Cerbera Clutch issues

[shaunmorris]

Sorry for the long post but I am having a nightmare with my Cerbera clutch. The car is a 1997 4.2 AJP with 26,000 miles on the clock. About 6 weeks ago the slave cylinder failed and while the gearbox was of, it was decided to fit a new slave cylinder and a new clutch as well. The garage advised that the new clutch was deeper that the original which I thought was odd but as they claim to be experts I allowed them to continue, so a new raceproven slave and AP clutch was fitted.
The problems now begin as since then the car has not moved for more than a few miles before the clutch fails.
so some questions
1) is the raceproven slave a direct replacement for the original 1997 slave cylinder
2) was the early clutch smaller than the current AP racing item.

If the answer is no and yes would this be the cause of hydraulic problems.

As far as I know the car is totally standard and was fitted with the original clutch and slave before the failure.

The garage claims that the AP clutch is the only one available, but the size difference worries me and I suspect is the cause of the problems.
I assume the raceproven slave is the same size as the original.

Any Ideas

[RUSSELLM]

If that’s the original clutch coming out, have a look at this.....

https://www.pistonheads.com/gassing/topic.asp?h=0&...

Edited by RUSSELLM on Tuesday 7th May 19:39

[Thunderroad]

Hi Shaun,

I had a similar problem with my 96 4.2, i think the earlier cars had a different flywheel, i ended up removing my flywheel and bellhousing and got them machined to fit, i still have a record of the measurements somewhere. But i think the recognised fix is to change the old flywheel for one of the newer ‘lightweight flywheels’ but I recommend you take some measurements to make sure it all fits while its apart, to save having to do it all again.

I see you are in the south west, anywhere near Plymouth?

Good luck, Simon.

[shaunmorris]

Thanks, I thought things were not correct, you would expect a specialist to be aware of this, I'm up in Bath.

[Thunderroad]

Ah, Bath, thats a shame, a bit far away for an evening visit!

I would ask the garage if they had to make any alterations (and if so, what they were) to the existing flywheel or the bellhousing before they fitted the new clutch pack? If not then i would suspect there is no gap between the clutch release spring fingers and the slave release bearing.

Is the clutch now constantly slipping?

[Thunderroad]

Here is some info i posted on this a few years back when i did mine.

[CerbWill]

Interesting. There were also 2 standards of bellhousing. My (1996) car had the early type which was changed by the previous owner when he had clutch slave issues.

[Jimm218]

I remember how long this took me to figure out!

So, I discovered that the bell housing, clutch, slave cylinder and flywheel are all different from the early 4.2 and the later cars.

The bell housing is a different casting and the new clutch apparently fouls. My car had the later bell housing but all the other early bits.
The flywheel has a deeper cutout in the centre to allow for the springs on the new clutch plates.
The slave cylinder is 5mm longer than new ones
The clutch pack is 5mm thinner than the new ones and has no springs in the clutch plates. I managed to get a look at the technical drawings from AP themselves.

In the end I had my old slave machined at work to make it shorter, picked up a flywheel from someone on here and it has been in the car and working for quite a while now.

Unfortunately there is no way around having the newer parts. It is all or nothing.

[TwinKam]

Are there any definitive (rather than comparative) characteristics e.g. casting numbers on bellhousing, thickness of flywheel, length of slave?...

[shaunmorris]

Everything fits together but after just a few depressions I loose the hydraulics.

[Thunderroad]

So once the hydraulics have been lost, do they come back after a while of waiting?
Or are they totally gone and you have to do something to make them come back?
Perhaps the system needs a good bleed?

[gruffalo]

Are all the holes in the different parts of the slave vertical to allow the air out and the fluid in?

When you say you lose the hydraulics, does it lose fluid?

[Cavey]

shaunmorris said:

Thanks, I thought things were not correct, you would expect a specialist to be aware of this, I'm up in Bath.

Shaun apologies for the post hike but I'm near Bath and wondering if you use anyone locally for bits on the Cerb? Have recently bought one and have booked it in to TVRSW for a good going over but it's a long way for minor things.

Cheers

Martin

[DCerebrate]

The above answers sound the most likely to resolve your issue. Would suggest checking the master cylinder. Fluid appearing anywhere? One other issue I had to contend with was scoring on the part of the bellhousing where the slave sits. That meant I had to go for a remote Tilton slave cylinder. A better longterm solution although the measurements for full actuation of the clutch are crucial to success of the installation.
Good luck and let us know the outcome. Btw competition clutches in Leeds can often rebuild an old clutch.

[Byker28i]

Cavey said:

shaunmorris said:

Thanks, I thought things were not correct, you would expect a specialist to be aware of this, I'm up in Bath.

Shaun apologies for the post hike but I'm near Bath and wondering if you use anyone locally for bits on the Cerb? Have recently bought one and have booked it in to TVRSW for a good going over but it's a long way for minor things.

Cheers

Martin

Just mail order from TVRParts https://tvr-parts.com/

[Byker28i]

I didn't go AP - I think mine was Helix? However as you've said the clutch was a different size and wouldn't disengage. Now this may have been a factor that some were delivered with thicker plates than spec.

Also on my 4.2 '97 engine the flywheel was different and needed machining for the clutch to fit.

[Cavey]

Byker28i said:

Just mail order from TVRParts https://tvr-parts.com/

Cheers but I meant having work done rather than getting parts.