Clutch slippage

[adam quantrill]

I'm getting a bit of slip - mainly in 4th but occasionally in 3rd too. Mainly on low-down revs, say booting it at about 2k will do it.

I wonder if there are any simple things I can try to sort it out first, rather than stripping it all out and replacing the clutch. Ther must be loads of meat left on it, it's only done 19k miles! I was thinking:

1. Trying a few standing starts feeding the clutch in at high revs, maybe that'll burn off any accumulated crud?

2. Checking the action of the slave cylinder - make sure it's letting it out OK.

3. Get some Trichloroelthylene in between the clutch plate and the flywheel, to clean them and get more grip. I might need to drill a small hole in the bellhousing to do this and spray it in there.

Any other ideas?

Edited by adam quantrill on Wednesday 5th September 15:09

[rev-erend]

Sure..

Less power - as if..

New clutch..

I'll get me coat

[GreenV8S]

adam quantrill said:

1. Trying a few standing starts feeding the clutch in at high revs, maybe that'll burn off any accumulated crud?

Or at least put the current clutch out of its misery!

[rev-erend]

GreenV8S said:

adam quantrill said:

1. Trying a few standing starts feeding the clutch in at high revs, maybe that'll burn off any accumulated crud?

Or at least put the current clutch out of its misery!

It's been tortured already .. for the love of god mate .. give it a decent burryal

[adam quantrill]

rev-erend said:

Sure..

Less power - as if..

New clutch..

I'll get me coat

Yeah since I filled up this morning the power has come back a bit, maybe the fuel went off while I was on holiday?

A new clutch is obviously an option, and probably a 3-plate one too to handle the torque, if I was to replace it. But in the past I've experienced this sort of thing on other wedges, and it has gone away on its own.

[rev-erend]

adam quantrill said:

rev-erend said:

Sure..

Less power - as if..

New clutch..

I'll get me coat

Yeah since I filled up this morning the power has come back a bit, maybe the fuel went off while I was on holiday?

A new clutch is obviously an option, and probably a 3-plate one too to handle the torque, if I was to replace it. But in the past I've experienced this sort of thing on other wedges, and it has gone away on its own.

Adam - Leigh cut a small'ish whole in his bellhousing .. big enough to free off a stuck clutch..
guess it would also be useful for spraying cleaning fluid and small enough to not cause bellhousing breakage issues.

I'm not fond of the twin or triple plate clutches - as they have high wear charistics ..

I've gone for the mcleod 10.5 inch single (9.5 is std)..
Real Steel do them for about £300 and then you need to have the flywheel redrilled for the bolts and the steel release arm shoutened by 10mm.

Oh - V8 Tuner also does them too..

Action is no heavier than std.

[adam quantrill]

Yeah I tried it at BBWF - it seemed just the same.

I had a look at the catalogue, so you have to get a plate plus the clutch cover presumably.

Did you have your actuating arm shortened by cutting and welding it? Why does it need to be shorter, does the clutch sit higher off the flywheel?

Lastly, Rev, did you manage to do this with the engine & g/b in situ (more or less), presumably you had to get the flywheel out to drill (& tap?) it too.

"The clutch will take up to 350 bhp, but should not be used with nitrous." Bugger.

[matt-man]

I say...GIVE IT HELL!!

Possible RESULTs:
1) New Clutch required
2) Fixed Clutch and some lovely number 11's!

Edited by matt-man on Wednesday 5th September 19:02

[JamieG]

Ah, someone else with clutch "issues"- my baby is off to Offords tomorrow (on a lowloader) for some clutch work. Can't wait to get her back!!

Edited by JamieG on Wednesday 5th September 19:07

[The Colonel]

My 450 has been slipping a bit, since BBWF in fact. Only in 4th and 5th when booting applying max torque.
Not been driving it too much lately, because I want it to last until the springtime, when I can afford to have a new one fitted.
It’s an engine out job, - so it’s going to be quite pricey local to me. I don’t fancy the easyway method of cutting the chassis, dropping the gearbox and welding up after.

Anyway if you can get to Sheffield, FYI Richard Thorpe will do clutch change for standard price of £300 labour, which is an absolute bargain!

I was a bit miffed at my clutch going at 27,000. A knowedgeable inde I know said it could be failing from lack of use (the last owner did 7000 miles in 11 years). What happens is the clutch springs weaken because they are not exercised enough.
As we all know – you should use your wedge regularly to keep everything working nicely. But if you are not going to use it for any length of time, then keep the clutch pedal pressed to the floor with a piece of wood between pedal and seat.

The other possibility is that TVR may have put a in a 400 clutch at the factory – who knows?
The recommendation is to fit the Griff 500 clutch – I am told this will be fine.

Maybe mine will improve with a bit more usage and the problem will go away

[The Colonel]

Adam - it is worth trying the cleaning fluid stuff
Where is your biting point though? - if it is right up near the limit of travel, then oh no not much meat left!

[rev-erend]

adam quantrill said:

Yeah I tried it at BBWF - it seemed just the same.

I had a look at the catalogue, so you have to get a plate plus the clutch cover presumably.
Yes

Did you have your actuating arm shortened by cutting and welding it? Why does it need to be shorter, does the clutch sit higher off the flywheel?
No turned down on a lathe top of clutch fingers are 10mm higher when both clutches are on the floor budget about £30 for this if you dont know someone with a lathe

Lastly, Rev, did you manage to do this with the engine & g/b in situ (more or less), presumably you had to get the flywheel out to drill (& tap?) it too.
This is a high precision job to centre the assembly - I gave this job to a machine shop to do to the flywheel

"The clutch will take up to 350 bhp, but should not be used with nitrous." Bugger.
Sure they would say that but a progressive system is much kinder to clutches and driveshafts..

