Clutch work on my N15CS, some interesting challenges

gpzkat · Sep 23, 2024

norton bob said:
The clutch lever i was referring to is inside the box . The Bar lever is important too. 7/8 " pivot to nipple centers needed. 1" is no good, 11/8" even worse .

Yep got that I just went off on a tangent about the other end.

gpzkat · Sep 23, 2024

mdt-son said:
Tom, why don't you fix the root cause? Your oil pump appears to be worn out. Get a new one! Or send the one you have to AMR for an upgrade.

As for your new clutch plates, they can probably be milled down slightly with the correct cutter. Oily clutch plates should be cleaned using a TCE substitution + Fuller's Earth, as described in the Workshop Manual. Oil level in the primary needs to be kept at the bare minimum; lower run of the chain should barely touch the oil surface.

- Knut

Yes I plan to correct the root cause. I am saving my shekels.

gpzkat · Sep 23, 2024

baz said:
After suffering with major clutch slip on my BSA B44 and replacing the friction plates and then replacing the plain plates
Trying an extra plate
Heavy duty clutch springs etc
I hand decked every plate friction and plain both sides until everything was absolutely flat
Plus I tack welded an extra plain plate to the pressure plate and decked that too the clutch was transformed
No more slipping so I could back the tension off the springs which made it lighter to operate
No dragging no slipping and apart from the Norton aluminium pressure plate it's very similar clutch

I'll get this sorted. I shall endeavor to persevere. I've read through the oil pump rebuild and it's not beyond my skills, just be patient. I think buying a new one would tick me off if it didn't work, or worked for a while, which is what they seem to do anyway. I'd rather have a go at fixing it, and keep about 3 mitigation plans up my sleeve anyway. I will see if I can get it right and if not, OK fine. I have plenty of oil pressure with this pump, am not gonna blow the motor. Just the damn sumpin sumpin. I have it apart and it looks decent, nothing scary going on. After a complete rebuild I am chuffed to find so many things RIGHT with its bike so I won't let this get me down. My timing and primary chain tensions and overall condition of the engine looks great. Charging system, ignition, brakes (re-laced disc on front) power, carburetion spot on, etc. Gotta look on the bright side.

As for clutch plates, I have cleaned off my original oil-soaked ones once already. It worked fine but got contaminated later, my fault. All my clutch springs are in spec. I can put one or two old plates in or deck the new ones, or both. I basically took the original plates, cleaned them, threw them on and they were great, if a bit of a Kung Fu grip, till oil spoiled the party. From the first ride away I was shocked that they even worked. I wanted to test other major systems first and incrementally improve later - which is now.

Oh. Gonna look at the cable at both ends but that is tangential.

Going through my parts pile i found some nice aluminum Barnett plates and a bunch of SS discs - Commando stuff I don't need. They look pretty good and if anyone wants them let me know.

Update: Spoken for already by a fellow alumnus in good standing.

Clutch work on my N15CS, some interesting challenges

gpzkat · Sep 25, 2024

I have had a try at freshening up the oil pump, this pic is in the 'nearly done' stage. I did just a bit more on the end plate to remove the gear mark on the left side. I have no real reference point, this being my first, but I did my best based on some instructional info I found. It seems in pretty good shape overall, again, I'm no expert but it all appears servicable. Using a straight edge and doing several tests got it to what seems like a very good state. We shall see, shall we not?

I don't want to use this word too strongly, but I sort of hate the idea that an oil pump is the fault/cure of all this nonsense. I'll fit it back up and have a good look at the results, mitigating things by checking the seals, then after it's all back together,. I will keep it more upright, drain the sump and measure to see if the pump 'fix' worked etc. I know that the pump cranked out great pressure so that should only get better, I should guess. I want to work on the centerstand too, I had a go at it before but things were just wrong. I don't give up easily though.

Schwany · Sep 28, 2024

There is a post in the Commando forum about a bad wet sumper. In reply #7 there is a link to a video from Andover Norton about how to do exactly what you are doing with the oil pump. At or near the end of the video the Andover Norton engineer in the video says the pump will still wet sump, and nothing can be done about it. Him I believe.

