a properly engineered conversion with all steps done properly.
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green96v4
V4 Mad

Canada
737 Posts

Posted - 19 May 2016 :  13:35:02 Show Profile Reply with Quote
Thanks Derek, I'll take a closer trawl through any other posts on the forum, see if there is mention elsewhere...

Cheers for the insights
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pchristy
V4 Guru

United Kingdom
1790 Posts

Posted - 19 May 2016 :  17:21:41 Show Profile Reply with Quote
My car has a diaphragm clutch, but it was on the car when I got it, so I can't help much with the fitting. BUT, the information I have is that the mod (on mine anyway) was engineered by Nick Senecal and Chris Partington. I believe the diaphragm clutch now offered by Malbrads is the same design. I have no idea if the Highgate is the same.

I DO know that the Malbrad clutch comes with an exchange flywheel. I appreciate the OP is in Canada, but it might be worth getting in touch with Malbrads and see what they have to say.

--
Pete
"Duct tape is like the Force: It has a light side and a dark side, and it binds the Universe together!"
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green96v4
V4 Mad

Canada
737 Posts

Posted - 19 May 2016 :  18:46:58 Show Profile Reply with Quote
Hi Peter

I actually phone Malbrad this morning, he's just told me he has a box of Sachs friction plates that are going back as they're effectively useless and is transitioning over to the diaphragm clutches with a flywheel exchange. Not cheap (quoted me £400 including the exchange) but he's also stated no-ones making the standard ones anymore.

He also suggested removing the nut on the adjustment screw and adding just a thin washer so I could potentially wind the screw in a little tighter - I'm going to try that first before pulling the engine and begging my wife for funds to replace a replaced clutch!!

I was also thinking if that doesn't work (long shot), I would do as Derek has suggested and have the flywheel machined. If Malbrad require it as an exchange unit I have nothing to lose other than putting it back in the car only to find it still isn't working!
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