Primary bolt/socket sizes?

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interstateOz

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Hi all, I'm in the process of removing my primary from the engine, I have it all opened up but just wondering what size are the bolt heads that bolt the primary to the engine, I think there's 3 of them and they have tabs on them? Do I need to bend the tabs up to undo them too? I'm guessing these bolts are 1/2 as I only have a metric set and 12mm is too small while 13mm too big? Thanks guys Adam
 
if i purchased a set of Metrinch socket set and spanner set do u huys think this is all id need, ive never heard of them before but i read a post on here saying they were all that was needed? will they even do the engine, primary and gearbox bolts?
 
Yes, you need to bend the locking tabs down to remove the bolts. You need a 1/2" socket or wrench to remove them. There's not much in the way of metric fasteners on the Norton. Plenty of British sizes, though. A set of BSW/Whitworth sockets and wrenches would be handy, but you can get by pretty well without them if you have both inch and metric tools.

Ken
 
Also what size id the top for nut that bolts to the frame the yokes, is it the 1 1/8? as its hard to get a big shifter in to turn there, and my metric sockets dont fit it.
 
interstateOz said:
Thanks Ken, so when people say whitworth is this the same as an imperial set then?
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Generally, yes. Imperial is a descriptive term for fasteners commonly referred to as British, like BSW, BSF. BSW stands for British Standard Whitworth. There are also BSC, BA, BSP, BSTP, CEI, ME, and who knows what else. The usual American thread forms are UNC (Unified Coarse) and UNF (Unified Fine). UNF used to be SAE, and is still referred to as that by some folks. You also see both referred to as Standard, or American, or Inch threads by us common folk.

A little internet searching will find more than you ever wanted to know about different thread forms. britishfasteners.com is a good one for reference.

Ken
 
interstateOz said:
Hi all, I'm in the process of removing my primary from the engine, I have it all opened up but just wondering what size are the bolt heads that bolt the primary to the engine, I think there's 3 of them and they have tabs on them? Do I need to bend the tabs up to undo them too? I'm guessing these bolts are 1/2 as I only have a metric set and 12mm is too small while 13mm too big? Thanks guys Adam
Click to expand...

Adam, mate do yourself and the bike a favour: you serously need to invest in a) the workshop manual and b) some AF and Whitworth tools. Its not big bucks. What you are doing at present is going to make you and the bike unhappy.

Mick
 
yeh i realise this mick and thats why im trying to find out whats best to get as i dont wanna wreck or strip anything. I saw the metrinch tools which are meant to do both what are your thoughts on these? Mick could u list what AF and Whitworth tools youd suggest straight off the bat to get as a minimun?

Thanks mate
 
interstateOz said:
Hi all, I'm in the process of removing my primary from the engine, I have it all opened up but just wondering what size are the bolt heads that bolt the primary to the engine, I think there's 3 of them and they have tabs on them? Do I need to bend the tabs up to undo them too? I'm guessing these bolts are 1/2 as I only have a metric set and 12mm is too small while 13mm too big? Thanks guys Adam
Click to expand...

It sounds like yours are 1/2 inch (12.7 mm). The bolts on my '73 850 are 7/16" AF, which is a bit bigger than 11 mm. Yours may have been changed over to 5/16" bolts, the originals were 1/4", maybe it's different if it's a Mk III. I'm not sure if these were originally SAE or BSF threads. They have the same thread pitch, I believe, and a 1/4 BSF bolt has a head that's SLIGHTLY larger than 7/16" AF, so a 7/16" SAE socket will be a slightly snug fit on a 1/4 BSF bolt. You definitely need to undo the tab washers prior to loosening the bolts.

-Eric
 
Thanks BrianK but I do have all the workshop manuals already on CD I think it's a cd made/called KimCD man has every norton manual on it, although I'd much prefer to read a hard copy I might look around for. I'm pullingvthe motor out of my 1970 s type as it had a 72 motor put in it by some previous owner and I have sourced an original case with oil lines in correct spot as they were different the early ones, I'm thinking if trying the metrinvh set of sockets and spanners maybe they apparently do both.
 
Eric - they ended up being 7/16 like u thought just put an open ended spanner on it and the 7/16 is the one, thanks mate.
 
interstateOz said:
Also what size id the top for nut that bolts to the frame the yokes, is it the 1 1/8? as its hard to get a big shifter in to turn there, and my metric sockets dont fit it.
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The lower yoke nut is 1-5/16", the same size as the chromed fork top nuts.

The 3 primary bolts are 3/16 Whitworth but as you discovered, a 7/16" SAE will also fit.
 
maylar said:
interstateOz said:
Also what size id the top for nut that bolts to the frame the yokes, is it the 1 1/8? as its hard to get a big shifter in to turn there, and my metric sockets dont fit it.
Click to expand...

The lower yoke nut is 1-5/16", the same size as the chromed fork top nuts.
Click to expand...

However, if it's his 1970 'S' model, then the nut will be at the upper end of the stem which I believe could be 1-1/8"
 
interstateOz said:
yeh i realise this mick and thats why im trying to find out whats best to get as i dont wanna wreck or strip anything. I saw the metrinch tools which are meant to do both what are your thoughts on these? Mick could u list what AF and Whitworth tools youd suggest straight off the bat to get as a minimun?

Thanks mate
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Adam,

The immediate stuff that will help with 90% of the fasteners is - AF fits the chassis and Whitworth the motor & tranny. The most used spanners are:

1/4 AF, 5/16AF, 3/8AF, 7/16AF, 1/2AF, 9/16AF and 5/8AF. Get ring / open ender combos. Sockets in the same are very useful.
3/16W, 1/4W and 5/16W as ring spanners are important, and note in sockets 1/4W and 5/16W. Try to get 3/8" socket drive as 1/2" drives tend to be to chunky to fit down the cylinder head recesses.

Try Bunnings or better still Just Tools in South Melbourne (they have a website catalogue). Note Whitworth is sometimes rare to find at retail, so check Ebay, usually some old codger has a bunch of Pommie tools for sale.

Mick
 
LAB - yeh u were spot on the nut was at the top above the upper yoke, was extremely hard to get off fir some reason, minor surface rust in a little bit but even on the clean thread it was a battle I eventually one though :) Mick - u won't believe it I went around to my dads and he gave me his socket set from 30+ years ago and halfvthd bits ate whitworth the other half AF so I'm happy as, a friend gave me a witworth spanner to so I'm happy, thanks for the advice. Update- motor, gearbox and primary are out the bike has mow been stripped so I'm happy, frame is beautiful just needs a clean up where someone had put a side stand on in the wrong spot after the original had disappeared for who knows why, will grind off and finish back, already got the new side stand lug ready to go :)
 
T95 said:
The rocbo version loads right up on my computer, while the britmoto version takes several minutes.
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Once the britmoto manual pdf has downloaded, you can "save a copy" to your computer (in your document file, or wherever else you want to keep it) so there's no need to download it each time you want to look at it.
 
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