I did the ball bearing and spring in the timing cover in the 1980's. It didn't work more than 7 weeks before the sump had more oil in it than it should. More than 1/2 liter and building. Back then I drained the sump before every ride. I actually thought I'd removed that ball bearing at some point, but 27 years later after a long parking in the corner of the garage. I took the timing cover off and the ball bearing fell out. lol

gpzkat · Sep 28, 2024

Schwany said:
There is a post in the Commando forum about a bad wet sumper. In reply #7 there is a link to a video from Andover Norton about how to do exactly what you are doing with the oil pump. At or near the end of the video the Andover Norton engineer in the video says the pump will still wet sump, and nothing can be done about it. Him I believe.

I did the ball bearing and spring in the timing cover in the 1980's. It didn't work more than 7 weeks before the sump had more oil in it than it should. More than 1/2 liter and building. Back then I drained the sump before every ride. I actually thought I'd removed that ball bearing at some point, but 27 years later after a long parking in the corner of the garage. I took the timing cover off and the ball bearing fell out. lol

Thanks, yes I watched that video. That plus the other guidance I've reviewed cover the process pretty well. Maybe mounting the oil tank under the engine is the only solution

Seems if it's gonna sump and do the leak I may want to drain it after the ride not before, when it cools off anyway. We shall see if my work on the pump did anything.

I will have it back together today with some fixes to the chain case position, moving it closer to the engine by removing 1.2mm of gasket and using Hondabond. sealed the 3 screws. Why on earth Norton tapped the holes through to the crankcase... oh never mind. New clutch cable with adjustment set correctly, re-use of two older plates is just right, dimensionally in the basket. I replaced the crank end seal for good measure while the sprocket was off. I'll use the Type F and I believe it will all be good, and manageable.

gpzkat · Sep 30, 2024

Well, oil's well that ends well I suppose. I rode 2 hours through local canyons and 2 lanes with my son on his Tenere 700 yesterday and had another ride today. He insisted on going 75 for long stretches due to light traffic, and so I did too, and even passed him a couple of times at 85. I'm thankful that my gearing is tall....maybe too tall. The clutch doesn't slip at all. There were a couple of drips of ATF under the bike after the ride, but after cinching up the screws a little, it stopped. The new primary chain case gasket may absorb a bit and need a 2nd cinching, my guess anyway. I try not to over-torque steel bolts in alloy threads.

The oil in the tank (15W-40 Rotella T4 which I get because it is fine for wet clutch in my other bikes) has not dropped at all after the ride and sitting. I am hopeful. It was sumping quite rapidly before. I would get about 1.5 liters out of the sump after 5-7 days and the tank would empty in 2 weeks.

gpzkat · Oct 1, 2024

This is a nice sight. My cookie sheet clean as a whistle in the morning.

Schwany · Oct 2, 2024

I can't remember how many times I thought my Norton didn't leak anymore. The fantasy never lasted more than a couple of weeks.

Give it some time. It'll mark its territory eventually.

Run your finger under the primary cover seam.

gpzkat · Oct 2, 2024

Schwany said:
I can't remember how many times I thought my Norton didn't leak anymore. The fantasy never lasted more than a couple of weeks.

Give it some time. It'll mark its territory eventually.

Run your finger under the primary cover seam.

Oh for sure, I know it will leak, just happy to have slowed it a bit.

Gilesy · Oct 3, 2024

RGM supply two thicknesses of friction plates, 3.5mm and 4.5mm. I had the same issue and the 3.5mm plates fit in clear. Part number 82M11

gpzkat · Oct 25, 2024

Bike is running so well now. Gonna ride down to San Clemente Cars & Coffee and take a video. I made little funnels and taped them to the cables of both my current running bikes ('83 GS1100E and the '66 N15CS), worked in some clean motor oil, and they both are a LOT better. I always flake out on this one maintenance item but vow to be better. I have one of those gadgets to use with a spray can but I'm too cheap to buy the spray. Motor oil seems fine.

My 19 y/o son calls the Norton "The Contraption", but he loves riding it. He sees the difference between the Norton and the Suzuki as a gigantic leap, yet it is only 17 years. From the Suzuki to his '22 Tenere is more than double that, but is much less of a leap in function. We rode 230 miles a couple days ago, all over eastern San Diego county, and he rode the Suzuki more than his own bike. Not bagging on the Norton, it's just from another era and you have to get on its wavelength and enjoy the buzz. Literally and figuratively.

