Commando 1974 gearbox

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Egholt

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Oct 30, 2014
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Im new here , I have just bought a Norton Commando 850 1974 in parts .
Starting to overhaul the gearbox .
First of all I need a new gearbox Shell , where is the best place to buy a new Shell ?
My Shell have the number 063906 , I can buy a NOS Shell with number 065207 , will this fit ?
What is the best quality , a NOS or a new reproduktion ?
Is there a list of all the bearings in the box with sizes and the best brand ?
Any upgrades I should do , now Im in there ?
Lot of questions but Im new to Nortons .

Regards Michael from Denmark
 
You can buy a new shell from Andover Norton or the stronger version from Quaife.
Bearings are also available from AN as are rebuild kits with the bearings, bushes and new hair clip type springs.

The original layshaft bearing (Made in Portugal) is the most popular check as is cracking between the bearing bores but given the need for a new case probably does not matter.

http://www.andover-norton.co.uk/
 
Mick Hemmings does a uprated layshaft bearing an can supply any other spares you need. He only stocks genuine Andover Norton parts and is always happy to help. What he doesn't know is not worth knowing, he's been there done that an got the tea shirt then used it to clean the bike with.
RGM are another good supplier you may want to use as you start the long process of emptying your bank account that some folk call bike restoration. :D
 
Egholt said:
My Shell have the number 063906 , I can buy a NOS Shell with number 065207 , will this fit ?
Click to expand...

065207 will fit, however that is the part number for the 850 MkIII gearbox shell, so a few specific MkIII parts will be required, such as the 065148 quadrant and 065209 bush, etc. and the neutral switch hole will need to be blanked off.
 
Although Quaife list a stronger shell, they no longer make, or sell them.

The shell sold by Andover Norton is strengthened over the original and is well made. I fitted one to mine ans am happy with it.
 
Fast Eddie said:
Although Quaife list a stronger shell, they no longer make, or sell them.

The shell sold by Andover Norton is strengthened over the original and is well made. I fitted one to mine ans am happy with it.
Click to expand...

Does Mick Hemming not sell quaife boxes?

J
 
auldblue said:
Fast Eddie said:
Although Quaife list a stronger shell, they no longer make, or sell them.

The shell sold by Andover Norton is strengthened over the original and is well made. I fitted one to mine ans am happy with it.
Click to expand...

Does Mick Hemming not sell quaife boxes?

J
Click to expand...

Yes he does. But not with the strengthened shell. The Quaife strengthened shell had ribs cast into it.

I don't know what shell Mick uses when he builds a new box, I imagine it is AN.
 
Fast Eddie said:
auldblue said:
Fast Eddie said:
Although Quaife list a stronger shell, they no longer make, or sell them.

The shell sold by Andover Norton is strengthened over the original and is well made. I fitted one to mine ans am happy with it.
Click to expand...

Does Mick Hemming not sell quaife boxes?

J
Click to expand...

Yes he does. But not with the strengthened shell. The Quaife strengthened shell had ribs cast into it.

I don't know what shell Mick uses when he builds a new box, I imagine it is AN.
Click to expand...

Yes, Mick's Quaife boxes use the A-N shell - I have to admit to being a bit miffed mine wasn't built with the the Quaife shell, but that's all that's available now.

Ask Quaife about anything Norton and the point you straight to Mick.
 
I will go for a AN Shell .
Next question , will a gear set from a 850 cc mrk 3 fit a mrk 2 850 Shell and inner/outer cover ?

Michael
 
yes.

Egholt said:
I will go for a AN Shell .
Next question , will a gear set from a 850 cc mrk 3 fit a mrk 2 850 Shell and inner/outer cover ?

Michael
Click to expand...
 
OK , I will go for a AN Shell .
Need new gears and shafts ?
Main shaft is bend .

Will a gear set and shafts from a 750 cc 1972 fit for my Mrk 2A ?
I understand only the 2. gear is different ?

So will a 750 gearbox be driveable for the 850 engine ?

Michael
 
no
Egholt said:
Need new gears and shafts ?
Michael
Click to expand...

buy a new one if more the .010 bend

Egholt said:
Main shaft is bend .
Michael
Click to expand...

yes

Egholt said:
Will a gear set and shafts from a 750 cc 1972 fit for my Mrk 2A ?
Michael
Click to expand...

yes but must use both main and lay as a set

Egholt said:
I understand only the 2. gear is different ?
Michael
Click to expand...


yes again

Egholt said:
So will a 750 gearbox be driveable for the 850 engine ?
Michael
Click to expand...
 
Lots of good info here:

http://www.oldbritts.com/ob_tech.html

Scroll down to the gearbox section, but you are likely to find other things of interest in that list.

Here is some more reading:

http://www.archives.jampot.dk/Technical ... 987%29.pdf

There are some wonderful DVDs with Mick Hemmings on both engine and gearbox rebuilding. They are available here:

http://www.archives.jampot.dk/Technical ... 987%29.pdf

I wouldn't be afraid to call Mick Hemmings for specific questions or even better take a trip to England and stop in for a visit!

http://www.mickhemmings.com/
 
These gearbox failure , is it mostly on 850 cc , or is it the same problem for 750 cc engine ?

Michael
 
pretty much on ALL commando's. the gearbox was made for a lot smaller CC and lower HP bikes when it came into use and was never truly redesigned for 30+ HP.

Egholt said:
These gearbox failure , is it mostly on 850 cc , or is it the same problem for 750 cc engine ?

Michael
Click to expand...
 
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