Who has successfully installed a clutch rod seal on Atlas or N15?

[gpzkat]

I have one of these.... http://atlanticgreen.com/ddacrs.htm

I put the regular nut on with washer and the clutch housing (the first part to go on) cinches up well against the gearbox main shaft. When I put this extended nut on to the point of the housing being snug, there's no threads left to put the seal retainer in.

First pic shows the nut turned all the way in - there's a thick lock washer underneath it, and it's got no inner threads to spare in order to insert the O-ring seal holder.

Second pic shows the inner seal holder, I think it must need to slip over the end of the shaft, but it does not. It may get close if it could set fully on the end of the shaft, but not close enough to snug up the clutch housing. I am not sure what I'm missing, some spacer? On the shaft itself under the clutch housing I have a thrust washer. There is little in the way of diagrams to help me here that I can find.

Shows the nut screwed in until the clutch housing is snug against the main shaft. No threads, and if I put the seal housing in and tightened it, damage would ensue one way or another (either it would not slip over the end of the shaft and it may deform, or it would slip over and crunch the O-Ring and possibly split the end of the seal housing).

Ay Carumba!

Should this slip over? I'd have to modify the outside surface of the shaft (sand it with emery) to make it do so.

 

[texasSlick]

I have the Comeau (dynodave) clutch rod seal on my Atlas. You should dispense with the stock clutch retainer nut and use only the extended seal nut.

Slick

 

[gpzkat]

I have the Comeau (dynodave) clutch rod seal on my Atlas. You should dispense with the stock clutch retainer nut and use only the extended seal nut.

Slick

Yes, thanks Slick, that's what I have done. First pic's the extended seal nut only, trial fitted with the lock washer under it, tightened to the point that the clutch basket's snug to the main shaft.

The instructions say hand tighten the extended nut, which would leave some threads on inside to screw in the seal housing. Then tighten long nut. That would mean it never cinches the basket up, and on mine it just pushes the seal housing out as it doesn't fit over the end of the shaft, which I believe it should.

 

[texasSlick]

I have one of these.... http://atlanticgreen.com/ddacrs.htm

I put the regular nut on with washer and the clutch housing (the first part to go on) cinches up well against the gearbox main shaft. When I put this extended nut on to the point of the housing being snug, there's no threads left to put the seal retainer

According to the first two lines of your post reproduced above........ you put the regular (stock) nut on ..... and in second line say "When I put extended nut on ......"

That reads like you have two nuts on the clutch shaft!

Slick

 

[Schwany]

On the shaft itself under the clutch housing I have a thrust washer. There is little in the way of diagrams to help me here that I can find.

I am most likely misinterpreting what you are describing. No thrust washer behind the clutch on mine. If there were a thrust washer behind the clutch that slid down over the splines, the washer would butt up against the sleeve gear when the clutch is torqued down and the clutch would not function as a clutch.

There should be some treads showing past the nut on the mainshaft after the clutch is torqued down against the thick lock washer. There is on mine. Unfortunately, I don't think I have any images that show this clearly.

Dave's clutch rod seal part for the old clutch is nice. I didn't think they were available any longer. I came up with my own, but it is not a very glamorous solution, or machinist's tour de force. It does work. Although I have a feeling its MTBF is kind of short.

Not an Atlas or N15, but it's the same clutch.

 

[gpzkat]

According to the first two lines of your post reproduced above........ you put the regular (stock) nut on ..... and in second line say "When I put extended nut on ......"

That reads like you have two nuts on the clutch shaft!

Slick

Ha, no worries it was definitely convoluted wording.

 

[gpzkat]

I am most likely misinterpreting what you are describing. No thrust washer behind the clutch on mine. If there were a thrust washer behind the clutch that slid down over the splines, the washer would butt up against the sleeve gear when the clutch is torqued down and the clutch would not function as a clutch.

There should be some treads showing past the nut on the mainshaft after the clutch is torqued down against the thick lock washer. There is on mine. Unfortunately, I don't think I have any images that show this clearly.

Dave's clutch rod seal part for the old clutch is nice. I didn't think they were available any longer. I came up with my own, but it is not a very glamorous solution, or machinist's tour de force. It does work. Although I have a feeling its MTBF is kind of short.

Not an Atlas or N15, but it's the same clutch.

Thanks, I got from BritCycle a couple months ago. I was unsure whether there should be a thrust washer there, with your info I'll remove. Makes sense. I think it's a spare intermediate shaft (timing gear spindle) as I purchased a new one.

Mark at BritCycle said to send pic of old nut and new, and he will check if maybe I got a Commando one. They are great with customer service in my limited dealing with them. So hopefully that pans out.

 

[robs ss]

I think there may be seals especially for early clutches - I have one on my ES2 and will see if I can find records of where I got it.
Another alternative is to do what our @ludwig did using an old valve (just needs to be 8mm dia)
Obviously the existing pushrod will have to be shortened to suit. The "necked" section to accept o-rings needs to be machines to suit ID of o-rings. I am planning to do this on my 650ss.
Picture below will explain.
Kudos to ludwig!
Cheers
Rob
(I have been having problems posting photos so will do so in a separate post when the issue is sorted - worth looking at!)

 

[mdt-son]

Ha, no worries it was definitely convoluted wording.

gpzkat, to me it looks like you have a non-stock mainshaft. The outer end is missing! The correct mainshaft 040001 looks like this:

MAINSHAFT PRE COMMANDO AMC GEARBOX, 9 1/4" LONG

www.rgmnorton.co.uk

This may explain why you have fitting problems. RGM shows the various mainshafts in another photo.

