classic motorcycle forum

I managed quite a session today, buckle up folks fair and foul, this is going to be a long one!

First order of business was to check out the studs on the clutch hub, one of them was slightly loose and was trying to figure out if there was anything I could do about it.

I spent some time on the Andover Norton shop web site, it's great, lots and lots of diagrams, and information, including half-decent photos of every component.  I've no idea exactly what my clutch is, but I'm pretty sure it's late '50s-'60s so I started there. 
This is the standard spring stud :


As you can see (hopefully), there's a flat on one side of it.
This image is a bit clearer: (it's a "Manx" clutch stud, but I don't think there's much difference)
.

So - the stud is keyed.  That means that I can tighten it up with the nut on the reverse side!


So I did


A good start!

Now that washer behind the hub doesn't align centrally... but I think it's close enough.


I then whipped off the drive sprocket to clean up the threads for the locking washer


And fitted it. Did the nut up as tight as I could (the spanner kept slipping off because of the dished cog), fitted the lockwasher and got on with the chain.


I tried fitting the chain connector, but putting the spring back on was prooving awkward, I wonder why...


Well, that would explain that...


So I dug out the tobacco tin full of chain bits...


and had a furtle..

EVENTUALLY... I found something that would have to do...


The plates on the new connector are a tad wider, but the pins and the gap between them are correct.


I initially fitted the new connector with the original plate... but it looked like there'd be too much movement, so I ditched that idea.


So I fitted the connector plate with the plate that it came with, and it fitted ok.

However.. it was a tad tight on the clearance to the clutch hub,




I must have faffed about for an hour or more trying to reconcile the drive chain clearance and the clutch hub, with that washer behind the clutch hub apparantly not giving the required clearance.  I even dug out a thicker washer, but that didn't help either.

One odd thing I found was that if I did up the clutch hub nut tight... the entire gearbox locked up, which made no sense.

I faffed and faffed.... pulled the clutch hub off and put in on again with different washers etc etc...

then eventually realised that, after a long and confused perusal of lots of diagrams and workshop manuals (which, as said previously, were less than clear).... that the $%^&&ing washer wasn't supposed to be there!

There's NO menting ANYWHERE that I could find of a washer being fitted behind the clutch hub.

If you look at this photo, the gearbox input shaft with the visible splines on it, runs inside the output shaft.  They both rotate in the same direction, but at different speeds (dependant on the magic that happens inside the gearbox). 


The clutch hub is also supplied with splines,


(obviously), but the key thing is that they're cut to a specific depth, so when the hub is pushed onto the splined shaft, and pushed up tight: IT'S IN THE RIGHT PLACE. It's tight on the shaft, but it's NOT so far up the input shaft that it interferes with the output shaft. 


The $%^&&ing washer was locking the two shaft together!!  Once I realised this I spent a very confused half an hour or so trying to fathom why on earth that washer had been fitted.

Eventually I gave up and fitted the sodding hub without it, the gearbox moves freely and easily!


Unfortunately... the new chain connector spit link now interfered with the clutch hub!!
The chain is a thin-plate thing and "just" clears the clutch hub - but the split link has longer pins than the rest of the chain, so it just catches the clutch hub.

So I ...err.. refitted the thing backwards.


IE with the spring-clip on the "inside" of the chain run, the spring clip is still swimming in the right direction... it's just going to be an absolute !"£%^% to get off again...

But it clears the clutch hub.


I nearly forgot to fit the cush drive screws.


Then went back to cleaning the rest of the clutch plates.


As I think I said, they're sintered metal plates, not cork, so need to be clean and kept dry.
Eventually I got them all done,
Hopefully they're all in the same order and orientation, I tried to keep them the same: apparently they "set" a bit like brake pads do.


Then I tidied up the adjuster screw in the pressure plate


Including cutting the slot a bit deeper



Much better!


Before I completed the clutch refit, I turned to the gearbox to have a think about this issue of oil apparantly getting down the clutch push-rod tube.

Firstly I realised that the inspection cover must be an aftermarket item...


Because there's no breather hole in it


There's supposed to be a pinhole to allow the gearbox pressure to equalise as it gets hot and cold.  Without it, the only pressure relief passage that the gearbox has is the clutch push rod tube...



I've been doing some research and there's 2 fixes for this issue that are generally agreed upon (at least within the Norton Owners Club anyway....)

Fit a breather tube to the gearbox to allow pressure equalisation by a different passage, and/or modify the push rod to carry one or two o-rings to prevent the oil getting to the clutch.

I've decided to do both. 

So - I first dug out a few o-rings to see if I had anything reasonably close to the size.
This is a tad large.


but I have a few more...


closer


Maybe too small?



Eventually I found something close, and started the cut the small channels in the push-rod.
The clearance between the push rod and the gearbox mainshaft is minimal, and the o-ring mustn't interfere too much with the movement of the push rod, so the o-ring needs to protruce from the surface of the o-ring by only a tiny amount.

