New owner of Hymac 580B

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Re: New owner of Hymac 580B

Post #81 by Jeremy Rowland » Fri Mar 22, 2019 9:06 am

Andy80 wrote:Thanks for your input Jeremy. Yes yes i have understood that they changed part from time to time. I think i will try to get someone to turn them down for me. As you said the tolerance is important. I want them to fit tight :thumbup:



Measure the inside of the ram bores where the bushes are to fit you will need 0.002" to 0.0025" (0.05 to 0.06mm) interference on the bush, just be aware that the bush could close in a little so if you have a reamer that is good; I prefer the adjustable reamers myself, worst case scenario use a flapwheel on a drill but be careful not to make the new bush oval. :thumbup:

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Re: New owner of Hymac 580B

Post #82 by Andy80 » Fri Mar 22, 2019 10:38 am

Is this what you mean by reaming Jeremy? https://www.youtube.com/watch?v=Yi2YSkVzb7s
Do you mean reaming the surface inside the cylinder ear where the bush is to fit?


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Re: New owner of Hymac 580B

Post #83 by Jeremy Rowland » Fri Mar 22, 2019 12:00 pm

Andy80 wrote:Is this what you mean by reaming Jeremy? https://www.youtube.com/watch?v=Yi2YSkVzb7s
Do you mean reaming the surface inside the cylinder ear where the bush is to fit?



Yes Andy that's what I mean; because the bush is an interference fit then it may close up slightly when fitted thus preventing the pin from fitting into it, the reamer will ensure that the bush bore is perfectly round and the correct size for the pin.

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Re: New owner of Hymac 580B

Post #84 by Andy80 » Fri Mar 22, 2019 12:17 pm

Have been thinking a little about mounting of the new bushings. The bushings should probably not be assembled tight together, i think there should be some or a few mm spacing between them, as the lubrication channel opens out between them. If they get stuck together, which they risk to be when the pin is knocked in, the fat will not be able to penetrate between?
How do you avoid the bushes getting together when the pin is knocked in?
Närbild bussningar i.jpg
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Re: New owner of Hymac 580B

Post #85 by Jeremy Rowland » Fri Mar 22, 2019 3:06 pm

Andy there should always be a gap for the grease to lubricate the bushes; the bushes should be tight enough in their bores so as not to move when the pin is knocked in, the pin should be a nice slide fit into the bushes, sometimes it helps to grind a small 'lead in' onto the end of the pins, I used to do this with new shackle pins when I worked on the lorry's many moons ago now.


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Re: New owner of Hymac 580B

Post #86 by FOWLER MAN » Fri Mar 22, 2019 7:28 pm

Hi Andy,
If you are worried about the bushes moving together in their housing and shutting off the grease supply just use Loctite or a similar product when you fit them. That will secure them in the housing even if the bore is as much as 40 thou.(40,000") over size.

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Re: New owner of Hymac 580B

Post #87 by Andy80 » Fri Mar 22, 2019 7:43 pm

Thanks Fred. Will see how good fit it will be after i have them turned. Think i still have Strong Loctite filler on the shelf since i worked on the drive bearings :thumbup:


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Re: New owner of Hymac 580B

Post #88 by Andy80 » Thu Apr 04, 2019 10:11 am

A colleague turned down the bushes for me and today I finally got time to mount.
Had a self-made tray that centered nicely in the bush when it was pressed in
DSC00975.JPG

DSC00968.JPG

Soon realized that i needed much more force than a ratchet to push in the bush
DSC00971.JPG

On the other cylinder (closest to the cab) the hole where the bush where to fit had become about 1 mm oval. These bushes i had therefore turned 1 mm larger. Then I had to make the bush a little oval so that it would fit in the hole.
A guess real mechanic would cry when seeing this but the belt sanders came in use :thumbup:
DSC00984.JPG

DSC00986.JPG

I got tight said the girl ;)
DSC00993.JPG

Then start the machine to center the hole for the pin
DSC00997.JPG

Done
DSC01004.JPG


There was a big difference when I got rid of the play in the bush. The machine now runs smooth and nicely, no moving of the pins. Tested to scrape ice and it was like a new machine to operate :)
Also made a little video clip of the changing bush job:
https://youtu.be/BeJi_mNxnU8
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Re: New owner of Hymac 580B

Post #89 by Jeremy Rowland » Thu Apr 04, 2019 11:02 am

Well done Andy :claphands: that is the correct way that bushes should be fitted nice and tight; still trying to get up to my machine, changing the boom hoist rams is the next job on the list.

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Re: New owner of Hymac 580B

Post #90 by Andy80 » Thu Apr 04, 2019 11:06 am

Thanks Jeremy :) Wish you good luck with your boom cylinder job :thumbup:


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