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rethreading damaged bolt.

Discussion in 'General' started by David-imoddavid, Oct 1, 2018.

  1. David-imoddavid

    David-imoddavid Well-Known Member

    I replaced the wiper transmission on my car over the weekend and damaged the ends of the threads on the stud the holds the wiper arm. I should be able to repair the damaged threads with a die. Store manager at NAPA said to use the same diameter as the original - 10mm. I've never done this but it seems logical to step down to at least a 9mm. If ya' don't know, ask so I'm asking what ya'll do? Advice greatly appreciated.
     
  2. Boman Forklift

    Boman Forklift Well-Known Member

    I would use the same size or a thread file.
     
  3. gpz11

    gpz11 Well-Known Member

    Ya need to figure out what thread size and pitch it is first.

    You can then use a die on it or like Rob suggested, use a thread file on it.
     
  4. peakpowersports

    peakpowersports Well-Known Member

    Depends on how damaged the threads are. If they are just a bit wonkey a thread file can straighten them out. If they are fubared, I'd personally just order the other stud, way less work than downsizing it and finding the right nut.

    Or just JB Weld it :)
     
  5. peakpowersports

    peakpowersports Well-Known Member

    Rob beat me to it with the file
     
  6. gpz11

    gpz11 Well-Known Member

    Take a picture of it to show us how bad it really is.
     
  7. GRH

    GRH Well-Known Member

    no such thing as a 9mm thread by the ISO standard, if the threads aren't too bad run the same size rethreading die over it to straighten them out, put the nut on with red loctite and don't over tighten
     
  8. David-imoddavid

    David-imoddavid Well-Known Member

    photos of both sides. Length from the end to where the flare for the spline starts is 3/8"
    thread.jpg
     
  9. fastedyamaha

    fastedyamaha Well-Known Member

    Good lord dude, you aren’t supposed to use an impact gun on that
     
    notbostrom likes this.
  10. David-imoddavid

    David-imoddavid Well-Known Member

    Seriously - would JB Weld hold it? My wife suggested glue but if JB would work I'd try it.
     
  11. David-imoddavid

    David-imoddavid Well-Known Member

    Did that with light pressure. Original part had steel bolts - this is aftermarket
     
  12. David-imoddavid

    David-imoddavid Well-Known Member

    got it
     
  13. peakpowersports

    peakpowersports Well-Known Member

    Absolutely. Just know that next time you need to get it off your grinding and cutting. And of course its not Broom approved.

    And after looking at the pics I'd just put copious amounts of red loctite on her and run it down. Should be fine.

    Or find another nut and run it on and off a few times by hand.. should straighten those out, they don't look to bad. Then use the original with some loctite and call it a day.
     
  14. Kurlon

    Kurlon Well-Known Member

    You want a thread chaser, not a die. The chaser doesn't cut, it drives the metal back into place. The die will just cut the moved metal out of the way leaving you with a very weak thread.
     
    GixxerBlade and pscook like this.
  15. gpz11

    gpz11 Well-Known Member

    True, a thread chaser would be better but that should clean right up, doesn't look all that bad.
     
  16. David-imoddavid

    David-imoddavid Well-Known Member

    Just had a look at the nut (with my glasses on this time) and the threads there are damaged as well. Gonna head to Ace for a couple of nuts and loctite.

    Thanks folks - this old man appreciates it
     
  17. peakpowersports

    peakpowersports Well-Known Member

    Buy one in stainless and use that to chase the threads. Then just a normal nut to secure the stud once the threads are cleaned up.
     
    David-imoddavid likes this.
  18. Woofentino Pugr

    Woofentino Pugr Well-Known Member


    Yet we make M9x1.25 taps for a few companies. :D

    <-makes custom taps. :D
     
  19. GRH

    GRH Well-Known Member

    That's why I added "not by the ISO standard in" before I hit send, given the depth of knowledge and experience on the this forum someone (you) had to contradict me:)
    Somewhat on topic
    I bought a dividing head recently and wanted to be able to screw a 3 jaw chuck on it. Got a piece of cast iron to make an adapter plate. The mfr made the spindle nose with 2.3125"-6 tpi threads, which doesn't show up in the machinist handbook or anywhere I could find so I had to wing the minor diameter to get it right. Took a lot longer trying to sneak up on the dimension and fit checking before getting it right

    IMG_0236.jpg
     
  20. David-imoddavid

    David-imoddavid Well-Known Member

    Got'er done! The replacement transmission had soft zinc bolts as did the new nut. Used a brass nut to chase the threads a couple of times and put the wiper arm back on with no problems. Knowing to match the 1.25 versus 1.50 thread helped a lot as well.

    Thanks again folks.
     
    gpz11 likes this.

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