Why not?

Discussion in 'General Harley Davidson Topic' started by Adamal47, Jul 19, 2012.

  1. Adamal47

    Adamal47 Active Member

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    Recently while I was doing some cleaning and looking things over I noticed the kickstand was kinda wobbly. Upon further review I noticed that one oth the three bolts was missing and another was loose. So I proceeded to take apart the floorboard assembly and remove the kickstand. I tried to remove one of the remaining kickstand bolt to see if it would fit into the empty hole left by the missing bolt. When I tried to remove it the head snapped clean off. Was able to get it out with a pair of vice grips. Replaced all three bolts with new grade 8 bolts. I also noticed that both bolts that held the rear exhaust bracket to the frame had also snapped. Going to replace those with grade 8 as well. So now for my question(s). Does anyone else have problems like this of bolts breaking? Why doesn't everything come grade 8 from the factory? Is it bad to replace with grade 8 bolts?
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  2. Bodeen

    Bodeen Well-Known Member Staff Member Moderator Contributor

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    While I haven't broken many bolts, I have broken exhaust hardware and saddlebag hardware. Grade 8 is a good move. My bike had some grade 8 bolts on the it from the factory. The primary cover, cam chest cover for instance are all grade 8. Seems that of all places to use a grade 8, the jiffy stand mount would be one of them.
     
  3. Iceman24

    Iceman24 Well-Known Member

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    Exactly...HD's "should" run/last as long as cage so why not ensure "quality" hw is matched to extend life...??
     
  4. Jack Klarich

    Jack Klarich Expert Member

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    Bolt Torque Chart | Portland Bolt Having a look at this chart may help you to understand the torquing and clamping force of the different grade bolts:s Grade 8 is a very good choice in critical fastener applications, they will be a harder grade of bolt making removal of broken fasteners more difficult , that said they should have been installed from the factory and placed on your periodic check list(Except) head bolts which should not require any retorquing
     
  5. Midnight Reign

    Midnight Reign Active Member

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    Dont know if it is true or not but have been told in the past that although grade 8 bolts have a higher strength they are also more brittle and tend to break more often in a high vibration enviroment, as well as being more suceptable to failure under shock loads. once one of these bolts has failed they a much more difficult to remove.
     
  6. bigfish_Oh

    bigfish_Oh Member

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    I would tend to agree here, and if the bolt is stronger what is the next weakest link? I always replace old tractor manifold bolts with what was original, brass bolts, takes the heat changes and easier to remove if broke or stripped, same idea. They don't always take a cheap route to be cheap.
     
  7. michael martin

    michael martin New Member

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    I would disagree with the idea that grade 8 bolts are brittle, or more brittle, than say common fasteners. But, they are certainly tougher and have a much higher tinsel strength.
    Grade 8 fasteners are commonly found in aircraft where vibration is a common problem, so a brittle bolt would be problematic. :)
     
  8. papacierra

    papacierra New Member

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    I ve worked in the steel industry for over 30 years. Grade 8 bolts are stronger but will break, they don't bend much. Grade 5 witch is a standard will bend quite a bit before it breaks.