Technical Catastrophic Clutch Failure

[Pugglt Auld Jock]

Not what I would use or do

Asking for trouble in my opinion

Not what you would chose to do koalar - The grease on the input shaft splines I'm guessing? I certainly wouldn't apply grease in any quantity but I do like a very sparing application of specialist clutch spline grease which is extra sticky and designed for this application: https://www.sachsperformance.com/en/sachs-service-greasing-clutch-disc-hub-spline. I do this by applying a light coating with a brush - so it gets right into the splines - then wiping most of it off again with a cloth before sliding the driven plate on and off again a couple of times and then wiping off any excess which this action disturbs. I never get problems with driven plates binding up on their splines or with grease throwing off to the detriment of the friction linings.

 

[bugsymike]

Not what I would use or do

Asking for trouble in my opinion

This is a contentious issue, I personally was taught back in 1969 to put a thin smear of copperslip or similar on the splines, check the new centre plate slide easily down the spline on the input shaft and the clutch release mechanism and then wipe off the excess. Since then I have done it on every clutch I have fitted and none has had a problem doing this, further more since 1982 they were all regular customers so if any issues I would have heard about it.
I appreciate others do things differently

 

[koalar]

Not what you would chose to do koalar - The grease on the input shaft splines I'm guessing? I certainly wouldn't apply grease in any quantity but I do like a very sparing application of specialist clutch spline grease which is extra sticky and designed for this application: https://www.sachsperformance.com/en/sachs-service-greasing-clutch-disc-hub-spline. I do this by applying a light coating with a brush - so it gets right into the splines - then wiping most of it off again with a cloth before sliding the driven plate on and off again a couple of times and then wiping off any excess which this action disturbs. I never get problems with driven plates binding up on their splines or with grease throwing off to the detriment of the friction linings.

Correct the advice is to slather copper anti seize on the input splines

Wrong product

Wrong quantity

But each to their own.

 

[Pugglt Auld Jock]

This is a contentious issue, I personally was taught back in 1969 to put a thin smear of copperslip or similar on the splines, check the new centre plate slide easily down the spline on the input shaft and the clutch release mechanism and then wipe off the excess. Since then I have done it on every clutch I have fitted and none has had a problem doing this, further more since 1982 they were all regular customers so if any issues I would have heard about it.
I appreciate others do things differently

Me too Mike, back in those days it was copa slip for me too. Although I never had problems with it I changed to the specialist grease when it was recommended to me by someone else and I do think it's marginally superior - not as if it's expensive so why not use something specifically designed for the job? Only thing I ever noticed with the copper based greases was that when you stripped an old one down that had been in service for a number of years the grease had solidified into a sort of semi solid which wasn't doing much lubricating. I haven't really noticed this with the specialist grease, although I have to admit I've not done anything like the number I did with the old copper grease and I'll be doing even less now due to old age, arthritis and other "ailments" rather curtailing my ambitions.

 

[koalar]

This is a contentious issue, I personally was taught back in 1969 to put a thin smear of copperslip or similar on the splines, check the new centre plate slide easily down the spline on the input shaft and the clutch release mechanism and then wipe off the excess.

The advise was

“benefit from a good smear of anti seize paste.”


But this is not what you are doing If you

“wipe off the excess.”

Which is correct advice in my opinion

Although I wouldn’t use anti seize as a preferred choice

 

[koalar]

No doubt

@portland_bill

Can give some tips and hints as I believe they work on clutches warranty deportment for years



The original gearbox splines has a thin smear on the splines from factory with what appears to be a very thin grease, very close to dry

I guess after millions of cars Fiat should have perfected the assembly to give the least warranty repairs

 

[bugsymike]

No doubt

@portland_bill

Can give some tips and hints as I believe they work on clutches warranty deportment for years



The original gearbox splines has a thin smear on the splines from factory with what appears to be a very thin grease, very close to dry

I guess after millions of cars Fiat should have perfected the assembly to give the least warranty repairs

In all the clutches I have fitted, starting with Borg and Back spring and finger type and on through diaphragm ones till retirement I have never had to make a claim, I suspect a lot of warranty claims came down to abuse in some form, either by driver or the fitter (note I say fitter not mechanic or motor engineer) the only time I have felt concern was when LUK changed materials and went for a softer action as customers could almost make the clutches slip from new until properly bedded in, something that never happened in the past. I mentioned it to my supplier just in case I had to make a claim at a later date but they seemed to improve with bedding in.