Which means cutting the little channels is going to be a "little bit, and check" "repeated and often," sort of job, which is why it's still not finished!

I'm doing the cutting by putting the push-rod into the drill and applying a very small file to it as it rotates.  The file is ~1.22mm wide, and the channel should be "around" 0.7mm deep, which is going to depend muchly on the o-rings I think.

This is roughly what 0.75mm looks like compared to the thickness of the rod.



While I was faffing with this process, I inadvertently lost an o-ring in the sodding shaft.


??

Worth keeping an eye on the tappet clearance: if it moves more you'd better investigate. If it doesn't move, it's not unusual to see hardened steel caps (think shallow bucket) on top of the valve stems to increase the effective length of the valve. With the rocker arm acting directly on the end of the valve stem it's important that the stem is hard enough to stop it either wearing or mushrooming.

Leon

I disagree with the 'reinforcing the weak spots' idea. Why spend money, time and effort shoving reinforcing tubes inside other frame tubes when a more thoughtfully designed headstock lug and fitting decent grease nipples would have prevented the whole issue happening in the first place. Not much chance of that happening in British lightweight world was there. Their whole world seemed to revolve around their race to the bottom of cheap and nasty. Price seemed to be the sole criteria for the majority.

My '39' Montgomery is a perfect example. I never appreciated how a firm could use the one rear axle lug for every machine in its range, from a 125 two-stroke to a 1000cc vee-twin. And make same universal lug right or left handed by bashing off the the various unwanted bits to suit either the left or right side of the frame. Or how one could further cheapen a set of pressed steel forks seemingly identical to those on my Excelsior by not fitting the friction dampers used by Excelsior and eliminating all means of link and spindle adjustment with an anti-rattle Thackery washer on the end of each spindle. I won't go on to mention the centre stand made of angle iron nor the saddle mounting using the same angle iron. In the end its just so nasty you have to love it. Its pure runt of the litter territory.

We do digress. Its a pity we don't have the frame number. I'm curious to know whether this Waratah is one of the mis-war imports or immediate post war.

One final note. Leg shields were a standard fitment on the Excelsior version. They don't show up well on the usual catalogue illustrations but they're there. They were attached to the front down tube by the usual clamp on cross pieces. One look at the carburettor position and you can see why Excelsior fitted them.   
   

Its not unknown for the front down tube to break on these wee beasties. My Montgomery frame was broken and brazed up just below the head stem lug when I got it and two of my Excelsior frames have repairs to the top tube immediately behind the head lug. I think its a combination of poor fork lubrication and skimping on the head stem lug plus of course making the whole frame as cheaply as possible.
When the forks stiffen up through lack of grease all the road shocks are transmitted through them to the main frame loop which "lozenges" over big bumps with the top tube bending. This eventually finds the frame loop weak point and it fractures there. Usually either the top tube immediately behind the head lug or the down tube immediately below the head lug. This is why I have a complete fixation about fitting modern 'zerk' grease nipples to girder forks and keeping them well greased. Not only do you get a much improved ride you also get better road holding and give the frame a chance of survival. This is just another one of the little subtleties you learn from riding British lightweights.
 
Given the cost of restoration I think the $600 offered to date is about top dollar for what is on offer.

My only serious question is about the provenance of the offending head stem lug. Was the lug considered part of the forks and provided by the fork maker or was it a separate item sourced by the frame maker? That is, to Excelsiors own design? Anyone know?

Dull one tonight.

Just cleaning the clutch mostly.

..


Obviously there's still photos!

Plates and accoutrements set for some BZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZT


Cleaning the basket in petrol, I also brushed the hub off with petrol



Brass brushing the plates (the BZZZZZZZZZZZT got a lot of the "fresh" oil off I think, but there's still a lot of ancient gunge.


I should point out that these are definitely modern items, they're sintered bronze, like brake pads (which a huge amount of sense if you think about it - brakes and clutches are basically the same thing, just doing opposite jobs)

This is preying on what's left of my mind...


The only way that adjustment can be SOO at the end of it's range is if
a) the push rod has shortened...
b) the valve has shortened...

neither of which seem terribly likely....

or c) the rocker arm has bent!

Or maybe d), the cam follower has bent!

Basically... SOMETHING has got shorter, which is why the valve-clearance opened up... but for it to open up nigh on over a millimetre in 60 miles...

I'm beffuddled.

The basket and hub seem to have cleaned up nicely, I still haven't been able to split the hub out (to check the cush-drive rubbers), but sod it. If they're holding the thing together that hard, they're obviously still pretty solid.


I am slightly concerned though because one of the studs is slightly loose, and I can't see how to tighten it up...

Nice clean accoutrements.


3 Clean plates.... got this far and my hands started to ache,


The rest are separated to let the moisture get trapped


 so giving it a rest for the night.  Have a good weekend all.