Hi
I am in the process of getting my bike back on the road , and in the process of setting the ignition timing, during this I have not been able to select the gears to get it into top gear to enable me to turn the back wheel to rotate the engine, I have the gearbox casing off at the moment for polishing so I can not operate the clutch, however no matter how much I move the gear lever I can not seem to get the gearbox into Neutral or any gear, is this normal or am I doing something wrong, the gear selector seems to be moving ok , not very experience with gearbox's so any guidance would be appreciate
Thanks
Mike
Hi Mike,
Are you turning the wheel a bit as you try to select a gear? Bear in mind that the gear box is usually turning when selecting a gear. This make it a lot easier for the selectors to move the gears.
Dave.
You don't need to operate the clutch to change gears, if the engine is not running.
Try rotating the back wheel by hand while operating the gear lever. It should then click into place. If not, then you have other problems.
HI thanks for the feedback, looks like I have other problems !
I have been trying to turn the wheel wheel whilst operating the gear lever as you suggest, but to no avail, when I bought the bike I wheeled it into the garage in neutral and put it on its stand with no problem, seems I have put it into a gear whilst trying to find top gear to spin the engine for ignition timing and cannot get it out now, the selector seems to move up and down with no problem, but I cannot tell what is happening inside the box
The bike has been completely rebuilt before I bought it , I'm thinking is something simple that I am missing
Thoughts/ suggestion ?
Cheers
Mike
I had a simililar problem when I rebuilt my A10. I couldn't sort it with everything in place and ended up removing the gearbox and rebuilding it again. I think I found the problem in that I had indexed the quadrant one tooth out of position. Re assembled carefully and everything now works well. That had similar symtons as it seemed alright until I put it in gear to turn the engine to do the mag timing - then the change mechanism just jammed up even though the shafts were turning.
Hi Captain Mike,
Is it an A10 or an A65? A65 does not need indexing but if it is an A10 then as Pete says it needs to be indexed. There are dots to help with this.
Dave.
Hi
Dave/Pete
Yes it is a A10 pluger, looks like I will have pull the gearbox apart, this will be a learning curve for me, so I will research it first, is there a way to do it without removing the box from the bike ? has anybody else done this ?
will update progress when I get the time to do the job
Thanks
Mike
Hi Mike,
You do not have to remove the box from the bike but there is bit of stripping to do. I had to do this on my wife's '51 Flash and from memory the outer and inner gearbox cases have to removed. I think that the box needs to be in second gear and then as the inner cover is put on the dots must line up on the selector. It is easy to let it drop at the last minute and this could what has happened. New gaskets will probably be needed.
Dave.
Looks to me like the gear change lever is not moving the gear cam plate after having a closer look
Thanks Dave
At this point in time I have no Idea what gear the gearbox is in, However I will remove the inner casing to see if I can understand what is going on
Thanks for the help
Mike
My A10 was a swing arm model with the totally separate gearbox. I don't know if your plunger has this box or the semi-unit item where the box is bolted to the engine. If it's the latter then I can't really offer any advice. If it is the separate box then I found it easier to take it off the bike as I couldn't manipulate anything in the gear box even with inner cover removed. You have to remove the primary drive, the clutch and the casings to get at the grub screw which holds the selector shaft in the gearbox. By the time you've done all that it easier to to drop the rear right engine plates off and take the box out. You can then put the gear box on the bench to rebuild it. A lot of work I'm afraid but it was the only way I could do mine.
Hi Again
After doing some research I have found out that my 57 Flash Plunger has the semi pre unit box bolted to the engine, so I am not enthusiastic about pulling the engine out to get the box out
As for the problem ; I can move the gear selector arm by hand up and down without the cam plate moving inside the box, this leads me to believe either something has dropped off or the gear selector arm plunger has not been set correctly, I want to remove the gearbox inner cover to assess what has happened if I can, my question is, what is the procedure for removing the gearbox inner cover with the box it still in the bike, I have tried pulling it off but not sure if I need to remove the kick start ratchet pinion and other parts, any advice will be appreciated
Cheers
Mike
Hi,
You will need to remove the kick start ratchet mechanism as it is attached to the main shaft which has the clutch on the other end. Once this is off the inner cover should come off. As it is on long studs it may take a bit of wriggling. It does sound like it was not indexed on assembly.
Dave.