 

[DaveMcT]

Car manufacturers are only concerned to get the vehicle through the warranty period. Hence, (so called) filled for life gearboxes and engines with no dipstick. Back to the clutch - enough anti-seize to spit off and cause damage would have to be ridiculously slathered on. Anyone capable of replacing a clutch knows this.

 

[portland_bill]

Anti-seize (usually copper based) can cause slip or judder if it gets onto the friction lining. How much is needed to cause an issue will depend on the specification of the clutch.
The 80s Golf clutch, also used in Maestro and Montego 1.3 & 1.6, had only just enough clamping pressure, with very little reserve. Even a very tiny trace of copper goo would cause judder, and a whole fingerprint quantity would cause it to slip. I've seen other clutches with significant quantities on the lining, and no effect. Copper goo has almost no resistance to centrifugal forces, and heads for the lining. Any lubrication on the splines needs to be minimal, wipe it on, wipe it off, leaving a trace. A soft pencil is very good, as the graphite works well, and does not attract dust.

 

[bugsymike]

AS Dave says "Anyone capable of replacing a clutch knows this."
Since in over fifty years I have never had any CBJs, which is what we jokingly used to call "come back jobs" by poor workmen, I would say the minimal amount of copperslip or similar applied, was sufficient enough to do the job, but no more.
In 1969 when I started, I suspect there wasn't the propriety tube of specific grease available unlike today.
Over that time I have fitted clutches to literally every different make around , including those mentioned above and I can honestly say, apart from my earlier mention about LUK, never a hint of clutch slip or judder from jobs I have done, you don't keep regular customers in some cases well over 30 years or more by sending out poor jobs. When manufacturers started to include a tube of suitable grease/lube I would use it, in the same way some suppliers started to include lube for their cylinder head stretch bolts.
Something I have noticed about the Motor trade, is whilst all being highly experienced. we all have our own ways of doing things which we consider to be the only way, based on the way we were taught and are happy to argue our way is the only way, unlike people like solicitors who are very reluctant to attack another solicitor.

 

[Sfrontato]

Well I took another deep breath and fitted a new Valeo clutch kit to replace the genuine Fiat one. I also replaced the eBay release fork with a Birth item. Inspection of the two release forks against each other didn't identify much. The Birth had slightly better splines, but in operation nothing of consequence. The maximum throw of the forks in situ was the same, slightly less for the Birth.

With the Valeo and genuine Fiat clutch on the kitchen table, the Valeo had 18 fingers, the Fiat one 12. Both same diameter (181mm). The fulcrum ring was larger in the Fiat clutch. The height of the fingers of the Fiat clutch off the table surface was ~44mm, whilst the Valeo measurement was 40mm. Considerably different release bearing design, but similar stack height.

On a hunch, fitted the Valeo.... resulted in perfect clutch and gear change. Absolutely no drag.

Will be following up with supplier on what has happened here - the part number appears correct.

Of use to others is that I can confirm Koalar's measurements of slave cylinder throw are correct, and a good reference point to establishing whether the hydraulics are at fault (not in this case). They are also good reference for a new clutch aswell as worn ones.

On the third repeat of this job, I removed the driveshafts using a steel security cable and a garden fork as a slide hammer - a more sophisticated description of this is available on YouTube, but the technique works beautifully. No bashing of driveshafts with chisels.

Thanks to all for help and advice, in particular Koalar. My kids are now very happy they have a working Panda.

 

[koalar]

Well done on sticking with it

I do feel your pain having to drop the gearbox yet again. Not nice in summer much worse in December

I do hope you at least get your money back on the clutch. Although I doubt they will compensate for the lost time

 

[Pugglt Auld Jock]

Valeo in both our Panda and my boy's Punto and working perfectly. Our local Fiat indy recommends Valeo too.

 

[koalar]

I just buy the cheapest £40 clutch

Last few taken out have been AP I suspect original. It’s hard to explain but they are nicer to drive.

 

[Pugglt Auld Jock]

On the third repeat of this job, I removed the driveshafts using a steel security cable and a garden fork as a slide hammer - a more sophisticated description of this is available on YouTube, but the technique works beautifully. No bashing of driveshafts with chisels.

Thanks to all for help and advice, in particular Koalar. My kids are now very happy they have a working Panda.

I've always used my big Melco tyre lever between the inner joint casing and one of the gearbox casing bolt heads. Always worry when I get a tight one that I'm going to damage the gearbox case though. I've seen the fork kits that work with a slide hammer but have never done anything more than looking at them and now a days I'm not exactly doing this sort of stuff every day, or week, or even month for that fact! Rather like the idea of a bit of steel rope - there's some draped over my engine crane right now - and I have a large home made slide hammer which I'm sure would do the job. Must think about that a bit more. Thanks for making me think about this. Well done on persevering with this and getting such a good outcome.

