Clutch Replacement

fhernand · 04-17-2004, 06:01 PM

I have finished my clutch replacement project today. I have some questions for the experts: QUESTION?

When I took my flywheel to get resurfaced, I did not really noticed how the "pilot bearing" (1978SC not a bolted on bearing but slips on) went in on the wheel. When the machinist gave me back the wheel, he told me he pulled out the bearing but could not tell me how he pulled it out. Going through the tech articles and my porsche manuals, I can't tell if the bearing slips in from the back of the wheel or the front?? I am assuming that it slips in from the back so that it is sandwiched between the wheel and the front of the engine shaft. HELP!

Also, once everthing was in, I pulled out the alignment tool to find that the clutch pad moves a little inside the pressure plate. How much slack should the clutch pad have inside? Should it not be tight inside squeezed between the flywheel and pressure plate? I can put my finger inside and move it around. I am afraid the the tranny shaft will not slide in. . .HELP. Thanks

keithdog72 · 04-17-2004, 06:27 PM

I'm not sure about that bearing, but I will look it up when I get a chance. The pressure plate, however will tighten the clutch up once you start to torque the PP bolts. there are little metal "prongs" on the pressure plate that allow it to compress when you tighten it. Also, its good practice to tighten opposing bolts equally (ie tighten one bolt, move on, tighten, move on) you get the idea. Good luck.

fhernand · 04-17-2004, 06:38 PM

Thanks Keith, I did tighten up the PP bolts to specific torque and I could still move the clutch. HUM? Maybe more torque? I was thinking that if that "pilot bearing" was not put in correctly, there would be some space between the plates. . .

john walker's workshop · 04-17-2004, 07:29 PM

well that's just not right. the bearing is sandwiched between crank and flywheel, so that wouldn't be it. can't say i've ever had that problem, and don't really see how it would be possible. the disc starts to get clamped right from the beginning when you start to tighten the pressure plate bolts.

Zeke · 04-17-2004, 07:39 PM

You have to take that back apart. Something is really wrong as JW says. Something is in there that shouldn't be. Look everything over carefully and see that no damage is done.

When you go to tighten the PP bolts, they should hold the disc in place before they even get within a 1/4 " of home. OK, maybe that's a bit generous, but you get the idea. That's why he said go to opposite sides in a pattern while tighening.

masraum · 04-17-2004, 08:36 PM

Hmm, maybe they took too much off of the flywheel, but I'd guess that they'd had to have taken tons off to get to that point unless there had already been some removed. Yep, what they said, "not good."

johnsjmc · 04-18-2004, 04:46 AM

Check the flywheel where the step is at the edge .If the shop radiused it instead of completing the cut then the outside edge of the pressure plate may be stopping there before clamping the disc.

john walker's workshop · 04-18-2004, 07:32 AM

it's a flat flywheel, no step. did they machine only the disc contact surface, thereby creating a step that dropped the disc deeper? wierd.

johnsjmc · 04-18-2004, 08:30 AM

The lip I,m talking about is to locate the edge of the pressure plate It is definetly there but should be level with the disc contact surfaceI believe. There are good pictures and specs in a thread started by
" chrisp "01/05/2004Title is "flywheel condition how do I tell if it,s OK

fhernand · 04-18-2004, 08:16 PM

Well guys I took all your ideas and suggestions. I woke up last night at around 4AM breaking my head with this matter. I doubled checked the kit boxes making sure that the part numbers matched what I got from Pelicanparts. All was good.

The flywheel does have an outter lip the circles around the entire plate. Actually, the lip helps the clutch plate stay in place, not tight but just in place). Masraum, at first I also thought the machine shop took too much off so a measured the wheel according to specs. It is within range. I took everthing back out today and checked the entire matter over again. I put the old clutch plate back in and this, fit just snug up against the flywheel with no slack. HUM? Of course, the old clutch plate is the rubber center type and not the spring centered. They are different in thickness in the center only and not the disc pad.

What got me thinking that the plate was not right was my book on 101 projects by Dempsey (may not be the correct spelling) He states that once everthing is complete, pull out the allignment tool and everthing should be snug and tight.

Well, at this point everything is back together again. There is still slack in the clutch plate but not so much that I can't shake the tranny for it to enter. Any other ideas, please keep them coming guys. You have been of great help. . .

fhernand · 04-19-2004, 10:03 AM

Here is the problem with my clutch plate not being tight behind the pressure plate. It so happens that when I took my flywheel to get resurfaced, the machinist did not take down the outer lip also, of course, this would leave a space between the flywheel and the pressure plate which would explain why the clutch plate is still turning and loose after all bolts being screwed tight. Boy do I have a bone to pick with the machine shop! Well, lesson learned and I have put in a footnote in my manual so that this does not happen to me again. Hopefully the machine shop can fix the problem. I had Wayne at Pelican send me the true machining thickness for the flywheel. I know these are not cheap. Thanks guys.

ChrisBennet · ChrisBennet's Garage

When I have something done by machine shop, I give them photocopies of the relevant manual pages and specs. The less you leave to chance the better.
-Chris

Rick Lee · Rick Lee's Garage

Flywheels aren't that expensive. I'd rather buy a new one for $200 than pay $75 for resurfacing the old one and go through what you're doing now. Or are 915 flywheels that much more than those for G50's?

fhernand · 04-19-2004, 01:40 PM

Richard, a new flywheel is $230. If I do get another it will be at the cost of the machine shop and not mine, if you no what mean. They charged me $45 to resurface plus headaches. I will go down to see them today with the flywheel on one hand and my calipers on the other. They told me that they would fix the problem and do some extra work for me down the road. I will just take the fix for now. It is a very reputable shop that has been in the area for a long time.

Chris, I like your idea. I have the spec's already.