4 spring clutch with cush drive

[bsa-bill]

Hi everyone, quite sure someone can help me on this
I'm fitting a four spring clutch with cushdrive to my project, a couple of concernes
1 - I have heard that it's not good to run this clutch with a cushdrive on the crank also, although I do know someone who has and can't recall him having any problems

2 - the centre nut, centre nut washer and tab washer that I have just don't seem right ( I think they are for a non cush for four spring clutch )

I have just ordered these parts from Draganfly for the cush drive clutch as they all have different part numbers to the parts I have, only thing is the centre nut comes up with the same part number in the shopping cart as the centre nut I have, I assume this to be Draganfly suggesting the nuts are the same.

If any body would like to comment or can point me to a service sheet covering this cush drive clutch I would be very grateful.

All the best - Bill

[trevinoz]

Bill, the non-cush hub is obviously different to the cush type. The non-cush has a flat on the side of the centre which the tab is bent over. The cush has a hole in the side to accept a tab.
The cush type, being Triumph, has a smaller main shaft and consequently a smaller nut across the flats so there is room to fit and bend the tab. The BSA nut and shaft take up most of the available room in the centre so it is difficult to fit a tab washer, if you could get one.
You could make a special tab or do as I do, use Loctite.
I have had no trouble using the cush clutch with the crank cush, but if you are concerned, either remove the crank spring and fit a solid sleeve or remove the rubbers from the clutch centre and weld the spider to the hub.
Probably a good idea to replace the hub rubbers if you are going to leave it original.
Trev.

[Chrisf1]

Hi Bill i have both cush drives on mine without any problem in fact it is probably a smoother take off Chris

[bsa-bill]

Many thanks Chris and Trev
I have a nut, nut washer and lock washer on order from Draganfly, they are listed for B31/33 so may or may not be what I require, they are for the Triumph 4 spring clutch with cush drive though so we will see probably in the next two days.
Thanks for your re-assuring comments re using two cush drives, I'll go with them

All the best - Bill

[bsa-bill]

Well nothing arrived from Draganfly yet,  however while searching in my shed for a missing nut I found what I think are the parts I need,
Must have ordered them and forgot ( this project has been ongoing for five years plus ).
So I have a washer that is recessed on one side, a tabwasher with two short and one long thinner tab and a nut with an extention.

I'm presuming the tab washer goes between the nut and the washer and the nut goes with the exended bit through the washer but why is the washer recessed and which way does it go

All the best - Bill

[snowbeard]

so not to steal the thread, but is this a part from a british bike?  I have a four spring cover that fits it quite nicely, but that and this are all I have in hand.  it has a faint stamp of H.D. on it, so I thought perhaps it was harley, but no one I know has id'd it as such?

part number on it is 452 31

[trevinoz]

Bill, I fit the washer with the recess inward as I assume it is meant to ensure that the clutch centre is held tight against the clutch sleeve. The parts book shows the tab washer under the washer but that doesn't seem correct.
As I said earlier, I don't use the tab washer, I loctite the nut.
Trev.

[bsa-bill]

Thanks Trev
Agree re the tab washer
And the nut does go extended bit towards the gearbox ?

I intend to use the tab and a bit of locktite

All the best - Bill

[trevinoz]

Yes Bill, the extended end to gearbox.
Trev.

[bsa-bill]

assembled it yesterday Trev and hit a snag, it runs out of thread if fitted with the extended bit facing the gearbox so put it on reversed.
but after a nights thinking I could put a washer or spacer in there ( between recessed washer and nut ) so it has enough thread.
BTW anybody got a torque for that nut on mainshaft?  I have it to around forty lbs/ft at the moment

All the best - Bill

After a little more thought ( takes a while but I get there ) the reason it runs out of thread could be because the adapter is going too far up the taper, so at the moment I'm atempting to take it off, it's not proving to be easy and if it's that tight maybe I should leave it as is and just go for an extra washer.
Life with an old bike can be frustrating but it's never dull.

All the best - Bill

[bsa-bill]

Well got the adapter off, it was certainly on tight enough to drive but may well be going to far up the mainshaft taper before it gets tight.
I,ve bought a new one and will try it, if theres no difference than the original will sell on.
It does look a bit funny at the splined end as if it has been machined there are about four internal threads, think that could well be right though from memory.
 anyway time will tell, meanwhile there's plenty other bits to be getting on with

All the best - Bill

[BSA_54A10]

bill,
The different models had a different position of the sprocket on the mainshaft .
All mainshaft tappers are the same so to get correct primary chain alignment some of the clutch centers have bigger holes in them than others so the sit closer to he gearbox or further out on the main.
Measure the size of your old one and check it against the new.

[trevinoz]

Bill, a quick check is to put a straight edge between the basket teeth and the engine sprocket. If the clutch centre is too far along the main shaft it will be clearly seen.
Trev.

[bsa-bill]

checked alighnment when I put it on Trev - seemed to be good
Should get the new adapter tommorow and try it on if it is the same then the two washer method will have to do

All the best - Bill

[bsa-bill]

I ordered a new nut and washer from Tri Cor it arrived today, ( Draganfly sell you the same nut as for the non cush drive and it's not right as it wont go through the washer)
The new nut from TriCor seemed to have a shorter extention so I measured it against the one I had, there is 90 thou difference (shorter) which would give me another two threads I think
Coupled with maybe a bit more length on a new adapter should help.
I have no connection with TriCor but can recommend them for any bits that were shared with BSA

All the best - Bill