New clutch slipping - 9" clutch confusion!

[moodoo]

Guys,

Amazingly enough the 2.2 engine I've just built starts, idles, revs, and runs reasonably OK, at least for the few miles I drove it on Sunday. I do have a couple of engine questions, but I'll write a different thread about those..

My main problem is that the clutch is slipping. The car drives OK, but when you're changing gear and letting the clutch back up, especially in reverse or first, you can hear the clutch 'hissing' (which I presume is the friction plate sliding past the flywheel rather than gripping onto it), and there's no good bite point really. It does take drive OK, and once you get on the move it's OK, but still gear changes just don't 'feel' right. The clutch pedal is also really light - I don't know if this is just due to the new clutch, or whether the old clutch I had on the 1.9 engine I replaced was just heavy.

I have put in a brand new complete clutch assembly. I bought a 2.2 flywheel too, and had the friction surface skimmed.

The possible reasons I can think of are:

1) Faulty clutch somehow - I bought it off ebay as a 'bought it, but never fitted it'. It wasn't in a box, but did look pretty new apart from storage marks/dirt. Maybe a seller was pulling a fast one?!

2) Oil leaked onto the clutch. My rocker cover was leaking a bit at first, but I was so happy that the engine actually started and ran that I didn't notice, and I ran the engine for a while in the garage before taking her out. Could oil have leaked down the back of the head and got onto the clutch? The engine face of the flywheel is bone dry, so I don't see that oil could have got to the clutch face.

3) The shop machined the flywheel too smooth, and the friction plate can't get a good grip? The surface wasn't super-shiny, just looked like a normal machined finish to me.

4) When I got the flywheel skimmed, I didn't tell the machine shop to machine the flywheel mounting surface the same amount. My mistake. They can't remember how much they took off my flywheel, so I don't know how big that step is now. If this step was too big, it would leave the clutch struggling for grip, and would make a light pedal too, right?

I think it's probably no.4 - anyone any other suggestions?

Thanks,
Fin

Edited August 6, 2015 by moodoo
Changed title to better describe issue

[andyc]

How did you adjust the cluch cable?

 

Andy

[wayne ingham]

If it was number 2 you will have smoke from the clutch /gearbox ,A new fly wheel is smooth,I think is number 4 , it is just like worn clutch ,the gap from the clutch cover and fly wheel is to big

[moodoo]

I adjusted the clutch cable first using the stud on the gearbox, and then just a little on the cable. Pedal is at a good height, and there is clearance both in front of and behind the release arm in the 'window' on the gearbox.

No, no smoke or bad smell of oil etc...

[wayne ingham]

As you pointed out in number 4 When the fly wheel has been skimmed the bolting face will have to be skimmed the same amount to make the gap correct .The gap is bigger than the clutch plate so the clutch will slip

[moodoo]

OK, now I'm completely confused.

I pulled the flywheel off, to find it had virtually no step, see the pic. Step is about 0.6mm. Now the flywheel I bought was from GM6, from a 6-cylinder car, but I understood that flywheels for 9" clutches were the same regardless whether they were 6-cylinder, or 4-cylinder (2.2 Rekord).

The clutch assy I bought, again it was listed as being for 2.2, or for early senator etc.

So I think the flywheel and clutch I have are a 'pair'. But something isn't right. The same 230mm diameter clutch kit (QKT133AF) is listed by QH for 'HD' 2.0 Manta, as for 2.2 Rekord, early senator etc. But a Manta flywheel will have the step, whereas the flywheel I have has no step.

Anyone got any idea what is going on? Have I got the wrong flywheel? Or the wrong clutch? Does a 2.2 flywheel/clutch not have a step, and something else is wrong with my setup?

 

[wayne ingham]

Fly wheel off the car ,Bolt the clutch cover to the fly wheel (no clutch plate fitted ) see how big the gap is from the clutch cover is to the fly wheel ( Put blue tack in and see how thick the blue tack is)Than see how thick the clutch plate is .You will see if the gap is to big.No oil on clutch ???? We have a car in with no drive clutch padal is OK but the clutch worn to XS.Are you over adjust the clutch ,try adjusting the clutch padal so it 1/2 way down (sorry about the picture I was just trying something new)

[lamchop77]

Fin,

 

The step on the clutch face should be about 2.5mm. I think what is happening is that when you tighten the clutch cover down its going too far to the point where it wont work properly. Try fitting with a packer between the clutch cover and flywheel put it back in and see if you can feel the diaphragm "pop" as it release the friction plate. Don't drive it like this obviously!!!!

 

Chris

[moodoo]

So the step is 2.5mm on a 9" flywheel, not 4.5mm like the smaller 8/8.5" flywheel?

