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  • #16
    What transmission? Year? model & make did it come out of?


    • #17
      The babbit mandel will be undersize. The problem is how thin the babbitt is and the shell. In most babbitt work the material is much thicker as is the housing. And then there is holes or grooves in the housing, for the Babbitt to lock in so it cant spin or work loose..
      TO CUT the groove.. you set a tool at about 40 thou depth of cut, then run it in a crank or two of the carriage by hand while it turns slow...and maybe back out.. scary, best test it out first on scrap..


      • #18
        if you think about it, a helical groove is not such a great idea as it appears, because it considerably reduces (50%?) the load carrying capability of the bearing (assuming a hydrodynamic regime in there). is there an oil feed hole? in that case a straight, axial groove might do the job. or a few of them, if the oil is supposed to get in there by itself. is there a pump?


        • #19
          I assume this is what needs replacing. Does it have to be while metal? If it doesn't I'd consider a bronze bushing, either make one from scratch from suitable raw stock on the lathe.

          If it has to be white metal (= babbit as far as I know) then likely you could cast a new one if you can get your hands on babbit. I don't think it has to be cast in place. It would IMO be easier to cast it as a separate part. Cast the outside oversize and the inside undersize so you have material to remove, make it decently undersized so the thing won't be too frail.

          The next steps would be identical regardless if you are starting with a blank from bronze or white metal.

          -Machine the outside of the blank on the lathe until it's the right dimension (I guess it's a press fit),

          -Take a skim cut on the inside so that the inside is concentric.

          -Machine the blank to the proper length

          -Drill oil hole in the right place

          -Press the blank into the housing and mount the assembly to you mill table. Then indicate it concentric (also make sure it straight in the Z-axis) and use a boring head to turn the ID.

          -Finally cut the grooves by hand

          I am not an expert but I think that's how I'd do it.

          Edit. I don't think this is a part meant to be cast in place either, I have a friend who has cast babbit bearings in place when restoring an 1887 saw mill and those later came apart into two halves so they could be scraped for fit and also shimmed if needed. I don't see one can do that here.

          Edit 2: I believe white metal is really nice and easy to turn, like bronze.
          Last edited by DennisCA; 01-08-2021, 04:40 AM.


          • #20
            you cant cast it in there because babbit will shrink.


            • #21
              A piece of oilite costs $255.This is for a piece 165mm long, the minimum length they will cut. Pb1 bronse is about $26 for a 100mm long piece . If pb would work I would think its the easiest way of doing this. Could it not just be machined to size ,ID and OD , crossdrilled and the grooves hand ground out .? Then just banged into the housing or is pb not up to this job .?

              I wonder if it could be possible to machine a piece of steel to correct OD and just fill the tube up with babbit and machine the ID in a lathe and then do the grooves afterwards.
              How would one tin the babbit to the outer steel tube. ? Is there a special flux to do this or does babbit stick like sh1t?


              • #22
                OP: Search for DU bushings. (Delrin Urethane) You'll find the bushing on someone's shelf.


                • #23
                  Originally posted by I make chips View Post
                  OP: Search for DU bushings. (Delrin Urethane) You'll find the bushing on someone's shelf.
                  Delrin Urethane are suspension bushings.
                  Not what this is.



                  • #24
                    du bushings | McMaster-Carr


                    • #25
                      this is not a job for a machinist, its a job for a good parts man. a bushing close in size to that can easily be found and honed to fit. easily grooved, even crudely, will allow enough lube to allow it to live.
                      regarding the video, I've found after many years doing that job if you want it to last you need to change the yoke, and rebalance the shaft.
                      san jose, ca. usa


                      • #26
                        That bushing looks and from your explanation so far sounds like it might be produced using the same method as used for the shell style main bearings for engines. At least as far as the harder outer form and soft bearing face as described seems to go. I don't think that's the sort of thing you're going to do at home all that easily.

                        As for lubrication I gather that this housing sits in a position where there's standing oil at the far end where it connects to the other bigger housing and an oil seal and dust boot fits onto the near visible end of the housing as seen in the picture.

