Chaincase to Z plate clearance

I'm rebuilding my old Commando and went mad on new parts including a new frame, gearbox cradle, isolastics and Inner chaincase, so far its been a painful build both financially and mentally, I've built god knows how many from the ground up but this one is doing my head in!
Today I tried fitting the inner chaincase (new from Andover), because I had the crankcase welded a few years ago I had to relive the inner a little to fit over the weld, not an issue and the old one was fine but was very scabby. I noticed the holes for the crankcase wouldn't line up so after much pissing around I relieved about 2mm of material so I could get the bolts in.
It all lined up fine until I tried the Z plate and spacer on the top bolt, lookis like instead of the 2-3mm clearance the chaincase is sitting high at the back and I have no clearance.
I'm suspecting the gearbox cradle but later this week I'll do a measurement of everything and see whats occurring.
Has anyone experienced this before?
Pretty fed up at the thought of a strip down again just when it looked like it was making progress

Oh and today my new sidestand doesn't fit properly on my new frame, I awaiting the outcome of that one...............

You didn't say where you bought all these new parts, so it's possible that some tolerances are not being met? Does the old inner chaincase fit any better?
I can tell you that my 74 has at least 3mm clearance for the inner and outer chaincases to the Z-plate, all the way around from the iso mount on top to the footrest mount, where the gap gets even bigger.
I suppose you could relieve the Z-plate too, but It seems something else is going on...

Frame and chaincase from AN this year, gearbox cradle from RGM about 11 years ago, Something is definitely going on!, just means a whole load of work I didn't expect.

OK after a sleepless night I had a Eureka moment, today I removed the mounting stud for the inner chaincase and managed to line everything up, it appears the mounting hole in the gearbox cradle sits a couple of mm higher than any of my other Commando's, on reflection this may be the issue as it is the fulcrum point and with the chaincase being so long a couple of mm in the middle (or 80 Thou) can make a fair difference at the back of the chaincase.
So initial thoughts are to simply slot the hole in the gearbox cradle a bit however I have now no confidence in any of the parts so will first of all do a thorough dimension and straightness check.

At least the world (Commando world) seems brighter for now...........

Gino Rondelli said:

OK after a sleepless night I had a Eureka moment, today I removed the mounting stud for the inner chaincase and managed to line everything up, it appears the mounting hole in the gearbox cradle sits a couple of mm higher than any of my other Commando's, on reflection this may be the issue as it is the fulcrum point and with the chaincase being so long a couple of mm in the middle (or 80 Thou) can make a fair difference at the back of the chaincase.
So initial thoughts are to simply slot the hole in the gearbox cradle a bit however I have now no confidence in any of the parts so will first of all do a thorough dimension and straightness check.

At least the world (Commando world) seems brighter for now...........

Click to expand...

Top man!

Onwards and upwards...

Fast Eddie said:

Gino Rondelli said:

OK after a sleepless night I had a Eureka moment, today I removed the mounting stud for the inner chaincase and managed to line everything up, it appears the mounting hole in the gearbox cradle sits a couple of mm higher than any of my other Commando's, on reflection this may be the issue as it is the fulcrum point and with the chaincase being so long a couple of mm in the middle (or 80 Thou) can make a fair difference at the back of the chaincase.
So initial thoughts are to simply slot the hole in the gearbox cradle a bit however I have now no confidence in any of the parts so will first of all do a thorough dimension and straightness check.

At least the world (Commando world) seems brighter for now...........

Click to expand...

Top man!

Onwards and upwards...

Click to expand...

+1 try not to let the set backs get to you ,it will be worth the effort when it's done

If you had the old cradle (or any functioning cradle), you cd compare it to the new pc from RGM, see if the holes are in the same place?
And no, sorry, I'm not gonna tear my bike apart so I can send mine for your comparison... 8)

Gino Rondelli said:

OK after a sleepless night I had a Eureka moment, today I removed the mounting stud for the inner chaincase and managed to line everything up, it appears the mounting hole in the gearbox cradle sits a couple of mm higher than any of my other Commando's, on reflection this may be the issue as it is the fulcrum point and with the chaincase being so long a couple of mm in the middle (or 80 Thou) can make a fair difference at the back of the chaincase.
So initial thoughts are to simply slot the hole in the gearbox cradle a bit however I have now no confidence in any of the parts so will first of all do a thorough dimension and straightness check.

At least the world (Commando world) seems brighter for now...........

Click to expand...

Good that you found the problem, but as I read the description, the mounting stud is sitting too far outwards (horizontally) rather then high (vertical)?
If so, it may be that the RGM cradle uses a thicker plate t hen the original, or that the cradle is being pushed over towards the the left side of the bike by something.

Edit - I had a very similar problem, which was caused by the fool who assembled the top gearbox bolt wrongly - see misalignment-mystery-t26799.html. I had to give myself a stern talking to after that one /Edit

This sort of problem seems to be typical of Nortons, you change one thing and you have to change or alter several others. For example, I fitted rearsets, resulting in the kickstart interfering with my leg. Bought a folding kickstart from RGM, now I have to change the gearlever (or reverse it), which also means that I'm very interested in the reversed gearbox camplate thread as well.......

Good luck, I'm certain you will sort this out.

SteveBorland said:

Gino Rondelli said:

OK after a sleepless night I had a Eureka moment, today I removed the mounting stud for the inner chaincase and managed to line everything up, it appears the mounting hole in the gearbox cradle sits a couple of mm higher than any of my other Commando's, on reflection this may be the issue as it is the fulcrum point and with the chaincase being so long a couple of mm in the middle (or 80 Thou) can make a fair difference at the back of the chaincase.
So initial thoughts are to simply slot the hole in the gearbox cradle a bit however I have now no confidence in any of the parts so will first of all do a thorough dimension and straightness check.

At least the world (Commando world) seems brighter for now...........

Click to expand...

Good that you found the problem, but as I read the description, the mounting stud is sitting too far outwards (horizontally) rather then high (vertical)?
If so, it may be that the RGM cradle uses a thicker plate t hen the original, or that the cradle is being pushed over towards the the left side of the bike by something.

Edit - I had a very similar problem, which was caused by the fool who assembled the top gearbox bolt wrongly - see misalignment-mystery-t26799.html. I had to give myself a stern talking to after that one /Edit

This sort of problem seems to be typical of Nortons, you change one thing and you have to change or alter several others. For example, I fitted rearsets, resulting in the kickstart interfering with my leg. Bought a folding kickstart from RGM, now I have to change the gearlever (or reverse it), which also means that I'm very interested in the reversed gearbox camplate thread as well.......

Good luck, I'm certain you will sort this out.

Click to expand...

I hear you there Steve!

I went through 3 or 4 different rear set set-ups before landing with something I liked cos of the knock-on effect of different issues.

In the end, I realised that my other bikes, all being up-for-up kinda meant it seemed to make sense to make the Norton up-for-up too, and that realisation changed the options for rearsets as it meant I could use a reversed lever and automatically get an up-for-up pattern.

But at least I now have a large box of footrests and pedals for future projects !!

Fixed today, it appears (by checking my other Commando's....always good to have another one or two to reference against) the hole for the chaincase fixing bolt was too high by about 1/4" , so a simple slotting of the hole has brought back alignment, don't know why and like I said earlier it was at least 10 or 11 years ago I bought it. Everything else seems to measure up ok so the resurrection of this bike can continue. Hopefully get it finished before Christmas and looking forward to seeing how it goes with the new Fullauto head.