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  • How to make this.

    This was asked on a four wheel drive forum. It is a white metal bush for a transfer case.output shaft.The bush is not available anymore.How difficult is it to line a metal bush with white metal and then to machine the ID true. How does white metal machine. What kind of tolerances are needed for white metal. Could it be cast meaning that no machining needs to take place.

    Also it has oil grooves running the length of the bush. I am curious to know how this course looking groove could be done on a manual machine. It looks like a square thread but of extreme course pitch.
    Click image for larger version

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    Last edited by plunger; 01-07-2021, 03:11 PM.

  • #2
    I don't think you can buy the "white metal " you are thinking of except in a form for casting.
    ask them if bronze is acceptable. That you can make
    we can explain the groove later , what we need to know is, does groove stay in bushing or can it come off the end ?
    it looks like it comes off the end , easier to do. How long is bushing ?
    be prepared for bushing material to cost around 20 bux or more per......... inch... and having to buy 13 inch minimum..

    Comment


    • #3
      Babbitted sleeve. Make the sleeve, or melt it out of that one, add some, and re-cast it in place.
      2801 3147 6749 8779 4900 4900 4900

      Keep eye on ball.
      Hashim Khan


      It's just a box of rain, I don't know who put it there.

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      • #4
        How would the groove be done. ?If this is cast in place how smooth or accurate is the id afterwards ?Does it not leave air pockets and bubbles or does it pour nicely and mold perfectly around the shaft. ? Would it need to be scraped for clearance afterwards.?

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        • #5
          The groove is simple on a lathe with a sufficient feed rate for the lead, in the inch system this is expressed as "inches per revolution".

          Comment


          • #6
            The OEM of that part made a lot of design decisions based on what they could do and what other companies that they may use to out-source it are capable of doing and at what prices. For instance, they MAY and please notice that I emphasize MAY, have cast it in place knowing that they had or could make a simple tool that would follow it's path and clean it up as needed. Or they MAY have a supplier of castings that could do this by whatever means.

            YOU are working under a completely different set of circumstances, with a completely different set of techniques at your disposal. This is not unusual. Much MAINTENANCE work is done with entirely different methods. J Tiers suggests one such method above. But he did not address the groove.

            Your options cover a very large range from completely redesigning that entire part, perhaps even using an entirely different type of bearing (roller bearings come to mind). The part could be machined from solid (billet) material (aluminum?) with proper recesses for roller bearings.

            On the other end of the spectrum you could go along with J's melt and re-pour suggestion using a core (a piece of shaft) for re-casting the bearing material. That core would have a spiral made of square or rectangular stock attached to it. The core itself would be removed first and then the spiral that forms the groove would follow. After you finish the bore to the final size, then a shop made clean-up tool could be attached to that core and be made to follow the course of the groove, cleaning it up as needed. I doubt that the exact cross section of the groove is of any importance so most, if not all of the clean up would be made on the edges. Or those edges could be cleaned up manually with some kind of scraping tool.

            Could that groove be cut in a lathe. Sure it could. It is an internal threading operation with a very coarse thread pitch and perhaps an unusual cross section. But you are going to need a lathe with enough swing to accommodate the overall assembly and that is capable of being geared for such a coarse pitch. Oh, and a face plate to mount it. On the bright side of that, you can probably use a pitch that is just close to the original: an exact match would not be necessary.

            To me, the big question before deciding how to proceed would be WHAT ARE YOU CAPABLE OF and WHAT IS AVAILABLE IN YOUR SHOP OR IN YOUR AREA.
            Last edited by Paul Alciatore; 01-07-2021, 05:29 PM.
            Paul A.
            SE Texas

            And if you look REAL close at an analog signal,
            You will find that it has discrete steps.

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            • #7
              Ok guys , most machinists will cut the groove freehand, unless it's a figure 8 that cannot go off th edge.. takes a bit of skill ..
              another way is Sharpie mark the path and cut it with ball burr on die grinder..
              pour Babbitt .. jeez it's 4x4 stuff they gonna beat the bark off it and come crying back to you if it fails. ... if they even pay you what you want to cover your cost... been there..done that..
              bronze will maybe hold up... but you be walking funny after you hear today's price..

              my analysis...gonna cost you 250 plus to make the first 150...back........ correct me if I am wrong..
              Last edited by 754; 01-07-2021, 08:45 PM.

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              • #8
                Babbitt is the original material and a good way to fix the problem. Babbitt is available in many grades for many applications, many including high speed and extreme loads. Babbitt is fairly easy to cast in place and fit. I have never done anything that long but others have and can offer advise. In basic form, you would use a form and cast around it in place. Once cooled remove the form and scrape/machine to fit and then cut, thread, grind the oil grove. Done and done. The biggest issue will be determining the alloy and grade of the bearing material. If you have access to a damaged piece of the original bearing you may be able to send it to a supplier for type testing. Unfortunately buying small quantities of specialized casting alloys is hard to do and expensive if you can...
                Robin

                Happily working on my second million Gave up on the first

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                • #9
                  It looks like a DU bushing, Which means Dry Un-lubricated.
                  Or at least that is what it used to stand for, because now
                  more and more I see them with grease or oil grooves.
                  Very common to see them on grease lubricated king pins.
                  But if availability was limited, bronze would be my choice.
                  Aluminum bronze is really tough, 954 comes to mind.
                  I imagine if times were tough, 6061 aluminum would make
                  a fair bushing for a transmission if lubricated with oil.

                  -Doozer
                  DZER

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                  • #10
                    Is that the exact part you are looking to work on? If so, a google search of that part number does show availability at places and probably for a cost of less than it would be to try and fix it for someone.

                    Doozer, my guess would be that there is oil inside lubricating that. The end looks machines for a lip seal.

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                    • #11
                      that is a mass produced product. there is no way you can't find an OE replacement one somewhere sitting on a shelf.
                      -paul

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                      • #12
                        Try searching under "plain bearing", you might find something adaptable.
                        Len

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                        • #13
                          The bushings are steel on the outside bronze on the inside with an oil grove.

                          You might what to see this:

                          https://youtu.be/_UEGuOQ_XkA

                          Find a transmission rebuilding shop and run it by them. I bet you they'll have one sitting around.

                          Comment


                          • #14
                            The bushing cant be bought seperate. You have to buy the whole housing. But its difficult getting this part delivered to our neck of the woods . It also has a spiral oil seal which also cant be obtained. I wont be making this but am curious how to go about it.

                            I was wondering how easy it is to machine white metal. If it were cast around a dummy shaft would it be too tight .?If too tight would one make a dummy shaft ever so slightly larger or would scraping to fit be a better option. The bush is about 60mm long I believe.My lathe has a 6mm leadscrew so I believe that would be the coursest thread I could do to get the grooves done. Could this be thread milled on a manual milling machine. ?

                            The idea of hand grinding the groove using a dremel is a good one. I am following this closely as I had an application for this the other day and did not know how to go about it.

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                            • #15
                              Originally posted by outlawspeeder View Post
                              The bushings are steel on the outside bronze on the inside with an oil grove.

                              You might what to see this:

                              https://youtu.be/_UEGuOQ_XkA

                              Find a transmission rebuilding shop and run it by them. I bet you they'll have one sitting around.
                              Nice video. Just love the slide hammer tool. Very clever.

                              Comment

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