12 replies to this topic

[geoff-d]

I have a verto clutch new fitted recently that I can change gear no problem using just the top 1/4" of the pedle .

the old clutch was the same really .

its had a new clutch master & slave + Hose previously .

removed clutch this weekend & checked over all seemed ok. replaced worn clutch lever arm Short & clutch plunger + clevis pins so all new.

refitted & tested biting point the same but pedle is smoother .

so my question is what next ???

 

Edited by geoff-d, 04 July 2016 - 12:23 PM.

[Italianjob]

Not sure why anyone would have a problem with their clutch working.. I've had loads of cars over the years some have high bite some low! Until you encounter a real problem i'd suggest you stop wasting money trying to fix something thats not broken. 

[geoff-d]

apart from the fact that its on the point of slipping . it will slip if you just touch the pedal. and as I don't want to sit on the side of the rd with a clutch not working I thought that preventive maintenance would be best. but thank you for your technical help. 

Any one with some constructive ideas are welcome.

Edited by geoff-d, 04 July 2016 - 02:39 PM.

[Cooperman]

The other issue with a clutch which 'bites too soon' is the risk it may 'overthrow' and cause damage to the crankshaft thrust bearings.
It sounds like a problem with the geometry of the operating mechanism and if not resolved could lead to early clutch plate failure.

Possibly the release bearing is not properly seated on the plunger. Alternatively there might be a build-up of adverse manufacturing tolerances in the mechanism and mounting bracket.
Without inspecting it 'in the flesh' it is hard to be more specific.

[geoff-d]

Ok thank you cooperman . No simple answer then so out it comes again. Good job I forgot to refit two of the bolts that hold on the wokcover

Edited by geoff-d, 04 July 2016 - 10:42 PM.

[Cooperman]

You could consider fitting a pre-Verto clutch/flywheel as that is a better option.

The pre-Verto is lighter and has full manual adjustment.

If you do go this route you either need to fit the pre-engaged starter ring to the pre-Verto flywheel or fit an inertia starter motor, which is quite a simple thing to do.

[geoff-d]

It's already on a inertia starter so I may go down that line. I am going to nurburg ring early August so will have to sort something out soon

[tiger99]

It seems to me that as Cooperman says, there may be a tolerance build-up. It may be possible to identify the exact cause. But check the other stuff like incorrectly seated thrust bearing first, just in case it is something as trivial as that.

 

If there is significant pressure on the thrust bearing, to the point where the clutch is tending to slip,, the first thing I would do is measure the lever position from a suitable point on the clutch casing, then unbolt the slave cylinder and see if the lever can be moved back beyond that point. (You will want to put a strap around the slave to prevent the pistion popping out, if it hasn't got an circlip. No point needing to bleed the hydraulics yet, nor spill fluid on paintwork) If so, it was being hung up by the hydraulics and/or the slave pushrod is too long. With the slave cylinder out of the way, you can feel the lever for free movement of itself and the plunger. You will be able to feel the point at which the release bearing contacts the clutch.

 

While the slave is dangling on its flexible hose, ensure that its piston will push back fully. There should be a light spring in there of course, to take up clutch free travel, but it must not be stiff.

 

If there is difficulty pushing the slave piston, check that the pedal is hanging freely on the master cylinder push rod, and not obstructed by anything to prevent it returning fully, and that the pedal return spring is intact.

 

When you put the slave back in place, first insert the push rod, and then put the slave on its mounting and bring it forwards beyond the point at which the bolt holes line up to make sure that with it bolted down, there will still be clearance behind the piston so it is not forcibly applying pressure on the rod, except for the light spring.

 

None of that should take very long, and should give some idea of where the problem lies.

 

Finally, is your master cylinder the CLUTCH type, not a BRAKE type? Unlikely, but stranger things have happened.

[geoff-d]

with it all together in the car I can move by hand the clutch lever arm so in doing that I am removing the clutch release bearing away from the clutch. the release bearing is held into place with the rubbero-ring . so I am thinking that the pressure plate is not holding the clutch plate hard enough against the flywheel. so it only takes a small amount of movement for it to disengage. ?? its a clutch from
mini-spares think it is a ap kit

[Italianjob]

I have a verto clutch new fitted recently that I can change gear no problem using just the top 1/4" of the pedle .
the old clutch was the same really .
its had a new clutch master & slave + Hose previously .
removed clutch this weekend & checked over all seemed ok. replaced worn clutch lever arm Short & clutch plunger + clevis pins so all new.
refitted & tested biting point the same but pedle is smoother .
so my question is what next ???

My apologies Geoff, wasn't meant to poke or prod at you, but you didn't actually say it was that bad but just that it had a high bite. Did you fit the uprated clutch kit?

[tiger99]

Your in-car tests do tend to suggest that the external bits are in good order, which does cast suspicion on the pressure plate. Or, the friction plate is too thin. I assume that an uprated clutch kit should supply parts which are compatible, but maybe isn't.

 

I don't think that there can be any other conclusion, because there is not much scope for assembling it wrong, and you would know if it was something like an oil leak causing slippage.

 

I have to say that the quality of many spares these days is highly suspect.

 

You could probably take it apart and do some measurements. Bolt it up on the bench and see how much compression there is, i.e. the air gap at the bolting points when you just stack the flywheel, friction plate and pressure plate. Then compare with the same thing measured on a good clutch, if someone here happens to have one apart.

[geoff-d]

I have a new clutch to try & Compair it to but that is from the same supplier. I will
check it out & report back

Edited by geoff-d, 06 July 2016 - 07:07 AM.

[geoff-d]

just to keep this up to date.
fitted a new clutch kit standard AP 3 part clutch from minispares (green dot) same ish ?? biting better as not spun out like the one removed but not great & will Soon be the same as the one I just removed. out came that clutch kit & I fitted another 1 LUK kit that is new came with some parts i had. all fixed now even gives a sort of thud if you let peddle off to fast at biting point.
so 3rd clutch new arm & clutch lever arm Short & clutch plunger + clevis pins smooth & working as it should

Edited by geoff-d, 19 July 2016 - 08:06 AM.