removing/replacing norton magneto bottom nut?

L.A.kevin

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Mar 11, 2012
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I spent the better part of 2 hours yesterday lying on the concrete floor of my garage extracting that bottom nut on the magneto of my 60 Dominator. That thing is a PITA to remove and install.

What tricks do you folks use for this job. And, before you suggest it, I looked into using an A10 long nut, but it won't fit my bike because the crankcase interferes with it.

thanks,

Kevin
 
Magic dust (only available through connection to Santa Claus)

or

The way you did it.
 
That long A10 nut should actually work. It may need to be wasted a little in the middle and offered up with the other two nuts loose enough to allow the mag to lift up a little while you slide the lower long nut into place. Hold the washer in with grease.
 
johnm said:
That long A10 nut should actually work. It may need to be wasted a little in the middle and offered up with the other two nuts loose enough to allow the mag to lift up a little while you slide the lower long nut into place. Hold the washer in with grease.
Click to expand...


The casting on my crankcase prevents this. The web extends out far enough, right in this area, that it puts it about .150" off the centerline. I'm not about to go dremeling on the crankcase for clearance.

Keep the suggestions coming. I appreciate it.
 
L.A.kevin said:
I'm not about to go dremeling on the crankcase for clearance.
Click to expand...

Why not ? Its only a mm or 2 required...
Early Model 7 dommies (Nortons first twins) don't have clearance for the waisted BSA long not,
and slightly later versions have quite a pronounced V cast into the cases so the nut DOES have clearance.
I've always thought that was an excellent improvement.
Although the pronounced V does look like a potential weakness
- we would have thought it should have been 'dremmelled out' to a less stress-inducing curve...
 
I agree....it is a PITA squared. This nut has got to be the mother of all nuts I ever removed.

I removed the gearbox cover to get more room to work the spanner and see where the spanner needed to go, next I removed the oil supply/return tubes and manifold ( you can just pry the manifold away without removing the flex hoses), then I ground a little off one jaw of the open end wrench to get just a bit more angle on a turn....you can only get about 1/16 turn per application of the spanner.

Norton went to a bolt with a nut inside the timing case....I looked at going to this, but it would mean spot facing something off the inner timing case to clear the magneto drive chain....I was not willing to do that. Maybe a thin nut with exactly the right length bolt might clear the chain. You might look into it....but first you have to get the blasted nut and mag off!

When you put it together, be sure the stud has clean threads and the nut can be run up and down its full length with your fingers. Use an internal lock washer and do not use lock tite or any other thread sealer so the next time it comes off will be easier.

Slick

Good luck
 
The later distributor (mid-'67 to mid- '69) used a similar setup, except the bottom is a nut and bolt. On both my '67 and '69, I took a dab of contact cement and glued the nut to the distributor housing, then ran the bolt through the inner timing chest into the nut and carefully started it. Once on, its not that hard to hold the nut in place with a screwdriver (a wrench is nearly impossible) while ratcheting down on the bolt. Bolt head clears the sprocket and chain.
 
BillT's solution might be a winner. I would try to come up with something better than contact cement to hold the nut....having the bolt pop it off time after time while trying to get it started would drive me as crazy as fighting it as it is. Dunno what ... I have seen cages for nuts, but don't know how to apply that concept. Maybe JB weld the cage to the mag flange, and let the nut float inside the cage.

If I were to split the cases, I would definitely modify the timing case to pass a socket head 1/4-28 machine screw thru from the mag side to the timing case, then spot face the timing case as required to get clearance. There needs to be a crush washer seal on the nut ( or bolt as BillT suggests) . The existing stud is 5/16 - 18, so if you put in a 1/4 bolt, there will be a large gap.

Once I undid all mentioned in my first post, putting the mag and nut back on was a piece of cake....it is just the next time we all worry about.....

Slick
 
I use an off brand 7/16 box end (ring spanner) wrench. I then carefully grind off excess metal around the outside of the "ring" , or box end for clearance. Then cut the opposite end of the wrench off to shorten it. Works perfectly.
 
skipsoldbikes said:
I use an off brand 7/16 box end (ring spanner) wrench. I then carefully grind off excess metal around the outside of the "ring" , or box end for clearance. Then cut the opposite end of the wrench off to shorten it. Works perfectly.
Click to expand...

if the person with the problem hadn't tried that sort of thing, I'd be disappointed in him.
 
