Technical Clutch heavy. (almost) everything replaced

[Pugglt Auld Jock]

What an interesting post PB. During my time in the trade I've "sorted" many clutches and a juddering clutch is quite a common complaint. In my experience due usually to either contamination of the friction lining (often due to a failed gearbox input shaft seal and less often to a failed crankshaft seal) or a "cooked" driven (friction) plate and the high spots on the pressure plate/flywheel thus caused. Very occasionally though, after reassembly with new components and vigorous rubbing down of the flywheel face with emery cloth, there would still be a small amount of detectable judder - nothing like as bad as before. Now I'm wondering? You've given me something to think about there and something to carefully check if I ever do another clutch.

Hope you are keeping well? Poor Mrs J has been quite ill for best part of a fortnight with some nasty virus. It's frightened the pants off me that it might be Corona but we went to the Airport drive through test centre - which wasn't exactly "drive through" we spent about an hour and a half crawling and creeping, slipping the clutch a LOT (cringe), a car's length at a time, in an endless serpentine queue, and got checked. Luckily the results are negative - our Doc thinks it's a derivation of flue or similar which she's had - She's almost back to normal now, just exhausted, so I guess her immune system must be at an all time low just now. We are being very careful about contact with others.

What an absolutely horrible year this has so far proved to be. What with Mrs J having been seriously ill 3 times now (once requiring hospitalization with pneumonia) and further serious illness in our immediate family I feel as if I have been emotionally bludgeoned!

Now I'm wondering what the airport experience has done for the clutch which took a real hammering in the queue at the airport. (cooling system coped well though with the fan running almost continuously) Awfully glad I don't have one of those automated 'boxes - like our Dualogics or the VAG DSG's with their dry clutches. I think creeping is probably extremely bad for them? However it's making a change to be worrying about something mechanical, which I can probably "sort" if it goes wrong!

Take care everyone and don't let your guard down against this sodding virus!
Regards
Jock

 

[Pugglt Auld Jock]

I'm having a similar problem with my glamorous assistant.

Mornin! Just been out and braved the spotty rain. Quite inaccessible with the battery tray in place isn't it? However managed quite easily once I'd removed the front of the air filter and the fresh air supply pipe. Didn't have to disturb my far better half either as I found an old stool leg which was just the right length to fully depress the pedal - that was lucky!

Ok, the total movement of the lever (ie the extension of the slave piston/rod) is exactly 20mm or 13/16ths of an inch in the language I understand best. The clutch works well with a bite point about half way, or possibly just less than, half way up from the floor. It feels very nice and "right" at that.

By way of general comment though I would say that both our Panda and my boys Punto clutch pedal feel is a bit on the soft/slightly mushy side when compared to the other vehicles in the "family fleet". I have bled both out several times and the feel doesn't change and there is no sign of any air. Kenny's "merry men" have also bled the Punto twice with no further improvement. I've come to the conclusion that this is just the way they are - both feel exactly the same - Both cars have had complete 3 piece Valeo kits fitted with the Punto having all it's hydraulics replaced and the Panda having a new slave cylinder. They drive absolutely fine. The pedal effort is a little more than our other vehicles, but only just a little and not as heavy as my old 1.9tdi Seat Cordoba was. I've now stopped obsessing and just drive them.

Hope that was helpful? please don't forget to update us on your progress, I'm coming back to this thread every day with great anticipation!
Kindest regards
J

Perhaps of interest is that the clutch on Felicity, our old 1992 Panda Parade (there's an identical one for sale on the forum right now - even the same blue/purple colour) was the heaviest of any car I can remember owning. In fact she cracked part of the lever mechanism which I had to weld up.

 

[onecleanfinger]

I have learned more about clutches from this thread than I could have ever imagined! Well the 3 part clutch kit box from S4P was well packed and I didn't drop it so unless it had previously been mishandled I don't think it would have been the problem. When I fitted the friction disc I found my Laser clutch alignment tool to be fairly useless for this application as the small end of the cone was a bit too big so I had to make up some improvised sleeves with various sockets and threaded rod to centralise the friction disc. I assume this all worked because the gearbox went back on relatively easily.

Anyway, I've been out to measure the throw on the slave cylinder pushrod. Mine moves exactly 22mm for a full press of the clutch pedal.