Schwany · Oct 26, 2024

gpzkat said:
Bike is running so well now. Gonna ride down to San Clemente Cars & Coffee and take a video. I made little funnels and taped them to the cables of both my current running bikes ('83 GS1100E and the '66 N15CS), worked in some clean motor oil, and they both are a LOT better. I always flake out on this one maintenance item but vow to be better. I have one of those gadgets to use with a spray can but I'm too cheap to buy the spray. Motor oil seems fine.

My 19 y/o son calls the Norton "The Contraption", but he loves riding it. He sees the difference between the Norton and the Suzuki as a gigantic leap, yet it is only 17 years. From the Suzuki to his '22 Tenere is more than double that, but is much less of a leap in function. We rode 230 miles a couple days ago, all over eastern San Diego county, and he rode the Suzuki more than his own bike. Not bagging on the Norton, it's just from another era and you have to get on its wavelength and enjoy the buzz. Literally and figuratively.

I agree with your son. Contraption is a good analogy for a pre-Commando. Too bad I can't fit that many characters on the license plate.

Valsp · Tuesday at 2:01 AM

gpzkat said:
Well, one thing leads to another. My clutch was the original from '66 and all I did was clean it and it worked fine - for a while. I stupidly put oil in the chain case after reading the manual. Up to then it had ATF but I was out, so off I went like a fool and then it slipped. I drained it out, cleaned again but slipping continued after a bit.

I got new friction discs and Type F ATF and set about changing it, but as I did, I saw the primary case had a lot more oil vs ATF than it should, given my cleaning. My bike wet sumps badly, and I saw oil drooling down from the seal behind the main sprocket. I drained the oil from the sump and it stopped. All this stuff adds up. I never could get the centerstand to work worth a damn, and gave up on it, and the side stand is too short - it is correct but Norton didn't see fit to extend it for the N15's extra suspension travel I guess. So it leans way over and sumps badly, which seems to be dousing the clutch with engine oil, at least that's my current thought. It all adds up to a very precarious situation with the old (but quite 'pumpy') oil pump possibly being the start of the chain of events.

My clutch springs and its other parts besides the new friction plates are servicable, but with the new friction plates being .17" or so, vs my old oil soaked originals being .14", and yet again, it all adds up to a nuisance. The very last plate hardly engages the splines due to the added thickness. I have to screw in the adjuster so far to get the lever/cable to disengage that the nut won't bite on the adjuster screw. The last 'half' plate looks like it will just spin outside the splined basket, the stack is too fat for the basket. I am wondering if I should pull out a plate/disc or what. What a pain. Riding the Norton is fun but working on it is tough, taking 27 things apart to try to fix one problem.

Andover Norton list the following

5 x CLUTCH PLAIN PLATE (EXTERNAL DOGS) 0.080"(2mm)

5 x CLUTCH FRICTION PLATE (3/8" INTERNAL DOGS)21259 4.5mm thick

They also list a CLUTCH FRICTION PLATE (1-SIDED 3/8" INT'L DOGS)0.110" (2.8mm) thick

When I fitted the 5 plates as suggested I was in the same position as yourself without using the single sided plate.

Looking at earlier Atlas models I noticed that they only listed 4 plates. I removed 1 friction plate and 1 plain plate and added the single sided friction plate. They fill the clutch basket and when the clutch is freed they are still just inside the basket. I have only just got the bike on the road but on a short 16 mile trip it worked beautifully. I use early ATF without friction modifiers in all my bikes and have not suffered from clutch slip so far

I have extended the side stand and it now works great. Work is in progress on the main stand and I will post some photos when done.

They are a pain to work on, as you say every time you go to fit something you find you have to undo most of what you have earlier don to get it on

gpzkat · Tuesday at 9:11 PM

Valsp said:
Andover Norton list the following

5 x CLUTCH PLAIN PLATE (EXTERNAL DOGS) 0.080"(2mm)

5 x CLUTCH FRICTION PLATE (3/8" INTERNAL DOGS)21259 4.5mm thick

They also list a CLUTCH FRICTION PLATE (1-SIDED 3/8" INT'L DOGS)0.110" (2.8mm) thick

When I fitted the 5 plates as suggested I was in the same position as yourself without using the single sided plate.

