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Clutch Drag ==> Stalls

Discussion in 'Norton Commando Motorcycles (Classic)' started by Tornado, Apr 2, 2019.

  1. dynodave

    dynodave

    Joined:
    May 28, 2003
    Wash (scrub) plates with kerosene is OK
    First, adjust clutch with cable LOOSE, adjust for 1/4 turn is fine. A commando clutch will run for a LONG time before the clutch wears that much.
    THEN adjust cable as you like for engagement position.
     
  2. Tornado

    Tornado VIP MEMBER

    Joined:
    Dec 5, 2017
    Yup. I'm getting pretty good at the plate clean ups...done it twice in past six months. Late last season I had issues while riding along with clutch not fully releasing when trying to shift. RPMs would stay high as clutch pulled in, throttle grip rolled off...was a bit unnerving! This was a few rides after having flooded primary when crank seal blew out after wet sump start up. Had oil blowing out mainshaft opening all over rear of bike.
    Replaced blown seal but did not know the plates would need cleaning...just thought that oil would not hurt them as that's what I was running in Primary anyway, as per spec. Now I know contamination does not happen only if level is correct.

    Did the plates at a fellow Commando riders place. He recommended oven cleaner and it did a nice job ( but he didn't have gloves some my fingernails were stained for days!).
    Issue was completely resolved.
    Following my gearbox work, I re cleaned all plates upon reassembly for good measure...that was less than 80 miles ago. Here we go again!
     
  3. ashman

    ashman

    Joined:
    Jul 11, 2010
    The Norton clutch plates don't like oil and normal motor oil is no good in the primary although it the days it said to run motor oil in there, so ATF F is just right and is made for the early Ford transmissions that had clutch plates inside, and only need between 5 and 7 fl oz in the primary as the oil slashes up onto the primary chain to keep it lubed, if any gearbox oil finds its way into the primary then a clutch seal be a good idea, but I have never had that problem in over 40 years as I don't overfill my gearbox, its the only way oil will get down the clutch shaft if its over filled, I also put grease on my clutch rod.
    Having a main crank seal blow and fill up the primary is not good and needs to be fixed straight away and to pull the clutch plates out for a good clean, but to do the seal the cover has to come off anyway.

    Ashley
     
  4. NPeteN

    NPeteN

    Joined:
    Nov 20, 2018
    Having the same issue, suppose a more thorough plate cleaning is in order. Let us know how it goes for you.
     
    Tornado likes this.
  5. Tornado

    Tornado VIP MEMBER

    Joined:
    Dec 5, 2017
    @dynodave
    D.D.: Sent you a PM on this but haven't heard back. Can you confirm you got my order for the seal? Payment sent to your AtlanticGreen account as per website instructions.
    Cheers.
     
  6. illf8ed

    illf8ed

    Joined:
    Dec 30, 2003
    The clutch nut sounds OK. My experience with broken circlip is the adjustment freeplay at the clutch lever keeps changing. If that isn't the case for you then the C-Clip is less likely. I was having similar problem with clutch grabbing and replaced all the fiber and steel plates ('72 model). With new parts it's a very pleasant clutch. I have had the clutch rod seal in mine for several years now and it's presence didn't help or hinder.
     
  7. Tornado

    Tornado VIP MEMBER

    Joined:
    Dec 5, 2017
    I'm thinking part of my issue...not having level ground in my parkade where all my work efforts need to happen....means getting the fluid levels correct there is not going to happen without measured fluids being poured in...can't rely on the level plugs to get it right. Greasing the clutch rod does not appear to have any protective effect on plate contamination.
    Actually, this is all good news....as I was fearing there was something much more going on inside my gearbox...second guessing my winter efforts. I'm awaiting the rod seal before performing the plate clean up as doing it now means repeating next week...nice sunny weather here is mocking me >:-(
     
  8. ashman

    ashman

    Joined:
    Jul 11, 2010
    The first time I did a gearbox oil change I used the level plug and a few weeks later I got gearbox oil in my primary and clutch slip, I found out the level plug put more oil in than the reconmended messuring amount so after that I used a messuring cup and put the reconmended amout in by the bible I mean workshop book and have never had any more gearbox oil find its way into my primary, plus the small bolt at the bottom of my level cube stripped so it been apoxy in, yes I was young and a bit rough in them days, but its still glued in as I haven't used it since.