I was figuring that there should probably be no step on the 9" one...and the fact that I had about 0.5-0.6mm step was the reason why the clutch was 'almost' ok, but was slipping during gearchanges. Given that my machinist has skimmed the friction face, and that there may have been a little wear there already, I figured I had gone from 'zero' step, to 0.5-0.6mm, hence some slippage. If I space the clutch back a further 2.0mm using packers, will there not be even less pressure on the flywheel, and more slip?

If the 9" flywheel is designed to have 2.5mm step, I have no idea how the flywheel I bought ended up with almost none...unless the previous owner had it modified for some oddball reason. You never know I guess.

Given that I took the engine out to take the flywheel off, putting it all back together to with packers in, and then have to take it back out again to take the packers out...arrrggghh...!

[611]

Hey Fin

I have a pic of my flywheel but its from above and you cant work out if it has a step or not and it was so long ago that i put it in that i cant remember what it was like. Im not sure if i can see or feel if it has a step with it sat in the car. (mind you i have not mine going so im not sure if it will help?)

I had a google for some pics but again nothing side on showing a step or not. You could call GM6 spares as im sure he would know or have one he could check?

I had a look on the opel gt site, lots of clutch info on there, but you need to be registered to see the images. Im sure i registered once so will see if i can login and take a look.

Here is my pic.

http://www.theopelproject.com/wp-content/uploads/2012/04/240420121441.jpg

I can have a look tomorrow as im out in the garage.

 

Andy

Fin

On ebay, GM6 spare. Only small pic, no large version, but looks like face should be flat?

http://i.ebayimg.com/00/s/NDgwWDY0MA==/z/K5sAAOSwPgxVPnl~/$_12.JPG

Andy

 

[611]

Fin

A previous post of mine for clutch help and i say in the post this flywheel is flat unlike the one from the 2.0l which has a step, so i think you need to get that one machined flat and that should solve the issue?

 

 

Andy

Im getting one of these for mine :-)

Clutch and flywheel.

http://www.opelgtsource.com/store/gt/clutch/CIH-9.html

[wayne ingham]

Hear is a document showing a clutch set up .The gap between i & h is to big .You will not get pressure from the cover onto the clutch plate ,so the  clutch plate will not grip the fly wheel or thr clutch cover 

See above hop this has helped 

Edited August 7, 2015 by wayne ingham

[upk]

What intrigues me here is you say slipping during gear change. From your description at top of thread I would confirm your thrust bearing is free to release and pressure plate is acting quick enough when you release the clutch pedal! I am assuming that it's not slipping after gear change is finished but only straight after clutch release on gear change?? You could have a duff pressure plate!

kev

[moodoo]

Andy - funny, yes, I came across that thread of yours this evening too! You were basically asking almost the same question that I am. If you could just please hurry up and get your car going to check how yours works, sometime over the weekend would be good! 

Kev - yes, it was like there was no real proper bite point, and you could actually hear the disc slipping, and making a 'hissing' noise, but it would take up drive eventually. Once you were in gear, it was ok. I did check that once the clutch pedal was fully released that the cable was slack. As regards duff pressure plate, maybe, see option 1 in my opening post! The clutch I bought looked new, but maybe the guy who was selling it knew something I didn't?!

The other 'strange' thing, as I said above, was that the clutch pedal felt much lighter than before. I was thinking today that maybe the 0.5mm step I have was the cause ( since the bigger gap between pressure plate and flywheel surface would mean less force clamping the friction plate), but also maybe its because the pressure plate is bad? Is there any way to check it, other than putting it in the car, and find it slips?!

Just one other thing - I have the 5 speed box, I don't need a different release fork for the bigger clutch, right?

Thanks as always guys, 

Fin

[wayne ingham]

When you got the fly wheel skimmed the gap form the fly wheel to the pressure plate has got bigger so you not getting to correct pressure from the clutch cover .A new plate is 7.2 ?? mill thick, (this is from a Nissan clutch document) worn clutch plate (22,000miles) is 5.8 mill thick ,A clutch plate which  is worn to XS is 4 mill thick .So if you got your fly wheel skimmed 2mill??.You will have a 2 mill Bigger gap which means you can get a slippin clutch.EG if your clutch plate is 7.2 mill thick and the gap is + 2 mill??? Gap.You are fitting a cluch plate of 5.2 mill ,so you will get clutch slip.So The matel that was removed from the fly wheel face has to be removed from the  face where the pressure cover is bolted onto,then you will get a gap of 7.2 mill.Hope this makes sense.Have put this question to technicians in the workshop all agree that this is the most possible fault ?...

