christiandk

Well Racer-Mark it was your year old post that made me understand plus the help from my Aussie friend Dave.

Hope this will help others.

Cheers,

Christian

And I can vouch for the .5mm tollerance. Would not like to do this under the car with spark plugs in...yiekes!

GlenL

Wow. You really don't understand how the clutch works.

mark kibort

Glen, you might have caught me there. If you machine the flywheel, the entire surface would be machined down...... sorry, just trying to give you the benefit of the doubt of why the "push back H" techniques works for you and no one else... all i can say is that it has to be something in your sytem that is not in a stock system. other causes for your anomaly behavior could be:

1. your clutch lever arm is pulling the pressure plate further back (most likely)
2. you have changed the slave cylinder and/or bell housing.
3. you have changed the slave cylinder push rod

just guessing on your end, but it is you that doesnt understand how the clutch works, if you think pushing the H's back is a good idea... its not.... why in the heck did i have to adjust the clutches in Scots and my car when the H's did migrate back?? reason.... because when the H's are pushed back , the INT plate pushes the disc into the pressure plate and it spins up the driveline. its that simple.

Now, who doesnt know how things work here?

EDIT: maybe you had your INT plate ground down... now that would change the overall distance that surface travels rearward, right.. ALSO, "relined" discs? hmmm... maybe those were thinnner than stock? as we talked about, its only .5mm to make it work or not ! (thats only 19 tho....0.019" )

mark kibort

haha.. yes, with a good , long breaker bar length socket, you have to be strong and with one arm rotate the engine and the other arm brace yourself. then use the screw driver to press down the H's from the Max position (or a position that is a little too far back..... and thats why pushing them back from the start is a BAD idea) then, rotate and repeat. its a little tiresome, BUT, if you can do this on the bench as we have talked about, that will save some work for sure. Looks like that would work because the H setting should be the same if you put that same disc on a flywheeel and put the INT plate on there and push. you can even demo the "glen" technique.... push them all the way back, and then push on the INT plate til the disc makes contact to the flywheel and measure the gap.... if its greater than 1mm, its going to be a problem when installed.

Vilhuer

Simple question. How far you think pressure plate moves when clutch it pressed? 1.5 to 2mm or something else? Meaning how much space you think disk II has on properly working clutch when pressure plate is where slave cylinder moves it when pedal is pressed?

If H's move when intermediate plate is released due to vibration etc. they are not working correctly. It means they have to be tightened. Factory design do not allow this. I think I have posted pictures of solution to this problem over 10 years ago. All it takes is three bolts and few spring washers. Once that mod is done it is possible to set H's tightness to correct setting.

mark kibort

well, if we agree that the H allows for a total movement of 2mm, then we know the pedal pushed in will make the pressure plate move, at least this far.
the push rod, lever arm and TOB all have to pull the pressure plate friction surface further than that. as you know, even a half pushed in clutch pedal doesnt release the driveline.

The H's moving IS the problem and its why your idea worked as well as my idea of pinning ... yes, in 2008, i pinned mine and have not looked at them since. its not a fluke that my Hs were too weak. perfect for the street, but on the race track, they couldnt handle the force of 6500rpm and the small friction values of the H....im not sure any used INT plate will work perfectly for racing, but mind did for about 5 years or so. Scots did for about 2 years. if you think about it, its a lot of force for a little vibration when that INT plate is spinning at 6500rpm, held in place by only 3 flat springs . any axial force is transfered directly to the H adjusters for which they are resting on (via the flat spring pressure) and then they can move... dont think it takes much force. So, i would pin them or even do your technique. since i would never run a race car on worn out discs, i would say , in my case, pinning them for life is fine. if the discs ever wear down too far, i just replace the discs. not a big deal. so far, those discs have lasted 15 years of racing!

