transmission variations

seattle##gs

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Oct 28, 2014
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There are a few changes that happened inside the box. I have a few gear sets and surplus gears. Is there anything written down about the different gears and how to spot them by number of teeth and measuring. I know a little bit about the AHB markings and the groove cut in the second gears as indicators. Some of these letter stampings are not clear.
 
The information I have is for the Commando.

1st., 3rd. and 4th. gear ratios didn't change although the sleeve gear and layshaft 4th. were changed from serial 128646 due to a revised tooth form so are dimensionally different...

New sleeve gear is larger then my old sleeve gear

I purchased a new sleeve shaft gear from a guy how had new old stock. I installed it but it fit too tight against the mating gear. It was very hard to turn. I remove the new gear sleeve gear and compared it with the old sleeve gear. Using a micrometer I found the new gear was larger in diameter...
www.accessnorton.com www.accessnorton.com

...I don't know what markings - if any, the pre-128646 sleeve gear and layshaft 4th. had.

The 128646-on sleeve gear is marked 'AH', with a '6' or '9' on layshaft 4th.

Stronger 3rd. gears were introduced from serial 133488 and both marked 'AH'.

2nd. gear ratio changed from 18/24T to 18/23T from 306591 on the 850 Mk1A and later (Mk2, 2A & Mk3) models. Marked AHB with the grooved dogs. The original 18/24T 2nd.gear pair is marked 'AHA' by Andover Norton but presumably originally marked 'AH'.

The single (outer end) circlip sleeve gear 064991 was introduced as far as I know on the Mk2/2A, also marked 'AH'.

Twin circlip sleeve gear 065854 as far as I know, was introduced on the Mk3 and marked 'AH...3'.

Any gears marked RSxx are not genuine Norton.
 
I don't know how you do it L.A.B. My mental picture is you sitting at a huge desk surrounded by massive walls full of reference books and original Norton factory drawings, patents and work procedures. You get an e-mail request, stroll over to the correct shelf, pull out the desired material, adjust your glasses and provide incredible detailed information on 50 year old machines. I remain a fan!
 
"...adjust your glasses and provide incredible detailed information on 50 year old machines....
Click to expand...
I agree AC... perhaps L.A.B. is the man to create that technical reference for all...

"list for the Commandos that has engine/gearbox changes by year or engine number"
Click to expand...
 
Atlas Commando said:
I don't know how you do it L.A.B. My mental picture is you sitting at a huge desk surrounded by massive walls full of reference books and original Norton factory drawings, patents and work procedures. You get an e-mail request, stroll over to the correct shelf, pull out the desired material, adjust your glasses and provide incredible detailed information on 50 year old machines.
Click to expand...

Actually, a very small desk and files are generally on computer plus I have a few 'Norton' books. :)

YukoNorton said:
I agree AC... perhaps L.A.B. is the man to create that technical reference for all...
Click to expand...

It's a possibility.
:)
 
A minor update, at s/n 147846 toughened kick-start pawls were introduced. Should have a little M marked on the side.
 
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