Rob Edwards

Toast-Int shaft ok -toast- toast-toast.

islaTurbine

Thanks. Anyone got an updated intermediate plate in decent condition for sale? 928Intl doesn't have any.

What's also strange is that the guide tube and intermediate shaft are the updated post-1980 versions, but the two clutch discs and the intermediate plate appear to possibly be original to the car.

karl ruiter

Wow, that does all look pretty bad! Maybe it was driven for a while slipping.

Petza914

The splined shaft looks like it might be OK. Everything else, not so much.

islaTurbine

I think what’s actually the situation here is that the intermediate plate was updated but the original ring gear was reused... I’m gonna get some feeler gauges to measure the intermediate plate spring clearance to make sure.

Update: intermediate plate was original for diameter-centered flywheel

Cheburator

Helix Autosport in the UK just made a brand new intermediate plate from scratch to repair a broken one for my racer. Your best bet is to call them and ask to speak to Rob. Tell him that Alex Popov has sent you and explain your problem. The price should be around 1/2 of what Porsche wants for a new plate. They can also repair your pressure plate and re-line your friction discs. All in, it will be maximum 1/2 price of what Porsche wants. If you are worried about quality - Helix are contracted to Porsche AG to produce the release bearings for the two types of 928 clutches. Hence they do know about our twin-disc and single disc clutches. They have scanned one of each - I lent them the pieces and are able to make anything on demand. I hope this helps.

Alex

islaTurbine

Thank you for that information. Which model year intermediate plate did they make for you?

SwayBar

Alex, very nice...

Have you run the new clutch yet, and do you have pictures?

islaTurbine

Here's another head-scratcher:

The WSM lists the 1980 revisions to the early clutch disks, short shaft, intermediate plate, and guide tube but it says nothing about the flywheel. The early flywheels were diameter-centered and have a slight lip that the clutch assembly installs into instead of using the centering pins that most folks have to deal with. But the WSM seems to be silent as to which flywheel is to be used with these updated post-1980 parts.... So if I buy the new, post-19080 clutch components (which appear to have been superceded by Porsche), will they be incompatible with an early diamter-centered flywheel?

Maybe I'm over-thinking this or missing something obvious?

GregBBRD

People, on another thread, are wondering why I'm making a new single disc clutch, for these cars...
it took me almost 15 years to figure out all the "tricks" to these dual disc clutches. For those years, I just automatically assumed that every clutch I did, I would need to take it in and out two or three times to get it to properly release.

Amazingly complex, with more tricks than I can count to make it work.

These days, now that I know all the tricks, I can actually do this job once....and make it perfect.
Expensive (parts wise), but perfect every time.

For instance:

You actually may be better off finding a good used "early" intermediate plate!
One of the things that occurs is that the "H" stop pieces wear, slightly, over years of use. This slight wear will usually make the travel of of an early intermediate plate around 1mm, which is the perfect dimension for the "late" clutch discs. This slight wear will also will make the travel of a late intermediate plate over 1.4mm, which usually means that if.the rivets and springs on the late intermediate plate are too worn to not move (once adjusted), the "lift" off of the front disc will be too far and the rear disc will drag. Super common.

Cheburator

The clutch came out of a 1984 UK race car, so I am guessing, the intermediate plate was based on 1984 MY clutch, The aluminium ring that holds the steel plate and starter ring broke, hence HELIX had to machine a new aluminium ring on their CNC ring. While they were at it, they also produced a new steel plate, using the one in my car. The H-adjusters were replaced with new ones too.

New clutch is still sitting in the box. Will try and take some pics. Posting them on here is a faff. Any advise on the easiest way to do it?

Btw, HELIX has scanned my twin-disc flywheel, which was converted to run in a late 1995 GTS. Thus they would be able to offer a complete solution to anyone who wants to convert a 1987-1995 single disc to twin disc, negating the need to chop a S4 auto flywheel for the timing ring. Price - around $300 before shipping and import tax. Cannot argue with it, can you? And it would be lighter than the OEM/Self made solution...

islaTurbine

Thanks for that. I'm still trying to get a handle on the flywheel situation and I've got to get that resolved before I can figure out which intermediate plate I need.

islaTurbine

Some more pics as I get more stuff removed. Unfortunately I also found a weeping RMS, but it’s easy and cheap to correct though it will take a lot of elbow grease and BraKleen to clean up the area.

My car is VIN 338 and I presumed it should have had the early/rare small ball mount for the clutch fork due to that. But apparently it was upgraded to the larger ball mount at some point.

Is this clutch fork what would be considered the pre-upgrade version? It appears that the pivot area for the throwout bearing is very slightly curved/convexed.

Mrmerlin

TOB and release arm are updated you want one side to be curved and the other to be flat Meaning that your arm has curved contact area and your TOB is flat ,
other versions had these surfaces swapped where the arm was flat and the TOB is curved,
also make sure the fit of the guide tube to the TOB is snug,
and the TOB to the inside of the arm is also snug

islaTurbine

Thanks Stan.

on a side note, I definitely found at least some of the culprits producing the whirring driveline noises. The throwout bearing is quite crusty, loud and whobbly. And I can hear lots of noises and feel loose movement when I spin the TT shaft with my hand. The pilot bearing doesn’t look, sound, or feel too bad but she’s getting replaced regardless.