Help replacing dipper stick bushings, mini-excavator KX41

   / Help replacing dipper stick bushings, mini-excavator KX41 #1  

Sodo

Elite Member
Joined
Apr 21, 2012
Messages
3,198
Location
Cascade Mtns of WA state
Tractor
Kubota B-series & Mini Excavator
There are clever and experienced folks on this forum.
I'm wondering if any of you can offer tips to get these worn bushings out.

Bushings were so worn out it was letting the thumb bend the pin... until the pin broke.
I welded the pin while waiting for my new parts, and it fractured again 3x, quickly which was no surprise.

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As you all prob know, when a pin breaks by fatigue, there's a whole bunch of subsurface cracks in there that you cannot weld up and it will just break again at the next crack over that the weld did not penetrate.

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The bushings are so worn there's no face to push on.
It's pretty much a taper.


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Hope you like the pics!

Well if anyone has experience getting tapered bushings out I'm all ears!
I'm going outside now to start this battle.
I'll bring my phone and if you can offer tips it won't come too soon!

Hope you're all healthy with fam members & gramps etc all safe.
 

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   / Help replacing dipper stick bushings, mini-excavator KX41 #2  
Torch and cut them out....
 
   / Help replacing dipper stick bushings, mini-excavator KX41
  • Thread Starter
#3  
Thats a great way ! But if I can just find my danged O/A torch. That would do it! Ive burned steel out of cast....can I burn this (steel) bushing out of mild steel Safely?

Along those lines what about welding a bead inside, will it shrink?
 
   / Help replacing dipper stick bushings, mini-excavator KX41 #4  
I watched my boss burn lug nuts off a truck front rim and not wreck the threads I guess it depends on how good you are... I don't think it will shrink heat expands it you need to slice it ....:)
 
   / Help replacing dipper stick bushings, mini-excavator KX41
  • Thread Starter
#5  
But when it cools a weld shrinks.

Theres the oft-told-tale of that one mythical feller...
who got a bearing race out by welding a bead in a circle around the inside,
then he smokes a cigarette and listens for the race to "TINK"! ( fall out ).

========

OK I got it.
Thanks for the smokewrench suggestion Peter.
I looked all over for my torch
....and not finding it, hatched this plan.

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Welded the old broken pin inside, and pounded it out.

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Now I have another problem.
It's been bored out and the bushings were oversized,
and my new $45 each Kubota bushings and $19 seals are loose in the hole.

Dang.

Where can I get oversized bushings?
Looks like I have to find a lathe....

Actually I need to clean up the bore too.
This dipper stick is not so big... I can unbolt it and take it to a machine shop.
 

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   / Help replacing dipper stick bushings, mini-excavator KX41 #6  
Welding around it will shrink it just make sure you do go AROUND or a zig-zag pattern around it not just a couple of beads straight in and out.
 
   / Help replacing dipper stick bushings, mini-excavator KX41 #7  
actually, the bushings are probably hardened steel, if a file won't nick it, that's what it is, if you made those bushings on a lathe, you'd have to use hardenable steel, turn it, then have it hardened by a shop that does that. it's tricky to properly harden steel. and a shop would have the Rockwell tester to check them.. an alternative is to weld up the inside of the hole, and have a machine shop rebore the hole to a proper press fit for the stock bushings.. another way is to have them make a mild steel bushing instead of welding the inside of the hole. the hardened steel bushings would then go inside that..
 
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   / Help replacing dipper stick bushings, mini-excavator KX41 #8  
Replaced several on my IHI, and a torch is what I used. Cut a line in the bushing all the way thru, and knocked it right out.

GREAT photos by the way ! Like that you embedded them in the post so you can see good detail instead of just using thumbnails.
 
 
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