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help with cluch assembly

Posted: Sat Jun 05, 2010 1:47 pm
by morris-out
Hi All, sorry for the long post, just trying to put you in the picture.
Wondering if someone could spot what I am doing wrong or have something incorrect with my clutch gearbox assembly.
Story.- Fitted clutch on to flywheel and gearbox on to engine without problems, then engine and gearbox into the car.
Problem.- when I came to connect the clutch linkage to the clutch lever I noticed that I was using all the adjustment on the clutch connecting rod in order to get rid of the slack, presumably before the thrust bearing exerted any pressure on the thrust plate.
Removed the engine gearbox, dismantled everything and could not see anything wrong, reassembled and this time before putting everything into the car tested the clutch lever for play, (quick learner me) and I had the same problem.
So far I think I have eliminated the following:
Having the wrong clutch – it is a 1098 clutch as far as I can see.
Having the wrong clutch lever- Is the straighter one and the thrust bearing is nicely centred so not the 948 one.
Having the clutch lever fitted the wrong way round.
Having the clutch friction plate fitted the wrong way round.
I have noticed that once the clutch is centred and ready for tightening, with about 5mm to go it pulls the thrust plate in, therefore this would make the thrust bearing travel a lot further before engaging the thrust plate.
As seen in the pictures it is there is a big difference when fully tightened, so is this the problem and what is causing it?
Wrong flywheel, me being stupid, this is fine or something else?
Thanks
Dennis[frame]Image[/frame]

Re: help with cluch assembly

Posted: Sat Jun 05, 2010 1:51 pm
by morris-out
I seemed to have lost some pictures here is one with the tightened clutch and the thrust plate pulled in.[frame]Image[/frame]

Re: help with cluch assembly

Posted: Sat Jun 05, 2010 1:56 pm
by linearaudio
Thrust bearing worn out? It is carbon and works on a sacrificial basis, so does "die" eventually. The thrust area should move in as you tighten the bolts, this is the sign of the spring(s) compressing. Within reason, the more greater the amount, the more "meat" is left on the clutch, hence as the clutch linings wear, the thrust area moves out from the flywheel face and reduces the pedal clear play, ultimately causing slip unless the adjustment is backed off. A lot of people can't get their head around this and think you shoul gain clearance as the clutch wears!

Re: help with cluch assembly

Posted: Sat Jun 05, 2010 2:23 pm
by morris-out
Should have mentioned that the thrust bearing is new, I keep thinking the problem would be solved if the flywheel was counter sunk by 5mm then the thrust plate would not be pulled in when the clutch housing is tightened.
Thanks

Re: help with cluch assembly

Posted: Sat Jun 05, 2010 2:57 pm
by morris-out
This is a picture of the clutch before the housing bolts are tightened up, about 5 mm to go but see how far the thrust plate sticks out. It may be correct but it certainly pulls the plate in a lot when tightened up.[frame]Image[/frame]

Re: help with cluch assembly

Posted: Sat Jun 05, 2010 7:31 pm
by bmcecosse
Back to basics - did all this lot work ok before? Or is it a 'mélange' of parts that have not worked together before ? And - you say the thrust is new - but is it the right one ?? Also - not sure if this is possible - but is the plate in right way round ?

Re: help with cluch assembly

Posted: Sat Jun 05, 2010 9:36 pm
by mike.perry
The 1098 clutch lever will only fit the 1098/1275 boxes and the 948 lever will only fit the 803/948 boxes as the pivot is different. If you have the forks the wrong way around the thrust bearing would drop out the first time you pushed the clutch pedal (been there, seen it, done it :( )
Are you sure that you have the 1098 thrust bearing? The pivot for the 1098 thrust is behind the bearing and on the 948 thrust it is through the centre line of the bearing.

Re: help with cluch assembly

Posted: Sat Jun 05, 2010 9:42 pm
by morris-out
Thanks for your answer.
The engine and gearbox have not worked together, the engine has been refurbished and the gearbox purchased separately.
The clutch is a mixture of old and new but all 1098 as far as I'm aware, will check everything again.
I will make sure that the thrust is correct.
Here is a photo of the flywheel
Thanks
Dennis[frame]Image[/frame]

Re: help with cluch assembly

Posted: Sat Jun 05, 2010 9:54 pm
by morris-out
Hi Mike
I'm sure I have the correct lever for the 1098 box, I will have to check the thrust bearing again, will take a photo when there is some daylight, though everything seems to be nice and central. I think this may turn out be be something embarrasingly obvious, at least I hope so, I can cope with that.
Cheers
Dennis

Re: help with cluch assembly

Posted: Sat Jun 05, 2010 10:13 pm
by bmcecosse
Fly looks fine - probably wrong thrust bearing.

