Stripped Clutch Nut

[dsmess]

Ducati Guys,

I’m doing some mods to my ‘66 Mark3.
Kick starter coil spring conversion.
Power Dynamo alternator
Battery, regulator, & fuses
Dyna S ignition
Advance unit modified for increased advance

I finished most of the work, and was installing the nut on the clutch shaft. The new alternator is slightly wider so the crank gear
Has moved outward. They include a wider spacer to put behind the clutch housing so the gears still match up. This reduces the
Shaft protrusion out of the clutch hub, when the nut was screwed on and lightly tightened, the end of the shaft appeared about
Flush with the outer nut edge. I attempted to tighten it to 60 ft-lb, but it stripped at about 50 ft-lb. I am hoping the shaft is harder than the nut. The shaft threads appear ok, but I am not certain. I will see if a new nut will tighten properly.
I am not anxious to put in a new shaft.
Dave

[Eldert]

Hi Dave

you can remove a little material from the inside of the clutch centre that faces the nut with a lathe and fit a 8mm tall nut instead of a 6 mm one



Eldert

[Bevel bob]

with the use of some nut retainer and one of those new design lockwashers you could use less torque.

[dsmess]

Thanks for the useful replies.
Eldert, if I remove 2mm from the rear of the hub,
Do you see any problems with clutch operation
With the hub extending further into the clutch housing?

It seems 45 ft-lb should be adequate using
Locktite blue and a lock washer.
Years ago I had a 900SS which experienced a loose
Clutch nut. I don’t remember details of the fix.

[dsmess]

Whoops, I see you were saying remove material from the nut side, not the rear!
D

[LaceyDucati]

The shaft thread is harder than the nut and I've never seen a gearbox shaft thread strip. Nuts do strip occasionally, mainly through age and previous abuse. Use a good quality replacement nut, modify the front face of the hub centre (as Eldert suggests) and torque the nut to 50 ftlb. The torque of the nut holds it tight, not the loctite.

Regards Nigel

[dsmess]

I found another nut which tightened ok at
50 ft-lb. Evidently, the old one was damaged
When removed. It is good to know the shaft is harder than the nut. Probably best to always use a new one.
D

[Ventodue]

<snip> Probably best to always use a new one.

Yup ...