- Knut

 

[gpzkat]

gpzkat, to me it looks like you have a non-stock mainshaft. The outer end is missing! The correct mainshaft 040001 looks like this:

MAINSHAFT PRE COMMANDO AMC GEARBOX, 9 1/4" LONG

www.rgmnorton.co.uk

This may explain why you have fitting problems. RGM shows the various mainshafts in another photo.

- Knut

It's the right one, the nut that contains the seal is about 3x the length of the original, so it's hiding that end when it's screwed in all the way.

The word I got back is that the inner piece containing the seal (2nd pic in original post) should slip over the end like I suspected. So I am going to use some sandpaper on that protruding end. It's quite close and it will cause no issues to trim this. I'm mainly worried that the seal retainer will protrude just a bit when the main nut is screwed all the way in. We'll see next week when I get back to it, thanks for input.

 

[robs ss]

@ludwig photos (should have been part of post #8 above but... problems!)


I just had a thought (dangerous, I know!) that you could machine the "waisted" groove for o-rings into the pushrod itself.
Anyone see a reason why not?

Cheers

 

[texasSlick]

@ludwig photos (should have been part of post #8 above but... problems!)
View attachment 97014View attachment 97015

I just had a thought (dangerous, I know!) that you could machine the "waisted" groove for o-rings into the pushrod itself.
Anyone see a reason why not?

Cheers

I had that thought as well! I dismissed it thinking that would be too easy ..... must be a reason why no one has done it that way.

Slick

 

[Schwany]

That's a belt drive Commando dry clutch in Ludwig's Norton, not that it matters for the clutch rod.

I'd throw caution to the wind and try the groove in the rod, but I'd buy another clutch rod as a spare just in case it turned out there is a good reason for not doing it. That clutch rod might be too long and wobbly to put in a lath. Easier to cut it shorter and do the groove in a small length part. I wouldn't know though, because I don't own a lath. Only reason I'd try that is because I don't have the kit solution.

gpzkat, hold your course and keep on doing what you are doing. It is supposed to work.

 

[Junglebiker]

Putting the pushrod into a lathe would be easy as long as you have a lathe small enough to clamp down on something of that diameter. Wobbliness should not be an issue, as you can have the bulk of the pushrod in the chuck and only have a short part of it sticking out where you want to machine it. My bigger concern is with the finish on the inside of the countershaft; how smooth is it? Are there drill marks that might cut up an o-ring but not damage a pushrod? I like the idea, but there has to be a reason why it's not already being offered by somebody.

 

[mdt-son]

Putting the pushrod into a lathe would be easy as long as you have a lathe small enough to clamp down on something of that diameter. Wobbliness should not be an issue, as you can have the bulk of the pushrod in the chuck and only have a short part of it sticking out where you want to machine it. My bigger concern is with the finish on the inside of the countershaft; how smooth is it? Are there drill marks that might cut up an o-ring but not damage a pushrod? I like the idea, but there has to be a reason why it's not already being offered by somebody.

Mainshaft, not countershaft. Yes, lack of surface finish is one of my concerns too. Plus, the waisted part will have to be rather thin, as the pushrod clearance is small at the outset. I believe machining the hardened rod requires a cubic boron nitride insert. You can't machine it by a regular boron insert. The rod is probably case hardened, and this hard layer will be lost by machining the waisted section. The rod surface acting as "bearing" to the O-ring will have to be polished. All effort considered, I'd say this is too much work to dispense with the special nut.

- Knut

 

[baz]

I think I must be missing something here
The clutch pushrods are made of silver steel and are easy to machine
The ends are heated cherry red and quenched to harden
At least all the ones for British bikes I've seen/made so far have been?

 

[Junglebiker]

Mainshaft, not countershaft. Yes, lack of surface finish is one of my concerns too. Plus, the waisted part will have to be rather thin, as the pushrod clearance is small at the outset. I believe machining the hardened rod requires a cubic boron nitride insert. You can't machine it by a regular boron insert. The rod is probably case hardened, and this hard layer will be lost by machining the waisted section. The rod surface acting as "bearing" to the O-ring will have to be polished. All effort considered, I'd say this is too much work to dispense with the special nut.

- Knut

right, mainshaft, of course.

 

[Schwany]

I think I must be missing something here
The clutch pushrods are made of silver steel and are easy to machine
The ends are heated cherry red and quenched to harden
At least all the ones for British bikes I've seen/made so far have been?

I doubt your missing anything unless you started with my post. If you started where I butted in on cutting the seal groove into the clutch pushrod you would be missing relevance. lol

 

[ludwig]

.. lack of surface finish is one of my concerns too ...the waisted part will have to be rather thin ... I believe.....probably...

The inside of the mainshaft has indeed a rough finish, that is why the slot has to be 5- 6 mm long and polished.
The idea is that the O-ring stays put, and the rod slides.
The waisted part is 4.5 mm in dia..
O- ring from an (old) Amal set screw (everyone has those lying around..)
Although 2 pieces is the better way , machining the existing rod is really no problem.
Cheap and easy, no extra nut that can come loose or may no fit..

 

[gpzkat]

I got it fitted, the end of the shaft had some old oil buildup and I zipped it off with crocus cloth. The end of the rod doesn't protrude as much as the inner seal holder won't go in as far as the one pictured on the maker's link. But it's enough for the clutch adjuster to contact it. I believe it will be fine.