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  • Chief Seat Post Bushing

    Decided to tackle the seat post bushing today on the 42 Chief. Found the seam on the existing bushing and started to work it with a chisel until I could get the needle nose on it and twist it out. Got the tube cleaned out and spent some time with a pick getting the solidified grease out of the grease hole. Everything was looking good and I pulled the new bushing from Greer's out of it's package. Went to see how tight it was going to be getting it started and it dropped right in and twists. Crap! Measured it all out. The frame tube ID is 1.195 and the OD on the bushing is 1.180, leaving .015 clearance.

    Found some other threads about seat bushings and read about someone using JBWeld to hold in a loose bushing. That is not really what I want to do here. I am thinking I may have to buy some bushing stock and take to a machinist to turn down as I do not have a lathe (although this would give me a great excuse to buy one now as I have always wanted one!).

    Were original bushings just as pictured in mine with no collar on the top? Or did they have collars and mine is missing/replaced? I assume you really want the collar to keep it from working down into the tube over time.

    Am I missing something? Any ideas? Anything and everything appreciated.

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    Attached Files

  • #2
    Thoughts:
    1.Contact Geers see if they have "over-sized" bushing.

    2. McMaster-Carr sells brass shim stock in various thicknesses.
    Could "wrap" new bushing with 0.006 or 0.007 shim stock and solder JB weld?
    OR
    Was your old bushing loose in frame? or was Post loose in bushing?
    If "slop" is between post and old bushing use shim stock between post and bushing: solder, JB weld and put old bushing back in service.
    Just my 2 cents. Let us know.

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    • #3
      How is the ID of the bushing vs the seat post OD? Is that clearance correct?
      Starklite lists a bushing. You could try calling and see what the OD is on their bushing.

      If the ID of bushing is correct and you want to retain it place. I would use Loctite 638 green retaining compound. At .015 clearance on the diameter you will have a gap of about .007/.008 around the circumference which is within the spec of the 638. This retaining compound has never failed me and have used it in MUCH more demanding applications.

      I'd hope the ID of bushing is correct but if not, I'd probably have one made.
      Jason Zerbini
      #21594
      Near Pittsburgh PA (Farm Country)
      Allegheny Mountain Chapter http://amcaamc.com/

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      • #4
        Fifteen thou, RMS,...

        Should be within knurling range.

        ....Cotten
        AMCA #776
        Dumpster Diver's Motto: Seek,... and Ye Shall Find!

        Comment


        • #5
          I might try tinting the outside of the bushing with some 95/5 or 50/50 solider to take the space on out side of post bushing and might be all you need for a tight fit.

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          • #6
            All this assumes the ID is right for the spring post.
            AMCA #41287
            1972 FX Boattail Night Train
            1972 Sportster project
            1971 Sprint SS350 project
            1982 FXR - AMCA 99.25 point restoration
            1979 FXS 1200 never done playing
            1998 Dyna Convertible - 100% Original
            96" Evo Softail self built chopper
            2012 103" Road King "per diem"
            plus 13 other bikes over the years...

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            • #7
              I had the same problem with my'48, turned a new manganese bronze bushing to a tight slip fit in the frame tube and a .002" clearance on a new seat post.
              tom

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              • #8
                Poked around on this some more today. Here are some answer and additional info...
                • The old plunger assy was pretty much shot, except for the plunger which I plan to have hard chromed. The lower assy was totally corroded with wrong springs and missing parts. When evaluating the Greer's assembly, it made more sense to buy the complete kit even though I did not need the plunger.
                • I can't comment to the play with the old assy as I did not check it when disassembling, but it also did not move up and down. It had wear on it and the upper portion has been subject to blasting, so it had a blasted finish to it. I decided to replace it.
                • The old bushing is out and not re-usable. It is 4" long, compared to Greer's bushing at 3.5". It had thickness readings from .020 to .029 at various points on the top and bottom, so it had a little wear. I did notice it has a JB stamped on it.
                • I took a picture down the hole and the frame seat tube was drilled 4.2" down as I could see a lip at the bottom. It also feels like a grooved or ribbed texture down to the lip (see pic). My assumption is that the lip was to prevent it from ever slipping down the tube?
                • I put the bushing in and noticed more side to side movement than front to back. After rechecking the ID, I was getting 1.1925 front to back and 1.198 side to side.
                • The Greer's bushing measures as stated in their catalog. 1.180 OD. The "new" plunger does not slide in, but I was told I would need to hone it to fit. The "old" plunger fits perfectly, but once I do the hard chrome, I would need to hone to fit as well. The old plunger bottom with good chrome was 1.120 and the upper worn portion was at 1.1275, which matched the new Greer's plunger.
                Paul.....calling Greer's to ask (along with Starklite as well)

                Skirted....will consider Locktite if all else fails. I would need to make sure not to get any in the grease hole, but would need to make sure I have it around the oil hole to seal it. Otherwise, I assume I would be pushing grease into the gaps between the bushing and the frame tube and then have grease running out the top and bottom?

                Cotten...I know what a knurl is, but have never even thought about doing it myself and not sure how to go about it. The bushing has a .025 thickness, so that seems kind of thin for putting a good knurl on it. How does one go about this?

                Silver65 and Greasy...I like both of these and will likely be taking one of these routes.

                Great feedback and I appreciate it all. I will let you all know what comes of my phone calls this week.

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                • #9
                  Originally posted by rms337 View Post
                  Cotten...I know what a knurl is, but have never even thought about doing it myself and not sure how to go about it. The bushing has a .025 thickness, so that seems kind of thin for putting a good knurl on it. How does one go about this?
                  That's pretty thin indeed, RMS!

                  I would consider making a mandrel to fit inside for support, perhaps by using the worn plunger.

                  .....Cotten
                  AMCA #776
                  Dumpster Diver's Motto: Seek,... and Ye Shall Find!

                  Comment


                  • #10
                    My '48 had larger bore then Greer replacement. Used brass shim and soldered it then brazed to frame at top.

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