Author Topic: A10 layshaft bushes  (Read 238 times)

Offline JHG1958

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A10 layshaft bushes
« on: 22.11. 2019 17:26 »
Can you get oversized bushes for the layshaft?  The bushes are badly scored as is the layshaft. The layshaft is loose in the bearing but it  hard to say of that is normal or important. 

Online RDfella

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Re: A10 layshaft bushes
« Reply #1 on: 22.11. 2019 18:04 »
As far as I'm aware nos layshafts don't exist. I ground down mine until it was clean and then turned up an undersize bronze bush to suit. Easy to do on a lathe but you'll need a proper cylindrical grinder for the shaft.
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Online JulianS

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Re: A10 layshaft bushes
« Reply #2 on: 22.11. 2019 18:24 »
The layshaft small bush and journal are often scored.

NOS swinging arm type layshaft on ebay at the moment;

https://www.ebay.co.uk/itm/BSA-A7-A10-B31-B33-Gearbox-Layshaft-f-Swing-Arm-Mod-42-3019/163941607486?hash=item262bae683e:g:84AAAOSw29ZdyteN

Plunger layshaft is different.


Offline JHG1958

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Re: A10 layshaft bushes
« Reply #3 on: 22.11. 2019 19:10 »
Thanks for this it is a good spot.  At £130 plus £40 for the bushes I think I will see about getting my layshaft reground. This BSA is proving expensive but I suppose I should not be surprised.

Offline Swarfcut

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Re: A10 layshaft bushes
« Reply #4 on: 22.11. 2019 19:19 »
The Layshafts are certainly different, but identical as regards length, the shaft diameters and splines. The essential difference is in the position of the circlip locating groove for the pressed on pinion. The pinions of plunger and S/A boxes are different, having the circlip location machined to match the appropriate layshaft. As long as the layshaft matches the pinion type, they should interchange, but then the rest of the gear pairs may have to be selected to match, as over the years the gear engagement dogs vary in shape slightly...."pointed versus flat"  Worth a try, you might be lucky with what you have.

Worth asking your local crank grinder to put a shine on the damaged layshaft.

Swarfy.

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Re: A10 layshaft bushes
« Reply #5 on: 22.11. 2019 19:37 »
Can you get oversized bushes for the layshaft?  The bushes are badly scored as is the layshaft. The layshaft is loose in the bearing but it  hard to say of that is normal or important.

Short answer yes, there are suppliers who sell them, this relevant ? https://www.a7a10.net/forum/index.php?topic=6053.0
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Online chaterlea25

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Re: A10 layshaft bushes
« Reply #6 on: 22.11. 2019 20:41 »
Hi All,
The shafts are not that hard and can be turned readily with carbide insert tooling
The most important thing is to dial in the unworn part of the shaft to absolute zero runout
Forget doing this on a lightweight mini lathe  *eek*

John

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Re: A10 layshaft bushes
« Reply #7 on: 31.12. 2019 00:40 »
As far as I'm aware nos layshafts don't exist. I ground down mine until it was clean and then turned up an undersize bronze bush to suit. Easy to do on a lathe but you'll need a proper cylindrical grinder for the shaft.

every layshaft I've ever seen is worn, so I get my engineer to clean up the shaft and make bespoke bushes.
A good rider periodically checks all nuts and bolts with a spanner to see that they are tight - Instruction Manual for BSA B series, p46, para 2.
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