Gearbox gears with pitted teeth

Discussion in 'Norton Commando Classic Motorcycles' started by fiatfan, Nov 13, 2017.

  1. fiatfan

    fiatfan VIP MEMBER

    Joined:
    Aug 9, 2015
    If practically every tooth on the gears in the gb are pitted, more or less, are they to be converted to candle holders? (I mean we're getting closer to christmas....) I wonder if it's a definate yes or no with no grey zone in between?
     
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  2. acotrel

    acotrel

    Joined:
    Jun 30, 2012
    I was at a race meeting years ago and had a gearbox problem. I opened the end cover and did not notice I got a piece of rag caught up in it when I put it back on. The result was that I pitted most of the gears in my close box. I later sold the bike back to the guy who originally built it and he continued to use that gearbox for a while. But it is not what you should be doing. If you blow a gearbox, you are almost certain to crash.
     
  3. Jerry Doe

    Jerry Doe Administrator VIP MEMBER

    Joined:
    May 21, 2003
    Candle holders! I had to make that decision too when re-doing my 750, it was borderline. Not worth putting them back in. RGM have pretty good prices.
    Just my 2 cents
     
  4. Onder

    Onder

    Joined:
    May 11, 2010
    Mine didnt have pitting they had horizontal lines in them. But after looking at my Royal Enfield gearset they looked great!
    If you can afford to, replace them.
     
  5. Torontonian

    Torontonian

    Joined:
    Dec 28, 2009
    Time to $pend.
     
  6. NortonMKIIA850

    NortonMKIIA850

    Joined:
    Jul 20, 2017
    I checked each of my gears against this OldBritts technical page http://www.oldbritts.com/gearbox_d.html and my bank balance, and ended up replacing just three of the gears – yes, I know you're meant to replace them in pairs. But I followed the advice on that page and feel fairly relaxed about it. I won't be blaming OldBritts if it all goes horribly wrong, but I do think their advice is reasonable. The point being, although I haven't seen your gears, I wouldn't take it for granted that they all need changing. You can make your own choices, partly depending on how you ride your bike. My bike has no performance mods, and although I ride it fairly enthusiastically I wouldn't say that I thrash it. So far all seems fine, I'll let you know if that changes.
     
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  7. fiatfan

    fiatfan VIP MEMBER

    Joined:
    Aug 9, 2015
    Thanks all, looked at the pics at oldbritts and mine aren't that bad at all, so I'm gonna take a really close look before deciding what to do. Have trouble with the housing as well, so this might get really expensive. Just bought lots of parts for the box (close to £500), but not one gear included in that.....The smart thing to do would of course be to buy a brand new box, but....£££....hard call.
     
  8. SteveBorland

    SteveBorland

    Joined:
    Nov 15, 2010
    I managed to get a near new set of internals off FleaBay last year, for a very reasonable amount. Keep an eye on the US site and something might turn up whilst saving up for a new set from RGM.
     
  9. fiatfan

    fiatfan VIP MEMBER

    Joined:
    Aug 9, 2015
    I really want to buy as little as possible from the US, thanks to the customs fees and taxes they lay on you over here. Yes there's often good prices but in the end your'e screwed anyway. So I'm trying to find what I need here in the EU instead.
     
  10. gortnipper

    gortnipper VIP MEMBER

    Joined:
    Nov 11, 2013
    There is an ad for a standard used 4 speed AMC cluster in our NOC NZ newsletter for $350 NZ or about £182. Let me know if your interested and I can pass the owners details on to you.
     
  11. SteveBorland

    SteveBorland

    Joined:
    Nov 15, 2010
    Hmm, what makes you think that Denmark is cheaper than Sweden :)

    One way of doing this is to acquire a good friend in the US. If they are a _really_ good friend then they make frequent trips to (in your case) Sweden, and have space to carry stuff. Really good friends like this are quite hard to find though.

    A lesser good friend is willing to receive odd shaped packages and post them on as a gift - it's amazing sometimes what presents turn up on your doorstep.....
     
  12. htown16

    htown16 VIP MEMBER

    Joined:
    Apr 29, 2009
    I'd say it depends on how much you plan to ride it. If you are going to only ride say a couple of thousand KM a year, like a lot of collector bikes, I would just go ahead and reuse them. If you plan on really using the bike for long distances and touring I would replace them. My 72 had a fair bit of pitting on the gear faces but I reused them. Just rebuilt a BSA box and it also had pitting and I reused them also.
     
  13. Mike B

    Mike B

    Joined:
    Oct 16, 2015
    Unless their is a noticeable "step" on the tooth face, I would re-use them. I first opened my '70 Commando's gear box in 1990, where I found pitted gears. I consulted with a Norton mechanic, and he said that it was not unusual, and that I should re-use them. I did so, and 85,000 miles later, no problems.

    Mike B
     
  14. Mike B

    Mike B

    Joined:
    Oct 16, 2015
    By the way, their is always a grey zone.......

    Mike B
     

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