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Subject: Generator Bushing Removal

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Owen H    Posted 06-23-2018 at 21:05:59 [URL] [DELETE]        [Reply] [Email]  
  • Generator Bushing Removal
  • I have a 3 brush generator and I want to replace the bushing. How do I get it out?

    Tim Daley(MI)    Posted 06-24-2018 at 05:31:38 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Generator Bushing Removal
  • Is this the 9N/2N 1-wire/3-brush unit or the 8N 3-wire/3-brush unit? One option is to take the generator to your trusty local starter/alternator shop guy and let him do it. He has the right tools plus the know-how on what to do so nothing gets mucked up. You may also want it rebuilt of its been a long time -worn brushes, field coils, and armature may need servicing. You'll have the generator already removed and will need to be disassembled to get to the bushing so why not a 100% inspection at least? If the genny gets a motoring test, if not performed with the 6-V/POS GRN source as it will be wired as, the unit may need to be polarized upon re-installment. Just curious as to how you determined the bushing needs replacing? Are you already rebuilding the generator yourself and have gotten that far? With any generator it is crucial to have a belt tensioning device in use. The 9N-10000-C and the 2N-10000 generators used a different tensioning device than the 8N generators.



    Tim Daley(MI)

    Owen H    Posted 06-24-2018 at 09:18:41 [URL] [DELETE]        [Reply] [Email]  
  • Re: Generator Bushing Removal
  • Mine is the 3 brush 8N unit. I have it pulled apart and the rebuild kit. I just wondered how to get the bushing out.

    BlasterStumps    Posted 06-23-2018 at 21:35:53 [URL] [DELETE]        [Reply] [Email]  
  • Re: Generator Bushing Removal
  • pack the hole of the bushing with heavy grease. Then take a bar with a very close OD to the hole size, place it on the grease inside the bushing and wack it with a hammer. The bar pushes the grease in behind the bushing forcing the bushing out. You could also tap threads in the bushing and insert bolt and pull it out.

    Neither idea are mine.
    Mike in CO

    Tony C    Posted 06-23-2018 at 22:57:38 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Generator Bushing Removal
  • You need a fit close to interference to make the grease procedure work and it does, but it's messy. Tapping the bushing and pulling it works best unless the bushing is so worn you can't get deep enough threads with a nominal sized tap to take the strain. Good news is the bushing isn't in there gorilla tight. You may have to cut the bushing with a small cape chisel.

    Begs the question: How are you going to fit the new one? Make a driver or just use a drift and hope it doesn't get cocked starting in?


    owen h    Posted 06-25-2018 at 10:34:25 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Generator Bushing Removal
  • Tony, that's a good question, how to get the new one in. I guess I had not thought that far in advance. What about using a hydraulic bench press. Will the end cap that holds the bushing take the banging and pressing? Seems a little on the fragile side, but what do I know.

    Tony C    Posted 06-25-2018 at 14:36:57 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Generator Bushing Removal
  • Well, you know enough to ask relevant questions.

    If you haven't gotten the bushing out yet I would seriously consider not replacing it, unless it's really wallowed egg shaped.

    Do it when the end plate is disassembled and rigidly support it. You can use a small bench press but make sure the end plate is mounted level very rigid and the bushing starts straight. Go slowly. You will feel when the bushing bottoms.

    A bushing driver would be ideal, but if you don't have one you can use a big drift punch or a big flat washer with a smaller drift and tap it in. Make sure you start it straight. Be gentle. If you start it crooked and simply beat it into submission it will deform enough run tight on the armature shaft. It's an interference fit on steroids rather than a press fit.

    You can make an adequate bushing driver from a piece of stock with a larger diameter than the OD of the bushing. Use a bench grinder to grind to about 3/4 of the length of the bushing and round enough to fit in the bushing. If you have a drill press you can take it to the "finished" dimension with a file. You will be surprised how nice a fit you can get if you are careful.

    Hope this helps.

    Jim    Posted 07-12-2018 at 19:58:10 [URL] [DELETE]        [Reply] [Email]  
  • Re: Generator Bushing Removal
  • Tony, I for one think you really give good practical advice. Some folks ideas are just too technical for me and I get lost but yours and the way you explain it I can follow.

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