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Layshaft Advice

Discussion in 'Norton Commando Motorcycles (Classic)' started by NPeteN, Jan 6, 2019.

  1. NPeteN

    NPeteN

    Joined:
    Nov 20, 2018
    Going after the bearing. Will I need any unusual/custom tools to unlock the box?
    The mass of information regarding the gearbox on the forum has left me somewhat confounded being new to the Norton. Don't get me started on the oil threads, good lord. Its easy to get lost.

    Anyone with experience (seems most everyone) have a clear procedure for attempting gearbox work in situ? Been through the Old Britts tech pages, out of my depth there.

    Thanks for the help.
     
    Last edited: Jan 6, 2019
  2. concours

    concours VIP MEMBER

    Joined:
    Dec 29, 2011
    Last edited: Jan 6, 2019
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  3. concours

    concours VIP MEMBER

    Joined:
    Dec 29, 2011
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  4. NPeteN

    NPeteN

    Joined:
    Nov 20, 2018
    Thank you concours. Will put an order in.

    Off topic but stock sprockets take 98 link chain correct?
     
  5. Ron L

    Ron L VIP MEMBER

    Joined:
    Feb 27, 2004
    Layshaft bearing - A torch or heat gun and blind hole bearing puller with slide hammer. Sometimes the old bearing comes out with the layshaft, sometimes it needs a little persuasion, sometimes it's a pain in the butt.

    You will also need whitworth sockets for the case nuts.

    You can remove the clutch operating lever body lockring with a punch and hammer, but it will damage the ring. A proper tool will keep from doing damage.

    If you are doing a total gearbox strip (recommended!). A 1 1/2 inch socket or ring spanner for the gearbox sprocket nut (LH thread).
    For the primary, you will also need a clutch spring compressor and front primary sprocket puller. A two or three legged puller may work, but proper one can be made from a sturdy bar, a couple of 5/16-24 bolts and 7/16 center bolt and nut.

    I know many will disagree, but by the time you dismantle the primary and find a way to lock the sprocket to loosen the nut, etc. I find it just as simple to remove the head steady, inner primary, and a couple engine to cradle studs to rotate the engine down and pull the gearbox. Then I can take it to the bench to dismantle and use the parts washer to thoroughly clean and inspect the case.
     
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  6. Ron L

    Ron L VIP MEMBER

    Joined:
    Feb 27, 2004
    It depends on the size of your gearbox sprocket. If memory serves me, it is 100 links for a 19 tooth. 20, 21, or 22 will take more. Usually buy 110 link box and cut to size.
     
  7. N0rt0nelectr@

    N0rt0nelectr@ VIP MEMBER

    Joined:
    Sep 15, 2014
    I think the original chains were 99 links from the factory but I don't know of any chains that come with an odd number of links. So Ron is right about getting a 110 link chain and cut to fit. You will need a chain breaker for that.
    John in Texas
     
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  8. NPeteN

    NPeteN

    Joined:
    Nov 20, 2018
    I only ask because old Britt's sells a 98 link chain. Figured I'd save myself some hassle if possible.
     
  9. NPeteN

    NPeteN

    Joined:
    Nov 20, 2018
    Thanks Ron,
    I agree, and Im usually the kind of person to be thorough about a thing like this but I haven't got alot of the specialty tools. That and I just replaced all my isolastics and remounted the engine so I'd be undoing some work.

    Is there anything I should be looking for that might point to a definite need for a rebuild?

    Might have to just bite the bullet.
     
  10. RoadScholar

    RoadScholar VIP MEMBER

    Joined:
    Dec 28, 2008
    If your gear box is still a factory virgin, and you will be removing the counter-shaft sprocket, then removing the unit from the cradle takes another 5 to 10 minutes. If the layshaft bearing stays in the case put the shell in a preheated oven with the bearing facing down and in about 5-10 minutes you'll hear it drop out. Be aware that the shell will emit fumes that aren't considered as pleasant as "napalm in the morning"...

    This is not a place to cheap-out; halfway jobs invariably produce halfway results, so measure everything and check both shafts for true; examine the gears and the engagement dogs. If you have the slightest doubt about any part, post a picture, many will offer their opinions.

    Best wishes.
     
  11. Torontonian

    Torontonian

    Joined:
    Dec 28, 2009
    Yours is a 750. You will be replacing the sleeve gear bushes with 850 style updated type. The kickstart pawl should be carefully inspected for slippage wear and possibly upgraded too if need be. I fit a F.A.G. roller layshaft bearing , but others fit upgraded ball. Heat and cold. Good luck.
     
  12. htown16

    htown16 VIP MEMBER

    Joined:
    Apr 29, 2009
    Propane BBQ grill won't stink up the house.
     
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  13. NPeteN

    NPeteN

    Joined:
    Nov 20, 2018
    I've got the AN layshaft replacement bearing already. I'll have to order the additional bushes from Old Britt's along with the tools.
    It's a virgin box, I'll cross check with the AN rebuild kit to complete the order.
    The hits just keep on coming!

    Good call on the outdoor oven. Indoors is NOT an option for me...
     
  14. concours

    concours VIP MEMBER

    Joined:
    Dec 29, 2011
    I used a heat gun, gearbox in situ.
    I hope you have the bike up on a lift.
     
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  15. Bernhard

    Bernhard

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    Apr 20, 2011
  16. batrider

    batrider

    Joined:
    Aug 9, 2008
    Did mine in the bike. Bearing came out on the layshaft with heat so no puller needed for me. I did end up pulling off the primary cases and replacing the sleeve bushings and all the other bushings and bearings. And the bent mainshaft too!
     
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  17. NPeteN

    NPeteN

    Joined:
    Nov 20, 2018
    I am a fish out of water in that no, I have not attempted a job like this before on a machine I am not familiar with. I agree that in some instances having a knowledgeable outside party conduct the work is almost always preferable. I am also of the mind to tackle the rebuild myself as it is my machine and I'd like to be as familiar as possible with it.

    The classic mechanics instructions you linked to help alot. Thanks.

    Bike is a foot off the ground. Another reason for considering full removal, my back.
     
    Commando750 likes this.
  18. concours

    concours VIP MEMBER

    Joined:
    Dec 29, 2011
  19. olympus

    olympus

    Joined:
    Aug 5, 2017
    Weld a piece of 12mm studding into the bearing centre keeping it nice and vertical. i used a piece 1"x 1" box across the top face of the box with a hole drilled in it Run down a 12mm nut and pulled out the bearing
     
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  20. Tornado

    Tornado VIP MEMBER

    Joined:
    Dec 5, 2017
    Been watching numerous blind bearing removal videos on YouTube....using hydraulic pressure from wet pieces of paper/shop towel/bread/candle wax/gear grease/peanut butter/silicone sealant etc etc....seems to always work where other methods fail (heat/picks etc).



    Any good reason not to give it a go on my layshaft bearing R&R?
     
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