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Join Date: Apr 2015
Location: Henderson/Las Vegas, Nevada
Posts: 9
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Clutch Noob with pinhead questions.

Hello, fellas.

For starters, I have never done any work on a manual transmission whatsoever, so I have no clue about what is "normal" etc.

1979 5 speed 928 104K miles.

Replaced clutch master and slave. And, as a side note, I oriented the new master the way the old one came out, which I eventually discovered was upside down. Gee, I wonder why I was having problems bleeding. Duh. Re-oriented and bled to the point of only having about an inch of play from "pre-loaded" at just touching. Bad grinds into any gear. So I cranked the rod in til I felt resistance, then backed off a little, taking up about an inch of useless travel. Shifts much better, but still a grind/quick chunk going into first.

Ok. Read article about the three point adjustment deal. Figured I'd give it a shot. Also ordered new ball cup bushing so when I got her apart, I would do that job, too. Well, I crawled under there, pulled slave and starter, dropped bottom plate, and lo and behold the clutch fork just completely wobbles. Looked on top. Ball stud snapped. Great.

But ok, nothing major functionally so I'll keep going the direction I'm going because I can still shift enough to pull it around the driveway. Well, I reach up in there and the throwout bearing casing turns freehand and is completely separated from the clutch fork. There's a lot of slop in the throwout bearing casing/housing, too.

So the questions are...

1. Is the clutch fork pressed to that bearing, or is it some mamby-pamby "as long as it touched under pressure it won't wobble out" deal, like what I'm seeing now? In other words does the clutch fork actually attach in some way to the throwout bearing casing, or does it literally just rest there and is only held in by registered position under minimal force? It just seems strange to me is all.

2. When I read to push the fork with a prybar to disengage the clutch, where am I supposed to hinge the prybar now that the bottom plate is gone?

3. I am not positive this is the original clutch, or that it is dual disc at this point. I see the flexplate/flywheel(?), the intermediate plate, and the pressure plate. But it's under pressure so I can't see inside at all. There are two sets of (guides?) the long flat pieces of metal that flex/hinge, one on each side. Is there only one set of these on a single disc system? Yah. I know. pinhead question, but I'm not taking anything for granted on this car.

4. The high pressure hard line is smashed right under the starter. Where can I get a new one of these, or, will steel brake line work to replace it?

Take it easy on me. I have admitted my ignorance in this area. Thanks in advance.

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Porsche. There is no substitute.

1979 928 US. Black and Tan, 5 Speed.
Old 04-14-2018, 10:21 AM
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Join Date: Feb 2011
Location: denver
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hey vegas - i'll answer the ones i have an idea about
1. no the fork is not physically attached to the throw out bearing, the bearing is attached to the pressure plate springs (fingers) with a clip - the fork is "trapped" between the bearing and the pressure plate - when the slave and top ball cup are installed and in good condition the fork is pretty solid in place but yes it can still move around a bit - there is always a little pressure on the fork and so the bearing spins at all times when engine is running - something that's different from most cars where the bearing only spins when clutch is pushed
2. try wedging a block of wood in there somewhere to give you something to pry against?
3. if you see an intermediate plate it is a dual clutch system - the pressure plate pushes the rear disk into the intermediate plate which in turn pushes the front disk into the flywheel - when clutch pedal is pushed the pressure plate releases the rear disk which releases the intermediate plate - that plate has internal springs which move it rearward a tiny bit which then releases the front disk

it's, in my mind, an overly complicated system - if all those parts are not in good shape and freely moving it can cause one or both of the disks to drag a little bit - this can cause the the grinding you're experiencing - also that missing ball cup will not let the fork disengage the pressure plate enough
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Old 04-14-2018, 09:07 PM
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Thanks for the insights. I don't have the clip then because the fork wobbles off and falls down immediately.

But should the throwout bearing casing be wobbly and able to slide back and forth?

I saw a YouTube on how and where to pry so the next step is to adjust the three tension deals. And of course replace that ball stud that broke.

Thanks again.
Old 04-15-2018, 08:43 AM
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the fork has nothing holding it on top since your ball stud is gone so it will be excessively loose - but it should still be trapped by the bearing - as to the bearing it can move around on the pressure plate fingers but it should not come away from them

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Old 04-15-2018, 04:18 PM
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