The BSA A7-A10 Forum

Technical (Descriptive Topic Titles - Stay on Topic) => Gearbox, Clutch, Primary => Topic started by: Topdad on 06.07. 2011 14:37

Title: gearbox.
Post by: Topdad on 06.07. 2011 14:37
Good afternonn everyone, finally got round to doing this. Just in process of moving house ,dealing with solicitors AND not being able even to get out on the bike! Here's the problem and I know it's something daft that I 've done but i can't get my head sorted  . advice and required asap. (also here's one piece of other advice; don't move house after 38 yrs where did all the crap come from??)
rebuilt the box on my '59 A10 during winter new layshaft bearings and layshaft reground plus 1st gear rebushed , likewise rebused mainshaft sleeve gear ,renewed all bearings in the case even down to outer cover kickstart bush and gear selector bush. all components checked and then rebuilt in clean area and found gear selection vague ie would work then not . filled with oil modern stuff just to lube it , and eventually over a couple of days bingo all 4 cogs and seemed ok. replaced in frame and adjusted chains and clutch ,4 springer quite good cond , used a pointer to get the pressure plate level and clutch works fine no drag and clears fine. Engine fired up 3rd kick ,after 10 mths after 10 mths wow ??? runs fine, clutch in, into 1st ,ok, 2 nd ok then 3rd gear lever vague and had to "feel "the gear in  with my toe 4 th okay down everything took 2 attempts and had to stop engine to find neutral , only got it after a few up and downs on the lever.  Adjusted the clutch cable and that sorted that prob re neutral although I restarted the problem selection wise is still there and so ***** off I left it  ( please excuse that but just left it so that you can tell how urgent this is ) Any help please, was considering adjusting the cam plate  adjuster would that help ,over to you guys best wishes Bob Hebdon.
Title: Re: gearbox.
Post by: bsa-bill on 06.07. 2011 15:31
Hi Bob
more g/box experts will have more to offer but, as regards the camplate plunger the advised settings is two threads showing beneath the lock nut.
My own experience of problems in converting a two gear box to four gears involved renewing the selector pawl  ( the double clawed bit attached to the gear lever )

This created another problem with the gear lever not returning to middle position after down changes, this was cured by using two gaskets on the outer cover.

hope this helps
Title: Re: gearbox.
Post by: Goldy on 06.07. 2011 18:10
The selector pawl is always worth looking at for gear selection problems. Also if you have fitted new bushes some are slightly too long or too thick on the flange which can cause binding and hence selection problems. All the best.
Title: Re: gearbox.
Post by: chaterlea25 on 07.07. 2011 00:06
Hi Bob,
Just another thought  *idea*
What oil have you put in the primary case?

John O R
Title: Re: gearbox.
Post by: Topdad on 07.07. 2011 09:55
 Bill and Goldy,I forgot to mention I changed the selector pawl 'cause the old one was showing wear but i'm just wondering if it could be something in the outer case .re John O'r ,still running it with the case off just oiling by drops at present, however, just thought I forgot to drain the other thin oil off ,I only really put it in to check for oiltightness and in my haste to get it running forgot to change it and refill ,do you think this could effect it? Many thanks for all your swift replies any thoughts gratefully received Bob H 
Title: Re: gearbox.
Post by: Topdad on 28.07. 2011 18:04
Hi everyone , I've just had a couple of hours on the a10 and the engine's running sweet but can't say the same about the 'box. It's still a mess , will go into 1st and select neutral no problem, 2nd sometimes but not any further. Further to Muskys suggestion I've tightened the cam plate adjuster , and loosened it and back to 2 threads visable. no change. Doe's this suggest selector pawl problems like bill suggested ie 2 gaskets etc, or should I bite the bullet and strip it down insitu and take it from there. I am now at the end of my tether  and would really like to ride this thing again !!!!!!!! even if only to it's new home. All ideas welcome. regards Bob H.
Title: Re: gearbox.
Post by: RichardL on 28.07. 2011 19:43
I'm  not going to be much help in analyzing the problem by remote control. I've been inside my gearbox once, when I rebuilt it in 2005, but inside the outer cover several times. I can't think of anything under the outer cover that would cause the problem, but I have some questions that might help understand or find the problem. Can you put it in gear by hand with the engine off? If you can, with the clutch in, does the gearbox feel smooth as you hand turn the rear wheel? Can you execute gear changes while hand turning the rear wheel?

Anyway, given that various camplate plunger adjustments don't help, it sounds like it's going to have to come apart, but you may want to wait a bit for others having more experience inside the gearbox than I to chime in, just in case they know the exact location to apply the hammer from the outside to make it work.

