Author Topic: Gearbox overhaul  (Read 3041 times)

Offline huddie

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Gearbox overhaul
« on: 17.10. 2012 13:32 »
Hi All, As the box is out see my last post, I have decided to look at a couple of issues I have with it.
The font cover is off now so with your advice hopefully I can make a start.

First problem is that the kick start jams occasionally. What is this likely to be. The quadrant, the Ratchet pinion or the Ratchet cog itself??. What should I look for to determine if the bits are worn or servicable as I haven't got new replacements to compare them with?.

Second problem 4th gear is difficult to select (only occasionally), if I put my toes under the lever and attempt to move it up a fraction then I can get fourth easily. I must point out that there is no decernable movement of the lever when I put my toes under it!!
The spring looks ok except that I would of thought that the two spring tangs should be crossed over the pivot but are not. I say this because on my other bike 74 kawa S3 the tangs have definitely got to be crossed. It it's not the spring is it more likely to be the selector plate or the quadrant in the inner cover??
Hope you guys can help.
Regards Huddie

Offline duTch

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Re: Gearbox overhaul
« Reply #1 on: 17.10. 2012 14:03 »

 Dunno off-hand Huddie, you'll just have to look and play with it, maybe the indent plunger/spring needs attention?     
      I think the Kickstart jamming has some kind of part number? similar to sometimes not being able to select a gear whilst stationary(engine off?), just roll the bike in (or out of) gear, as my perception is that the start quadrant and mainshaft ratchet gear teeth just sometimes don't mesh readily.
 The box isn't difficult, just take your time, and play with it-help ain't far away!
 Cheers duTch

  Nb I have a plunger now and though similar,maybe forget what I did know 'bout the S/a box
Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy
Australia

Online muskrat

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Re: Gearbox overhaul
« Reply #2 on: 17.10. 2012 14:25 »
 G'day huddie, have a look at the ratchet pinion bush but also check the kickstarter spindle and lever spindle bushes. All 3 of my A's do it now and then.
4th gear could be a number of things. Sounds like a selector plate or associated parts problem. Check for excessive play or misalignment in all parts. The spring is right.
Cheers
'51 A7 plunger, '57 A7SS racer now a A10CR, '78 XT500, '83 CB1100F, 88 HD FXST, 2000 CBR929RR ex Honda Australia Superbike .
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Offline chicago

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Re: Gearbox overhaul
« Reply #3 on: 19.10. 2012 00:45 »
hi , my kickstart jams because the first tooth on the kickstart quadrant has snapped off and makes it jam. youll prob know this already but when the kickstart jams just pull the clutch in.
all the best, chicago
Location: north west madchester.
Preferred location: somewhere warm and dry.
Bike: 1953 plunger Longstroke engine.

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Re: Gearbox overhaul
« Reply #4 on: 19.10. 2012 09:46 »
 That reminds me, chicago, I dremeled the first tooth on one of them (can't remember which one) to help engagement. Must be the cafe as it does it less now.
Cheers
'51 A7 plunger, '57 A7SS racer now a A10CR, '78 XT500, '83 CB1100F, 88 HD FXST, 2000 CBR929RR ex Honda Australia Superbike .
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Offline huddie

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Re: Gearbox overhaul
« Reply #5 on: 19.10. 2012 14:52 »
The teeth on the kickstart quadrant look fine but I want to strip it out of the gearbox cover to have a good look. My Haynes comic says to use the clutch lever as a stop to prevent the kick start spring from unwinding, which I have, but what is the prefered way of removing the tension in order to be able to dismantle the kick start mechanism. It I just release the clutch arm while holding the kick start spring pressure how far is the kick start lever going to move before the tension is removed. Having released the tension, stripped it and put it back how does one retension it?
Hi Muskrat, what exectly did you do to the first tooth!! what profile has it got now?
Regards Huddie

Online bsa-bill

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Re: Gearbox overhaul
« Reply #6 on: 19.10. 2012 18:04 »
there's not a tremendous amount of pressure on it Huddie.
Hold the cover in a vice or place it on the ground with your foot on it and just pull the kickstart lever back off the clutch arm and let the clutch arm swing in/down