.Note the document is from Nissan and only as an example.

[mantasrme]

I did a clutch change on a 2.4 with a 2.2 9" setup earlier in the year and have a couple of pictures that might help. I must admit that i didn't actually measure the difference between the 2 parts before taking the flywheel to be skimmed, but my local engineer is very good and always matches the surface skim to the mounting area so i don't need to worry.

From this pic it looks like the outer and face should be level.

And this was after the skim, which to me looks like it was all skimmed at the same time.

Not sure if the 0.6mm you currently have is your only issue though as that shouldn't be enough to get slip i wouldn't think. A worn clutch will loose more than 0.6 before slipping

It might be that your clutch cover is part of the issue, a softer clutch pedal means that the clutch cover springs are weaker than the old cover (as that is what you are pushing against) Those springs are also what grips the clutch disc, so if they are really soft they won't be gripping hard enough. You describe the slip at gear change, so maybe they are moving slow when you release the pedal and not gripping up fully straight away, then after a moment of slip they grip. Did it slip under load at all when not changing gear?

One other thing to check if you have your flywheel re-skimmed is that the bolts holding the clutch cover on do not bottom out in their holes.

 

[moodoo]

Thanks again guys. You'd think alright that having a 0.5mm ish step wouldn't cause an issue. The only thing that makes me wonder about that, is for the 4.5mm step in the manta flywheel, the factory manual says this dimension is +/- 0.1mm!! That's a pretty tight tolerance. Think I'll get mounting face skimmed flat anyway, it seems like that's how it should be, and that won't make anything any worse.

The clutch pedal was definitely much lighter than before, so yes, maybe the  pressure plate is the issue. I only drove it a few miles, but couldn't get the clutch to slip at all, only time something felt not right was when changing gear. 

[moodoo]

Arrrrgghhhh...! Ok, so took engine out, took flywheel off, got flywheel skimmed flat. Bought new clutch pressure plate and disc, fitted them and the freshly skimmed flywheel, put the engine back in, and its made precisely no difference! It's still slipping as you release the clutch pedal! 

Does the clutch need time 'bed in', against the freshly skimmed flywheel? What else could I be doing wrong?!

I saw a couple of posts on opelgt.com, saying that the 4.25" distance of clutch fork to bellhousing surface should be increased to 4.75" for larger diameter clutches. About 4.5" is about the most I can get without running out of thread on adjuster on gearbox, but surely that last 1/4" can't be my problem?

Please...anyone any suggestions? Anyone else have 9" clutch/flywheel...did you have to do anything special to make it work? Different release fork? Anything?

At wits end...spent months and loads of money building a new engine, which actually seems to work, but can't get to use it because of the stupid clutch....

[mantasrme]

Clutch doesn't need time to bed in, should be fine from the first go.

I fitted a new 9" plate and cover to the above flywheel after skimming and then adjusted the clutch cable to the right gap for a 2.0 (as listed in the haynes) then adjusting the other end of the clutch arm by the bolt to get the pedal level with the brake pedal it all worked fine.

As its just the same with a skimmed flywheel, different cover and clutch plate then i start to think its something else in the setup. As it eventually clamps up ok its something slowing the return of the pressure plate to clamp the disc to the flywheel. Which can really only be the pedal, cable, release bearing, or clutch arm.

The pedal would be obvious as your foot would come away from it as you lifted it, so i'm guessing thats off the list

Have you checked the clutch cable for free movement? If the clutch cable outer was crimped/ collapsed inside etc then it could be limiting the return of the cable as you release the pedal. Then as the clutch cover spring pressure slowly pulls the cable through the clutch bites fully. Admittedly with a lighter feeling clutch its unlikely, as whenever i've had clutch cable issues its always made the clutch pedal heavier, but worth checking. The heat from the manifold can melt the inner liner and cause issues.

Just undo the lower end from the clutch arm and try pushing the inner cable up and down, should move freely while the outer stays put. Also worth checking the outer is routed smoothly through the engine bay and not caught/bent (unlikely as you've had the engine out, but running out of ideas now)

Also with the cable undone does the clutch arm move freely, there should be a bit of movement in it. I've seen one gearbox that was missing the original ball headed adjuster for the clutch arm and had a bolt with the head ground smooth-ish instead. But the end of the arm didn't pivot easily on it so i changed it.

Then its just if the clutch release bearing is the wrong size for the tube it slides up and down. But i can't see that being tight enough to slow the release of the clutch and you not noticing when fitting the bearing.

At that i'm out of ideas i'm afraid. Its then time to get someone else around to have a look at it with a fresh pair of eyes.

