Misalignment Mystery

I was going to fit the primary chain case to my rebuild tonight, but when I place it, it's badly misaligned. If I align the inner on the crankcase, the gearbox top bolt hits the sprocket shield on the inside of the primary chaincase. If I set the chain case so that it clears the bolt, the crankcase is off by 12mm or so.
How can this occur? The engine & gearbox both seem to be sitting correctly in the cradle. There is very little play in the gearbox bottom bolt, so presumably it is correctly located. The engine also looks to be correct, but the two do not align when the inner chain case is fitted.

I tried slacking off the engine bolts to see if anything over, but of course nothing happened.

All these bits are original, and last time I had everything in bits (last year), there was no problem in assembly. Obviously I've cocked up somewhere, but I simply cannot see where.
Any ideas?

I have some photos which I can post tomorrow.

/Steve in Copenhagen.

A photo would be useful

The top bolt head should be on the opposite side, with the sleeve nut on the primary side locating into the adjusting slot - is yours like this?

Andy there are two different types, one where the bolt itself has a rounded head with two inner tangs that locate in the slot on the primary side with the nut tightening from the timing side. The other type is where the tangs are on the nut itself. The tangs prevent the nut or bolt moving when tightening from the opposite end.

Steve,
Is the gearbox top bolt spacer in the correct position?
Part number 03.0023 on a 72 model.
Dave

Here's a bit more info.
Gearbox - I'm using the RGM double sided adjuster setup, and actually (thanks to your comments!) have noticed that I've put this in from the wrong side. I'll swap this over of course, but it should not affect the vertical alignemnt as far as I can see. The inner chaincase is fouling on the bolt, so there's definitly no space for the head.
As I mentioned, all this has not changed, unless the workshop pixies (evil lille buggers!) have deformed the cradle

While I'm doing this, is there any problem with flipping the TS gearbox adjuster so that it's in front of the top bolt rather then behind it as standard? It would be easier to get to and I don't seen any problems with doing this. The extra adjuster on the DS is already forward of the bolt for this very reason, but I seem to remember something whih prevents this in the TS?

At somepoint, the gearbox spacer has been left out, so the cradle is slightly bent on the top. I managed to get the standard spacer in, but it makes the gearbox rather difficult to move, so I think I will go back to the thinner spacer I was using before. Next time I pull everythnig apart again (hopefully not in the near future), I'll have a go at removing the bend, but I don't think it's critical right now.

Due to a lack of better ideas, my current plan is to remove the headsteady (one of the really neat Dave Taylor types, again this was on the bike last year), loosen all the crankcase - cradle bolts, remove the front iso bolt and move the engine upwards, then try to reseat it. If I offer a bottle or three of best English bitter to the Norton gods, perhaps it will resolve it'self?

I should be able to post some photos when I get home today, but it's not possible at work.

SteveBorland said:

Here's a bit more info.
Gearbox - I'm using the RGM double sided adjuster setup, and actually (thanks to your comments!) have noticed that I've put this in from the wrong side. I'll swap this over of course, but it should not affect the vertical alignemnt as far as I can see. The inner chaincase is fouling on the bolt, so there's definitly no space for the head.

Click to expand...

Yes, the bolt head goes timing side.

B+Bogus said:

Click to expand...

swooshdave said:

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Thanks LAB, that picture does ring a bell - perhaps that's the solution to the whole problem - I hope so
Any comments about flipping the TS adjuster over in the same way as the DS in your lovely pictures?

SteveBorland said:

Thanks LAB, that picture does ring a bell - perhaps that's the solution to the whole problem - I hope so
Any comments about flipping the TS adjuster over in the same way as the DS in your lovely pictures?

Click to expand...

They're not actually my pictures, but with the adjuster forward I would think it will be directly behind and possibly be fouling the scavenge oil pipe?

Good point, on my bike I've blocked this off and drilled a vent in the crankcases as per the CNW valve, tapped for a hose barb which connects to one of the XS650 PCV valves. I might still have space for the adjuster there.

/Steve.