 

[Sfrontato]

Thanks both - yes Puggit, the steel rope trick worked a treat. Used a plastic coated cable which was useless as a bike lock, but came in handy. It was 5mm diameter, and this must have helped as it was thin enough to get into the slight taper on the driveshafts next to the gearbox. The NS came out with one swing, the OS with two. Now cannot find the YouTube video I got the principle from! The garden fork is not quite a slide hammer - must be a name for swinging it in this way.

With the Fiat branded (AP branding on driven plate, FPT on both plates) and Valeo clutches side by side, the latter looks better quality. The release bearing is also more sophisticated. Turns out the original was a Valeo, now I can see what an intact one looks like.

I'll try and claw back some of the cost - relieved its back on the road though. Can see how vehicles get to end of life so easily. It's a great little car so worth the effort.

 

[portland_bill]

Drive shafts can sometimes fight back, for no apparent reason.
When I replaced the offside drive shaft seal, the shaft refused to release. Heaved, sweated, swore, left it for another day. A few days later, tried again, still no release.
Another week, gathered some enthusiasm, crawled under again, and it just popped out without fuss.
The nearside, no trouble at all.

 

[SPORTPACK50]

Drive shafts can sometimes fight back, for no apparent reason.
When I replaced the offside drive shaft seal, the shaft refused to release. Heaved, sweated, swore, left it for another day. A few days later, tried again, still no release.
Another week, gathered some enthusiasm, crawled under again, and it just popped out without fuss.
The nearside, no trouble at all.

Had you, by any chance, had your Weetabix on that particular day?!

 

[Pugglt Auld Jock]

Drive shafts can sometimes fight back, for no apparent reason.
When I replaced the offside drive shaft seal, the shaft refused to release. Heaved, sweated, swore, left it for another day. A few days later, tried again, still no release.
Another week, gathered some enthusiasm, crawled under again, and it just popped out without fuss.
The nearside, no trouble at all.

It's strange how some do that isn't it. I think it's the position of the circlip in it's groove. If it's managed to get itself all to one side I think that's where the problem comes from. I tend to give it a couple of good strong jerks with my big tyre lever and if it doesn't jump out I turn the shaft about 1/3 of a turn and try again. I don't just keep on yanking on it without turning the shaft to a new position. I think this technique tends to shuffle the circlip back to a more central concentric position where the chamfer in the splines can more easily compress it. Very occasionally though I've come across one which just puts up a real fight and I just keep on with the rotating and levering and usually it eventually comes out. Indiscriminate violent forcing might embed the circlip into the sharp ends of the splines which is why I never use excess force. I came across this once with a Mini (proper "old" Mini) CV joint and ended up with the shaft in a vice and me hitting ten shades of **** out of the CV with my 2lb ball pein. the circlip eventually fractured into multiple pieces as the splines cut into it and did a fair bit of damage to the the whole thing so I ended up sourcing a shaft from the local scappy and just substituting it. Probably should have done that at the outset as I wasted a lot of time messing about with the old shaft.

 

[bugsymike]

It's strange how some do that isn't it. I think it's the position of the circlip in it's groove. If it's managed to get itself all to one side I think that's where the problem comes from. I tend to give it a couple of good strong jerks with my big tyre lever and if it doesn't jump out I turn the shaft about 1/3 of a turn and try again. I don't just keep on yanking on it without turning the shaft to a new position. I think this technique tends to shuffle the circlip back to a more central concentric position where the chamfer in the splines can more easily compress it. Very occasionally though I've come across one which just puts up a real fight and I just keep on with the rotating and levering and usually it eventually comes out. Indiscriminate violent forcing might embed the circlip into the sharp ends of the splines which is why I never use excess force. I came across this once with a Mini (proper "old" Mini) CV joint and ended up with the shaft in a vice and me hitting ten shades of **** out of the CV with my 2lb ball pein. the circlip eventually fractured into multiple pieces as the splines cut into it and did a fair bit of damage to the the whole thing so I ended up sourcing a shaft from the local scappy and just substituting it. Probably should have done that at the outset as I wasted a lot of time messing about with the old shaft.

I have had similar aggro with a Honda outer CV joint not wanting to let go to fit a CV boot, in the end I took the whole shaft out, put it in a vice and as I tapped the inner end off, the outer just dropped off !!!