Author Topic: A10 Gearbox problem  (Read 1993 times)

Offline a101960

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A10 Gearbox problem
« on: 21.07. 2009 13:06 »
Let me begin by stating that I am not particularly adept at mechanical diagnostics or repairs which is a distinct disadvantage when owning old motorcycles. I can do things like setting the timing or adjusting the tappets but that is about as far as my capabilities extend. I have a gearbox problem on my A10. About half of the time the box works just fine, however sometimes there is a problem engaging  first gear when stationary. Mostly it engages properly with a distinct clunk and I can feel it engage, and sometimes it engages in compete silence and without any ?feel? if you see what I mean. Under these circumstances I have no idea weather I am in gear or not until I let the clutch out. A similar thing happens in second gear also. Mostly it goes into gear with a clunk and I can feel in engage. Now this only seems to happen going up the box. Incidentally the gear pedal is reversed to accommodate rear set foot rests therefore my change sequence is the same as a Triumph (one down three up). There does seem to be a bit of ?slop? on the gear pedal  and if I lightly lift the pedal before operating it then quite often the box behaves normally. Could this be a tired or faulty return spring? Or is this a symptom of something more sinister? This problem is completely random in nature and by that I mean the box will operate normally and then the problem will manifest itself only to correct itself again. The problem never appears or rarely appears when I start up. It usually happens when I am riding. There does seem to be a bit of lateral movement on the gear pedal shaft. By that I mean that I can move it in and out. Could this be the cause of the problem? And if so how could it be fixed? Like I said I do not have a great deal of mechanical knowledge, and I have no insight to the workings of gearboxes at all.

John

Offline Dynamo Regulators Mike

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Re: A10 Gearbox problem
« Reply #1 on: 21.07. 2009 13:35 »
Hi John
I reckon there is a good chance that your selection problem is down to a faulty return spring. They can split across and then along the legth of the spring so some tension remains, but not enough to return the selector mechanism to its 'mid-point' as it were. I have had 2 spring go like this over the years. Poor pattern parts play their part here as well.
Mike
Mike Hutchings
A10, B50, T800; 1,2,3 (& DVR2)
Director, DRL www.dynamoregulators.com

Offline a101960

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Re: A10 Gearbox problem
« Reply #2 on: 21.07. 2009 16:36 »
Mike

Thanks for your reply. Do you know where I might source a good quality spring? There many suppliers of BSA parts but the whole topic of parts quality is a minefield. I have had so many bad experiences with poor quality even from BSA specialists.

John

Offline Dynamo Regulators Mike

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Re: A10 Gearbox problem
« Reply #3 on: 21.07. 2009 18:01 »
That is one of the eternal questions, is it not?
Recently bought a B33 oil pump drive spindle which was marginal. But used it as all others I tried were out of stock. Time will tell on that one.
The g'box return spring I have fitted on the Flash at present is not really quite right. There is more play in my lever than on most but otherwise the spring rate seems ok (one I bought was way too stiff, would have worn through my boot in months I reckon) and the gearchange is acceptable. Slightly the wrong angle at the ends I suspect.
In a few purchases I have yet to be disappointed by Lightning Spares. Their move across the road should be completed now. Brian Pollitt is a genuine expert, and I don't think he would tolerate anything less than first class product.
Happy hunting John, please let us know here how you get on.

Mike
Mike Hutchings
A10, B50, T800; 1,2,3 (& DVR2)
Director, DRL www.dynamoregulators.com

Offline rocket man

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Re: A10 Gearbox problem
« Reply #4 on: 23.07. 2009 19:50 »
try srm engineering they supply good quality parts num 01970627771