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At last I am back working on rebuilding the gearbox and drive side on my 650SS, Its been a long time getting this far what with both of us catching Covid19 and my wife also had a stroke and seizures but she is now much improved and bossing me about as normal.

I rebuilt the gearbox and tested gear selection, all good. Have also refitted and renewed various clutch parts, Thanks NOCSHOP. I refitted the alternator and adjusted both primary and rear chains. When I turn the engine over using the crankshaft nut, everything working in the wrong direction, everything seems to be working well.

But when I try rotating the rear wheel in either direction the wheel will not rotate unless in neutral. I have tried this in all gears including top which is the least irreversible.

The kick start will not move even in neutral but does move if I use the clutch lever.

I cannot think this is normal?

Thanking you in anticipation and extra bonus points for pointing out my stupid mistake.

Regards Roger

 

 

 

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Cam timing wrong ? valves meeting piston ?.  Wrong barrels/sleeves  , conrods  not enough clearance to cylinders  cut outs?.Primary chain snagging on alternator housing?.A  valve rocker hitting the underside of cylinder head due to incorrect pushrod?. 99 pistons fitted (too long)? Miss located pushrod?.

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Sounds like you might have more than one gear selected at the same time. I had a car like that once. It drove perfectly OK, but when I pushed the gear lever forward when stopped still it engaged first and third at the same time. There was a missing interlock component but maybe you have a bend selector fork?

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Roger, you say gear selection is good and also good when you rotate the engine. If the engine rotates there appears to be nothing wrong there.  Also if the engine rotates then so must the g/box mainshaft. Despite what you say I think you have a problem in the g/box. Have you tried removing the primary chain selecting a gear and then try to turn the rear wheel.

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Separate the two elements by disconnecting the primary chain, re-try your wheel turning/kickstart pushing and confirm gearbox status. I'm in team G/box for this one

Confirm that then we  can  delve  deeper...

 

Jon 

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Hello Ian, disconnected the P/chain but all still the same. I will start by dismantling the clutch and then the gearbox. If I pull in the clutch lever both the K/start and R/wheel will move/rotate until the clutch is almost completely released. Does not this rule out 2 gears selected?

 

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Its normal that the Machine will try to move with the Kickstart  if the bike is in any gear and it makes no difference if the clutch is in or out.  It does sound odd  but its true. .

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Get it into the “locked” condition and start to dismantle sub assembly at a time. Levers off, check the situation; self centring mechanism, knuckle, front cover and so on?  At some point it will be clear what is amiss. It may be deep inside, but the deeper you go the simpler it gets.

Good hunting

Jon

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Let's get things in order. Sorry if this is obvious but the question is confusing me.

The engine when running always turns the clutch basket through the primary chain. When the clutch is not engaged, that's all that the engine moves.

Engage the clutch and now the engine is connected to the gearbox main shaft.  If the gearbox is in neutral, the main shaft spins but the output (sleeve gear outside the main shaft) does not move.

The kick-start turns the main shaft (because the gear on the layshaft actually turned by the kick-start is in mesh with the main shaft 1st gear). If it is in gear and the clutch is engaged, operation of the kick-start tries to turn the engine and the back wheel. If the back wheel is on the ground, the bike tries to move. So that's no use. If the clutch is disengaged, the kick-start still tries to turn the back wheel if it is in gear.  Isn't that what you are seeing? Nothing wrong.

If the clutch is then disengaged when in gear, the kick-start still turns the main shaft and rear wheel but not the engine. So that's no use.

In neutral, when clutch is not engaged, the kick-start turns the main shaft freely. No use.

To start the bike, it must be in neutral (so main shaft doesn't try to turn the output sleeve gear and thus the back wheel), and clutch must be engaged so kick-start turns the engine.

Exactly which of the above is not happening? 

I met an Indian chap who had ridden old Enfields which (he said) had a rear stand. He told me he kick-started his bike in first gear with the rear wheel off the ground. He said it was to get more flywheel effect! I don't suggest you try...I imagine the primary chain would have suffered a shock load.

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Hi David and thanks for your very detailed notes.

Basically the situation is; everything works as expected if the primary chain is removed.

If the chain is in place the kick start and the rear wheel cannot move.

If I turn the motor over and the P chain is in place the engine will turn the rear wheel.

It has been suggested I might have 2 gears engaged at the same time but surely I would not be able to select all four gears and the engine would not be able to turn the rear wheel.

I had better start dismantling again.

