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Steve4012

Major clutch issues, anyone seen this before?

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I'll try and keep this brief. 

Recent engine out service on my '85 turbo included a new 3 piece clutch kit from SJ. After literally about 300 metres of up and down road to test I had a massive judder through clutch pedal. Gearbox back off and found clutch release bearing was somehow moving off centre to pressure plate hence the massive juddering by uneven pressure. This actually broke my new release bearing (see pic) and there was witness marks on the bearing where the clutch fork arm slipped across the bearing collar. Looked at pivot ball/ clutch fork and found a lot of play. Made a new larger split pin up to reduce this and got it pivoting with less play but it seemed to pivot off centre so that's no good. Phoned Steve at SJ who said there should be loads of play and in his words the fork should be 'floppy' so the bearing can centre itself. Ok new bearing bought, another clutch fork bought even though the original looked fine. Also looked a lot at the pedal end. Clutch always bit high with old and new clutch and the pedal was set as low as the thread on pedal would allow so I measured the throw of the slave pushrod and it was 27mm. I thought this was way too high so loads of gymnastics later got the pushrod throw down to 18mm at the slave (Steve said this should be 3/4"). It felt good and I believed I had found the problem, too much extension pushing the fork and bearing apart. Gearbox back on, correct grease in all the right places etc start car clutch jams 🤬🤬🤬🤬. Removed dust cover off fork and look inside and can't believe what I saw. Pressure plate splines are uneven, some on release bearing and some slipped off and literally jammed the clutch in place (see pic with red dots where splines are off bearing). It's the correct combination of flat splines and round bearing so not that. The fork is also off centre. I'm stumped and a bit 🤬 off!  Is Steve right, should there be a lot of play? The ball on the pivot is good and the fork is definitely fine also. New clips from fork to bearing. 

Any opinions welcome! 

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Is the spigot bearing in the back of the crankshaft missing?  Can't think of anything else that could cause this, although the symptoms seem severe.


British Ambassador to Florida, New York, Denmark and Newfoundland.  And Sweden.

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No, new spigot bearing and Nylatron washer fitted and verified there second time round also. 

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7 hours ago, Sparky said:

Is the spigot bearing in the back of the crankshaft missing?  Can't think of anything else that could cause this, although the symptoms seem severe.

I love all of this stuff, I read it then I think what the f&£k is a spigot bearing, not to worry I have  been to see Paul Weller tonight and he absolutely smashed it finishing with Town Called Malice and that is where I believe my technical ability stands with fixing cars. Sorry @Steve4012 I am being no help, my advice, as ever,  is give it to Sparky and buy him some gin 

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Yes, clutch forks appear very floppy on the pivot  (presumably at they only loosly locate on a single rounded pivot until the forked end is loaded up).

Release bearing anf clutch plate look mismatched to me.   (There are two variants on each).   There is simply no way that the fingers should be able to ride over the rlease bearing as shown in pic 2.   NB That stepped release bearing is very different from the versions I've seen.

 

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Yes, the elephant in the room!  I didn't want to say it but my only other comment would be incorrect kit.  So either the bearing has been supplied incorrectly - twice, or the pressure plate is wrong?


British Ambassador to Florida, New York, Denmark and Newfoundland.  And Sweden.

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Just spoken to Steve at SJ. He said he's never seen that before. Very unlikely the splines are too short but measure to make sure. I've compared the first broken bearing to the original bearing and they match in size so don't think that's the issue. He thought there was more likely a gearbox problem as the bearing tube should centre the bearing to the release plate. Does anyone know how the shaft of the release bearing locates/ centres in the gearbox? @Lotusfab is in gearbox mode?! There appears no option now but get the 🤬🤬🤬 gearbox back off! 

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Shaft of release bearing just locates in plain bearing concentric to the Shaft.   doubt that is your issue. I've dismantled at least 4 of these boxes and have not seen any issues with excessive wear or failure of that bearing

New Parts just look wrong to me

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38 minutes ago, Steve4012 said:

Just spoken to Steve at SJ. He said he's never seen that before. Very unlikely the splines are too short but measure to make sure. I've compared the first broken bearing to the original bearing and they match in size so don't think that's the issue. He thought there was more likely a gearbox problem as the bearing tube should centre the bearing to the release plate. Does anyone know how the shaft of the release bearing locates/ centres in the gearbox? @Lotusfab is in gearbox mode?! There appears no option now but get the 🤬🤬🤬 gearbox back off! 