    Ashley
     
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  9. Tornado

    Tornado VIP MEMBER

    Joined:
    Dec 5, 2017
    OK, Found why my clutch was sticking so dramatically....large volume of engine oil in primary...this happened a few months back and was due to a blown crank seal. Had replaced with new, metal type and it was in good position etc 200 miles ago when primary was last off for gearbox work. Today I found the uppermost inner primary cover bolt awol from the hole it was meant to thread in, which means crankcase oil free to enter primary. The tabbed washer was also out of position, Found manged at bottom of casing with bolt nearby.
    Clutch plates were so stuck a strong magnet could not separate against the suction of oil. Had to pry them apart with thin blade screw driver.

    Didn't have a fresh tab washer for the casing bolt, so used a "star" type washer and Locktite red. Torque is pretty low on these.

    Placed DynoDave rod seal (had to eliminate the hardened washer and just keep a fresh tabbed washer to achieve required exposed threads (0.140") on mainshaft. Also used blue Locktite and torqued to 40 ftlbs as recommended.
    Got the adjuster set as spec'd (1/4 turns out from first resistence).
    However, I'm finding if clutch pulled in, spinning rear wheel while 1st gear engaged, I'm hearing obvious rattling from the clutch basket. Not a simple scuffing, but a rattle. Final drive sprocket doesn't seem to be loose. If I turn rear wheel in neutral with clutch out sound goes away. With clutch pulled in in neutral, sound comes back. It diminishes to nothing as I gradually let out clutch while turning wheel.
    Is it just the plates rattling in their positions? No fluid present, freshly cleaned/degreased, cover off.
     
  10. lazyeye6

    lazyeye6 VIP MEMBER

    Joined:
    Feb 28, 2014
    I’m guessing clutch plates rattling.....or clutch center bearing trashed.
     
  11. Tornado

    Tornado VIP MEMBER

    Joined:
    Dec 5, 2017
    DynoDave just pm'd me saying the rattle is normal for completely dry/clean plates.
    I think I'm good to button her up and test ride...
     
    Last edited: Apr 9, 2019
  12. bill

    bill

    Joined:
    Jun 1, 2003
    the tab washer is where you can have trouble as it is to soft. you would be better off to use the hardened washer than drill and safety the nut along with locktite.

     
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  13. ashman

    ashman

    Joined:
    Jul 11, 2010
    The tab washers are soft but if used right they work with other things like locktite etc, they also need to be replaced everytime the bolts have been removed, I use stag sealent on the threads of the bolts and locking tabs, this stops any oil reaching inside the primary and the stag also stops the bolts from coming loose, I have worked on a mate's Norton and he just had the bolt in there with out anything, the tabs were on the bolts just not bent up, one bolt and tab was on the bottom of his primay and the other 2 bolts were just finger tight and he has been riding it around like that for a few months.

    Ashley
     
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  14. bill

    bill

    Joined:
    Jun 1, 2003
    the 3 1/4x20 bolts is NOT what i was referring to. it was the clutch hub nut. as to the 3 primary case bolts yes ALWAYS replace the lock tabs and use a thread locker/sealant.

     
  15. Tornado

    Tornado VIP MEMBER

    Joined:
    Dec 5, 2017
    Test around town was good. Shifting feels nice and smooth. Clutch not grabby like last outing.
    I'm getting new sound, more like a rattle...comes and goes while riding along at side street speeds, 2-3.5k rpm seems to bring it on more often than not. Goes away if clutch pulled in (but that changes rpm), doesn't seem road vibration related and can be heard at various road speeds. Seems to emanate from left side, maybe the primary case. Not selected gear depedant.
    Did not have it prior to today's clutch work. I did readjust primary chain tension to be looser than it was.
    Thoughts?
     
    Last edited: Apr 9, 2019
  16. o0norton0o

    o0norton0o VIP MEMBER

    Joined:
    Apr 27, 2015
    Too loose of a primary chain can sound gravely as it drags against the case. It can also make a metalic slapping noise as engine pulses toss the slack against the primary case.
     
  17. Tornado

    Tornado VIP MEMBER

    Joined:
    Dec 5, 2017
    Is it correct to assume primary chain gets tighter as casing/sprockets/chain gets up to operating temperature? I set it roughly 3/8" easy deflection full up/down...on loose side of 3/8". I do find it a bit of a judgement call how much force to use pushing chain up/down while measuring.
     
  18. Matt Spencer

    Matt Spencer

    Joined:
    Jul 25, 2010
    Id found the gumming , sliding the clutch , 23 T Sprocket .

    The way to wreck a Ferrarri clutch was said to be to ' SLIDE ' it .
    A Rover 90 ( 75 actually 1951 ) will take any amount of this .

    LETTING THE CLUTCH IN , as in throttling to match the engagement
    THEN whicking it up , Even being fearce releaseing , On Light throttle .

    And the gumming seldom if ever occurs .

    =========================================================

    On the 23 T though , youd let cars get a length before getting underway at the lights ,
     

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