The BSA A7-A10 Forum

Technical => Clutch, Primary, Gearbox => Topic started by: Johnny J on 14.01. 2015 17:16

Title: Clutch parts confusion...
Post by: Johnny J on 14.01. 2015 17:16
I am changing the clutch bearing, seal and sliding plate on my GF-1960 with 6-spring clutch and I have problems understanding which parts are which.

If I look at the picture "Clutch parts", No: 11, 12 or 13 cannot be found on my bike (if they are not further inward...).
As I understand it, 11 and 12 are only on Plunger models? but 13, "65-3833" Collar, Clutch Sleeve (Reverse scroll?) seems to be missing.

My supplier also suggested I should buy the cork gasket in the picture (which I did), this has number "66-3090", do I need this?



Title: Re: Clutch parts confusion...
Post by: bikerbob on 14.01. 2015 19:53
Your drawing covers all models but there are differences items 11/12 are not for the A series swinging arm but item 13 is the reverse scroll that fits on the end of the clutch center piece you  can buy these seperately and are a tight fit on the clutch center.
Title: Re: Clutch parts confusion...
Post by: Johnny J on 15.01. 2015 23:51
A thought, what do you think about putting silicone sealant between the inner primary and the chainguard(?) to prevent oil leaks?
Will it be an obstacle in any way, except when you want to remove the inner primary? It should be quite easy to cut through it at that time.
Only problem I could think about is if there is a reason to remove the chainguard and it's possible to do that without removing the clutch...
Title: Re: Clutch parts confusion...
Post by: Johnny J on 16.01. 2015 17:44
Don't think I need to do the above, after fitting the reverse scroll to the center it seems like a tight enough construction.
No wonder that it leaked alot before when there was no scroll, a totally open way out....
Title: Re: Clutch parts confusion...
Post by: bikerbob on 16.01. 2015 19:37
I don't think that silicone sealant is a good idea, for a start you would have to have the fully enclosed  chaincase front section fitted. Secondly and more importantly what is to stop the oil if it gets past the reverse scroll from going inside that section of chaincase and causing further problems.
Title: Re: Clutch parts confusion...
Post by: Johnny J on 16.01. 2015 20:15
No, I didn't seal it.

Another problem came up when I started to put things together, there was alot of play in the clutch bearing so I bought new cages with balls.
After mounting them there is no difference.
The obvious would be that the races are worn, but I couldn't see or feel the slightest wear on the outer race so I thought it were the balls that were worn. (no pun intended) :-)
This leaves the inner race, but I don't find it likely that there is so much wear on this and nothing on the outer?

Any ideas?

Here's a link to a video of the play: http://youtu.be/wfWq131OGt8
Title: Re: Clutch parts confusion...
Post by: chaterlea25 on 16.01. 2015 21:31
Hi Johnny,
Is the inner race a good tight fit on the shaft adaptor?
The pattern ones that have been supplied in recent times are 15 thou loose on the adaptor *warn* *warn*
I posted about this previously on here, Some suppliers withdrew their stocks after I contacted them, another insisted it was my "fault" and still sell the crap ones *problem* *problem*

I got over the problem by finding an original BSA one
Other than that beware if you go and buy new races !!!

HTH
John
Title: Re: Clutch parts confusion...
Post by: Johnny J on 16.01. 2015 21:44
Thanks John, I will check this more carefully tomorrow.
Title: Re: Clutch parts confusion...
Post by: KiwiGF on 17.01. 2015 01:10
The amount of play in your video would not concern me, though its a bit large, the chainwheel can only wobble when the clutch is pulled in anyway, and the range of movement possible (by the plates having a small gap when pulled in) is probably lesss than in your video, the centre of the clutch bearing is clamped by the clutch nut so cannot spin so it can have a bit of clearance over the shaft I guess, albeit this could cause the chainwheel to be not concentric with the gearbox shaft so is not desirable!

The clutch bearing would have to be pretty tight to prevent wobble at tbe edge of the chainwheel after all....and even if like that when new I suspect a bit of wear would allow the wheel to wobble.