                        If so and if there isn't an oil delivery gallery in the housing to provide force fed oil then the groove itself may be the "oil pump" for the amount needed. I've seen grooves like that in shafts or in the sleeve bearings before and the spiral is set up to either limit or encourage the oil flow based on the shaft rotation and the direction of spiral of the groove. The need for pushing or pulling being based on the needs of the item. In this case I'm thinking that the shaft rotation would be set up to lightly pump the sump oil from the main housing towards the end of the sealed end of the housing and it "escapes" back to the sump by flowing through the gap between the shaft and bearing. In effect the groove and rotation of the shaft forms it's own localized oil supply pump.

                        If that's the case you'd be wanting the proper clearance to the shaft so that it can work with this. And that being the case you only need to deal with relatively occasional metal to metal contact like at startup after sitting for a while. The rest of the time the motion of the shaft would keep an oil film in place to support the shaft.

                        As such and provided it really is that hard to get the parts then I'm thinking that the cheaper PB should suffice. But the trick would be in knowing the proper gap to be made. But again if it is valid to compare this style of bearing to the shell bearings on crankshafts how porous is the facing metal on the shell bearings? And is that what is actually on the ID face of this bushing? Or is it possible that it's a metal which can be electroplated onto a brass or steel outer shell?

                        Plus if I'm right about the groove being a passive rotation pump for the bushing it would be best if it were cut to the original cross section and fairly smooth helix. I'd start by playing with the gearing behind the end cover to see if I could alter things there and greatly step up the ratio between head stock spindle and the lead screw gearing input so it cuts far more coarse a lead. Like never mind 8TPI or 2.5mm pitch. A setup where the lead screw is sped up and cuts to cut spirals with the "pitch" shown for that spiral in the housing's bushing.

                        Of course PB for the bushing may or may not work well for this. Someone would have to try it the first time and then go out and drive the snot out of it to see if it works. Meanwhile those in need might not like not being able to drive around for that long.
                        Chilliwack BC, Canada


                        • #27
                          Looks to me like you could use flat material and roll it into a hoop- potentially making the groove beforehand- then figure out the fit and press it in.
                          I seldom do anything within the scope of logical reason and calculated cost/benefit, etc- I'm following my passion-


                          • #28
                            Originally posted by dian View Post
                            you cant cast it in there because babbit will shrink.
                            Not so.

                            Everything shrinks, yes. But it depends where it is cooled.

                            Heat the dickens out of the core piece, then after the pour, cool the OUTSIDE, and it should shrink away from the core. It will shrink toward the colder surface. With that thin a lining, I do not think you need to worry about it cracking, the babbit is ductile, and ought to easily stretch the tiny amount needed. Besides, the bushing will be shrinking inward.

                            The other poster is correct that it will not scrape well, because you cannot "print" it decently without a lot of work since it is not split, so it will have to be bored to fit and then have the oil groove put in.
                            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.


                            • #29
                              Originally posted by J Tiers View Post

                              The other poster is correct that it will not scrape well, because you cannot "print" it decently without a lot of work since it is not split, so it will have to be bored to fit and then have the oil groove put in.
                              I believe this is going to be true. How does white metal machine though .?I would think the simplest way of doing this is to machine a cylinder with the OD perfect for the housing. If one used a dummy shaft about a mm smaller than the finish ID then if it was clocked up and bored would this not be the simplest way to do it. If one took a pipe and filled it with babbit how do you ensure the babbit sticks to the pipe. Do you need to flux it .Then it would simply mean knocking your homemade bearing into the housing and its all done. .Pb I would think is still the simplest .
                              Here is a pic of what he is doing . The yoke will be cut off and you can see the new part to be joined .
                              Click image for larger version

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                              Last edited by plunger; 01-09-2021, 01:34 AM.


                              • #30
                                i dont get it. what part of that goes into the bearing/diff housing (or whatever it was) in the fist picture?