Maybach_Man

Hi
I know this is o/t... but what is the difference between the early and late intermediate plates??, or point me in the general direction.

Geoff

mark kibort

awesome. for some reason, i didnt know you did this! great job.

how stiff did you make it, as a rough percentage of clamping force?

mark kibort

Its not a common failure, but its common when they fail!

the H adjusters have a simple function, only to provide a back stop allow the pressure plate to retreat from the int plate. if they move, then this might not happen, and you get short shaft drag which spins the drive shaft and then makes it impossible to get from neutral to in a gear with the clutch depressed. it moves , as i found out, at high rpm, because that inner mass is only suspended and connected by the 3 flat springs. any wobble or change in RPM can create a radial force that can make the inner plate move axially and it doesnt take much of this "vibration" to move the h adjusters when you put the clutch in to shift at 6400rpm. if they are locked down, this cant happen, but as the clutch wears you want to be able to adjust the H adjusters forward .
the nut and bolt design looks like a good one and i think you might be able to perfect it to make a lot of friction , but still movable, plus make it so that if the friction isnt enough, that you can tighten the bolt and nut to keep the h tabs in place. my intermediate plate is not that bad, for street, but on the track, it moves after one session to where it has to be adjusted to get it into gear.. scots did the same thing. both are bolted down now with a pins.

Carl Fausett

The pics are fairly self-explanatory - easy for me to duplicate that's true.

But I hope to hear from end-users so I know this went past "idea" stage and it works well in the field.

Example: MrMerlin, it sounds like instead of "updating" either of the intermediate plates you had, you went back to your original one. Why?

Carl Fausett

Exactly - one of my questions about this modification. Do you want the H-tabs to have drag and yet move? (which begs the next questions "how much drag") or do you simply want to lock them down?

Carl Fausett

Mark,

the clamping force for each SINGLE DISK clutch system is posted here:
http://www.928motorsports.com/parts/clutchkitgt3.php

the clamping force for each of our DUAL DISK clutch systems is posted here:
http://www.928motorsports.com/parts/...kitgt3dual.php

mark kibort

2 x stock would be fine if i was to make an educated guess. that way its a pain to move, but when they are set , they stay. again, its the vibration of the floating 5lb centerplate that can hit them and move them when they are old.

mark kibort

it doesnt list the stock clamping force of the stock dual disc system, only the comparison of the stock single, vs sport (GTS?) and what yours brings.

also, do you sell the pressure plate alone, as that is what most folks would need, i would think , based on my past requirements and 420ft-lbs of torque from my engine being raced regularly.

Mrmerlin

the old I plate was reused because the H tabs were rusted and thus didnt move as easily as the new I plate H tabs,

this is a deal where the parts installed then the tabs are set then locked down then tested prior to refitting the bell housing.
I would surmise that since its a bit of a fiddly upgrade due to its location that a lot of 5 speed owners just put up with the dragging clutch.
However since its quite possible to mod the parts on the bench easily.
it wont take long to set the tabs once the I plate is installed ,
once thats done the clutch will work with precision

Carl Fausett

It looks like a good mod, and I'm "on board" with it, but would like to hear from some that have done it and are driving it now...

Thanks for your input!

Vilhuer

'78-79 version I
No centering pins. Entire package is just bolted together. Only centering action is flywheel outer rim which sort of forces pieces into line.

'80-83 version II
Three similar centering pins added to make sure all parts are properly centered. Flywheel changed to flat one. Parts can be installed any way compared to each other. All are internally balanced.

'84-86 version III
One centering pin is changed to different size. This makes sure intermediate ring can only be installed one way compared to flywheel and crankshaft. This is due to TDC trigger build into intermediate ring.

If aim is to make similar part as original factory setup H need to move. How much drag is correct is easy to answer when one understands whats purpose of said H tabs. Way intermediate plate works is that three flat springs around intermediate ring push it away from clutch disk I whenever pressure plate is moved back. Reason for H is that their try to stop intermediate plate from moving more than play between H has room. By limiting intermediate plate movement back towards disk II they give disk II room to move between intermediate and pressure plates. Thus H need to remain still and must be tight enough not to move when three flat springs push intermediate plate against them. But they must move when pressure plate pushes entire clutch together.

Reason for old advice to push three H all the way back is that when H work as they should installing clutch will set them automatically to correct position. When disk I wear thinner pressure plate will push intermediate ring forward and H's need to move with it. When they do they will automatically limit intermediate plate movement when pressure plate is pushed back and give both disks about same room to move freely between flywheel, intermediate and pressure plate.

So how to set H tightness is fairly simple. Make them tight enough so that they can be set manually in any position along their movement range and flat springs can't force them to move at all. At same time make sure they are not too tight and will move when pressure plate forces intermediate plate forward.

We did mod in message #5 pics almost decade a go to relatives car. It hasn't moved much over the years but I can give guarantee clutch works 10 times better than unmodified parts ever did.

Carl Fausett

Erkka,

That's an excellent response and write-up. Very informative and accurate.

Mrmerlin

it would be best to duplicate the picture in post 5
It does require a set up when installed,
but once its set you shouldnt need to mess with the adjuster for a while

Carl Fausett

I agree. Thanks for your input!

Dave928S

Incorporating that mod will give a good rebuild Carl ... worked for me, and way better than the the rivets, which have hugely varaible frictional resistance even when relatively new. I just couldn't get mine to stay adjusted with rivets.

Here's the page which has Errkas post on the way he did it, which I followed .... https://rennlist.com/forums/928-foru...f-into-19.html

That mod is brilliant ... and a big thanks to Errka for his original post two years ago detailing it ..