I have seen it said that the position of the outer race in the chainwheel is crucial to prevent clutch drag and maybe wobble, if the position is wrong it certainly can cause drag, and certainly if the position is adjusted so the chainwheel is pushed close to the backing pressure plate (behind the chainwheel) wobble can "appear" to be reduced anyway, but I have to say I am not 100% convinced the position is supposed to be used to adjust this ......but it might be worth checking it is correct, though I do not think the correct position is any manual I've seen........
Title: Re: Clutch parts confusion...
Post by: Johnny J on 17.01. 2015 13:45
Hi Johnny,
Is the inner race a good tight fit on the shaft adaptor?
The pattern ones that have been supplied in recent times are 15 thou loose on the adaptor *warn* *warn*
I posted about this previously on here, Some suppliers withdrew their stocks after I contacted them, another insisted it was my "fault" and still sell the crap ones *problem* *problem*

I got over the problem by finding an original BSA one
Other than that beware if you go and buy new races !!!

HTH
John

John, yes you were right, guess a big part of the play is the inner race not sitting tight on the adaptor.
Question is, where do I find a proper inner race? Anyone bought one recently thats sits alright?
Title: Re: Clutch parts confusion...
Post by: chaterlea25 on 17.01. 2015 19:35
Hi Johnny,
Send an ebay message to this seller on Ebay, motor0921
http://www.ebay.com/sch/m.html?ssPageName=STRK%3AMEFSXS%3AMESOI&_ssn=motor0921&rt=nc

Sometimes he has NOS ones for sale

I have given up on 6 spring clutches   *problem* *problem* *problem*
Just too much hassle

John
Title: Re: Clutch parts confusion...
Post by: morris on 17.01. 2015 23:46
I may be wrong here, as I don't know this type of six spring clutch, but shouldn't the inner basket lock up the bearing's inner race so it can't move? In that case adding a shim might help.
Or if it's not that, maybe there's to much play between the inner and outer basket? I had an issue like that on the plunger's six spring clutch with an aftermarket inner basket. This clutch is of a different type though as on this one the back of the inner basket has a roller race which butts up against a thrust washer . I skimmed the race a couple of thou so the inner basket moved a little further on the shaft and this entirely eliminated the wobble.
Title: Re: Clutch parts confusion...
Post by: Topdad on 18.01. 2015 12:01
Hi Morris, you are trying to apply logic to this part when unfortunately logic wasn't used by Bsa to design this piece of crap.I have owned 2 a10s with this clutch and the first one was changed to the later tri-bsa one after many months of trying to get it to work ,the second one went into the bin before it had a chance to send me round the bend. I admire anyone who gets these clutches working but I have to say I'd rather ride the bike than curse it when it breaks at the side of the road miles from home.
Johnny sorry to go off on one but if you ge the chance swop the clutch for the later one do it honestly you won't regret it best of luck what ever you decide ,Bobh
Title: Re: Clutch parts confusion...
Post by: Johnny J on 18.01. 2015 13:57
I´ll consider that, the clutch plates have seen better days any how...
Any recommendations where to buy a 4-spring complete one?
Title: Re: Clutch parts confusion...
Post by: morris on 18.01. 2015 17:26
Agree with Bob there. the 4 spring is a far better clutch. I have one on the SA. Never any bother with it.
Most dealers do them. Here's an example;
http://www.degroot-bsa.nl/index.php?route=product/category&path=75_95&page=1
Title: Re: Clutch parts confusion...
Post by: bikerbob on 18.01. 2015 19:26
There are 2 complete 4 spring clutches for A7/A10 for sale on ebay at the moment  type in the following numbers on ebay   261734767797
221417469626
Title: Re: Clutch parts confusion...
Post by: Johnny J on 18.01. 2015 20:00
Thanks Bob!
The first item number goes to a gold necklace, but there's nothing wrong looking good driving around town. ;-)

Seriously, it seems like they cost around £350 with freight, a healthy sum..
I think I will start by ordering the inner race and if it doesn't sit right I will return it and propably go the 4-spring way.
I mean there was nothing wrong with the clutch before I took things apart.
Title: Re: Clutch parts confusion...
Post by: cyclobutch on 19.01. 2015 12:07
It's on my list to swap out my 6 spring for something 'better', but it keeps on working dammit. I guess the day will come.
Title: Re: Clutch parts confusion...
Post by: bikerbob on 19.01. 2015 16:40
 Sorry about that number it should be 261734767796 when I last looked it was at £165 with one bid and 2days to go
Title: Re: Clutch parts confusion...
Post by: morris on 19.01. 2015 21:37
I mean there was nothing wrong with the clutch before I took things apart.
Don't worry Johnny. Happens to me all the time... *smile*
Title: Re: Clutch parts confusion...
Post by: Johnny J on 19.01. 2015 21:56
Well, obviously it was "rocking" before as well and it did work alright, but who knows what will happen when I start putting things together. :-)

I have now ordered a new inner race, hopefully I will get it tomorrow or the day after.
If it fits ok I'll see if I can get the clutch working properly, if not I'll propably bid on the used 4-spring.

