Clutch adjustment?

correct...
(Just rounding things in my head)
but,
why get exact now?

quote:

Originally posted by Peter Fenlon:
the actuating arm is at the rearmost position, there is no adjustment left on the rod to enable another spline to be reached

Hi Peter,

I don't understand that statement, the clutch arm is infinitely adjustable on the splines (within the bounds of the ZF casing) as it has a through bolt and the shaft is machined in it's full circumference. The actuating rod looks to be at it's shortest with no threads showing after the locknut, so could be lengthened?

Julian

quote:

Originally posted by Joules:

quote:

Originally posted by Peter Fenlon:
the actuating arm is at the rearmost position, there is no adjustment left on the rod to enable another spline to be reached

Hi Peter,

I don't understand that statement, the clutch arm is infinitely adjustable on the splines (within the bounds of the ZF casing) as it has a through bolt and the shaft is machined in it's full circumference. The actuating rod looks to be at it's shortest with no threads showing after the locknut, so could be lengthened?

Julian

Hello Joules,
I meant that I could not reach another spline
in the forward direction (toward the slave cyl)
in lots of pics I see only about 4 threads in front of the slave cyl locknut. Bringing the lever arm rearwards would be easy, but the length of the rod is then much longer.

The lever arm is now I think in the correct place, i.e. just forward of "Centre" so the arc of travel is at its most economic, and no movement is lost.

I wish I could post some pics but am having "Bucket" problems.

Peter,

I still believe you may need to be one spline further back (away from the slave) and the rod lengthened, but let's approach it more scientifically, how long is your clutch slave rod? The TSB is fairly precise in that it should be 3.07 to 3.09"

What I have also encountered is the ridged barrel on the rod where the rubber boot sits is slightly larger than the slave bore and can bind up against the slave if the slave piston retracts all the way back impacting clutch operation. This could also be why you currently cannot dial in any free play.

Julian

Photo of clutch arm relative to slave;

As you all can probably guess I am thoroughly cheesed off and all the suggestions however well meant, will not give me half a millimetre between the clutch and flywheel and another half millimetre between the release bearing and the 3 clutch fingers.

My new longer throw slave is due on friday, so I shall fit that and go from there.

As yet no one has mentioned the reason why a longer throw slave IS available, and if the stock system is so easy to utilise why do so many dealers stock the LTSlave cyl????

I have had all spline options tried out with the actuating arm.
tried several bleeding methods vacuum etc etc.
pedal box out twice, changing the Effort reduction kit geometry.

changed back to standard master rod, dropping the ER Kit altogether.

Taken the gearbox out twice, fitted the correct parts eventually.

It was my fault I had the old spinner relined
I had no idea that it was a special item.

Fingers crossed , but thanks to all those who have contributed, best Peter.

I have empathy in your delemia, as in what has changed

I understand your actual slave stroke is not what is calculated based upon info I gathered from the internet. and the couple of members that were gracious enough to share their stroke makes it even more confussing

while waiting for the LT slave, have you attempted to measure the arm travel that will be needed to provide ToB clearance to plate clearance.

I could envision that different clutches would require increased arm strokes and thus the reason for the LT slave.

I am also waiting impatentaly for your resolution

If I had another 1.5mm I would be laughing teacakes.

Pete.

quote:

Originally posted by Peter Fenlon:
As you all can probably guess I am thoroughly cheesed off and all the suggestions however well meant, will not give me half a millimetre between the clutch and flywheel and another half millimetre between the release bearing and the 3 clutch fingers.

My new longer throw slave is due on friday, so I shall fit that and go from there.

As yet no one has mentioned the reason why a longer throw slave IS available, and if the stock system is so easy to utilise why do so many dealers stock the LTSlave cyl????

I have had all spline options tried out with the actuating arm.
tried several bleeding methods vacuum etc etc.
pedal box out twice, changing the Effort reduction kit geometry.

changed back to standard master rod, dropping the ER Kit altogether.

Taken the gearbox out twice, fitted the correct parts eventually.

It was my fault I had the old spinner relined
I had no idea that it was a special item.

Fingers crossed , but thanks to all those who have contributed, best Peter.

The shop manual does not refer to a clearance necessary between the disc and the pressure plate.

I think that only the "long throw" slave can solve this now.

The total assembly height of the your new clutch as an assembly is greater than the original.

In all fairness, the original clutch was "finagled" (messed around with) to get it to work.



The Dual Friction I have in my car does give me the clearances that I need.

If I remember correctly though, Hall told me to use a "long throw" slave with it. That is probably what is in the car now.

It is only a 10-1/2" disc which I would prefer to be 11" but life is just compromise after compromise and you need to pick your battles. One can't fight every one. There are just too many to deal with?

The 10-1/2 has a different engagement feel than the 11. It actually feels like it has less travel of the pedal, but it is probably just that it hooks up a little differently.

I feel the difference in my clutch foot.


Hang in there. Remember there are a lot of folks who can hit really hard, some call that fate. The champion, aka, just a survivor these days, is the one that can take the beating while others fail, shrivel up and cease to exist.

quote:

Originally posted by Peter Fenlon:
will not give me half a millimetre between the clutch and flywheel

What are you talking about here Peter?


