Author Topic: A7 6 spring clutch  (Read 3337 times)

Online bsa-bill

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Re: A7 6 spring clutch
« Reply #15 on: 03.09. 2013 16:01 »
Well you can see the bluing from heat at both ends so they have been heat treated perhaps the quenching went amiss. Although after half a century maybe a bit of this is forgivable.

any way you could buy a new one or I would grind the swell off the swollen end so it's parallel again and heat it to cherry red then quench it
All the best - Bill
1961 Flash - stock, reliable, steady, fantastic for shopping
1959 Rocket Gold Flash - blinged and tarted up  would have seizure if taken to  Tesco

Online Topdad

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Re: A7 6 spring clutch
« Reply #16 on: 03.09. 2013 16:45 »
I've got about 3 in a tin on the shelve and non seem to have such a pronoused indent as this as, also Bill could the discolouration be from misadjustment of the clutch not allowing any or enough free play from the cable etc? and then that would lend you to think maybe the pushrod was modified by a previous owner , just a thought BobH
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Online bsa-bill

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Re: A7 6 spring clutch
« Reply #17 on: 03.09. 2013 17:22 »
Bob I agree the indent is a bit more than should be, that could be explained by insufficient or ineffective heat treatment.
The discoloration (bluing) is fairly common, depends on the source you get them from I suppose some are heat treated some may just be harder steel and not need it, or heat treated before plated or whatever.
Don't think it's from poor adjustment, if that was the case it would be picking up and welding itself to the adjuster, and the clutch would be on the point of slipping all the time

Bill
All the best - Bill
1961 Flash - stock, reliable, steady, fantastic for shopping
1959 Rocket Gold Flash - blinged and tarted up  would have seizure if taken to  Tesco

Offline pjm01

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Re: A7 6 spring clutch
« Reply #18 on: 04.09. 2013 10:55 »
A near neighbour who has been a mechanical engineer all his working life and latterly a toolmaker looked at the clutch pushrod end through a poweful lens and concluded the 'belling' was caused by wear and pressure (probably).
Peter M

Offline wilko

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Re: A7 6 spring clutch
« Reply #19 on: 05.09. 2013 00:20 »
Because it had no freeplay.

Offline pjm01

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Re: A7 6 spring clutch
« Reply #20 on: 05.09. 2013 10:21 »
Puller arrived so I threaded it onto the clutch sleeve and did up the bolt .... result = nothing. Did it up a little harder, again nothing. Tried the most British of all solutions (went away for a cup of tea whilst I thought about it) and on my return the clutch sleeve was loose ....... result. Clearly the tea did it.
I wonder if anyone could advise how much play/feel should be felt at the end of the gearbox mainshaft .... can feel a 'minute' amount of movement. I'm a tad reluctant to get into replacing gearbox bearings at this stage but ...
Also (and sorry to be a pest) but what is the correct length of the clutch push rod (1959 A7 SS) ?
Really appreciate all your inputs and offers of help .... this must be the best forum ever.
Many thanks
Peter M

Offline morris

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Re: A7 6 spring clutch
« Reply #21 on: 05.09. 2013 13:02 »
Thanks to God for inventing tea!

There shouldn't be any movement on the shaft. Try to determine whether it's the bearing moving in the housing, or the shaft moving in the bearing (you can see the bearing when removing the small gearbox cover on the other side).
If it's the shaft moving in the bearing, you may get away by tightening the shaft nut.
While there, push the kick by hand and check the shaft for left to right play. If that's the case it's certain that the bearing is past it's best
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Online bsa-bill

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Re: A7 6 spring clutch
« Reply #22 on: 05.09. 2013 13:15 »
Quote
I threaded it onto the clutch sleeve and did up the bolt .... result = nothing.

once the bolt is tightened up you tap it with a hammer, but if tea works for you all well and good *good3*
All the best - Bill
1961 Flash - stock, reliable, steady, fantastic for shopping
1959 Rocket Gold Flash - blinged and tarted up  would have seizure if taken to  Tesco

Offline chaterlea25

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Re: A7 6 spring clutch
« Reply #23 on: 05.09. 2013 21:28 »
HI PJM,
There will be a couple of thou up and down  play to be felt in the gearbox mainshaft due to it running in bushes in the sleeve gear, there should be very little/no end float
Please read the other reply on the six spring clutch thread where I reason there is no fixed push rod lenght due to different plate thicknesses
I buy a 13in. length of 1/4 silver steel from my local engineering supplier and cut to suit then harden the ends

HTH
John
1961 Super Rocket
1963 RGS (ongoing)

Offline pjm01

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Re: A7 6 spring clutch
« Reply #24 on: 11.10. 2013 11:36 »
Sad to relate the saga continues ...... I ordered a 4 spring clutch conversion from a 'respected supplier' and had to wait several weeks before a complete kit of parts was available. Clutch centre needed to be 'fettled' to fit the clutch adaptor and the mainshaft nut did not fit ..... a second nut was sent which was equally bad. These only fitted when a local engineer recut the threads approx 10 thou greater diameter .... so I proceeded to put the clutch together. All went well untill the plain + friction plates were inserted and only 8 plates would fit on the centre leaving 3 over. Scratch head and call supplier "sorry sir we must have sent you the wrong centre, return it and we'll send the correct one. Is it in stock ? No and we don't know when delivery will be". Feeling a little frustrated, I had a cup of tea and had a trial 'put together' of the other parts only to find the hole in the clutch pressure plate was smaller than the diameter of the (new) push rod. Called supplier again, who checked his stock and found the pressure plates were all wrong ...... "when will you get correct ones .... don't know was the response".
I can understand the difficulties in sourcing parts for 50+ year old machines but there really needs to be adequate incoming goods inspection and quality control instead of leaving it to the poor old customer.
Have now done what I should probably have done in the first place and ordered a '4 spring conversion' from SRM ...... "yes sir we have one in stock and will send it to arrive tomorrow" furthermore I understand the kits are assembled in factory before sending out ........ I wait in keen anticipation.  Peter M

Offline muskrat

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Re: A7 6 spring clutch
« Reply #25 on: 11.10. 2013 11:57 »
G'day Peter.
The bad parts didn't have a W in the brand name by chance? Dodgy parts are becoming the norm.
Cheers
'51 A7 plunger, '57 A7SS now A10CR,  '83 CB1100F, 88 FXST .
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Offline fido

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Re: A7 6 spring clutch
« Reply #26 on: 11.10. 2013 12:09 »
Yes, I read elsewhere of a new rear suspension plunger for a Triumph Terrier failing after 20 miles use. I think I would try to get the old 6 spring working well!

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Re: A7 6 spring clutch
« Reply #27 on: 11.10. 2013 12:17 »
Peter, admire your persistence with that clutch but has a friend of mine says about such things " you can't polish a piece of ****, sorry Fido but I am sure that the SRM clutch will work and get you some reliability which you need,best wishes BobH.
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Offline pjm01

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Re: A7 6 spring clutch
« Reply #28 on: 11.10. 2013 16:17 »
It's 'tomorrow' and the kit was delivered as promised, what is more, it arrived assembled and looks very good indeed ..... so far I'm very, very impressed.
Peter M

Offline fido

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Re: A7 6 spring clutch
« Reply #29 on: 12.10. 2013 07:25 »
Sorry, I missed the bit about the SRM clutch. I was not suggesting there was any problem with their parts.