BSA service sheet 209 available in the members section details the procedure for stripping the gear box on a rigid/plunger A10 without removing the engine and gearbox from the frame. Interestingly it doesn't mention indexing - it must be significantly different from the separate gearbox mechanism. The symtons you describe, however, are exactly what I had when my box was wrongly indexed so it must be something in the way the change mechanism that is not quite right. Possibly the claw not fully engaged with the quadrant ratchet. Happy hunting.
Thanks Dave and Pete
I will report any findings, I thought I read that there was no indexing dots on the Plunger framed Gearbox's ?
Mike
Hi Mike,
Yes, there are no markings on the plunger but I think the procedure is the same. If you have a manual, even if for later gearbox, it should give the procedure and a photo of the selector lined up on the dots. Use this to get the right position with the gears in neutral.
Dave.
The plunger gearbox should have no gasket between the case and the inner cover. If one is fitted the selector claw doesn't engage properly and changes don't happen. There's not much tolerance there, and wear on the claw can have a similar effect.
Hi,
Now that could be the problem. I wonder if anyone else is having a similar problem as it looks like gasket sets come with a gasket for this joint.
Dave.
This is the service sheet for re assembly of the rigid/plunger gearbox.
All it tells about the position of the selector in the inner cover is that it should be "in a central position"
Also there should be as gasket at this joint.
The original BSA gaskets were quite thin paper, some later modern ones are from quite thick material and I think use of these later ones should be avoided.
Hi All
I have removed the inner gearbox casing and found that the gear selector arm was not moving the cam plate, it looks like it has not been set up correctly,
it had moved past the cam plate Lugs so could not move the cam to change gear as there is nothing there to grab hold of
I moved the cam plate down by hand then set up the gear level up and now can move into and out of gear, I found neutral but am not sure how to set it up correctly so I can select all gears yet, Indexing marks don't seem to be anywhere
Do not have to remove the box thankfully , just need to know how to set up the cam plate and gear lever now, will mess with it and update
Mike
Hi thanks for all the help, sounds like there is some debate on a gasket or not on the inner gearbox cover, mine has a thin paper one, I will try the gearchange with the gasket and without, going to the freezing lock up later today to try to set up the gearbox again, so will report back my findings
Theses forums are invaluable, once again thanks for the help, hope to have her on the road for spring after a forty plus year retirement
Mike
I don't know if this will help I don't know what the internals look like in a A10 box but I had the same problem with my A65 turned out to be the pawls that operate the cam plate where lose due to the grub screw being lose on the end plate, just a thought Roy
Hi All
went to the lock up and removed the inner gearbox casing to have a look around, I removed the gear selector arm and moved the cam plate by hand to see if I could find the gears,which I could, although 3rd and 4th seem a little more difficult than Neutral 1st and 2nd, however I can select them all by moving the cam plate by hand, the correct position for the gear level when putting the inner case back on is neutral and this is easily done
However when the gear change lever is put back on and I try to change gears I can only get 1st Neutral and second and attempt to go to third and fourth is met with resistance, and the once I managed to get it into fourth you could see the pawl had lost contact with the cam plate and could be moved around a lot
so it is a distance thing, the trouble is what to do next ? new pawl and cam plate ?
I have attached photos of the Pawl and the cam plate, to me the Pawl looks ok and the Cam plate doesn't look too bad either but obviously they are not meeting each other , I am more comfortable with the gearbox internals now but am not confident about changing the cam plate, if I could get one
Thoughts comments welcome
Mike
Another photo of the cam plate
Hi
Quick update the gear selection issue I have been having, after checking everything in the box and then remounting the gearchange lever with the two springs to return it to the neutral position, I found I could not move the gear level down for higher gears, again , after examining the casing that holds the two springs it is fairly worn in the area where the springs sit and consequently one of the springs has been coming out of its seating and getting wound around the gear change lever inside the Inner cover, after many attempts to get the springs to seat properly and moving the gear lever side to side whilst the outer cover was off I could see what was happening, I have managed to get them seated correctly to try to see if that was the problem and bingo ! yes it was, I can now select gears again !
A lot of head scratching for a issue that was not inside the gearbox but on the gearchange lever itself, lesson learnt, experience gained
Thanks for all the help
Regards
Mike
Hi Mike,
Good result and a lesson learnt is lesson shared. I now know what to check if my wife's '51 Flash has a gear selection problem.
What a good Forum this is.
Dave.