 

 

 

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Good luck. I wonder ( after a chat with RT of this parish), is the kick-start pawl the wrong way round? We Norton owners really are not blessed with enough good quality drawings to show us precisely how things fit together.  Especially sections.  The old manuals say things like "assembly is the reverse of disassembly"...which is hopeless when someone else (or even we) took it apart ages ago.

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suggest taking pictures: eg after removing outer cover, etc.

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Where are you Roger? Maybe someone could come over and have a look at it. Fresh pair of eyes etc. 

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Hi Ian, I live in East Dorset, yes new eyes would be much appreciated.

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You're a long way from me (Worc's) but maybe someone nearer might read this and offer some help. Good luck.

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Hello everyone, and thanks for your help but my problem persists; when I fit the primary chain on  my 1962 650SS the kick start lever will not move and the rear wheel will not rotate. Surprisingly when I rotate the engine backwards the rear wheel will rotate backwards. Has anyone encountered this before, and solved?

One of your replies suggested 2 gears might be engaged. Is it possible to have 2 gears engaged and yet still be able to select all 4 gears?

I have rebuilt the gearbox a few times now, I am not that familiar with the AMC gearbox but as far as I can be I am happy I have put the gearbox back together correctly, well I hope.

I have checked and there is a 0.020" clearance between the clutch back plate and sleeve gear so the sleeve gear and main shaft are not locked.

I did buy Mick Hemming's excellent DVD and followed it step by step.

I think I now know what frustration is like and am thinking of removing the engine and taking the 'box to an expert but would prefer to not do that.

Any helpful comments will needless to say be more than grateful.

Regards Roger

 

 

 

 

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A problem with the Kickstart Pawl would allow the rear wheel to rotate one way but not the other. perhaps the Pawl has been fitted the wrong way up.

Hi Phil, no I have just checked and my pawl and it is correctly fitted.

The problem seems to be similar to two gears engaged at the same time but I can select all four gears. Is it possible, with this gearbox, to do this if two gears are engaged at the same time?

Where a bush is used each item rotates freely.

 

 

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HI Phil,   I have found the pawl upside down on two bikes , All that happened was the pawl eventually slipped  after it wore  ,   Surprising that they work at all like this.

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There are two selector forks. One will disengage a gear and then the other engages another. A bent fork might cause a problem? I don't remember if both are the same and, if not, can they be fitted the wrong way round or swapped around?

Hi David, both forks are identical, I have checked for straightness and they can only go one way, that is with the forks back to back and the extended part, one pointing in and the other pointing to the outside of the box.

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In desperation I have ordered every bush/gasket/spring and ... from our NOC Shop.

While ordering I noticed there are 2 pawls mentioned; A2/418 and 9699. The pawl I have fitted doesn't look like either of them. Can this be the problem? The Kick Start lever seems to work when P chain disconnected.

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Interesting problem. Taking in order, does the engine revolve freely with the plugs out and primary chain disconnected? Are the plugs too long, and hitting the piston tops? Is the pawl in the gearbox set right? Checking with no primary chain fitted, one will not notice that the shaft and sleeve gear turn together. Are all gears in the right order, and the right way round. Are the parts in the gearbox all the same year, not a collection of a Barn Find? The gears can be fitted so that it does not work, I found that reassembling one. Good luck!

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Hi Paul and everyone else who tried to come to my aid. Have just received the bushes etc from Neil Shoosmith [thanks again Neil] which I will install and rebuild the gearbox again I hope for the last time; I am confident I have rebuilt the gearbox correctly after watching Mick Hemmings DVD several times [just to make sure] and the 2 or 3 times I dismantled and rebuilt it because I convinced myself I had made a mistake.

When all is rebuilt, as I said previously, the rear wheel locks up and the kickstart ever will not move. But I can rule the rear wheel by taking up the back lash in the chain and and can see the primary chain backlash taken up as well. So that leaves the engine except the engine will rotate when I use the nut on the drive side crank shaft nut, with or without the plugs in 

So the saga continues but it seem it might be an engine saga this time.

One good things has come out of this - I can rebuild the gearbox.

Thanks again for your helpful advice. I will let you know when I crack this problem or it ....

 

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Now you are an expert Box man ,a broken gearchange spring will hold no fears for you.! .If you look at the first reply to your  thread there are a few  ideas to be going on with !!.

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Why not go there and discuss the problem; I'm sure there will be willing support for you there.

 

Cheers

Jon

 



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