Author Topic: Dragonfly gearbox/clutch  (Read 1152 times)

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Offline SimonR

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Dragonfly gearbox/clutch
« on: 02 Sep 2021 at 15:34 »
Has anyone got any ideas to help me out?
 My Dragonfly has just become very difficult to get into first or second gear without masses of graunching.  I have taken up the fine clutch adjustment so there is only minimal play at the clutch lever and had a look at the gearbox and can see nothing obviously wrong i.e. I had the gearchange cover off and the quadrant and selector forks look OK ( to my inexperienced eye). Refilled it with 140 oil.

When running and in gear she seems fine, no nasty noises.  Its never been the smoothest gearbox especially getting into first but it got really marked this weekend and will only go in with a very firm foot and a loud graunch and is noisy going into second.

PS without the engine running, it will go into gear easily enough just gently pushing forward or rocking it

Any ideas will be much appreciated

Many thanks

Offline Red

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Re: Dragonfly gearbox/clutch
« Reply #1 on: 02 Sep 2021 at 16:51 »
I've had my Dragonfly for 50 years and for a long time I struggled with the gear change. In the end I stopped using 140 gearbox oil and instead used engine oil as is recommended for the Mark gearbox. Since then I've had no problems. Worth a try!


Offline Clive

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Re: Dragonfly gearbox/clutch
« Reply #2 on: 02 Sep 2021 at 21:11 »
Hi Roy,
About 50 yrs ago i had a Mk 5 with the same problem you discribe on your Dragon fly .After trying every adjustment possible the only cure was to remove the gearbox and even that was a struggle the clutch center spline and gearbox  spline where so worn that they wouldnt slide apart  much levering and jerking eventually caused a disconnect . A new friction plate centre and a gearbox mating spline coupling fixed the problem.
 The cause of the clutch splines failing ,   lack of lube, ever since i use copper coat and my !949 mk 3 has never let me down . its part of the bike you cannot service and spliting the eng /g/b is the only way
Clive  [Octogenarian]

Offline SimonR

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Re: Dragonfly gearbox/clutch
« Reply #3 on: 03 Sep 2021 at 11:02 »
Thanks for the ideas - I will try the oil option first and then taking the gearbox out - I really hope the oil option works!

Offline eddie

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Re: Dragonfly gearbox/clutch
« Reply #4 on: 06 Sep 2021 at 14:35 »
Another cause could be the actual clutch plate. When we were first forced to use non-asbestos linings, the early type type linings were made of a smooth grey compound - this worked OK but gave off a fine powder that eventually gathered on the six pins through the flywheel, causing the pins to drag and tip the pressure plate, with the resultant inability to completely free. Later generation linings were made of a woven compound (like Ferodo) and dont seem to suffer in the same way.