Before wasting a day (plus gearbox oil etc.) ripping it all out again, I think I will cut out that interconnector between the master cylinder pipework and slave cylinder pipework and replace it with a straight plain union in case there is a restriction in it through 10 years of gradual corrosion and internal swelling. My new slave cylinder came with a new pipe and I kept that just in case but for the master cylinder I tried to save a bit of cash by buying the cylinder only (and not the full cylinder/reservoir/pipe assembly) - that was a tip from another post where someone had compared the two (55225453 is the cylinder alone and costs about £60) so I've never replaced the pipework. Got to be worth a try!

Failing that I might just live with it - sure it will wear out the mechanical parts of the pedal assembly and hydraulics quicker but I don't want to pull it all apart again and still not find a problem.

 

[varesecrazy]

Perhaps of interest is that the clutch on Felicity, our old 1992 Panda Parade (there's an identical one for sale on the forum right now - even the same blue/purple colour) was the heaviest of any car I can remember owning. In fact she cracked part of the lever mechanism which I had to weld up.

Was that hydraulic Jock ?

Our Oslo 1986 panda ate cables..


pretty sure the 94/95 unos were hydraulic..
but didnt own a panda of that age for long..

 

[Pugglt Auld Jock]

No Charlie, it was a cable. The bit that fractured (which I think I talked about in another thread somewhere) was actually the bulkhead plate under the bonnet where the outer cable sheath rested. It split it and forced it back slightly through the bulkhead. I thought it was clutch adjustment but realized, after i'd adjusted it twice in as many weeks, that something was amiss! I had to dismantle it, weld it back together with a bit of reinforcement, and reinstall it.

I was on the verge of putting a new clutch in her just before her last catastrophic MOT which found too much rust to be worth us prolonging our relationship! We owned her for over 20 years and I sometimes wish, when I'm feeling nostalgic, that I'd just mothballed her and worked away at welding new metal into her. However I do have another life involving my dear wife, children and grandchildren, so probably just as well I didn't.

 

[onecleanfinger]

Well I've investigated the hydraulics in more detail. Having cut open my old master cylinder I measured the piston diameter as 18mm and calculated that if the force on the pedal from a big bloke with size 10 boots might be up to 1000N when the mechanical advantage of the pedal itselt if taken into account then the pressure in the hydraulic line will be around 39bar.

One of the only parts I haven't yet replaced in my quest to fix the heavy clutch is the hydraulic quick connect between the master and slave cylinder. I couldn't separate it in situ so I cut it out and made up a piece of spare tube and used a couple of stainless steel hydraulic connector unions (part number pMSC8L). I'd initially hoped to use pneumatic push fit connectors but they're only rated for 10bar. I also had some 8mm brass compression fittings for plumbing purposes but they're only really rated for 10 or 12 bar as well so I had to order the hydraulic unions which are rated for 100bar. The extra bit of tubing that was required to bridge the gap was cannibalised from the new slave cylinder. The hydraulic tubing is 8mm outer diameter and quite thick walled, maybe 1.5 or 2mm. If you heat it gently with a hot air gun you can actually bend it into any position you want - I made a nice curved swept elbow and cut the tubes on the car using a sharp Stanley knife to give a nice flat clean cut. I bled the clutch again the clutch feel is slightly lighter and perhaps more uniform in terms of its resistance throughout the pedal travel - it's not a night and day transformation by any means but I think it may now be "normal" again. Having said that I've lost perspective on what it should feel like by now. I compared with other vehicles in my fleet and it's firmer in the Panda. I tried using a block of wood and bathroom scales to quantify the difference. The Panda pedal peaks at about 20 to 25kg. The other vehicles at about 15 to 20kg. So it's quite similar. I can just about press the Panda pedal down to the floor with the thumb of my left hand. Does that seem about right??!

When I had the old quick connect off the car I was able to open it up. It's actually in good condition inside apart from a slight corrosion of the spring retaining fingers. There is, however, an inherent restriction in this type of fitting and this may have a detrimental effect on the operation of the hydraulics. Photos attached.

 

[DaveMcT]

That looks much better than my original connector. Mine had corroded solid and could not be separated (I cut it in half with an angle grinder to take a look). Fiat provide the cylinders complete with pipes. I just replaced the lot and job done.