James Bailey

Frankly most of the clutch problems are worn out H adjusters as Errka mentioned and worn grooves on the short clutch shafts which seldom get replaced. The commonly sold clutch master replacement lacks the required stroke due to an internal change and MUST be modified....
I sold lots of clutch discs, release bearings and pressure plates but few ever bought the other parts.....then wonder why it does not work right
the three straps from the adjuster to the intermediate plate are the springs in the system and they pull the intermediate back to let the disc float away from the flywheel. The gap between the intermediate and the pressure plate is larger if the master cylinder has full stroke.....

mark kibort

excellent points and other possibilities Jim.

christiandk

When the adjusters are all the way back the int plate, disc an flywheel wont make contact. And I have a brand new fat clutch disc.

Dave928S

Here are Errkas original pics. I've done that to mine, to restore adjuster friction, and it works beautifully.

Vilhuer

They will when clutch is installed. Pressure plate pushes intermediate plate forward which in turn pushes H's to correct position. Pressure plate keeps on pushing H's forwards as disk I wears thinner.

If you put clutch together and solidly fix H's into position this automatic wear adjustment is lots. You have to allow moving space in front of H's for disk I to wear. This in turn makes space for disk II smaller until disk I wears thinner. This means disk II will not disengage as well as it should.

christiandk

That makes sense.

mark kibort

this is true, but as was discussed, if you move the entire INT plate foward, the Hs will move until there is contact. (or install it as Vilhuer says, as the pressure plate willl move them foward) BUT, if you rely on the pressure plate to do this, you willl have TOO much gap to the rear where the INT plate will retreat and hit the pressure plate in most all cases. this is WHY there is a gap setting of .75 to 1mm. ( dont shoot the messenger, this is the reason for the porsche design.)

1. yes, this is true, but you dont want to start out with the Hs touching the INT plate in the front.. again this makes the entire gap potential to the rear, and thats too much for the INT plate to retreat.... it will touch the pressure plate and spin up the driveline with clutch depressed. (BAD)
2. I agree by fixing the Hs all the way forward, you lose automatic wear adjustment. BUT, if properly adjusteed, you have 1mm to the front and 1mm to the rear and this will allow for 1mm of wear before the adjusters would ever be touched on the front side. however, more than 1mm , and you fix the H adjusters, you will have an eventual problem. Ive fixed mine and have no issues and still have the 1mm gap..... one indication would be to see if the rear gap changes, that is your wear measurement.

Now, what does this mean?.. you said,"
This in turn makes space for disk II smaller until disk I wears thinner. This means disk II will not disengage as well as it should. "

Taking that at face value, ill assume you mean the adjusters pushed all the way forward. if you do this, the disc 2 is not released from the INT, disc 1 and flywheel........ hence the same net problem as too much rear H gap (but on the forward side) . however neither the disc 1 or disc 2 have any difference in gap. in other words, the discs are BOTH not able to retreat, almost equally. the only reason that the discs are removed from pressing on the flywheel, is the spring pressure of the INT plate. so with the Hs all the way forward, both discs are rubbing on the flywheel with INT plate in the middle. move the Hs even slightly back, and both disc 1 and 2 will retreat the exact same amount and allow the driveline to slow and stop to shift in to gear with clutch depressed. you can keep moving the H back rearward, until there is too much gap, whereas the INT plate and disc 2 will be resting on the pressure plate friction surface and create the same undesired effect of spinning up the driveline. so the real answer is , if the H is well adjusted, there is equal space in front and rear on the adjuster. (about 1mm). the reason that there is a front tab at all, is they dont want excessive gap to the rear, even when the discs wear. that would cause a lot more ratting around of the clutch discs and provide some instability for the floating disc as well if there were a greater distace that the INT plate friction surface would travel rearward. you dont want those non optimal angles of the flat springs at 6000rpm. the design is quite ingenouis and should not be questioned as much as it is. however, the bolt design the this list came up with , and My pinning design, are well though out and quite functional. (although, i would lean toward my pinning design, because you can do this on the car with no disassembly! )