961 clutch disassembly and inspection day 1

Boss302 said:

I don't have that tool. I'll figure a way to secure it. Cliffa`s idea sounds good. I just can't see paying that much for a tool I may use once.

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The tool is useful but you don’t need the tool just use two bolts from the stator magnet to hold it

Boss302 said:

Leo was good for the sale and some parts under warranty (battery, turn signal, chain guard) then he handed me off to Chris in service once the real problems started. Chris was pleasant to deal with but there was a problem with returning calls and they had my bike for 6 mos while the warranty faded away. I know they had their hands full dealing with a bike that must have seemed like a time bomb of unknown problems popping up with little support on how to fix them. I love the Norton brand and have for 50 years and I enjoy working on bikes and learning in the process. If this was my only bike I would be unhappy, but I don't depend on it so that's OK. I've decided if I stay on top of the potential problems hopefully it won't kill me by freezing up or coming apart on the highway.

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The poor communication was definitely on them but the problem really was that they were waiting for Norton and we’re getting the runaround and not getting parts as well

Completed primary side disassembly and inspection. Very happy to say everything is in great shape. Pulled the balance gear using Cliffa`s method of pulling the gear off the taper without disengaging it from the other gears, then using the magnet bolts to lock it before removal. Worked just fine. Yesterday I had removed the clutch plates and noted they were stuck together. Today I pulled the basket after checking it for any slop in bearings or rivets, etc. Tight as a drum. Bearing looks good. Starter gear looks good with some minor wear but all teeth intact. Upon inspection the rivets and cush springs and seats all appear like new. There is no evidence of the springs or seats having any wear and the rivets are tight and no signs of any wear and tear. I lightly sanded the clutch plates and washed them and reassembled the clutch . Used lock tight on all the interior small bolts that I had removed. Properly alligned the balance shaft to the crankshaft. (It was 2 teeth off in allignment) . Put the alternator magnet back on and buttoned the cover back on. Added just over a liter of fresh 10/40 motorcycle oil for wet clutches.
My conclusion is that the problems I was experiencing were due to sticky clutch plates from the tranny oil being corrupted with water. The only possible source has to be the tranny vent that was added when I had it in for the vent additions and engine noise problem 4 years ago. When I wash the bike water gets under the seat and into the airbox and then into the tranny vent tube. I have noticed it in the airbox and in the collection bottle down below after a wash.
Good to know all the parts in the primary case are holding up well. I can ride it with more confidence now. Have to charge the battery before I can test drive it . I plan to change the engine oil and change the tranny oil again soon to remove the small amount of water that was in the nondrainable oil.
Thanks for all the help. You guys are a great asset for information , for a bike that has no formal service network remaining. Some pictures of today's findings follow.

g.

Weld the rivets while you have it apart

City Garage said:

Weld the rivets while you have it apart

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Oops

Boss302 said:

Completed primary side disassembly and inspection. Very happy to say everything is in great shape. Pulled the balance gear using Cliffa`s method of pulling the gear off the taper without disengaging it from the other gears, then using the magnet bolts to lock it before removal. Worked just fine. Yesterday I had removed the clutch plates and noted they were stuck together. Today I pulled the basket after checking it for any slop in bearings or rivets, etc. Tight as a drum. Bearing looks good. Starter gear looks good with some minor wear but all teeth intact. Upon inspection the rivets and cush springs and seats all appear like new. There is no evidence of the springs or seats having any wear and the rivets are tight and no signs of any wear and tear. I lightly sanded the clutch plates and washed them and reassembled the clutch . Used lock tight on all the interior small bolts that I had removed. Properly alligned the balance shaft to the crankshaft. (It was 2 teeth off in allignment) . Put the alternator magnet back on and buttoned the cover back on. Added just over a liter of fresh 10/40 motorcycle oil for wet clutches.
My conclusion is that the problems I was experiencing were due to sticky clutch plates from the tranny oil being corrupted with water. The only possible source has to be the tranny vent that was added when I had it in for the vent additions and engine noise problem 4 years ago. When I wash the bike water gets under the seat and into the airbox and then into the tranny vent tube. I have noticed it in the airbox and in the collection bottle down below after a wash.
Good to know all the parts in the primary case are holding up well. I can ride it with more confidence now. Have to charge the battery before I can test drive it . I plan to change the engine oil and change the tranny oil again soon to remove the small amount of water that was in the nondrainable oil.
Thanks for all the help. You guys are a great asset for information , for a bike that has no formal service network remaining. Some pictures of today's findings follow.

g.View attachment 99754

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Great Work ! On my bike my trans vent goes down below the engine , not in the air box . I never get water in my primary. I have been in several rainstorms over the years. I glad you still like your bike !

TonyA said:

Great Work ! On my bike my trans vent goes down below the engine , not in the air box . I never get water in my primary. I have been in several rainstorms over the years. I glad you still like your bike !

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Take a look at the big picture in the middle of page one showing the area on the left side above the primary (thumbnail now below) When IMOC worked on the bike they did the crank vent catch seen behind the cylinders, and also put the primary fill cap vent tube on. You can see it running up toward the airbox and above. I never paid any attention to what all they rerouted. Appears they completely disconnected the box that sits behind the lower swing arm behind the tranny which I assume is part of the PCV system. Tomorrow I'll track that small tube from the primary fill cap to see exactly where it goes. I wonder if that was a standard modification deemed needed by Norton. Anyone else have this primary vent tube on their bike?