You could replace the coupling with some hydraulic hose but would need metal tube inside the plastic to prevent it crushing down. Use three worm clips on each side with the worms opposite each other. I did this on a previous car where the hydraulic pipe could not be removed with engine in-situ. It worked fine.

 

[onecleanfinger]

Just resurrecting my old thread. To cut a long story short I had a heavy clutch pedal on my 1.2 Panda. Sequence of events since the beginning:

Clutch started to feel heavy after about 30,000 miles and squeaking loudly from slave cylinder when the engine was hot / after driving for more than an hour.

Changed slave cylinder with LUK aftermarket one. Squeak gone but pedal still heavy. Bled repeatedly. No improvement.

Removed gearbox and replaced clutch with new 3 part genuine Fiat (AP branded inside the Fiat box) kit. Pedal still heavy. Knuckles grazed.

Bled repeatedly using all kinds of methods. Vacuum bleed, gravity bleed, pressure bleed. Changed master cylinder to rule it out.

Replaced quick release hydraulic connector with stainless steel hydraulic unions in case there was a restriction in it (there wasn't)

Clutch was still heavy but gears engaging OK. After about a thousand more miles I started to have some gear engagement issues and the biting point getting lower and lower. This quickly got worse until there was no longer enough "throw" in the slave cylinder to make the clutch operate adequately. Even inserting a home made cylindrical spacer between the end of the slave pushrod and the actuator arm to gain a bit more "throw" didn't work.

Today I removed the gearbox and bellhousing again (knuckles grazed again) and found that the pressure plate bolts were loose enough to undo with a nut spinner and there were gaps between the pressure plate and flywheel. So this seems to be the cause of my clutch drag issue. When I fitted them last time I torqued them up to the recommended 15Nm and I remember at the time thinking it didn't seem like they were tight enough but I didn't want to risk shearing them so I trusted the Haynes torque figure and boxed it all up.

So I think my clutch operating problem is the loose pressure plate. I don't know what the problem is with the heavy operation. Everything else seems perfect. The fork is straight and the bushes are new, the release bearing slides smoothly, the gearbox bull nose is undamaged and the splines all look good.

I could do with some advice on the following:

1. Are new pressure plate bolts necessary (Haynes says yes but I can't imagine any garage would replace them as they don't come with the new clutch kit). I re-used the original bolts last time.

2. Is 15Nm the correct torque? That doesn't really feel like enough torque to even clamp the pressure plate onto the flywheel properly. The 6 bolts are in 3 "pairs" rather than being equally spaced around the pressure plate . What is the best tightening sequence?

3. Loctite on the pressure plate bolts or not? I didn't last time.

4. I've got a new clutch kit and fork/ bushes ready in case I need them. Should I change them to rule them out (thinking of the heavy clutch issue) or is that just a waste of money. I can return them to the supplier.

Thanks

 

[Pugglt Auld Jock]

Clutch was still heavy but gears engaging OK. After about a thousand more miles I started to have some gear engagement issues and the biting point getting lower and lower. This quickly got worse until there was no longer enough "throw" in the slave cylinder to make the clutch operate adequately. Even inserting a home made cylindrical spacer between the end of the slave pushrod and the actuator arm to gain a bit more "throw" didn't work.

Today I removed the gearbox and bellhousing again (knuckles grazed again) and found that the pressure plate bolts were loose enough to undo with a nut spinner and there were gaps between the pressure plate and flywheel. So this seems to be the cause of my clutch drag issue. When I fitted them last time I torqued them up to the recommended 15Nm and I remember at the time thinking it didn't seem like they were tight enough but I didn't want to risk shearing them so I trusted the Haynes torque figure and boxed it all up.

So I think my clutch operating problem is the loose pressure plate. I don't know what the problem is with the heavy operation. Everything else seems perfect. The fork is straight and the bushes are new, the release bearing slides smoothly, the gearbox bull nose is undamaged and the splines all look good.

I could do with some advice on the following:

1. Are new pressure plate bolts necessary (Haynes says yes but I can't imagine any garage would replace them as they don't come with the new clutch kit). I re-used the original bolts last time.