I have cleaned the friction plates thoroughly, should I put a little bit of oil on them before assembly?
Title: Re: Clutch parts confusion...
Post by: morris on 19.01. 2015 22:45
Maybe others think otherwise but I'm not oiling them. They get oily soon enough.
Title: Re: Clutch parts confusion...
Post by: RichardL on 20.01. 2015 03:42
It's a wet clutch. It's going to be soaked in oil (or ATF), and that is how it was designed to work. So, cleaning oil off the plates seems superfluous, unless it's grease.

Richard L.
Title: Re: Clutch parts confusion...
Post by: unclerob on 20.01. 2015 11:34
If used 4 spring clutches cost that much nowadays I'd bite the bullet and buy a Pearson or Newby one.....I fitted a pearson clutch a year or so ago and can't think of a better upgrade! Granted my original clutch was very much past it but the transformation was astonishing, much nicer gearchanges, never a problem finding neutral etc....plus you get a better oil seal arrangement and theres no need to adjust since spring bolts are just done up tight (unlike the Newby one I think?)
Title: Re: Clutch parts confusion...
Post by: Johnny J on 21.01. 2015 16:14
Got the new inner race today and it sits much tighter than the old one, even had some problems getting it on.
Have put the clutch together and it rocks much less.
Everything seems to work as it should, so I won't be bidding on the 4-spring...will take that leap at a later stage if necessary.
Title: Re: Clutch parts confusion...
Post by: East_Coast_BSA on 28.03. 2015 06:33
My six-spring was a piece of junk.  When I did my restoration, I bit the bullet and bought a four-spring SRM.  It's a "Night and Day" difference.  You can pull it with two fingers and find neutral with the bike running, sitting at a stop light.  They are pricey but well worth the money.
Title: Re: Clutch parts confusion...
Post by: oldbeezageezer on 13.08. 2015 12:49
I have just purchased and partially fitted an SRM 4 spring to my A10 s/a. I say partially because to fit the pressure plate I need to measure and cut the push rod. The instructions given are, or seem to be for an A50/A65 and I am not sure how to measure the push rod. SRM told me the clutch actuating arm should be 20 - 30 degrees away from gearbox gasket but Haynes says it should be parallel.

Can anyone confirm where the actuating lever should be when clutch disengaged please and how and where I measure push rod.
Thanks
Title: Re: Clutch parts confusion...
Post by: a101960 on 13.08. 2015 13:23
Quote
SRM told me the clutch actuating arm should be 20 - 30 degrees away from gearbox gasket but Haynes says it should be parallel.
SRM are wrong. With the clutch disengaged the actuating arm should be parallel. See the relevant page from the BSA A7 / A10 instruction manual.
(http://)
Title: Re: Clutch parts confusion...
Post by: oldbeezageezer on 13.08. 2015 15:22
Thanks for the reply A101960. That is how I set it with the original 6 spring clutch so thought it a bit strange to do the opposite for a new clutch.

Alan
Title: Re: Clutch parts confusion...
Post by: Topdad on 13.08. 2015 15:38
Erm, I read that as when fully withdrawn ie disengaging the clutch . At that point parallel to the gearbox edge , so  it starts out pointing approx. 30d out from the box edge with a little slack in the cable . Same as a brake , the brake arm is pulled up to obtain max leverage at approx. 90d ,or am I reading that wrong ? Bob
Title: Re: Clutch parts confusion...
Post by: RichardL on 13.08. 2015 18:45
Lucky for me this topic came up.

After reading, I went out to the garage to check the angle of my own clutch arm. It was right, having set it according to the "90 degrees to the cable" method but, in the process I discovered the cable was well frayed at the top. What to do, what to do? There is a vintage bike show this Sunday which I plan to enter. Voila! Once again my A7 barn find comes to the rescue with a good clutch cable that fit properly after trimming back the spiral armor to fit the top adjuster. 

