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Shoulder bolts needed for flywheel/pp balance?


tyson

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Hopefully someone can help me out here, I'm in an area where I barely know anything (different types of bolts and pressure plates etc)

 

I recently brought my new Fidanza aluminum flywheel and new South Bend Clutch to a local clutch shop to have them balanced.

 

The fidanza flywheel by itself is spot on.

When they bolted the pressure plate on the flywheel, the holes in the pressure plate were a tad larger than the bolts for the flywheel (I even got new bolts at Nissan) which allows slight variations in the pressure plate alignment each time it's bolted and unbolted.

 

The shop (reputable place, pretty much all they do is transmissions, resurfacing and balancing) says that it needs a shoulder bolt to be balanced correctly.  I tried a few places around town, even a specialty fastener store and nobody has anything--especially with a short enough shoulder to not interfere with the flywheel threads.

 

As always, ANY help is appreciated!

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What happened to the alignment dowels?  That's their function.

 

Ya know, after I left I wondered the same thing a bit...The flywheel came with dowels, and I figured they already pressed them in.

 

I didn't want to call and insult their intelligence....but maybe I should.

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Alright, I called them and they said the flywheel had no holes drilled in it for the dowel.  Only enough holes for the pressure plate bolts, which is why they figured the application would have used shoulder bolts.

 

So ummm.....I'm really confused.  They also said they wouldn't be at all comfortable drilling it for the pin, and I don't blame em.

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Sigh, why can't this be easy?

 

So, called Fidanza and they asked for some pictures.  Drove up to the shop and found out there was mis-communication between the shop and the phone guys.  It's drilled for the pins, but they aren't in the right spot.   The new SBC cover fits on the old flywheel just fine, so obviously Fidanza goofed.  Everything else was in spec, so it wasn't the wrong flywheel (that we can tell)

 

I'm learning way more about clutches and bolts than I ever cared to know.   I just wanted to unbolt and rebolt.

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Now I have Fidanza telling me that it's not a problem with their flywheel, and it must be a problem with the pressure plate.   The new pressure plate I got from SBC matches perfectly with my old flywheel.   The same, brand new plate does not match up with the Fidanza.   Fidanza is trying to tell me to run without the pins (which my machine shop strongly recommends against, and I don't blame them) or to find a new pressure plate which will match the Fidanza.

 

Their customer service is making me want to just send the damn thing back to them.

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Have you rotated the pressure plate to try all three positions of the dowels? It will only fit one way...

 

Also, I believe the Fidanza flywheel is a dual-pattern 225/240mm clutch; you will need to know which bolt pattern you are using. They do not interchange.

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You could have sent in a flywheel and the machine shop Blanchard ground the dowels off flush...

Never send a flywheel in without personally extracting the dowels,do not assume they will "do the obvious"!

 

Hope that story gives you some relief.

 

Dowels or shoulder bolts... Or bushings to Center the plate in the holes. And like stated, rotate the PP as the dowels will only go one way..and the fit should be TIGHT!

Edited by Tony D
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Thanks.  I'll check with the machine shop one last time on Monday and personally rotate the pressure plate on the flywheel.  I almost feel bad doing it, because I don't want to insult them, but they are human and can make mistakes too.  I could have sworn when I was back in there today that we rotated it a few times....

 

If it stil doesn't fit the flywheel is going back.  LOL @ the SBC selling Fidanza, if the problem does turn out to be with Fidanza it would be hillarious.

 

50% of me hopes that when I go to the shop I can rotate it and align everything.

50% of me hopes that it doesn't align, because I'd feel like an ass.  The shop has been open for +38 years, and it's the foreman who has been working on it.  I'd imagine in his career he's had to rotate a few things to get all the bolts to line up and wouldn't hesitate to have double, tripple or quadruple checked that they didn't line up before saying it wouldn't work.

Edited by tyson
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Make sure you have the correct clutch to match the fidanza flywheel...as I said before, the two available patterns do not interchange.

 

What clutch diameter did you purchase, and have you verified with fidanza that you have the flywheel for that clutch diameter? I thought they were double drilled, but I don't recall for certain.

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Xnke, it's the 240mm.

 

I picked all the parts up from the shop today since there's nothing else they can do for right now.  Not all the holes line up and Fidanza is swearing that this is almost impossible because the CNC program is locked in.  Says he has a factory flywheel and the fidanza flywheel and everything lines up perfectly.

I sent this video to Fidanza and I'm waiting for a response.

 

http://www.youtube.com/watch?v=0Rt66EUm4lQ&feature=youtu.be

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Well, Fidanza says to just run the 6 bolts like it's an 225mm, instead of the 9 bolts the 240mm Zs originally came with.  Hope to God it holds.  If this is the correct way to run the fidazna, they at least need to include some instructions with it saying that only 6 of 9 bolts might line up and that it's okay to run it that way.

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If the Fidanza flywheel did not come with the dowel pins installed, try to obtain a second pressure plate and compare the two of them to see if they match up.  If they do, take the pressure plate and flywheel back to the machine shop and have them bolt the two together and tweak the position of the pressure plate till the two are in balance and the pressure plate dowel holes are over undrilled portion of the flywheel.  Lock down the bolts in the balanced condition and match drill the dowel pin holes into a small depth dictated by the 1/2 the length of the obtained STEEL dowel pins after sizing the dowel pin holes in the pressure plate then using a numbered drill about .002 to .005 inch smaller in diameter. Then mark the flywheel and pressure plate clocking to that it can be reassembled to the balanced configuration.  Then remove the pressure plate, and drive in the dowel pins into the flywheel. 

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Well, Fidanza says to just run the 6 bolts like it's an 225mm, instead of the 9 bolts the 240mm Zs originally came with. 

Weird how a company can make a good name for itself and still do stuff like some guy like me in his garage making one-off parts.  No dowel holes and mount with six sloppy-fitting bolts.  I don't get it.  No competition, I assume.

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