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loose flywheel damage

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  • loose flywheel damage

    My flywheel bolts loosened up during last week's autocross. Pulled things out today and saw this:




    Mating surface on flywheel:


    Yes I did put Permatex High Strength Threadlocker on all 6 bolts during last year's installation. Today all 6 were loose. Do you think this crankshaft is still usable? And if so, should I reuse the flywheel (which does have all the surface bumps that may match the crank)?

    I'm also thinking of using lock washers in addition to loctite this time. This kind of damage is so frustrating.

    Thanks.

  • #2
    That's a lot of fretting... I'm betting the surface isn't parallel to the centerline anymore.. Sucks.
    '18 Chevrolet Volt - Electric fun hatch for DD duty!


    DefSport Koni Sleeve and Spring Perch Buy!!!
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    • #3
      The pittings on the crank are all under its flat surface, there are no bumps sticking out of it (the bumps are all on the flywheel's surface). I really hope the remaining undamaged area is enough for a new flywheel to sit on.

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      • #4
        It wouldn't surprise me if there was damage to the thrust bearing or mains also. Sorry to see it

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        • #5
          Might work in a pinch, but I wouldn't be surprised if you start taking out engine and/or trans bearings.

          It might appear to be relatively flat, but it's hard to tell unless you put a straight edge all over it.
          '18 Chevrolet Volt - Electric fun hatch for DD duty!


          DefSport Koni Sleeve and Spring Perch Buy!!!
          http://www.nissanroadracing.com/showthread.php?t=5902

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          • #6
            I ran a straight edge over the crank surface and found no bump sticking out. So I'll throw a good flywheel on and see how long that will last. It's a matter of tearing down the engine now or later; I think I'll procrastinate.

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            • #7
              I would bolt up the flywheel and check runout with a dial indicator just to be sure its square.
              98 240SX SCCA STUish

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              • #8
                thread locker or not....

                obviously your torque wrench sucks or you are using pre-used bolts, I have only ever seen that happen when someone used AT bolts for a Flywheel...not enough thread engagement,
                I am SKULLWORKS

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                • #9
                  I'll def check the runout.

                  @Tower: I used new MT bolts; would not cut corners there. I'd blame the Permatex threadlocker.

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                  • #10
                    I have never used thread locker on those bolts...FWIW

                    IMHO any torque to yield bolt shouldn't need a secondary retention mechanism,

                    maybe verify the holes are debris free with a thread chase next time?
                    I am SKULLWORKS

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                    • #11
                      Is the dowel pin still in the crank? Looks like it is, just making sure though (mine is steel on the SR IIRC).
                      '18 Chevrolet Volt - Electric fun hatch for DD duty!


                      DefSport Koni Sleeve and Spring Perch Buy!!!
                      http://www.nissanroadracing.com/showthread.php?t=5902

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                      • #12
                        The tiny brass-colored dowel pin? Yes it's there.

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                        • #13
                          Those bolts must have been hella loose to let it walk that much with the dowel.

                          I'm guessing it's a KA? SRs have a JDM as hell steel pin.
                          '18 Chevrolet Volt - Electric fun hatch for DD duty!


                          DefSport Koni Sleeve and Spring Perch Buy!!!
                          http://www.nissanroadracing.com/showthread.php?t=5902

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                          • #14
                            Sounds like you never played with the KA much Yes it was the truck motor shaking itself to pieces. I can't see the little dowel pin doing any good other than locating the flywheel for installation.

                            What if the flywheel had come off the crank completely? Flywheel + clutch + pressure plate = 35 lb flying saucer through your skull.

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                            • #15
                              The dowel actually does ALL the radial locating of the flywheel. The bolts just provide a clamp load (which is how all assemblies that experience torsion should be put together - trans to block, head to block, front cover to block, wheel to hub, axle to output shaft etc. etc.).
                              '18 Chevrolet Volt - Electric fun hatch for DD duty!


                              DefSport Koni Sleeve and Spring Perch Buy!!!
                              http://www.nissanroadracing.com/showthread.php?t=5902

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