Author Topic: Gearbox main shaft  (Read 1440 times)

Offline BagONails

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Re: Gearbox main shaft
« Reply #45 on: 09.11. 2024 13:05 »
Hi Craig, I've just realised who you are! Been a bit busy with my own disasters but started to catch up on a few threads on here and there you were.

I had a similar problem on my 59 A10. The rear drive chain was milling away the inner primary.
I stripped it all down and found even worse problems but ultimately with a lot of very good help on here I solved all the issues.
Just to recap:
  • Primary oil leaks actually more like cascades!
    Primary sprocket, chain and chainwheel all knackered
    Clutch misalignment to engine drive sprocket due to incorrect cush drive spacer and incorrect clutch adaptor that I ended up machining to reposition!
    Kick start issues
    Worn bearing in the gear box causing endfloat on the final drive, output shaft

so it sounds like you are going through something similar.

If you want some help give me a hoy and we can hook up when there's time.

Just on the drive chain clearance to inner primary case, the reasons mine was fouling were, incorrect heavy duty drive chain fitted by PO.
It should be a standard chain, not HD or god forbid an O-ring chain, there just isn't room.
Then my rear spacer was wrong, best to dry assemble it all without the spacer, then instal a spacer that just fits the gap.

I did these two things and cured the primary oil leak (inner cover no longer being distorted out of shape) and the grinding through lack of clearance.

I'm going to ride the Kwacka on the run tomorrow (at the back) while my A10 is in bits. My W looks like a desert sled Triumph conversion its cool but not a BSA!
Might see you if you're back on the road now?

Cheers B'oN aka Ian
Ian
59 GF A10
67 Spitfire under resto
2013 kwaka W800 Desert Sled (ex write off)

Nil Desperandum

Online chaterlea25

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Re: Gearbox main shaft
« Reply #46 on: 09.11. 2024 13:21 »
Hi Craigy,
I did write " add spacers" to the front screws *ex*

John
1961 Super Rocket
1963 RGS (ongoing)

Offline Craigy

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Re: Gearbox main shaft
« Reply #47 on: 09.11. 2024 20:44 »
Cheers, I understood it just misread it. I didn’t get a chance to mess about with it when I got home as too late to start.
I need to put the Cush drive and primary chain back on so will take a little while to sort.
Once done I’ll get back to you with the results
52 GF, 59 GF

Online chaterlea25

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Re: Gearbox main shaft
« Reply #48 on: 09.11. 2024 21:47 »
Hi Craigy,
Be very careful when trying to remove the screws, You may have bent one which would damage the crankcase threads as you remove it *eek*
John
1961 Super Rocket
1963 RGS (ongoing)

Offline Craigy

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Re: Gearbox main shaft
« Reply #49 on: 09.11. 2024 21:58 »
Hi John,

Thanks for saying. Just had a try…..both pretty tight.

Might leave it for now and have a think about best course of action
52 GF, 59 GF

Offline Craigy

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Re: Gearbox main shaft
« Reply #50 on: 10.11. 2024 04:56 »
Cheers, I understood it just misread it. I didn’t get a chance to mess about with it when I got home as too late to start.
I need to put the Cush drive and primary chain back on so will take a little while to sort.
Once done I’ll get back to you with the results

I know, I just forgot 😭. Even the guy that helped me did that when he was here…..and I still forgot.

Cheers Ian for the offer, I might (will)need it, just to make sure.

Have a look at the pics, this is what I found, 3 threads damaged. Would this be acceptable to replace with new…..or do I have to look at potential internal damage?

Sorry lads, you’ve been great and I still messed up ☹️
52 GF, 59 GF

Offline Craigy

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Re: Gearbox main shaft
« Reply #51 on: 10.11. 2024 04:57 »
.
52 GF, 59 GF

Offline Craigy

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Re: Gearbox main shaft
« Reply #52 on: 10.11. 2024 04:57 »
.
52 GF, 59 GF

Online groily

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Re: Gearbox main shaft
« Reply #53 on: 10.11. 2024 12:42 »
Internal damage extremely unlikely unless any of the screws has come out shorter than it went in leaving shrapnel behind. New screws, make sure not too long, and it'll be good.
Bill

Offline Craigy

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Re: Gearbox main shaft
« Reply #54 on: 10.11. 2024 13:32 »
Both out but damaged threads. I’ll order new ones. I assume they’re the right ones as all was good before I did this.
Inexperience shining through
52 GF, 59 GF

Online berger

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Re: Gearbox main shaft
« Reply #55 on: 10.11. 2024 15:47 »
Craigy a full photo of a screw would be good to see if you have the right ones

Online chaterlea25

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Re: Gearbox main shaft
« Reply #56 on: 10.11. 2024 19:32 »
HI Craigy,
"New" is no guarantee of correctness  *ex* *ex*
Are the threads in the crankcase OK?
shine a light in and rotate the crank until you can see the crank web "blocking" the hole,
measure the depth to the crank from the shoulder of the hole in the outer primary and make sure the screws are at least 3-4mm shorter,
The thickness of the crankcase is about 12-13mm but at the same time you need to make sure that you have as much engagement in the crankcase as possible

John
1961 Super Rocket
1963 RGS (ongoing)

Offline BagONails

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Re: Gearbox main shaft
« Reply #57 on: 10.11. 2024 23:47 »
Cheers, I understood it just misread it. I didn’t get a chance to mess about with it when I got home as too late to start.
I need to put the Cush drive and primary chain back on so will take a little while to sort.
Once done I’ll get back to you with the results

I know, I just forgot 😭. Even the guy that helped me did that when he was here…..and I still forgot.

Cheers Ian for the offer, I might (will)need it, just to make sure.

Have a look at the pics, this is what I found, 3 threads damaged. Would this be acceptable to replace with new…..or do I have to look at potential internal damage?

Sorry lads, you’ve been great and I still messed up ☹️

Hi Craig, good to see you out on your 'spare' A10 yesterday. Happy to help if I can. PM me and we can exchange contact details, should have done this yesterday!
I dont know how hard you hit the screws but if they are not bent the thread damage in the photo is minor on the screws themselves. What they have now done to the soft ally threads in the case on the way out is the question. If it were me I would clean the threads up on the screws, judicious use of swiss files and maybe a die and try them back in the cases to see how they feel. If they go in by hand with little resistance then should be fine.  I have assembled mine with Blue Hylomar on the threads as they communicate with the wet side of the crankcases and were leaking a little. Now solved.

I have the files and dies etc if you want and happy to come over to help you. *work*

Cheers Ian
Ian
59 GF A10
67 Spitfire under resto
2013 kwaka W800 Desert Sled (ex write off)

Nil Desperandum

Offline Craigy

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Re: Gearbox main shaft
« Reply #58 on: 10.11. 2024 23:52 »
Great cheers Ian….ill send my details
52 GF, 59 GF

Offline Craigy

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Re: Gearbox main shaft
« Reply #59 on: 14.11. 2024 04:20 »
Eventually!! (I hope 🤔)
I had the bike started yesterday and all seems ok. Just need to set clutch and test before i put the outer plate back on.
Thanks for all you help and advice, thanks to guys from BSA Club South Australia (Bag’o’nails + others) for coming round to help me.
Cheers lads 👍
52 GF, 59 GF