The clutch spring adjusting nut cannot be removed.

[yoshimasa negishi]

The clutch spring adjusting nut cannot be removed.

Hello.
I recently got a Douglas model C31 600cm.
I wanted to disassemble the clutch because it slipped.
The clutch spring adjusting nut cannot be removed.
I'm in trouble!

Is the adjusting nut a left-hand thread?
Do you know how to remove the adjusting nut?
Where can I get an adjusting nut?

[eddie]

The clutch adjusting nut has a normal right hand thread. Your adjusting nut may be jammed in the plate it bears on - this plate has 6 pockets in the underside that locate the springs, so cannot be rotated. I would suggest you take a piece of wood to use as a drift and try tapping the spring plate in toward the flywheel to free it from the nut. Apply a little oil to the joint between the nut and plate to reduce the friction between the two. Your adjusting nut looks to be in good condition, so will not need replacement - it is very unlikely that any damage has occurred on the underside. If your nut has been re-plated, there may be a build up of plating that is causing it to be tighter in the plate than normal.

  Regards,
                Eddie.

[douglas1947]

I would like to add to Eddies  solutions for open the nut, it could also be fixed with "loctite" to the  thread.
So a carefull warm up could help to open it (electric to save the colour and chrome).
Best is to use a good fitting hexagon nut socket to save the edge of the center nut.

Michael

[Roys rider]

In the latest (Jan 2020) Classic Bike, Rick Parkington recommended grinding down the 'lead in' of the socket to get a better depth of grip. This might help as this nut looks a bit thin.
Good luck.
Peter

[Bert]

Grinding down the lead in works well for thin nuts like crankpins and flywheels like this. I also use an air impact driver as the jarring action will loosen most stubborn nuts.

[yoshimasa negishi]

Hello

Thank you for helpful advice
The clutch spring adjust nut was removed with an impact wrench.

Removed flywheel and reassembled.
The engine has started.



But this time, the clutch drags hard.
Thank you

[Eric S]

Do you mean the gears crack when engaged?
I had much trouble with the clutch, re-did the bearings on the flywheel, ... but in the end I had the cone on the crankshaft damaged but also the crankshaft was loose so I had to open the engine.
Check the condition of the surface of the cone and check if the crankshaft moves sideways, it was quite noticeable on mine.
I hope it's not the problem as this involve rebuilding the engine but this is what happened on mine.

[yoshimasa negishi]

Hello Eric

Thanks for your advice
Check the sideslip of the crankshaft.
It seems that the clutch arm lift is not enough.
Review the arm setting position.

[Eric S]

I tried to find out for several months why clutch arm lift was not enough on mine so I had rebuilt the ball race on the flywheel, the cone and the camshaft was not tight.
Hope this is all that needed to be adressed and hopefully the engine will be tested in a few weeks/months.