Knocking / rattling inside primary drive case + backfire

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Get the tools and disassemble, assess what's needed and then order the parts. There is the clutch to look at as well and an upgrade on the locating circlip to do if nothing else.

order in circlip (or 2 ) 06-8072 as it is thicker to fit into the main shaft circlip slot. In true British fashion you will have to fetter it in order to drop into the slot fully home. It's thicker so I rubbed it a bit thinner using a circular motion on emery paper until it dropped into place with a couple of small persuasive taps with a small flat-faced punch.

 
M-Hawk said:
...can I just slacken the chain using the adjuster and see if the sprocket releases from the taper?
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It must already be loose on the taper as you said previously "The sprocket seems to have a very small amount of play to it.". If it wasn't already loose then you certainly would not have been able to move the engine sprocket on the crankshaft. There should be sufficient side play in the chain for you to see if the sprocket will move.
 
M-Hawk said:
I assume I need to remove the clutch at the same time, or can I just slacken the chain using the adjuster and see if the sprocket releases from the taper?
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The good news is that once done a couple of times, stripping and reassembling the primary is one of the easier jobs on a Norton.
 
I'm planning to tackle the clutch, chain and sprocket removal tomorrow (Tuesday). Watch this space / wish me luck. As you say, I'm sure once I've done it, it will seem simple. Providing I don't find any more random collars or parts that is!
 
M-Hawk said:
I'm planning to tackle the clutch, chain and sprocket removal tomorrow (Tuesday). Watch this space / wish me luck. As you say, I'm sure once I've done it, it will seem simple. Providing I don't find any more random collars or parts that is!
Click to expand...
You've come a long way.
Not sure of your skill set.

Evaluating a taper fit involves some further skills.
 
concours said:
You've come a long way.
Not sure of your skill set.

Evaluating a taper fit involves some further skills.
Click to expand...
The foundation of my skillset is that I've owned an old Land Rover for many years, and I used to own an 80's aircooled camper. I've tinkered with bikes on and off over the years too, but never split an engine or gearbox, and somehow never done a clutch. So tomorrow (the clutch) will be a first for me. I'm looking forward to it and I found a video on YouTube of someone doing the job, albeit on a slightly different age of Commando.

I've never evaluated a taper fit though - so, any tips are very welcome :)
 
M-Hawk said:
The foundation of my skillset is that I've owned an old Land Rover for many years, and I used to own an 80's aircooled camper. I've tinkered with bikes on and off over the years too, but never split an engine or gearbox, and somehow never done a clutch. So tomorrow (the clutch) will be a first for me. I'm looking forward to it and I found a video on YouTube of someone doing the job, albeit on a slightly different age of Commando.

I've never evaluated a taper fit though - so, any tips are very welcome :)
Click to expand...
Theres a youtube video out there with the guy doing the clutch disassembly without the spring compression tool. It popped off without hurting him. Im sure its not good for the bike. Dont use that video as your guide.
 
M-Hawk said:
I'm planning to tackle the clutch, chain and sprocket removal tomorrow (Tuesday). Watch this space / wish me luck. As you say, I'm sure once I've done it, it will seem simple. Providing I don't find any more random collars or parts that is!
Click to expand...
Blast, I’m gonna need some more popcorn:rolleyes:

Good luck though☘️☘️☘️
 
I use a locally bought automotive puller, called a steering wheel puller on package, for doing the crank sprocket. Came with pairs of several different thread long bolts to fit variety of items and one pair fit the norton sprocket fine.

Be sure to use locktite on the inner case three bolts even with locktabs. I had one come out despite just the lock tab and it chewed up the chain. Locktite also on the clutch basket nut and don't use the spec'd torque value to avoid damaging the 'C' clip beneath (others please confirm the lower torque for our hero as it escapes me at present).
 
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Tornado said:
I use a locally bought automotive puller, called a steering wheel puller on package, for doing the crank sprocket. Came with pairs of several different thread long bolts to fit variety of items and one pair fit the norton sprocket fine.

Be sure to use loctite on the inner case three bolts even with locktabs. I had one come out despite just the lock tab and it chewed up the chain. Loctite also on the clutch basket nut and don't use the spec'd torque value to avoid damaging the 'C' clip beneath (others please confirm the lower torque for our hero as it escapes me at present).
Click to expand...
I would be careful not going too low on this torque as I think I did on my Mk.2, maybe 35 lbs with red Loctite, because I was ripping down the highway minding my own business, went to do a lane change, gave it a bit of throttle, and suddenly I had no drive. Pulled over, tried to figure out what was wrong, but it didn't make any sense. I was in gear, clutch felt normal, but it was like neutral. Luckily I had a buddy following with a trailer with a freshly built Hornet that we swapped my bike with and I was able to carry on. When I got home, it turned out the splines had completely sheared in the clutch hub. All I can assume is that the nut wasn't tight enough and they took a beating back and forth and finally let go.

Edit: I followed the OldBritts advice, so I would've torqued it to at least 35. The next time, I went to 45 I think and so far so good.
 