Re: help with cluch assembly

Posted: Sun Jun 06, 2010 8:17 am
by Alec
Hello Morris Out,

"Should have mentioned that the thrust bearing is new, I keep thinking the problem would be solved if the flywheel was counter sunk by 5mm then the thrust plate would not be pulled in when the clutch housing is tightened."

I hope you are not still considering this step as that will reduce the spring clamping pressure and the clutch will have a very short life if it has one at all?

If you are certain about the inner workings, could you have mis-assembled the actuating linkage? All the bushes etc in place?

Alec

Re: help with cluch assembly

Posted: Sun Jun 06, 2010 8:30 am
by morris-out
Morning All.

Here is pic of the lever and thrust bearing I'm using, to my untrained eye it seems correct.
How much travel should that lever have before it 'engages'?
As I have previously mentioned when the gearbox is fitted to align everything before the clutch cover is tightened all seemes well, the problem only happens after it has been tightened, I hope I'm not sending you on a wild goose chase, this should all work.
Cheers
Dennis[frame]Image[/frame]

Re: help with cluch assembly

Posted: Sun Jun 06, 2010 8:49 am
by Alec
Hello Dennis,

as was stated before, that retraction of the thrust ring when tightening the clutch cover down is how it is supposed to behave. What you are doing is compressing the clutch springs and the linkage is reacting to that compression. It is not a problem. It is possible to fit the clutch centre plate back to front, but that doesn't give the symptoms you describe. (The projection in the centre faces the clutch cover.)
The thrust bearing looks normal, and indeed I've seen working (albeit worn out) clutches working where the carbon is flush with the metal housing.
As I said earlier I would look closely at the actuating linkage.

Alec

Re: help with cluch assembly

Posted: Sun Jun 06, 2010 9:01 am
by bmcecosse
Does appear to be the correct thrust - of course there should be clips holding it on!

Re: help with cluch assembly

Posted: Sun Jun 06, 2010 9:16 am
by morris-out
It does have some clips that are not particularly visible in photograph like the ones sold in ESM.
Retaining Clip-Release/Thrust Bearing
MMCBATH PART NO('S):COM708
Unfortunately I'm going to have to go to work now, so I will continue investigating later.

Thanks

Dennis

Re: help with cluch assembly

Posted: Sun Jun 06, 2010 9:59 am
by bmcecosse
Has the flywheel been machined ?

Re: help with cluch assembly

Posted: Sun Jun 06, 2010 11:11 pm
by marcusthemoose
i am in a similar position as you- i cannot get the thing to work- i also had the gearbox out and disassmbled the clutch thinking this was the problem, but it was not. i am now trying everything, including replacing the whole linkage,inc new bushes etc, and still have aload of grief. i was beginning to think it was me being idiotic, but you have the same problem. i cannot beleive that no-one has had problems like this before! it will be something really silly i suspect. i will watch this thread and let you know of any findings i make. good luck.

Re: help with cluch assembly

Posted: Tue Jun 08, 2010 9:19 pm
by morris-out
Hi.
This evening I have fitted the gearbox again and taken some photos, nice to be able to share this problem with marcusthemoose, makes 'doubly' interesting.
Anyway here are the pics showing the clutch fitted[frame]Image[/frame][frame]Image[/frame][frame]Image[/frame]
The third picture shows the travel of the lever before it engages, red 1 at rest black 2 point of engagement, distance about 2cm.
Yes the flywheel was skimmed and a new ring gear fited, should I fit in the car or is that lever travel exesive?
Thanks
Dennis

Re: help with cluch assembly

Posted: Tue Jun 08, 2010 9:24 pm
by marcusthemoose
mines about that aswell i should think. my next stage is to change the series 2 pedal to relay rod that i currently have to the plate type mechanism. apparently there shouldn't be any difference, but i wonder.

Re: help with cluch assembly

Posted: Tue Jun 08, 2010 9:49 pm
by morris-out
I was wondering if that could be a problem but this engine with another 1098 gearbox fitted the existing linkage without a problem.
I'm completely baffled as to what the problem is. I'm hoping for a eureka moment from one of our learned colleagues although I realise its hard to diagnose some faults and this appears to be one of them.

Cheers