The BSA A7-A10 Forum

Technical (Descriptive Topic Titles - Stay on Topic) => Gearbox, Clutch, Primary => Topic started by: Peter Gee on 20.09. 2018 19:08

Title: Quickley need dimensions of 4 Plate Cush Type Clutch Nut 42-3171
Post by: Peter Gee on 20.09. 2018 19:08

Appreciate folks. I have a number of nuts in my rummage boxes that are  correct hex size and bore but all have much  longer  spigots. I can turn these to suit.

This is what I need measured  for overall length and OD + depth of spigot.

(https://www.classicbikespares.com.au/wp-content/uploads/2018/05/423267.jpg)

Title: Re: Quickley need dimensions of 4 Plate Cush Type Clutch Nut 42-3171
Post by: JulianS on 20.09. 2018 20:09

The thread is 5/8 inch x 20 tpi.

Same nut as used on the alternator B31 and 33.

Photo is cross section of the B31 clutch you might be able to scale the nut from it.

Title: Re: Quickley need dimensions of 4 Plate Cush Type Clutch Nut 42-3171
Post by: coater87 on 20.09. 2018 20:31

Julian,

 I would like to spend so.e quality time in your library.

 Lee

Title: Re: Quickley need dimensions of 4 Plate Cush Type Clutch Nut 42-3171
Post by: Peter Gee on 20.09. 2018 20:41

Thanks Julian but am not sure I will.. I have the will but not the able!

Title: Re: Quickley need dimensions of 4 Plate Cush Type Clutch Nut 42-3171
Post by: trevinoz on 23.09. 2018 22:47

Peter I found the elusive nut yesterday.
Mine is 0.920 AF hex, spigot is 0.820 D X 0.215 deep.
Hex is 0.330 deep.
You also need the thick washer to go with it as well as the tab washer.
I can't find a thick washer at the moment but it goes over the spigot and has a recess machined into the bottom side.

Title: Re: Quickley need dimensions of 4 Plate Cush Type Clutch Nut 42-3171
Post by: berger on 23.09. 2018 23:32

as regards the washer don't do what my mate did and think the nut sits in the recess of the washer, then wonder why his clutch was snatching, I think its a hardened washer and he managed to crack it tightening the nut to try and sort the problem out.