And the other half a millimeter between Throwout bearing and your "3 fingers" is not enough! You need to take the ZF off and modify your Throwout bearing so it allows more spacing. I dont remember if you told us wether its the type with the various spacer rings? The spacing can ONLY be measured by separating the bellhousing from the ZF and bolt it onto the Engine. I posted some sketches a while ago, perhaps you have them. You CAN NOT rely by feeling on the arm alone if there is space between throwout bearing and your 3 fingers BECAUSE even if you push your throwout bearing full aft the arm can be rocked a little back and forth since the forks that slides the throwout bearing forward has some play. That is the play that can fool you and that is the REASON the measurements MUST be done with the bellhouse OFF the ZF and ONTO the engine.

btw did I mention NO SHORTCUTS?

Secondly the displacement on the MASTER and SLAVE are in direct relation. Displacement = Radius of bore squared and multiplied by π and multiplied by the stroke. I.e. if they have same bore they have same stroke! PROVIDED there is:

a) no damage/internal leak and/or the fluid supply to the master is not starved (can happen i.e. if wrong parts are used when rebuild and piston does not retract/return fully to open for reservoir fluid access to bore)
b) no air trapped somewhere. It can be really tricky to get all the air out. I mention this again because it is very likely.

So if your strokes does not match based on a quick calculation of the displacement there is something wrong like a or b above. It is really not rocket scientism but no room for shortcuts.

I am not reading this out of a book Peter, this is from working with these things and latest when I changed engine last year with different flywheel etc. I went thru the whole procedure again with removing the bellhouse and measuring for sufficient play between throwout bearing and clutch (multi fingers) It is unfortunately an essential and absolutely required procedure. Guess you can put it together with standard OE parts and be LUCKY there is enough space. But there is no guarantee for that.

Please let me know if I am confusing you and if my explanation is not making any sense?

Jan

Hello Goodroc,
in my time working as a service rep, for mobile Crane companies I have been to 50 countries in Europe Africa the mid East and Far east.

The reason I went there was only because I had experience of the product that other engineers in those countries didn't have.

I have to admit that your post doesn't really help, your experiences are OK for you of course but not in my case.

I will NOT remove my ZF for a third time been there and done that.

but thank you for your input.

Peter I dont have a crystal ball. But my estimate is you will end up removing it anyway rather sooner than later. If there is insufficient play between the components it will only get worse when everything gets to operating temp and also as your clutch plate wears the 3 fingers will come towards the throwout bearing and reduce the play until it eventually reduces to zero and the throwout bearing wear will then speed up.

quote:
Originally posted by Peter Fenlon:
will not give me half a millimetre between the clutch and flywheel

what were you talking about there?

And have you considered my other points concerning MASTER and SLAVE cylinder regarding starvation and air etc?

really only trying to help.

I found this (can't believe I didn't remember )

quote:

Originally posted by Peter Fenlon:
posted October 22, 2016 11:12 AM in "Throw out bearing touching clutch"

...info from McCloud...needs 12.7mm of travel from the time the bearing touches the fingers to full release.
You should get about 1.524mm gap between the pressure plate and disc at the time of full release.
..and you have a gap between the bearing face and the fingers of 2.54 to 6.35 when the pedal is in the home position..

so this implies you need (12.7 + 2.54 =)15.3mm at the ToB, this would mean you need (15.3 X 1.4 =) 21mm at the slave.

having the ToB just not touching when the pedal is in the home position would require (12.7 X 1.4 =) 18mm at the slave.

1.524mm is 60 thou and that sounds about right, I have always worked on a minimum 40 thou required.

This is one of those times I wish I was back in the UK, I'd hop in my car and go round and help fix it. I feel somewhat helpless from a such a distance.

Julian

Hello Folks,

I fitted the long throw slave this morning and I now have 1 mm clearance between the TOB and clutch fingers, and 20 thou between the flywheel and clutch disc.

Total travel of the slave cyl is now 15.5mm

I think the word in America is Geronimo!

thanks to all for their input. Peter.

Interesting that it appears McCloud stated the required stroke at the slave versus at the ToB

quote:

the word in American is Geronimo

Congrats, Peter!

Shouldn't you be yelling in Italian!


(Actually, "Geronimo" is what we yell when we start an unbelieveable adventure, like jumping out of a plane.... "Wahoo" is a good one for the extatic conclusion. Wahoo is also the famous mascot for the near-world-champion American Baseball Team, the Cleveland Indians...)

.020" is marginally ok when cold but as it heats up, the clutch will hang enough to grind gears.

Unfortunately you need to find another .015" minimum.

Off hand I would question the disc that you have.

It MUST be a dedicated Pantera disc with minimal Marcel. That is the only place you will find the needed additional clearance.

Peter,

Although you don't want to hear this, I agree with Doug, 20 thou cold isn't enough and there is still something amiss with your clutch system.

Maybe if you mash the pedal to the floor on every shift you'll find gears without grinding, but I'm pretty sure you need to get back in there and it might mean removing the ZF again.

Julian

I'm lucky, as I have not had as much trouble as Peter with either of my clutches (a stock 3 Finger, and a Centeforce diaphragm), but isn't there some amount of "wear" and "settling in" that will occur when a brand new clutch is installed?

Marcels compress, minor high spots are burnished off, and the disk compresses due to the thermal and friction environment?


Just hoping for the best.....

Rocky