Boss302 said:

Take a look at the big picture in the middle of page one showing the area on the left side above the primary (thumbnail now below) When IMOC worked on the bike they did the crank vent catch seen behind the cylinders, and also put the primary fill cap vent tube on. You can see it running up toward the airbox and above. I never paid any attention to what all they rerouted. Appears they completely disconnected the box that sits behind the lower swing arm behind the tranny which I assume is part of the PCV system. Tomorrow I'll track that small tube from the primary fill cap to see exactly where it goes. I wonder if that was a standard modification deemed needed by Norton. Anyone else have this primary vent tube on their bike?

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When Coote's first produced this trans/primary vent , David C. ran it to the top of the air box and into one of the fittings near the air box temp sensor. When Norton released their version (essentially a copy of Coote's) it went below the engine. It shows the route in the Norton 961 service manual .

Test drive today. What a difference. Clutch is smooth and engages and disengages properly. Noticeably less vibration from the engine with the balance shaft in its correct rotation. 2 teeth on the balance gear equals about 12 degrees of circumference. Ready for the prime riding season here in the desert southwest as it cools down from 100f to closer to 80 by early november.

@Boss302 great work. No doubt that reduction in vibration will contribute to some additional longevity too.

Gojuu said:

@Boss302 great work. No doubt that reduction in vibration will contribute to some additional longevity too.

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Longevity for both me and the bike, perhaps.

Nice to have the peace of mind from inspecting it. Knowing it is good now, you will have a good reference to compare to if the noise and vibration get worse in future. How many miles does the bike have? Mine had 5618 miles when it got so bad that I tore the primary down, and discovered that the rivets had come loose.

Ken

Likin the funky panniers Boss! Where did those hail from - they would suit nicely when I eventually do my old man high bar conversion! The fairing also - a thruxtion fairing retrofitted? More pics would be cool.

Late to the party here but did you pin the starter ring gear. I know thats something I'll need to do some day

lcrken said:

Nice to have the peace of mind from inspecting it. Knowing it is good now, you will have a good reference to compare to if the noise and vibration get worse in future. How many miles does the bike have? Mine had 5618 miles when it got so bad that I tore the primary down, and discovered that the rivets had come loose.

Ken

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I've got almost the same mileage as you. It had 1000 miles when I bought it. I must admit I was a little rough on the clutch when I first got it until I started reading about the problems. When the clutch started having problems with noise and rough engagement and incomplete disengagement I thought for sure I had big problems. That's why I was so pleased to find it was only bad lube and sticky plates. What do you think some fail and some don't? Is it riding style?

Stephen_Spencer said:

Likin the funky panniers Boss! Where did those hail from - they would suit nicely when I eventually do my old man high bar conversion! The fairing also - a thruxtion fairing retrofitted? More pics would be cool.

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The fairing is indeed for thruxton r and rs. I found it on Ebay used for about half price. I have a thruxton rs also so I grabbed this one up for the norton. It's almost a perfect fit. There's another thread from last year where some folks talk about the mounting. The panniers are cheap Chinese off Ebay for less than 100 dollars and my painter matched them nicely. I used the hardware that came with them with minimal modification. If you want I can see if I can find a link.

speirmoor said:

Late to the party here but did you pin the starter ring gear. I know thats something I'll need to do some day

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No. I'd heard of that too. Also recommended to weld the rivets. I was so happy to find the condition so good that I cleaned it all up and put it back together vowing to baby the clutch and roll on power smoothly. I wonder what factor is greater in causing the damage the starter driving the gear, or the clutch engaging under force. Not much to do about the starter but I can certainly be gentle with the clutch.

Boss302 said:

I've got almost the same mileage as you. It had 1000 miles when I bought it. I must admit I was a little rough on the clutch when I first got it until I started reading about the problems. When the clutch started having problems with noise and rough engagement and incomplete disengagement I thought for sure I had big problems. That's why I was so pleased to find it was only bad lube and sticky plates. What do you think some fail and some don't? Is it riding style?

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I don't think it's riding style. It appears to depend on who assembled the bike. There's a thread back somewhere about one of the earlier clutch failures, with some input from an ex-factory guy about how careful some of the assemblers were with the clutch basket rivets, and how careless some of them were. If I can find it, I'll post a link.

Ken

Boss302 said:

No. I'd heard of that too. Also recommended to weld the rivets. I was so happy to find the condition so good that I cleaned it all up and put it back together vowing to baby the clutch and roll on power smoothly. I wonder what factor is greater in causing the damage the starter driving the gear, or the clutch engaging under force. Not much to do about the starter but I can certainly be gentle with the clutch.

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Those are two separate issues as the starter ring gear is just for the starter to engage.

lcrken said:

I don't think it's riding style. It appears to depend on who assembled the bike. There's a thread back somewhere about one of the earlier clutch failures, with some input from an ex-factory guy about how careful some of the assemblers were with the clutch basket rivets, and how careless some of them were. If I can find it, I'll post a link.

Ken

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The rivets on mine looked very carefully applied, so maybe I'm one of the lucky ones.