2. Is 15Nm the correct torque? That doesn't really feel like enough torque to even clamp the pressure plate onto the flywheel properly. The 6 bolts are in 3 "pairs" rather than being equally spaced around the pressure plate . What is the best tightening sequence?

3. Loctite on the pressure plate bolts or not? I didn't last time.

4. I've got a new clutch kit and fork/ bushes ready in case I need them. Should I change them to rule them out (thinking of the heavy clutch issue) or is that just a waste of money. I can return them to the supplier.

Thanks

Well, the loose plate certainly would explain some of that but, I'm sorry, not the heavy pedal? Only thing to do I think is to get it all reassembled right and then try to find someone who is familiar with Pandas to try it out as they will know if yours is too heavy compared to the many they have driven.

So, now I'll try to be helpful.

1. New pressure plate bolts? Yes the Haynes manual for the Panda and for the Punto says to replace them. However Kenny didn't replace them on either my Panda or my boy's Punto when he put Valeo clutches in them less than a year ago. Until this year I would have done my own clutches but now, at 74 years young, Mrs J has prevailed upon me to start acting my age so I handed them over to Kenny. I've done lots of clutches during my years in the workshop - never replaced cover plate bolts that I can remember (unless damaged of course).

2. At first glance 15Nm (so about 10lbs ft in language I understand) seems pretty "light". But, looking at both the Panda and Punto manuals they both say 15Nm (actually the Punto says 16Nm) I looked up in my old Panda Manual (1999 Panda 999cc Fire engine - forerunner to our 1.2) and guess what? 16Nm!) Then I checked some of my VAG specs M6 cover bolts 13Nm M7 cover bolts 20Nm. So, not looking so "silly"? Then I fired up my 3/8 drive torque wrench and tried it. Hmmm? doesn't feel all that tight does it? I too wonder if it's properly and fully compressing the diaphragm spring at that before the wrench clicks? Did you go round them several times?

I then thought how I would be doing this job and although I would use a torque wrench on head bolts, big ends, etc I like to use one on calipers too, I would be just doing these cover bolts up "nice 'n tight" by hand. Of course (and I don't mean to sound like I'm bragging) I have years of experience doing this sort of thing so I know what "nice 'n tight" feels like whether the bolt is a big one or a tiddler so I'm not all that likely to strip or snap it. I think too that the tightening of the bolt as it takes up the diaphragm compression could be a factor in under tightening in a situation like this with a low torque on the bolt. Do the bolts have spring or shake proof washers? if so they really should be renewed. This can be difficult on some modern designs where the washer is captive on it's bolt and I just thought, if these are like that maybe this is why replacing the bolts is recommended? In which case, personally, I wouldn't bother. I'd reuse them with a bit of thread locker on them.

3. Thread locker? Well I quite like using it. The blue stuff (not the stronger red studloc) should be quite sufficient for an application like this and can do no harm - it's designed to be dismantled if required.

4. All I can recommend is carefully to examine and compare all the parts with the new ones and if they look Ok they probably are. I'm afraid that call has to be yours as you are the man on the spot! I'm a mean Scot so probably would take a chance and get my money back on the new parts!

Hope all that rambling is of some help? Good luck. Jock

 

[onecleanfinger]

That was incredibly useful thank you! I did a bit of research and the bolts are M6 x 16 Grade 10.9. There is no spring washer or similar but the head of the bolt has a slight flange to it like an integrated washer. The Fiat part number is 18750234 and the description is "screw and washer assembly". Given that nobody online seems to sell these I am fairly sure they're not routinely replaced by anyone. There are a couple of specialist fastener suppliers that stock them but I don't really want to have to wait days for them to be delivered and there's no sign of stretching in the threads from my visual inspection so I'm going to put them back in with some Loctite and make sure I keep tightening in the diagonal sequence until I'm certain it's all properly clamped up and seated. I checked the procedure on ePER and it actually says the torque setting is 10Nm which is surely too low, even for a relatively small M6 bolt.

Weather permitting I'll put it all back together in the morning and let you know how things go.

 

[portland_bill]

All good stuff from Jock.

