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Should I replace this diff output? (pic)

Discussion in 'Kraton' started by bicketybam, Aug 12, 2018.

  1. bicketybam

    bicketybam Premium Member!
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    I have had the dog bone pop out twice now. Is this the reason why?

    20180812_174518.jpg

    To me it doesn't seem like wear there would make the dog bone pop out. I also had the diff out drive come loose both times it happened: first the front one and on this occaison the rear one. I secured both using blue locktite on the set screws. But I'm not sure if it was the outdrives coming free that caused the dog bone to pop out or the wear shown in the picture. Thoughts?
     
    10pas2 likes this.
  2. -Dusty-

    -Dusty- Well-Known Member

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    That looks pretty chewed up. Mine has wear there too but I have yet to pop out a dogbone.
     
    #2 -Dusty-, Aug 12, 2018
    Last edited: Aug 12, 2018
  3. olds97_lss

    olds97_lss Premium Member!
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    I don't know what would cause wear there like that other than the dogbone causing it when it does pop out. I have (had) that issue on my savage flux in the front until I put thicker o-rings in the inside cups. Different design, but when it would pop out, the ears would bang the crap out of the edges of the cup. Looks like I took a hammer to them. I can't imagine wear in that spot is the cause of it popping out, but it could be a side effect.
     
  4. bicketybam

    bicketybam Premium Member!
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    I have an old nitro Savage X so I know what you are talking about. I went ahead and rebuilt the diff. It was missing a washer on the outside of one of the spider gears. The piniom gear on the end of the input shaft felt very rough too. I'll see how this one hold up.
     
  5. MeesterC

    MeesterC Premium Member!
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    That out drive cup is trashed. You will now have to replace the out drive cups. Pictures explain it all. 20180816_123442.jpg 20180816_123534.jpg
     
  6. bicketybam

    bicketybam Premium Member!
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    Thanks. I've master where the dog bone part goes a long time ago. It is odd that Arrma makes them like this though. Kind of a crappy design. The walls are thin there and when the cvd popped out it chipped away at it. It's since been replaced.
     
  7. MeesterC

    MeesterC Premium Member!
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    Cool, was just trying to help didn't mean to come across like a butthead. What I did to mine, as suggested by another member here, was heat treat them myself. I heated them up with a butane torch till glowing red and them immersed them in 20w50 motor oil till cool. Works well and haven't had a problem with wear or chipping yet, done almost a year ago and bash the crap out of it often. Just a little food for thought and maybe a helpful tip to avoid future problems, good luck and keep the rubber side down.
     
    Voltron7 and bicketybam like this.
  8. bicketybam

    bicketybam Premium Member!
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    No worries :) I will have to give that a try. Thanks Thanks for the tip!
     
    MeesterC likes this.
  9. JJAX

    JJAX Well-Known Member

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    I cut the lil rubber spacers you get for servos in half and put the in the drive cups so the dogbones don't have as much play.
     
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  10. olds97_lss

    olds97_lss Premium Member!
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    I used to do that to my savage center cups. Used engine oil with carbon in it helps too. If you can get the part hot enough to suck any carbon out of the old oil into the surface.
     
    MeesterC likes this.
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