Triton Thrasher said:
skipsoldbikes said:
I use an off brand 7/16 box end (ring spanner) wrench. I then carefully grind off excess metal around the outside of the "ring" , or box end for clearance. Then cut the opposite end of the wrench off to shorten it. Works perfectly.
Click to expand...

if the person with the problem hadn't tried that sort of thing, I'd be disappointed in him.
Click to expand...

I do have a short 7/16 cranked wrench. I don't like the sloppy fit on the whitworth nut. It also still took me quite a while to remove the fugger because of the inability to get more than a 16th of rotation. I was looking for other ways to skin the cat. Would still like to hear some other suggestions.

I'm thinking a wobble extension and a thin wall whitworth socket, which I have.

K
 
L.A.kevin said:
Triton Thrasher said:
skipsoldbikes said:
I use an off brand 7/16 box end (ring spanner) wrench. I then carefully grind off excess metal around the outside of the "ring" , or box end for clearance. Then cut the opposite end of the wrench off to shorten it. Works perfectly.
Click to expand...

if the person with the problem hadn't tried that sort of thing, I'd be disappointed in him.
Click to expand...

I do have a short 7/16 cranked wrench. I don't like the sloppy fit on the whitworth nut. It also still took me quite a while to remove the fugger because of the inability to get more than a 16th of rotation. I was looking for other ways to skin the cat. Would still like to hear some other suggestions.

I'm thinking a wobble extension and a thin wall whitworth socket, which I have.

K
Click to expand...

To LA Kevin:

Sloppy fit of 7/16 wrench can cause round off of hex points....then you will be in big trouble. Either use my suggestion to grind a little off one jaw of a Whitworth open end, or Triton T's suggestion to grind around box of Whitworth. I know we all hate to booger up good tools, but I then consider the tool to be a "special" and thus more valuable!
 
Hi all, the 7/16 SAE wrench would be too TIGHT not too loose to fit the nut, which is why I used an "off brand". It is in fact, more snug than my whitworth wrench. But due to its bulk, I needed to not only remove some of the outside diameter, but also the height of the "ring". This particular wrench is of the "offset" variety. I went through all my 7/16" wrenches until I found one that fit correctly.
[album][/album]
 
Thanks texasSlick and skipsoldbikes - tried both methods
The open ender ended up too weak by the time I had removed enough material to fit between magneto and nut.
The ring spanner worked though - used a cranked BS 5/16 (see pics below). Still a very tight fit, I had to bevel and round the "upper" lip on the ring between the one o'clock and 5 o'clock positions in the first photo. Can still only get half a flat tech time tough - better than nothing!
I've ordered one of the BSA long waisted nut from evilbay - not convinced it will fit the 650SS cases - I'll let you know.

removing/replacing norton magneto bottom nut?

removing/replacing norton magneto bottom nut?
 
Not to ask rude questions, but there is a 3 year pause in this thread !?
 
Rohan said:
Not to ask rude questions, but there is a 3 year pause in this thread !?
Click to expand...

It just goes to show the advice given in the Access Norton Forum is "timeless",

Slick
 
Rohan said:
Not to ask rude questions, but there is a 3 year pause in this thread !?
Click to expand...

Sorry, I wasn't aware there were time rules.
Having just recently joined as I encounter a problem I do a search and if I think I have something worth sharing I do
Do I need "guidance"?
Cheers
Rob
As a peace offering below is a photo of my grandad, Joe Craig, enjoying the sun with some of the works riders = I would have to dig out the original but I think from left it is Eric Oliver, Freddie Frith??, Stanley Woods, ???, and Grandad
It's a pity he died in a car crash the year before I was born - I would have liked to have known him
removing/replacing norton magneto bottom nut?
 
There certainly are no time rules !
And anything that contributes is welcome, of course.
But sometimes you have to ask if the discussion has run its course....

Thats an interesting pedigree you have there.
And a great photo.

I rather think that is Harold Daniell standing to the left. ?
Anyone want to put a date to this ?
We diverge....
Cheers.
 
Rohan - you're right about Harold Daniel - Dad told me it was Harold that coined the term featherbed after his first ride
I believe the photo was late thirties but will confirm when I find the original (scrawled on rear!)
I'll stop disrupting the thread now
Cheers
Rob
 
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