I have a copy of eLearn, the Fiat manual, so out of curiosity I had a look. Torque figure given is 1daNm, which is 10Nm, even lower. Barely more than finger tight. I'd have thought it would need more than that to compress the diaphragm spring, and of course that needs to be done before any thought of final tightening. As Jock says, once used to spannering, you get a feel, and most mechanics only use a torque wrench for the critical stuff, such as hub nuts and cylinder heads, the rest being 'appropriately tight'.

You've changed all the obvious probable causes of a heavy clutch, slave, master, and clutch itself. The release bearing needs to slide along the sleeve in the gearbox, and if worn, can tilt a little, and become tight. The release arm pivot bearings are also a possible tight spot, sadly, both require gearbox out.

Have you checked the pedal pivot?

 

[onecleanfinger]

Have you checked the pedal pivot?

Yes, the pedal pivot seems perfect. No side to side play, nicely greased and no sign of wear. The pedal feels very light and smooth without the master cylinder hooked up to it

 

[Pugglt Auld Jock]

'appropriately tight'.

Appropriately tight Bill? Must remember that one - I really like it!

We had several degrees of tightness. There was "not tight enough you idiot" - "Nice 'n tight" - "very very tight" (only the second very started with an F) and "OOPs that was far too tight, where's the ezzy outs?" (sure there was an F in there somewhere too)

 

[koalar]

15Nm is fine.

spotlessly clean

check the gearbox input shaft for horizontal moment

I use a drop of threadlock some cars do some don't I now just do all

there's no way to guess 15Nm. I have a small 1/4" torque wrench. Even that would struggle at 10Nm there not Good at there minimum setting. Torque wrenches should be stored at there minimum setting otherwise the spring weakens.


I tighten them diagonally opposite until they just pinch down then go round torqueing them down

seeing as you have had a problem I would check the pressure plate is flat


there's a few different types of release bearings if it plastic on the inside make sure its not marked up. Both plastic or spring steel types should slide easy on the tube in the gearbox and snap into place on the release folks.

the release folks should move freely both in the twisting motion and vertical. There should be a lot of vertical play. This is held in place when the release bearing is snapped into place


What make of clutch have you tried ?

 

[portland_bill]

What make of clutch have you tried ?

Earlier post said AP from a Fiat box, but this has set me thinking.

I was not aware that AP were OE suppliers to Fiat. I expected Valeo or LUK.

BUT! Some manufacturers still offer 'remanufactured' or 'reconditioned' clutches, as an alternative, and it appears form ePER that Fiat do. Recon clutches are usually sourced 'locally', so are not transported between countries. When reconditioning a clutch, the quality varies, and whilst any manufacturer marks should be removed, this does not always happen. When dealing with clutch warranty for a major parts supplier, we often had such units returned claiming to be ours.
A proper recon should dismantle the cover and replace the diaphragm spring with new, every time, as these get heavy with wear/use. If this is a recon done by AP themselves, I would expect this to have been done, so should be OK. However, if not an OE supplier, the diaphragm may be a little heavier than OE if 'near enough' is selected, rather than make a specific one for this application. I've seen diesel springs used for petrol applications many times. Even if this is a new unit, if AP are not OE, a heavier diaphragm may be used.

What was the Fiat part number purchased? This will show if new or reconditioned.

Any new clutch should be carefully inspected before fitment. Starting with, "was the box sealed?". It is not unknown for unscrupulous garages to replace a clutch due to oil contamination, or another reason with a clutch that is not noticeably worn, then clean the old one very well, and return it in the original box for refund, stating 'not used'. Then sadly, the next purchaser gets the old one.

How does the gearbox attach to the engine? Is it direct to the engine block, or is there a backplate? Backplates can get bent or cracked when hit, if the driver runs over something, then the whole thing flexes as the clutch is pushed.

 

[koalar]

should have added to clean the splines on the gearbox and make sure the plate moves freely along them


now to grease or not to grease there are two camps an you can argue both ways

in fact I have two gearboxes here and one has had a new clutch and hasn't Been greased. The other is straight out of a 500 and has.

personally I use a tiny bit of High melting point grease move the disc up and down the spines and then wipe as much as possible off.

it works for me. If things work for me I tend to stick that method.

 

[portland_bill]

now to grease or not to grease there are two camps an you can argue both ways

personally I use a tiny bit of High melting point grease move the disc up and down the spines and then wipe as much as possible off.

it works for me. If things work for me I tend to stick that method.

