Gearbox Spocket woes....

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olympus

olympus

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Well the big day has come.... wheeled out the Roadster into the sunshine... mounted an auxiliary tank to my step ladder coupled up strobe lamp and carb manometer
And yes she started after 7 kicks
Absolutely over the moon after 2 1/2 year restoration
All going well until I ran through the gears....and I have the most awful grinding, noise from around the front gearbox sprocket area...
Got up back up on the bench to see the chain which is standard 5/8x3/8 Is rubbing on the gearbox casing.
I can see that the spacer/seal runner is fitted.... it's difficult to see but I'm thinking I may have fitted the sprocket round the wrong way.
Before I pull off the covers can I ask if anyone has had side clearance issues with the standard 530 chain???
 
different chains have different thicknesses, old school renolds were the thinnest. The sleeve gear bearing might not be home,or the bearing to trans fit is loose , ( but thinking about it the trans wouldn't work if it was too far inwards ). I had trouble once when somehow I got a precommando sprocket that had the wrong offset. There is no way to install the sprocket backwards
 
I got the sprocket from RGM and the chain from AN... all new bearings fitted With. No end gloat noted.... I'll double check the sprocket off set against the one removed
 
The shimming of the inner primary case on the center stud could be the culprit. Also you might try just turning the master link around.
 
batrider said:
The shimming of the inner primary case on the center stud could be the culprit. Also you might try just turning the master link around.
Click to expand...

Is it hitting everywhere? Are you sure the RGM sprocket is correct? Compared to a known Commando sprocket?
 
olympus said:
Well the big day has come.... wheeled out the Roadster into the sunshine... mounted an auxiliary tank to my step ladder coupled up strobe lamp and carb manometer
And yes she started after 7 kicks
Absolutely over the moon after 2 1/2 year restoration
All going well until I ran through the gears....and I have the most awful grinding, noise from around the front gearbox sprocket area...
Got up back up on the bench to see the chain which is standard 5/8x3/8 Is rubbing on the gearbox casing.
I can see that the spacer/seal runner is fitted.... it's difficult to see but I'm thinking I may have fitted the sprocket round the wrong way.
Before I pull off the covers can I ask if anyone has had side clearance issues with the standard 530 chain???
Click to expand...
Yes, standard 530 chains are too wide. HD 530 chains are WAY too wide. Is the chain or just the master link rubbing? AFAIK, AN sells the correct chain which is not standard 530. PM me for more.
 
batrider said:
The shimming of the inner primary case on the center stud could be the culprit. Also you might try just turning the master link around.
Click to expand...

That might be the issue if the chain was rubbing the inner primary case, but I believe the chain is rubbing the gearbox, so shimming the primary case won't do anything to change the clearance between the sprocket and the gearbox...

Olympus, The oldbritts website mentions the possibility of shimming the sprocket, and sell shims for that purpose. The information is part of their O-ring chain conversion tutorial which I posted the link for below. They really are good people to order from, and have supplied norton owners with great "how to" information free of charge for many years.


The other thing you mentioned is checking the offset of the new sprocket. I think that may be where the discrepency lies. Whether your new sprocket is a "knock off" and out of spec or genuine and out of spec, I would bet both scenarios are possible.
 
marshg246 said:
Yes, standard 530 chains are too wide. HD 530 chains are WAY too wide. Is the chain or just the master link rubbing? AFAIK, AN sells the correct chain which is not standard 530. PM me for more.
Click to expand...

+1 one what Greg writes above. Different 530 chain widths is ... why I ordered my last 530 chain for a Norton from him. Good luck on fix ...
 
I replaced mine when the counter sprocket & clutch was magically done and notice the oiled chain turning silver.... moving forward I pulled it all apart finding my inner case being steadily worn through. Placed a thin shim washer behind the center mount and checked for excess stress, of which there was none, good to go. The 530 I purchased wasn't o-ring but it was heavier than the previous chain and would have caused a serious issue had I not been monitoring the work.
 
Many thanks for all your thoughts and ideas guys, these are appreciated..
The chain is only striking the gearbox casing, there is suitable clearance to the primary cover
Also checked there is no movement, lift or end float to the sprocket & is tight on the sleeve gear
I now have doubt as to whether both chain & sprocket are correct
The sprocket came from RGM
www.rgmnorton.co.uk

COMMANDO GEARBOX SPROCKET 20 TEETH 5/8" X 3/8"

5/8 X 3/8 COMMANDO GEARBOX SPROCKET 5/8" X 3/8" GEARBOX SPROCKET FOR COMMANDO SPR-N20T 20TEETH COMMANDO GEARBOX SPROCKET RGM NORTON SPRN20T
www.rgmnorton.co.uk
The chain came from AN
andover-norton.co.uk

Andover Norton Parts Drawings - Genuine Andover Norton Factory Parts - Commando Parts

Andover Norton Parts are the only Norton spare parts in the market manufactured to original drawings, within the factory-approved tolerances, from the correct materials, and with the correct finish.
andover-norton.co.uk
The chain purchased was a IWIS 5/8 x 3/8 (530) Pt No 06.5441
I ordered this specific to model, so i thought i was purchasing the correct one!!

So just to ask again, if were saying here that the 530 chain is too wide.... what should i be fitting??
 
Have you not approached AN with the problem? I too have a 530 chain waiting to be fitted (though it's not essential yet) purchased because that is sold as 'correct' fitting for these bikes (my MK3, at least)
 
olympus said:
The chain purchased was a IWIS 5/8 x 3/8 (530) Pt No 06.5441
I ordered this specific to model, so i thought i was purchasing the correct one!!
Click to expand...

That's an IWIS Elite chain in AN's photo (IWIS Elite was a chain Andychain didn't recommend) so it's odd that it is too wide as the IWIS 10-B Andy sold (and presume Jason still does) isn't.

olympus said:
So just to ask again, if were saying here that the 530 chain is too wide....
Click to expand...


What is the pin width?
 
Olympus, if you drop a vernier on your chain and let us know the width of it, I’ll do the same on my chain-man IWIS and we can compare.
 
My chainman IWIS 10-B measured about the same on a normal link pins, and 20.94mm at the masters pins.
 
Same here to both of the above (give or take a small margin of error).

Its not your chain.
 
I'm thinking it could be the sprocket as the sleeve gear, bearing & spacer were replaced at gearbox overhaul
Does any one know off hand what the sprocket offset is??
 
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