Pinning starter ring gear

spannerhands

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Sep 21, 2015
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Just getting a bit of work done ready for the riding season. I wanted to pin the starter ring gear as mentioned previously on here. I have taken the parts to a local machine shop with Richards dimensions . He has managed to drill the ring gear with no problem but the main drive gear is very hard and he cannot get through it. Is there a trick to this?
 
A normal drill bit wouldn't touch it, so I sharpened a carbide masonry bit. It went through fine, then I inserted hardened roll pins ( one inside the other for added strength). I used 4mm pins as I was concerned about getting too close to the root of the drive gear teeth and weakening them.
 
spannerhands said:
Just getting a bit of work done ready for the riding season. I wanted to pin the starter ring gear as mentioned previously on here. I have taken the parts to a local machine shop with Richards dimensions . He has managed to drill the ring gear with no problem but the main drive gear is very hard and he cannot get through it. Is there a trick to this?
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Sorry but that would concern me if the machine shop couldn't figure that out. Cobalt or Carbide drill bits are readily available as recommended and is known to any competent machinist plus they should already have a selection of Carbide bits if they work on hard metals. We have checked the hardness of a few of these gears and they are all over the place. If your shop has the ability to check the hardness he can figure out what will work best. Carbide bits typically work up to a hardness of 55-60 some even go up even higher so you should be fine .

The 4mm or smaller pin recommendation is spot on as well.
 
Thanks Cliffa. I will get a carbide drill and see if that will work. I was hopping to use a dowel pin and would probably need to ream to size which could still be a challenge.
 
TonyA said:
I wonder how New Norton will solve this ?
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With the new parts, that might be the old parts, but of course, they are not guaranteed to fit the old bikes! ID like to see in the primary of the new ones they produced. I bet its the same old/new parts. The issue really is how many "spares" do they have if any.
 
spannerhands said:
Thanks Cliffa. I will get a carbide drill and see if that will work. I was hopping to use a dowel pin and would probably need to ream to size which could still be a challenge.
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Thanks for the extra info city garage I had got some 6mm dowels to use this should be ok should't it?
 
spannerhands said:
Thanks Cliffa. I will get a carbide drill and see if that will work. I was hopping to use a dowel pin and would probably need to ream to size which could still be a challenge.
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I've machined hundreds of these gears with carbide tools, and its not a problem. Check out Cutwel.co.uk.
As for reaming the dowel size, just be carefull because the the standard tolerance of a reamer is H7 (0.0 / +0.012) which isn't a tight press fit on the dowel. A common mistake people make.
Try to look for a H6 tolerance reamer, or even a dia. 03.99 H7

Have a look at this reamer from MA Ford.

MA Ford Europe - Series List

www.mafordeurope.com www.mafordeurope.com
03.988 H7 Carbide Reamer : 27215700

Don't leave to much material in the after drilling, because the tiny reamer will have a very hard time cutting the material especially when it's hardened
I hope this info helps.
 
Nikoli said:
I've machined hundreds of these gears with carbide tools, and its not a problem. Check out Cutwel.co.uk.
As for reaming the dowel size, just be carefull because the the standard tolerance of a reamer is H7 (0.0 / +0.012) which isn't a tight press fit on the dowel. A common mistake people make.
Try to look for a H6 tolerance reamer, or even a dia. 03.99 H7

Have a look at this reamer from MA Ford.

MA Ford Europe - Series List

www.mafordeurope.com www.mafordeurope.com
03.988 H7 Carbide Reamer : 27215700

Don't leave to much material in the after drilling, because the tiny reamer will have a very hard time cutting the material especially when it's hardened
I hope this info helps.
Click to expand...
Hi Nikoli

I realised I had not thanked you for the information. The Ring gear is now pined and fitted. Peace of mind at last.

All the best David
 
BritTwit said:
I would certainly think so.
And a pretty easy fix for Norton too.
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Question for Stuart, is there a particular year that the 961 got significantly better.
Mine is a 2016 September bike.
Is it likely that the clutch will need pining .
Or was it really hit and miss.
 