 

[moodoo]

Thanks for the excellent reply David. I was 99% sure the clutch should work from first go, but a desperate man will grasp at any straw! 

It's like I can't get my foot off the pedal fast enough, that I'm holding the pressure plate back from clamping up. That, or something else is holding it back, like you said.

It sounds like you fitted pretty much the same setup as I have, except of course, yours works! At 4.25" the clutch does actually disengage, which again agrees with what you found. You didn't have to change release fork to go with bigger clutch? Mine doesn't have a return spring fitted on the release fork, should it? (Although I don't suppose that is my issue anyway.)

I'll check the clutch cable and the pedal again later, but I haven't noticed them doing anything 'unusual'. I do have a spare cable, I suppose it couldn't hurt to try it, just in case. One odd thing is that with the old engine/clutch, that distance was much less than 4.25". Stupidly I didn't measure it, but it was much less. This would leave the clutch heavier than it should be, since there wouldn't be such a lever effect, right? Now I can push the clutch to the floor with my hand, which I'm pretty sure wasn't the case before.

With the cable disconnected, I can easily move the release fork forward and back, there's definitely no binding or friction there.

Like you, I'm pretty much out of ideas, and unfortunately pretty much on my own here in terms of having someone come to look. One of the guys in work is into landrovers, and is pretty mechanically minded, maybe he could take a look if I can't figure it out. It's just really annoying not being able to figure out something which should be straightforward.

Thanks again,

Fin.

[mantasrme]

The one i fitted had a standard 2.0 gearbox, with standard clutch arm etc with no extra spring.

The more i try to remember back to setting the clutch up the more i think i didn't get the 4.25" measurement. Unfortunately Its not my car it is a customers, although i can see if i can get a measurement from it.

The bigger clutch setup is deeper than the original 2.0 version so sits out further from the back of the engine mainly the cover. That was proven by the struggle i had taking the gearbox off with the engine in situ, not a problem with a 2.0 clutch but wouldn't clear the cover on the larger setup. But i'm not sure about the relative position of the fingers and release bearing between the 2. If they are different then i think the 4.25" shouldn't work as the clutch arm angle would be different, although i can't get my head around angles and forces anymore to decide if you need more or less gap!

I'd say that if you can push the clutch pedal down with your hand its way too light so maybe change the angle of the clutch arm and ignore the 4.25" 4.5" etc. Its a bit of a pain (although less that taking the engine out again!) but i'd move the adjuster stud a fair distance and re-adjust the cable to get the pedals level and see how that works. If its worse then adjust the other way. If its better go a bit further and find the balance between good clamping up of the clutch and not too heavy a pedal.

[paulmanta]

I cant add much to this apart from ask a coupe of questions.

 

1:  Are the correct amount of shims/washers and rubber gromits fitted at the pedal end of the cable ?

2: Has the release arm been checked for straightness or cracks, twists ?

 

The first question affects the pedal position so if its wrong adjustment is often (incorrectly)  made at the gearbox end to compensate, the correct list of items at the bulkhead goes like this: Bulkhead hole, steel washer, rubber grommet, large machined chunk of steel, rubber grommet, steel washer, clutch cable outer sheath end .

 

The second question is also something that can cause adjustment problems, I normally switch to a cast type of arm from a Monza/Senator, loads of hassle over the years with bendy arms.

 

Edited August 31, 2015 by paulmanta

[moodoo]

Thanks guys. Didnt't get a chance to look at it really today, but hopefully tomorrow. I did check the order of parts at the bulkhead end of the cable though, and all parts are present as per your photo and list Paul. As to whether my arm is in good condition or not, I have no idea, if I hav to take the engine out again I will check. But I think if I have to take the engine out again, I might just give up and put the smaller flywheel and clutch on the engine, at least I know that works! At least that way I could at least get the engine run in. I still have the feeling that I've done something stupid, or missed something obvious though.

One thing, my clutch cable has a ball at the fork end, which (I think) means that I have the early (a series?) clutch fork. Maybe that fork has an unsuitable angle for what I'm trying to do?

Anyway, will look again tomorrow. Thanks a lot for the help guys, much appreciated, you're keeping me going!

[611]

Fin

This is the cable type i use to run on mine with the 5 speed. it goes through the clutch fork and then you adjust it at the fork end. Does yours just slot into the fork and then you adjust at the bulk head end?

[moodoo]

Thanks Andy, yes, my cable just slots into the fork, and I adjust it with an E-clip at the bulkhead, not like what you have in the photo. I think that means that my release fork is an A-series, or early B-series one. Whether that matters at all, I don't know. I wonder about the different lengths of the cables though...could you measure the length of that cable - the inner bit and the outer sleeve?