Re-assemble is as they say the reverse
All the best - Bill
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Re: Gearbox overhaul
« Reply #7 on: 19.10. 2012 20:09 »
G'day huddie, about 1/4 turn tension on the spring. I just rounded the leading edge and a few thou off the top.
Cheers
'51 A7 plunger, '57 A7SS racer now a A10CR, '78 XT500, '83 CB1100F, 88 HD FXST, 2000 CBR929RR ex Honda Australia Superbike .
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Online RichardL

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Re: Gearbox overhaul
« Reply #8 on: 19.10. 2012 20:50 »
I had the same problem with a jamming kickstart lever and, to my recollection, it is possible to buy a quadrant with a tooth pitch that does not match the pinion. It came down to pointy teeth on the quadrant versus somewhat flat-topped teeth. Pointy teeth being correct, in my case.

Richard L.

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Re: Gearbox overhaul
« Reply #9 on: 19.10. 2012 23:17 »
Hey, I knew we'd been over this before. Check out this link: http://www.a7a10.net/forum/index.php/topic,3220.0.html

Also, I think there is more if you search the word "pointy".

Richard L.

Offline chicago

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Re: Gearbox overhaul
« Reply #10 on: 19.10. 2012 23:52 »
That reminds me, chicago, I dremeled the first tooth on one of them (can't remember which one) to help engagement. Must be the cafe as it does it less now.
Cheers
hi muskrat, good idea, might have a go at mine, all the best fella, chicago
Location: north west madchester.
Preferred location: somewhere warm and dry.
Bike: 1953 plunger Longstroke engine.

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Re: Gearbox overhaul
« Reply #11 on: 20.10. 2012 03:22 »
Just make sure that IS the problem. Not good doing it and then later finding it was the bush or something else. *problem*
Cheers
'51 A7 plunger, '57 A7SS racer now a A10CR, '78 XT500, '83 CB1100F, 88 HD FXST, 2000 CBR929RR ex Honda Australia Superbike .
Australia
Muskys Plunger A7

Offline chicago

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Re: Gearbox overhaul
« Reply #12 on: 20.10. 2012 16:20 »
Just make sure that IS the problem. Not good doing it and then later finding it was the bush or something else. *problem*
Cheers
will do fella, cheer's, all the best, chicago
Location: north west madchester.
Preferred location: somewhere warm and dry.
Bike: 1953 plunger Longstroke engine.

Offline huddie

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Re: Gearbox overhaul
« Reply #13 on: 25.10. 2012 14:39 »
Hi all, Got the outer and inner covers off. looking at the kickstart first. The leading tooth on the quadrant looks like its been filed down, similar to Muskrat's mod. The nut holding the pinion on was loose!! (going to replace the pinion). Didn't need a spanner to undo it, guess thats's not good. I have aquired a kick start shaft thats in better nick than mine but the quadrant is missing so I will need to swap it to the new shaft. Am I right in thinking it is just pressed on? does it come of the shaft from the inner end or the kick start lever end, please?. There seems to be rather a lot of play in the kickstart outer bush. Does it make any difference again which way I press it out/in?. Does the new one need to be reamed after fitting?.
With the gear change, The two teeth on the selector plate look a bit worn to me, but it's probably going to have to go back in as they seem to be as rare as rocking horse manure. Going to change the return spring. Likewise outer gear change bush has quite a lot of play in it, This looks like it has to come out towards the inside of the case, again do they have to be reamed.
Hope you can help.
Regards for now Huddie

Offline Topdad

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Re: Gearbox overhaul
« Reply #14 on: 26.10. 2012 10:22 »
Good morning Huddie , from memory (over 16mths since I did mine ) the splines are only cut so far done the k/start shaft I simply supported quadrant on the vice jaws applied a little heat and tapped the shaft through the quadrant there was a little indent in the end of the shaft I guess from the lathe centre post which the drift was able to use to save damage . came apart very easily. Both gear change and kickstart bushes will need reaming and come out inwards ,if you can use the oven heat nicely with the joint and they'll almost drop out . I got my reamers from Tracy's tools in Torquay. Hope that helps BOBH. 
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