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hhh said:
I would be careful not going too low on this torque as I think I did on my Mk.2, maybe 30 lbs with red Loctite, because I was ripping down the highway minding my own business, went to do a lane change, gave it a bit of throttle, and suddenly I had no drive. Pulled over, tried to figure out what was wrong, but it didn't make any sense. I was in gear, clutch felt normal, but it was like neutral. Luckily I had a buddy following with a trailer with a freshly built Hornet that we swapped my bike with and I was able to carry on. When I got home, it turned out the splines had completely sheared in the clutch hub. All I can assume is that the nut wasn't tight enough and they took a beating back and forth and finally let go.
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Here is a quote from the OldBrits Torque Settings pdf:

"CLUTCH TO MAINSHAFT NUT: The factory torque setting for this nut is 70 ft lb., however this torque setting runs the risk of breaking the clutch locating circlip (06- 0752). It is recomended that you use locktight on this nut and torque to 35 or 40 ft lb. If you do want to use 70 ft lb. you should use a new circlip each time this nut is removed."

Full pdf is on the Resources section of this forum but you need to do a little hunting...direct link to download page here:
 
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A few things to note
It's looking like your primary has in the past been rebuilt by a horse
Hopefully the rest of it hasn't been subjected to such treatment
When you remove the engine sprocket and clutch assembly post some photos
Hopefully the taper on the end of the crank won't be too badly damaged
If it's looking ok make sure there are no burrs on the Woodruff key slot
Then lap the sprocket back on to the crank using fine grinding paste
Very steady as you go
You are looking for a uniform grey finish
Hopefully that's all it will need
When you remove the clutch always replace the circlip that sits behind the clutch on the mainshaft
Check the clutch center is a good sliding fit on the mainshaft spline
Check primary chain alignment
Throw away the clutch center nut tab washer if one is fitted and use loctite instead
Torque to 40 ft lbs
The three primary chaincase retaining bolts need tab washers or loctite or both
It may be worth checking at this point if the primary chaincase is shimmed correctly
The shims are on the chaincase retaining center stud behind the chaincase
I'd call 8 thou a minimum air gap for the alternator,10 thou better
 
Tune in for tomorrow’s installment…

“What lies beneath?”

Starring M-Hawk as “The mechanic”

Also Starring:

Mr.Myagi - Baz
Yoda - L.A.B.
Obi-Wan Kenobi. - marshg246
The Senate - Tornado, kommando, hhh, saber, MichaelB, Olympus
Philip Marlowe - Concours
Woody - Texas Slick
The Milkman - Estuaryboy
John Steed - Mart UK
Number 1 - Number 2
P.T. Barnum - Jerry Doe
Chin Ho - Kam Fong
The Lost Boys - Comnoz, Dynodave, Hobot
Sheev Palpatine - The previous owner

Stunt Coordinator - Fast Eddie
Special Effects - Boyer Bransden
Lighting - Joseph Lucas
Chief Grip - Tom Maselli


Filmed on location in Kent.

Our grateful thanks to Dr. Stefan Bauer, Mr. Bernard Hooper and Mr. John Favill for without them and many others this story could not be told.

MCNCCLXXXVWTF !!!
 
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Right on cliffa. This is better than any netflix sieries i have seen. Cant wait for tomorrows episode to drop. The outsiders would think we truly have lost it. Ok, most of us have. Fun thread.
 
cliffa said:
Tune in for tomorrow’s installment…

“What lies beneath?”

Starring M-Hawk as “The mechanic”

Also Starring:

Mr.Myagi - Baz
Yoda - L.A.B.
Obi-Wan Kenobi. - marshg246
The Senate - Tornado, kommando, hhh, saber, MichaelB, Olympus
Philip Marlowe - Concours
Woody - Texas Slick
The Milkman - Estuaryboy
John Steed - Mart UK
Number 1 - Number 2
P.T. Barnum - Jerry Doe
Chin Ho - Kam Fong
The Lost Boys - Comnoz, Dynodave, Hobot
Sheev Palpatine - The previous owner

Stunt Coordinator - Fast Eddie
Special Effects - Boyer Bransden
Lighting - Joseph Lucas
Chief Grip - Tom Maselli


Filmed on location in Kent.

Our grateful thanks to Dr. Stefan Bauer, Mr. Bernard Hooper and Mr. John Favill for without them and many others this story could not be told.

MCNCCLXXXVWTF !!!
Click to expand...
Funny as can be, but don't pick on a new guy who's trying - where have you been in the NorLuck debacles :)
 
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M-Hawk said:
Thanks MichaelB. I'm building my order now.

I've not pulled the sprocket yet. I want to have everything ready to go before I do that I think. If I want to get the sprocket puller, is it this? https://andover-norton.co.uk/en/shop-details/16314/extractor-assy-061037-06-0941-

Also, does anyone know if the woodruff key set includes a rotor key? https://andover-norton.co.uk/en/shop-details/23196 Or do I need the separate rotor key as well? https://andover-norton.co.uk/en/shop-details/16612

Andover product descriptions are somewhat sparse!
Click to expand...
Any gear puller will work to remove that sprocket. Got mine at an auto parts place.
 
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