Always a dilemma, as no lubrication leads to the plate sticking as the shaft rusts. But any lubricant can fly off and contaminate the friction linings.

Whilst dealing with warranty clutches, I have seen a lot of contamination from copper 'grease'. That should never be used as it has very little 'cling' and will fly off easily. A very tiny amount on the lining can cause judder, a blob the size of a pinhead can spread across the face and be enough to cause judder. I've seen one clutch contaminated with copper grease that had managed only a about 50 metres before starting to judder. (Maestro/Montego 1.3 & 1.6 were prone to judder anyway, and the gearbox inner shaft seal would leak, so that caused a lot of problems. The release shaft passed through the centre of the mainshaft, requiring a tiny seal. A VW gearbox, but strangely more trouble in the Austins than any VW.)

Your normal grease, used sparingly is a lower risk, as any on the lining should burn off, whereas the copper stuff will not. There is a risk that any grease may attract dust, and the clutch will create some of that of course.

A recommendation, from AP themselves during a factory visit, is to use graphite. A graphite spray is easy, but the shaft and splines can be rubbed with a soft pencil, then the excess wiped off. Good lubricity, won't attract dust, but tedious to apply. A use for a builder's pencil.

 

[Pugglt Auld Jock]

should have added to clean the splines on the gearbox and make sure the plate moves freely along them


now to grease or not to grease there are two camps an you can argue both ways

in fact I have two gearboxes here and one has had a new clutch and hasn't Been greased. The other is straight out of a 500 and has.

personally I use a tiny bit of High melting point grease move the disc up and down the spines and then wipe as much as possible off.

it works for me. If things work for me I tend to stick that method.

I very strongly agree with what you are saying here. In my opinion the problem you are addressing when "greasing" the gearbox input shaft splines is that of the driven plate not being free to slide on these splines and thereby not freeing from the flywheel properly when the pedal is pushed down. The reason for applying "grease" to the splines on the input shaft is therefore not to "lubricate" but to stop/minimize/delay the formation of corrosion which will causing the driven plate splines to "bind" on the input shaft splines. To achieve this you only need the very thinnest layer of grease. So apply some grease to the splines, work the driven plate to and fro on the splines to distribute the grease and then use a cloth to remove all but the very smallest trace of the grease. Any appreciable "blobs" of grease are only going to get thrown off onto the new lining/flywheel/clutch cover anyway greatly to the detriment of their operation! Remember this assembly is rotating at crankshaft speed so anywhere from, probably 800/900 rpm at idle to 2500/3000 rpm cruising down the motorway or even 6000 rpm in a moment of madness! No blob of grease I've ever heard of can withstand that, however I couldn't tell you how often I've cringed at the sight of one being assembled with the shaft thick with grease. The only exception I would mention is that if you have a plain bushed spigot in the flywheel a wee dab of grease in it is a good idea but if it's a ball race then there's no point. Of course most of our wee Fiat's don't even use a spigoted input shaft at all.

 

[onecleanfinger]

There's some great information here. A real wealth of experience, thanks again.

The Fiat clutch I fitted was from Shop4Parts, p/n S4P3168 (71752235). It didn't mention reconditioned and I assumed it was new. I've had the car from new and the clutch I took off was definitely AP so I can tell you that AP was an OEM supplier to Fiat.

I'd like to be in the position to tell you that all is well but sadly I haven't finished refitting it all yet. It took ages to get the clutch plate aligned (the Laser universal tool is no use for a small clutch) and I had mislaid the one that I made last time so I had go bodge up another one from a variety of old sockets, bars and heat-shrink. Then I had some trouble refitting the gearbox because I had no one to help me today. But it's back on now and I just need to refit a few ancillaries. Hopefully all will be OK.

Oh yes, and there is a backplate. and what a pain in the bum that is, flapping around and jamming itself in difficult positions as you wrestle with the gearbox. But I'm happy that it's all nicely bolted up now. Time will tell.

 

[DaveMcT]

A smear of high solids anti seize paste on the splines should be ideal. Enough to avoid fretting and stick/slip will not be enough to fling off. Ordinary copper grease is really not suitable - too thin and oily.