Hi Steve, have just seen this. My clutch is stil ,in pieces and I have ordered the same clutch kit! It hasn't arrived yet, if it's wrong and I have to take the gearbox out I won't be happy! The release bearing tube slots into the tube between the gearbox and clutch. Picture. If this tube is missing the bearing will move, if as I suspect younhave the tube then the pressure plate and bearing are wrong! Mines in bits still if you want to compare and Inhave all the original,parts! IMG_7442.thumb.PNG.7f7f73ba099ff571d25271678676f8cb.PNG

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Many thanks. Is the release bearing tube and housing tube viewable by removing the top cover plate? 

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If you don't want to take it apart you might be able to see the edge of the tube through the fork hole with a borescope. I have one if u want to borrow?IMG_7445.thumb.JPG.244c4ef12afb4e8b2d12ac684cfcb24b.JPGyou can see the tube edge in the picture.

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Ok thanks, I'll crack on with removal then if it's viewable from inside clutch housing. 

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The release bearing slide into the tube and the tube steadys it. If the inner bit is missing the release bearing will be all over the place. I should get my clutch today so can measure is all or you could come over and compare the fit?

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If the inner support tube was missing I suspect you would also have a major oil slick and severe graunching noises on your hands!!     Have a look at the 2 variants of CRB on SJ's website.  Neither version has that 'spigot' protruding thats pushed into the clutch pressure plate fingers.          

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I have no experience with S3 cars, so I may be wide of the mark, but that release bearing looks similar to the S4s which has a machined spigot pressed into it. Trouble is, it's five years since I did the clutch, and I'm struggling to remember. Found a photo or two, though.

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Margate Exotics.

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Thanks all for your input, it is much appreciated. The gearbox is back off and I hopefully have an answer. Both bearings measure the same at 58mm OD. The gap between the splines is indeed smaller on my original pressure plate. 49mm as opposed to 52.7 on the new one. So I have an overhang of 4.5mm either side on the old set up and only 2.65mm on the new so barely on the outer edge of the bearing. I'll email Steve at SJ the pics below and see what he says.

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I also had a look at the S3 parts book, and there are two different clutch covers, and two different release bearings, presumably they only fit as a matched pair?


Margate Exotics.

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10 minutes ago, Chillidoggy said:

I also had a look at the S3 parts book, and there are two different clutch covers, and two different release bearings, presumably they only fit as a matched pair?

That's right, straight fingers, round bearing and vise versa. I'm OK on that front. Thanks. 

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2 hours ago, Lotusfab said:

I should get my clutch today so can measure is all or you could come over and compare the fit?

Could you measure od of the bearing and the gap between the splines and let me know please Fabian? 

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Reply from Steve at SJ:

'That’s interesting but I really do not think it is the problem. I have sold loads of the covers.  I think there is something causing the bearing to be off line'.

I would appreciate your views...

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It just arrived. I have the flat bearing and rounded splines. Bearing diameter 58 mm, same as original! Spline diameter original 45 mm new 50 mm! I might have an issue!!!

I have almost the same overlap as you! I don't think the splines are close enough. When you press the pedal it will push the bearing to the point of least resistance i.e. Push the splines out of the way! I may have to contact Steve, I'm not happy to fit this as is! 

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17 minutes ago, Steve4012 said:

I would appreciate your views...

What about a bent input shaft?    After that, I've run out of ideas

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Just a thought, what's the measurement when they're pulled up tight onto a flywheel? That's when the release bearing acts on the cover springs.

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Margate Exotics.

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1 hour ago, Chillidoggy said:

Just a thought, what's the measurement when they're pulled up tight onto a flywheel? That's when the release bearing acts on the cover springs.

Good point. Not sure about the measurements when they're both bolted on but now I've removed the new pressure plate it measures 56.3mm at rest. The old one was also measured off the car at rest and was 49mm so the gap between the two has increased to 7.3mm larger diameter hole. 

I've spoken to Steve at SJ again. He still suggesting there's a gearbox issue but as the car was perfectly fine prior to this he's asked for it to be sent back. There's play in the bearing collar into gearbox but not dramatic and is expected and I think combined with a now very small tolerance from splines to bearing face it fails. 

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Yep good point! Will measure again when it’s bolted on. It may be ok!

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