Looking at earlier Atlas models I noticed that they only listed 4 plates. I removed 1 friction plate and 1 plain plate and added the single sided friction plate. They fill the clutch basket and when the clutch is freed they are still just inside the basket. I have only just got the bike on the road but on a short 16 mile trip it worked beautifully. I use early ATF without friction modifiers in all my bikes and have not suffered from clutch slip so far

I have extended the side stand and it now works great. Work is in progress on the main stand and I will post some photos when done.

They are a pain to work on, as you say every time you go to fit something you find you have to undo most of what you have earlier don to get it on

I put one or two (can't remember TBH) of the old plates in. Cleaned them up. I think mdt-son said to use sugar soap, and I read about it in some guide sometime back. I have no idea what that stuff is. The best degreaser I have ever got is cheap 'dollar store' stuff. It's a strong surfactant, it will take any grease off of anything, is just as good as a petroleum solvent, and it's a $1.25 a liter. It's all working fine now.

I haven't the patience or budget to deal with the side-stand properly. My 'solution' is a hockey puck in my pocket. And really, the only time I deploy it is a hot day, with a beaming sun on that of the bike, on black asphalt. I had a perfectly new bike go down that way once and learned my lesson.

The N15 is a funny bike. I am always amazed at how well it runs. It kicks over reliably, runs like a champ, goes, stops charges, sparks, and suspends just fine. But little things happen and I'm not 100% trusting of it. I just haven't learned all of its many foibles yet - but I'm getting there!

mdt-son · 2024-11-20T02:01:07-0700

gpzkat said:
I put one or two (can't remember TBH) of the old plates in. Cleaned them up. I think mdt-son said to use sugar soap, and I read about it in some guide sometime back. I have no idea what that stuff is.

I quoted the factory manual, which specifies use of Fuller's Earh, also known as Bentonite, which is a sort of clay. There are probably more effective oil absorbents available today.

- Knut

norton bob · 2024-11-20T14:15:14-0700

The late 50's and early 60.s AMC clutch used less plates and they were thicker , when the 650/750 came along they put thinner and extra plates in the same basket and used a thinner pressure plate . If you try to fit the earlier plates you get your problem. Suppliers dont always know the history. Thats why i said use the old plates. Glad it works.

gpzkat · 2024-11-20T19:48:31-0700

mdt-son said:
I quoted the factory manual, which specifies use of Fuller's Earh, also known as Bentonite, which is a sort of clay. There are probably more effective oil absorbents available today.

- Knut

Oh yeah, that was someone else mentioning the sugar soap, oops.

Off topic, sorta - I am deep into a rebuild of an '83 GS1100E and just had to order clutch plates for it. That's another bike with some foibles in the clutch area. The housing gets worn and the clutch chatters, synchronizing the 4 carbs is important. Plus the '83 differed from the surrounding years in plate thickness so I've had to research how to make things right.

I lucked into the two '83s, free with a stack of NOS parts and spares. I got the first one (red, in background) running a couple of months ago and it's a stormer, a spot-on runner The 2nd one in the foreground has blue bodywork which I like even more. It has CBR900RR brakes and original Koni adjustable shocks that I just rebuilt. Should be fun.

norton bob · 2024-11-21T00:19:31-0700

Sugar soap is a well known cleaning agent powder that removes the oil from surfaces ,used in hot water mainly to prepare painted surfaces for repainting . Availiable from decorating , paint suppliers etc. also used for kitchen cleaning.

gpzkat · 2024-11-21T00:26:15-0700

norton bob said:
Sugar soap is a well known cleaning agent powder that removes the oil from surfaces ,used in hot water mainly to prepare painted surfaces for repainting . Availiable from decorating , paint suppliers etc. also used for kitchen cleaning.

Ah, I looked it up, I know it as TSP and I think that's the common term for it in the US - tri sodium phosphate. We'd get a box, mix in a big bucket of hot water and sponge the walls down before painting. That's the only use of it I ever knew. A little went a long way.

Clutch work on my N15CS, some interesting challenges

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