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Mk-III sleeve gear in my 74, snap rings, short bushes.

Discussion in 'Norton Commando Motorcycles (Classic)' started by 998cc, Apr 14, 2019.

  1. 998cc

    998cc "Cheap" is rarely the least expensive. VIP MEMBER

    Joined:
    Oct 1, 2018
    Good day. Today, I am trying to finish up the gearbox with new bearings, 1st and 2nd gear pinions, bushes, springs, etc.

    Searching the forums, I have determined that the sleeve gear must be a Mk-III since it is fitted with circlips and longer internal bushes; the Andover kit I have is for the earlier box and includes shorter bushes that measure .875" each.

    1. Can the short bushes be used? I have seen in one thread that Loctite has been used on these and also saw that extra bushes have been installed.

    2. The outer bush has walked in about 5/16". Can one of the existing bushes be trimmed and pressed in between the two (new) short ones to keep them in place?

    3. I am a little embarrassed asking for direction here, but I am having trouble with getting the circlips out. They are essentially piston gudgeon (wristpin) type circlips with no provision to get purchase on them. Could probably make up special snap ring pliers to lift the ends out. What are the experts using?

    Thanks.
    ~998cc
     
  2. 998cc

    998cc "Cheap" is rarely the least expensive. VIP MEMBER

    Joined:
    Oct 1, 2018
    Update on my post:

    More research revealed the current sleeve gear offering for the 74 Commando has the same part number as the sleeve gear for the later Mk-III --longer bushes and circlips.

    To simplify matters, I ordered up a new sleeve gear. Gotta love air mail from the UK!

    ~998cc
     
  3. CanukNortonNut

    CanukNortonNut

    Joined:
    Aug 8, 2005
    "I am having trouble with getting the circlips out. They are essentially piston gudgeon (wristpin) type circlips with no provision to get purchase on them. Could probably make up special snap ring pliers to lift the ends out. What are the experts using"

    Well if you have a jewelers screwdriver set you can try getting it under the circlip. Mick Hemmings tried to do that in his video but he resorted to using a dremel tool with a ball end stone to grind a small clearance for the wire to get hooked out.
    Cheers,
    Thomas
     
  4. 998cc

    998cc "Cheap" is rarely the least expensive. VIP MEMBER

    Joined:
    Oct 1, 2018
    Good day Thomas.
    Yes. I tried the jeweler's screwdrivers to no avail and even modified a set of tongs for snap-ring pliers. I did contemplate the Dremel approach to add a notch in the gear or to simply grind the circlip into two pieces but decided the new sleeve gear was the best all around approach. There are a number of other tasks to do while the new gear is on it's way from the UK, so no worries.

    Regards,
    ~998cc
     
  5. gortnipper

    gortnipper VIP MEMBER

    Joined:
    Nov 11, 2013
    I used a pair of largish circlip pliers with fairly fine tips that could fit into the groove and spread the ends of clip enough to get a thin blade screwdriver under it to lever it out.
     
  6. Torontonian

    Torontonian

    Joined:
    Dec 28, 2009
    I'm looking at my notes on the mainshaft and it's circlip and it's saying to replace that circlip with 06-8072 . It's a bit thicker and stronger and will have to be fettled to fit tightly into the mainshaft home slot. The notes say to swirl it on emery cloth on glass plate to reduce thickness until it can be slid over the shaft and tapped into place in the slot. This took 3 attempts , reducing thickness each time. Never bend a circlip so go careful. Hope this helps.
     
  7. L.A.B.

    L.A.B. Moderator VIP MEMBER

    Joined:
    Nov 20, 2004


    Sleeve gear bush circlips, not mainshaft (clutch) circlip.

    https://andover-norton.co.uk/en/shop-drawing/127/gearbox-shell-gear-cluster-sprocket-mounting-bolt#
    Item '20' (x2).
     
    gortnipper likes this.
  8. gortnipper

    gortnipper VIP MEMBER

    Joined:
    Nov 11, 2013
    Ahh....
     
  9. L.A.B.

    L.A.B. Moderator VIP MEMBER

    Joined:
    Nov 20, 2004
    Using a Stanley/Utility knife and small screwdriver:



    It's the pre-Mk3 064991 sleeve gear assembly (circlip only at the outer end).

    Although the Mk3 sleeve gear outer end groove is further inside I think the circlip could still be removed in the same way but I haven't got a spare Mk3 sleeve gear to try.
     
  10. Torontonian

    Torontonian

    Joined:
    Dec 28, 2009
  11. 998cc

    998cc "Cheap" is rarely the least expensive. VIP MEMBER

    Joined:
    Oct 1, 2018
    Thanks L.A.B.! A new sleeve gear is in transit, but I decided to have a go anyway. It seems the Mk3 sleeve gear circlips are a tighter fit in the groove. The Utility knife blade was still a bit thick for the task, but a single-edged razor blade combined with the small screwdriver got under just enough to lift/push the circlip inward of the sleeve gear, turn 90 degrees then pull out. This was at the sprocket end where the bush had "walked" inward. The press mandrel, a chinese deep-well socket, miraculously just fits inside the circlip but still engages the bush; this allowed pressing the old bush inward providing room to remove the opposite circlip in the same fashion.

    The new bushes pressed in without incident; the bush in the sprocket end getting a smear of Loctite sleeve retaining compound prior to pressing. They are a bit tight on the main shaft and need light reaming.

    Regards,
    ~998cc
     

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