Richard L.
Title: Re: gearbox.
Post by: bsa-bill on 28.07. 2011 20:48
Hi Topdad, annoying as it is there might be a fairly easy remedy, Presuming you used the cogs that came out of the box because there is one cog used in plunger boxs that is not compatible with S/A.
I would take the outer cover off and using a large screwdriver to move the selector see how many gears you have, If you have not got four then the problem is inside he box
next thing to check is the indexing, with the box in neutral ,before fitting the outer cover , line the red dot on the selector with the corresponding dot on the inner case, if you did this (course you did) and the dots are correct try them one tooth out ( red dot a little down from it's mate or a little up), this worked for me
Title: Re: gearbox.
Post by: Topdad on 29.07. 2011 10:13
Thanks Bill, No the cogs are definately what came out of the box so that should be ok ,this gives me a plan to work to ,which is what I need at this time ,to close to the problem to see the wood for the trees, many thanks ,will let you know,fingers crossed, Bob H
Title: Re: gearbox.
Post by: muskrat on 29.07. 2011 15:15
G'day Bob, frustrating isn't it. Took me years to find a bent selector in the '51, and your problem sounds similar. Have you tried Richards suggestion. Next is Bills method of indexing with a screwdriver. Sort of sounds like one of the forks misplaced, like it is only engaged with one gear instead of two. Not ready for the hammer yet.
Cheers
Title: Re: gearbox.
Post by: Topdad on 30.07. 2011 09:59
Thanks Musky, hope I can look at it over this weekend so will let you all know of progress...........or not as thecase may be , cheers BobH
Title: Re: gearbox.
Post by: Topdad on 08.08. 2011 12:06
Morning everyone, I whizzed the end cover of and can move the selector lever to neutral doesn't what to move again ,either way , I didn't have enough time to slaken off the camplate adjuster so I may have left that to tight but not sure, will kep you posted, regards BobH
Title: Re: gearbox.
Post by: wilko on 09.08. 2011 22:32
When testing for gear selection you must always turn the mainshaft at the same time for the gears to mesh cleanly, or it might give you a false sense of hard selection.
Title: Re: gearbox.
Post by: Topdad on 10.08. 2011 09:39
Many thanks Wilco, I'll bear that in mind, regards BobH
Title: Re: gearbox.
Post by: brackenfel on 14.08. 2011 10:15
Don't know if it's any help here but I found that with a couple of boxes I have there's more than one way to "line up the red dots" ! By that I mean that I found that it is possible to make them appear to roughly line up in two positions. I found that the one that didn't look quite right was the one that worked..

Failing that it'll be a case of taking off the inner again (I got rather good at dismantling gearboxes when I redid mine) . Make sure you haven't left that thin spacer out on the layshaft, it's easily done!

Good luck,

Adrian
Bristol UK
Title: Re: gearbox.
Post by: Topdad on 16.08. 2011 09:33
Thanks Adrian, I tried Bill's idea on saturday , only had an 1/2 hr but the selector moved ,could get 1st and neutral easy, but the other 3 were still hit and miss. I've got about 4hours free this SAT so it will be sorted then, either it'll play nice or i'll strip the bloody thing down again and take it from there ,thanks for all the help from everyone and i'll keep you posted, when i sort it Musky and all the others in Oz will hear the shouit!!!! BobH ( or totally demented of Liverpool. )
Title: Re: gearbox.
Post by: Topdad on 22.08. 2011 10:22
Morning everyone, has I had planned on Saturday the wife was out getting her feet nibbled by fish??????? but on the plus side I had a day to sort out this 'box. Armed with the info from Bill and Adrian I had the kickstarter of the mainshaft and loosened the inner case pulled it back until the selector dropped and then repositioned with the dot 1 out, tightened up used the screwdriver to check and low and beyond 4 cogs and neutral. Rechecked and still okay, I was like a dog with 2 whatnots, ie extremly happy!!!! the neighbours must have thought there was a banshee in the shed or worse with all the shouts . Anyway end cover on and the gears clicked absolutely cleanly I was made up. I had to make a gasket and that was the longest part to getting all together. After an hour I had it all together oil in and ready to try . She started 2 second kick ,would have been 1st time but for the cloth in the carb!! tried the gears and they moved beautifully very positive ,very light and quiet ,my god it had been knackered before I hadn't realised how bad but it was still working. So I'm very happy and would like to thank everyone for thee thoughts and advice,particularly Bill  and Adrian now just MOT it and then it'll be business as usual, best wishes BobH.
Title: Re: gearbox.
Post by: bsa-bill on 22.08. 2011 10:36
Nice one Bob, hopefully I'm off to get an MOT today, just got to make a phone call see if they can do it today
Title: Re: gearbox.
Post by: Topdad on 22.08. 2011 12:24
Best of luck Bill , sure it will pass,regards BobH
Title: Re: gearbox.
Post by: bsa-bill on 22.08. 2011 12:42
Thanks BobH, yep just back passed OK, usual queerie regard the headlamp beam, not a lot of difference between high and low ( due I reckon to Mr Goffs halogen/British Pre Focus bulb).
Great day for a run down to Berwick and a natter to the guy who does the MOT, he's more used to scooters and off road stuff so an old classic makes a nice change for him
Title: Re: gearbox.
Post by: muskrat on 22.08. 2011 15:35
That's great to hear Bob. So you just have to tilt your head a little when lining up the dots.
 And Bill, good to hear the MOT went well, still a few months of riding weather left for you.
Cheers
Title: Re: gearbox.
Post by: Topdad on 22.08. 2011 16:12
Yes ,Musky, I'm chuffed also pleased I took your advice .....and hid the 4lb lump hammer! regards BobH.