Richard L.
Title: Re: Clutch parts confusion...
Post by: metalflake11 on 13.08. 2015 18:52
S.R.M. are right, it should be parallel to the gearbox with the lever pulled in. It's exactly the same principal as a brake lever on the brake drum.
Title: Re: Clutch parts confusion...
Post by: a101960 on 13.08. 2015 19:30
Quote
S.R.M. are right, it should be parallel to the gearbox with the lever pulled in.
Ah, metalflake 11, but that is not what SRM said according to what oldbeezargeezar posted.
Quote
SRM told me the clutch actuating arm should be 20 - 30 degrees away from gearbox gasket but Haynes says it should be parallel.
If oldbeezageezar has stated what SRM told him literally, then SRM were wrong in what they said. It is true that the actuating will end up being 20-30 degrees with the clutch engaged, but that is not the correct way to set up the clutch. Crucially the correct procedure is to set the actuator arm as described by BSA in the A7 / A10 owners instruction manual, which is to set the arm parallel with the clutch lever pulled in. That is not what SRM appear to have said.  What SRM actually said according to oldbeezageezar is misleading, and wrong.
Title: Re: Clutch parts confusion...
Post by: RichardL on 13.08. 2015 21:39
All very semantically confusing because engaging the clutch lever disengages the clutch.

Richard L.
Title: Re: Clutch parts confusion...
Post by: metalflake11 on 13.08. 2015 21:52
Quote
S.R.M. are right, it should be parallel to the gearbox with the lever pulled in.
Ah, metalflake 11, but that is not what SRM said according to what oldbeezargeezar posted.
Quote
SRM told me the clutch actuating arm should be 20 - 30 degrees away from gearbox gasket but Haynes says it should be parallel.
If oldbeezageezar has stated what SRM told him literally, then SRM were wrong in what they said. It is true that the actuating will end up being 20-30 degrees with the clutch engaged, but that is not the correct way to set up the clutch. Crucially the correct procedure is to set the actuator arm as described by BSA in the A7 / A10 owners instruction manual, which is to set the arm parallel with the clutch lever pulled in. That is not what SRM appear to have said.  What SRM actually said according to oldbeezageezar is misleading, and wrong.

All very confusing isn't it?
 If you look at the gearbox arm from above from the timing side, it should be where the hour hand would be at half past eight. When you pull the clutch in, it should be at nine o' clock. When the clutch is released the arm should be free to move slightly to prove it is not pushing the pushrod and not being pulled by the cable.
Title: Re: Clutch parts confusion...
Post by: oldbeezageezer on 14.08. 2015 20:43
well, thanks to all you and to bsa-bill from an old thread. I got earlier SRM fitting instructions which were a lot clearer than the one they gave me with the clutch. My dilemma was setting the actuating arm before cutting the push rod. With the advice I got out in the garage and did the deed. Cut the push rod, (and hardened the end) and fitted the pressure plate, springs and adjuster.
It seems to work ok.  I couldn't get the actuating arm at 90D to the cable so will have to do final tweaks when I get running.  It will probably be a while as I was going to refit the primary chain but now the new clutch doesn't wobble on the shaft, it doesn't fit.
While waiting for the new clutch to arrive I took the rocker box off to sort out the, or I should say, one of the oil leaks. New gaskets, gasket cement, push rod tool so all set. Fiddly job which I did not think would be easy but no matter which way I fiddled, I couldn't get the box back on. Discovered two of the studs are bent! I thought studs would be an easy thing to get but on my bike the rear studs are longer than the front and all four appear to have the same part number and from what I have read here, all the same length.
It looks like shorter studs at the rear will be ok but does anyone know a part number for the longer studs. By the way, my engine has an aluminium head.
Title: Re: Clutch parts confusion...
Post by: muskrat on 15.08. 2015 21:24
G'day OBG.
Alloy head rockerbox's have 4 studs the same size pt# 67-1117 http://www.nsamotorcycles.co.uk/67-1117-bsa-a7-a10-alloy-head----rocker-box-fixing-stud-4371-p.asp
The top rear tappet inspection cover stud should have flats to be able to remove it. Makes the job a tad easier.
Cheers
Title: Re: Clutch parts confusion...
Post by: oldbeezageezer on 16.08. 2015 09:08
Thanks for the info and link Muskrat. I will order some and hopefully get back on the road before the end of our summer. Guess it's just warming up for you to get out and about.

Alan