[adam quantrill]

rev-erend said:

Lastly, Rev, did you manage to do this with the engine & g/b in situ (more or less), presumably you had to get the flywheel out to drill (& tap?) it too.
This is a high precision job to centre the assembly - I gave this job to a machine shop to do to the flywheel

Nah I mean - I think you were saying at BBWF that you managed to fix it with the engine and gearbox still in, but split apart - is that true, or did you have to pull out either engine or g/b to get at the flywheel?

The Colonel said:

Adam - it is worth trying the cleaning fluid stuff
Where is your biting point though? - if it is right up near the limit of travel, then oh no not much meat left!

The biting point is maybe just above mid-point on the pedal travel at the moment. Are you saying the higher it is - the less meat (all things being equal)?

The Colonel said:

The other possibility is that TVR may have put a in a 400 clutch at the factory – who knows?

I should hope so - it started life as a 400SE. But - what's the difference, is it a higher spec?

Edited by adam quantrill on Thursday 6th September 00:01

[gsx600]

My clutch also slips until everything warmed up, but hten again I'm using the 4.0l clutch with the 4.5 engine, so expecting it to go bang sometime soon. Lasted 2 years so far

[rev-erend]

adam quantrill said:

rev-erend said:

Lastly, Rev, did you manage to do this with the engine & g/b in situ (more or less), presumably you had to get the flywheel out to drill (& tap?) it too.
This is a high precision job to centre the assembly - I gave this job to a machine shop to do to the flywheel

Nah I mean - I think you were saying at BBWF that you managed to fix it with the engine and gearbox still in, but split apart - is that true, or did you have to pull out either engine or g/b to get at the flywheel?

The Colonel said:

Adam - it is worth trying the cleaning fluid stuff
Where is your biting point though? - if it is right up near the limit of travel, then oh no not much meat left!

The biting point is maybe just above mid-point on the pedal travel at the moment. Are you saying the higher it is - the less meat (all things being equal)?

The Colonel said:

The other possibility is that TVR may have put a in a 400 clutch at the factory – who knows?

I should hope so - it started life as a 400SE. But - what's the difference, is it a higher spec?

Edited by adam quantrill on Thursday 6th September 00:01

Adam - I had the engine and box out over the winter anyway .. so they were apart.

But - I have done clutches with the engine in situ but moved forward.. but it will be tough because of the flywheel bolts but so long as you have someone to stop the crank from turning (front pulley bolt) then this should be do able.

[adam quantrill]

Thanks. Just double-checked the biting (and release) points.

Clutch starts to bit a little over half-way released.

Clutch starts to slip when you press the pedal maybe half an inch.

I wonder if there is plenty of friction compound on the clutch plate, but over time the springs that press it onto the flywheel have become less effective? On the other hand, the action seems no different to the 350i so maybe not.

Another thing - this _doesnt_ happen when the engine is cold, but does after it (and presumably the flywheel) warm up, which also points to some contamination possibly being the cause.

[The Colonel]

adam quantrill said:

The Colonel said:

Adam - it is worth trying the cleaning fluid stuff
Where is your biting point though? - if it is right up near the limit of travel, then oh no not much meat left!

The biting point is maybe just above mid-point on the pedal travel at the moment. Are you saying the higher it is - the less meat (all things being equal)?

The Colonel said:

The other possibility is that TVR may have put a in a 400 clutch at the factory – who knows?

I should hope so - it started life as a 400SE. But - what's the difference, is it a higher spec?

Edited by adam quantrill on Thursday 6th September 00:01

Re the biting point:
That's what I was told, but yours being only just above mid-point I think might be ok - maybe someone else could confirm this?

I was refering to my car when I said that TVR may have put a in a 400 clutch at the factory!

I assume when the models were current there would have been an uprated clutch that was fitted in the 450, but I dont know for sure.

[350zwelgje]

A small hole in the bellhousing should not be an issue as:
- there is a dust plate at the bottom anyway, and perhaps you can use this to spray some cleaning fluid.
- I made a large hole to replace the clutch release lever without touching anything else. And it is fine and have done over 1000km now including a drifting course.

I know it is only a humble 350i and your 400sx puts down a lot more (especially torque), but would expect no major issues here.

And think that you probably have to live with this situation and probably it goes away (as it often does with our reliable wedges), or replace a worn clutch with upgraded stuff as you planned. Clutch could be replaced without taking engine out, but seems to take as long and if it is necessary to machine anything (flywheel?) you have no option as to take the engine out.

Rob

[rev-erend]

Guys - the biting point is just 'mechanical'

If you imagine a lever with a fulcrum point somewhere in the middle - the bit point is actually decided by the height of the clutch fingers.. and that push of the release bearing 'over centre' to operate the diaphram.

If the plate is contaminated - spraying it is a temp fix .. you may actually have a problem going on ..

Box oil leak, engine rear main oil seal ..

At the end of the day - if it's shot .. bit the bullet and do it or fix it for long enough to enjoy whats left of summer and do it over the winter.

[adam quantrill]

rev-erend said:

If the plate is contaminated - spraying it is a temp fix .. you may actually have a problem going on ..

Box oil leak, engine rear main oil seal ..

So - I'd like to see if the temp fix works and then comes back or doesn't come back, and how long it takes. Then I'll know if I replace the clutch that I'll need to check some other stuff.