Around 2016 onwards we started thread locking the starter ring gear shoulder screws in place. A shoulder screw is essentially a bolt in pin. Trouble with the one's on the 961 is the allen key size is only 3mm....so torquing to a proper spec is hard work. Norton's solution was to thread lock the entire thing in ie the threaded part and the shoulder/shank. Anyone heard of an issue of a starter ring gear coming adrift on a engine built in the second half of 2016 onwards?
Also, clutch basket assembly...anyone seen a failure with the initials SB, PH or DB on it? That was myself and the two others in engine build at the time. We all took the peening of those rivets seriously....if we weren't happy with one, we'd have it ground off in the fabrication shop, and do it again. Prior to that, quite often sub assemblies were left to the apprentice to do.
 
Stu Bodycote said:
Around 2016 onwards we started thread locking the starter ring gear shoulder screws in place. A shoulder screw is essentially a bolt in pin. Trouble with the one's on the 961 is the allen key size is only 3mm....so torquing to a proper spec is hard work. Norton's solution was to thread lock the entire thing in ie the threaded part and the shoulder/shank. Anyone heard of an issue of a starter ring gear coming adrift on a engine built in the second half of 2016 onwards?
Also, clutch basket assembly...anyone seen a failure with the initials SB, PH or DB on it? That was myself and the two others in engine build at the time. We all took the peening of those rivets seriously....if we weren't happy with one, we'd have it ground off in the fabrication shop, and do it again. Prior to that, quite often sub assemblies were left to the apprentice to do.
Click to expand...
 
Stu Bodycote said:
Around 2016 onwards we started thread locking the starter ring gear shoulder screws in place. A shoulder screw is essentially a bolt in pin. Trouble with the one's on the 961 is the allen key size is only 3mm....so torquing to a proper spec is hard work. Norton's solution was to thread lock the entire thing in ie the threaded part and the shoulder/shank. Anyone heard of an issue of a starter ring gear coming adrift on a engine built in the second half of 2016 onwards?
Also, clutch basket assembly...anyone seen a failure with the initials SB, PH or DB on it? That was myself and the two others in engine build at the time. We all took the peening of those rivets seriously....if we weren't happy with one, we'd have it ground off in the fabrication shop, and do it again. Prior to that, quite often sub assemblies were left to the apprentice to do.
Click to expand...
That’s a relief, thanks for the information..
What’s your tipple?
 
Stu Bodycote said:
Around 2016 onwards we started thread locking the starter ring gear shoulder screws in place. A shoulder screw is essentially a bolt in pin. Trouble with the one's on the 961 is the allen key size is only 3mm....so torquing to a proper spec is hard work. Norton's solution was to thread lock the entire thing in ie the threaded part and the shoulder/shank. Anyone heard of an issue of a starter ring gear coming adrift on a engine built in the second half of 2016 onwards?
Also, clutch basket assembly...anyone seen a failure with the initials SB, PH or DB on it? That was myself and the two others in engine build at the time. We all took the peening of those rivets seriously....if we weren't happy with one, we'd have it ground off in the fabrication shop, and do it again. Prior to that, quite often sub assemblies were left to the apprentice to do.
Click to expand...
Hello Stuart , My 961 were loctited , I have a late 2014 November build. They were notified of the coming loose crank plate bolts and starter ring gear too in 2013 for sure by Norton Canada (David Coote and Peter) . So maybe all 2015 are safe ? Just hoping so. Thanks for your input , it is very valuable to us here on this forum !
 
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Thread locked on the threads or the whole bolt? Eitherway, yeah could have been 2015 onwards. I started in engine built around June 2016 iirc, and it was already a procedure by then.
 
Stu Bodycote said:
Thread locked on the threads or the whole bolt? Eitherway, yeah could have been 2015 onwards. I started in engine built around June 2016 iirc, and it was already a procedure by then.
Click to expand...
Whole bolt was loctited , threads and whole shoulder . This must be what saved mine from coming apart.
 
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