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Counterweight -> Flywheel bolts?

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Old Dec 14, 2003 | 01:51 AM
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Vagina Junction
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Counterweight -> Flywheel bolts?

Somehow they were not included with my clutch/flywheel/counterweight shipment... what am I supposed to use for this?
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Old Dec 14, 2003 | 02:01 AM
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Ahh Crap!! It's always something huh? Grade 8 at least. don't wont them snapping off. It's been a while since i saw them, I don't remember the exact size. Have you checked the box again for the 90 th time? Sometimes they are stuck to the sides or they get dumped out.
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Old Dec 14, 2003 | 02:38 AM
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I'm POSITIVE they are not in any of the boxes or cartons or shipping materials. Grade 8 what? Like...are they round-seat hex bolts and nuts? of what length? Lock washers? What torque should I use? Damnit...grrr.
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Old Dec 14, 2003 | 10:44 AM
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Well, I used 6 10mmx1.25x20mm bolts and lock washers with thread locker and torqued the **** out of it. The counterweight was already threaded, so that made things a bit easier.
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Old Dec 14, 2003 | 11:30 AM
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Good job finding the bolts size. By grade 8 i meant the strenght of the bolt. They go up in grades as they get stronger. 8 is one of the stronger/est ones. I just didn't want to see you use some packing crate grade bolts to hold on a MAJOR component. Sounds like you got it taken care of.( determined to finish this weekend huh?)
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Old Dec 14, 2003 | 01:25 PM
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Vagina Junction
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Oh, yeah, I used grade 8.8. This WILL be done tonight (not that I can drive it, since it snowed last night). Now to jack up the tranny...
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Old Dec 14, 2003 | 06:58 PM
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actually I think metric bolts use a differnt grade scale. Noticed I said I THINK. standard sizes go up to grade 8. Where as metrics go up to 10. But there on differnt scales. ie standard 8 isn't the same strength as metric 8. Someone wanna verify this?
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Old Dec 14, 2003 | 07:16 PM
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http://www.ultimategarage.com/metric.html

Also on the head of the bolts (and on many of the nuts as well) is the grade (tensile strength). Metric grade 8.8 is the standard automotive grade with a tensile strength of approx 120,000psi. The next common grade is 10.9 (9.9 is available but not very common) which carries an average tensile strength of 150,000psi. This grade is recommended for most drivetrain, cylinder head, suspension and brake applications. These bolts are typically "black only" although they can be obtained with a yellow zinc dichromate finish (more on that later). There is also available a grade 12.9 (176,000psi tensile strength). This is the grade BMW uses for flywheel and connecting rod bolts. These bolts are generally available as socket head (allen type) and come in a black finish. On nuts, you'll generally see the grade stamped as just "8", "10" or "12". Washers (split and flat washers) are not rated.
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Old Dec 14, 2003 | 07:23 PM
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Damn you posted just as I finshed looking it up in my old text books . Well heres my info anyways:

They are differnt grades. Standard Grade 8 has a yeild strength of 130000 PSI. A Metric Grade 8.8 has a yield strength of 640 MPa. If you do the conversion then 130000 PSI = 896.32 Mpa. So the Metric Grade 8.8 is weaker then a Standard grade 8.

What grade the flywheel bolts should be I dont know.
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Old Dec 14, 2003 | 07:36 PM
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Well, I used 8.8 Metric, and i'll be damned if I'm tearing it apart again to put in 10.9, so...we'll know if my legs are chopped off that it should've been 10.9

Also, if 12.9 is what BMW uses...8.8 is good enough for me
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