1st Gear Clutch Issue

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sturrubiarte

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Oct 29, 2014
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I read a thread from another rider with a similar problem and looked through the shop manual but couldn't come to a conclusion. My bike starts fine and down shifts perfectly. But if I try to disengage the clutch and shift to first from neutral it just grinds, as if its still engaged. As I mentioned all other gears work fine to down shift, beads aren'r broken clutch cable moves freely and has good tightness.

Heres the thread I looked through, maybe I missed something.

clutch-cleaned-now-bike-won-kick-t9546.html

Here are some pictures I took of the clutch disengaged and engaged.
1st Gear Clutch Issue

1st Gear Clutch Issue
 
Looks like the lifter mechanism is seriously under-adjusted (and the cable has been over-adjusted to compensate) as the lifter arm in the first (clutch engaged) photo is at the height it should be in the second (disengaged) photo so the clutch pushrod adjustment needs checking!

(To avoid any confusion the clutch is "engaged" when the lever is out and "disengaged" when the lever is pulled back to the handlebar)
 
If I'm understanding you correctly, you're saying that the arm, lifted by the bead when disengaged, should be adjusted to a lower position, when engaged, allowing for a higher position when disengaged?
 
sturrubiarte said:
If I'm understanding you correctly, you're saying that the arm, lifted by the bead when disengaged, should be adjusted to a lower position, when engaged, allowing for a higher position when disengaged?
Click to expand...

When the clutch is engaged (lever out) the lifter arm (with the cable nipple attached) should be nearly resting on the roller, and the cable should not be applying any lift to the mechanism.


1st Gear Clutch Issue


When the clutch lever is pulled in, the arm should be lifted to the approximate position shown in your (upper) photo, the hight of the lifter in the (lower) photo is excessive.
 
To correct this will I need to take off the entire side cover or will the cover I took off give me enough clearance?
 
sturrubiarte said:
To correct this will I need to take off the entire side cover or will the cover I took off give me enough clearance?
Click to expand...

What you need to do first is read section C35 of the manual on how to adjust the clutch mechanism: http://www.classicbike.biz/Norton/Repai ... mmando.pdf

The instructions in C35 say to back off the pushrod adjuster by "one full turn" however that is often too much, and a quarter to half a turn is recommended.

One thing to watch is that you don't operate the clutch lever when the pushrod adjuster is fully backed-off as the lifter arm can drop out of position, which results in an extremely heavy clutch pull.

If readjustment of the clutch lifter mechanism doesn't improve 1st. gear selection then you may have to investigate further and possibly strip the clutch (which requires a special tool to compress the diaphragm spring) to clean and inspect the plates (refer to manual).
 
What exactly is figure 48 referring to on the bike. At first I thought it was referring to an object that can be seen in the sight area of the clutch lever but its obvious I'm wrong. Not sure where to go from here.
 
sturrubiarte said:
What exactly is figure 48 referring to on the bike. At first I thought it was referring to an object that can be seen in the sight area of the clutch lever but its obvious I'm wrong. Not sure where to go from here.
Click to expand...

The pushrod adjuster is on the drive (left) side of the bike.

Remove (unscrew) the primary case access plug (Man.C35,2), you should then see the pushrod adjuster "C" (and locknut "B") as shown in Fig.48.
 
After the adjustment I notice no marked difference from where I begun. It is as if the clutch cable itself is too short or the tension of the arm that receives it, which is nonexistent, will not allow for the arm itself to lie nearly flat.

I'm curious though with the clutch at my current position, such as the aforementioned pictures, why wouldn't the clutch be continuously disengaged preventing any gear engagement?
 
You slacken off the clutch cable first before the adjustment, I remove it from the handlebar lever completely so it cannot interfere at all and grease the nipple on reassembly. I also had a clutch cable where the inner was too short once and only with a new correct cable could I get the adjustment right.

The other item to look at once you have the clutch adjusted correctly is the tickover RPM, if this is too high then no amount of clutch adjustment will stop the grinding, aim for 900 to 1100 rpm.
 
That makes sense when I consider it that way. I just find it interesting because not two days ago it was running completely normal then all of the sudden the clutch stopped working. Especially since when I sat in second, down shifting initially rather than up, it sat as normal but wouldn't work at all in first.
 
sturrubiarte said:
After the adjustment I notice no marked difference from where I begun. It is as if the clutch cable itself is too short or the tension of the arm that receives it, which is nonexistent, will not allow for the arm itself to lie nearly flat.
Click to expand...

If the cable won't allow the arm to drop to the position shown in my photo when fully slackened off, then there would seem to be a problem with the cable. If the inner cable appears to be too long, then the outer sheath can be shortened.

sturrubiarte said:
I'm curious though with the clutch at my current position, such as the aforementioned pictures, why wouldn't the clutch be continuously disengaged preventing any gear engagement?
Click to expand...

If that was the problem (cable inner too short), and the pushrod adjuster backed off to compensate for the over-adjustment caused by the cable, then the clutch would still work but perhaps not as well as it should.
 
Well I'd better invest in a new cable then, although it seems unlikely that the cable is too short since it worked just fine previously. Crazier things have happened though I suppose.
 
sturrubiarte said:
Well I'd better invest in a new cable then, although it seems unlikely that the cable is too short since it worked just fine previously. Crazier things have happened though I suppose.
Click to expand...

A new cable sounds like a good idea (assuming the handlebar clutch lever assembly is standard and is not the cause of the inner being too short?) and hopefully that will cure the problem, if not then it's back to "plan B", which would be to check primary chain adjustment, inspect the clutch plates, pushrod, and that the clutch nut hasn't loosened off, and if necessary, strip the lifter assembly?
 
Christ. That all sounds much more involved than I'd hoped. At least I have the clutch compression tool. It's just the perplexity of the thing, how it worked and all of a sudden doesn't.

Anyone care to explain how the small movement from lying flat to lifted by the lever just slightly disengages the clutch? To me it would mean there would need to be necessary tension on the arm initially for the slight movement to disengage. Although there's slight play so...
 
sturrubiarte said:
Christ. That all sounds much more involved than I'd hoped. At least I have the clutch compression tool. It's just the perplexity of the thing,
Click to expand...

It's all fairly basic 40+++ year old engineering, not rocket science, although I do suggest you thoroughly read through the manual and parts book to gain a better understanding of the perplexities. :)

sturrubiarte said:
how it worked and all of a sudden doesn't.
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No definite explanation for that, as yet (reason for plan B) .

sturrubiarte said:
Anyone care to explain how the small movement from lying flat to lifted by the lever just slightly disengages the clutch? To me it would mean there would need to be necessary tension on the arm initially for the slight movement to disengage. Although there's slight play so...
Click to expand...

Yes there must be some play when the clutch is engaged otherwise the lifter components would constantly rub against each other leading to rapid wear, or, in extreme cases the pushrod has been known to become heat welded to the lifter ball.
When set correctly the diaphragm spring should be lifted about 0.100" - 0.130".

1st Gear Clutch Issue
 
1st Gear Clutch Issue
[/quote]


Les,
Not to get of topic, but is that a modified shifter rubber or did you buy it that way. I had to use a piece of rubber hose in order to clear my boots.
Pete
 
I was looking at this diagram from andover and noticed what the adjustment was doing. Since the manual calls to tighten the screw clockwise until it is felt that the screw just touches the push rod.

1st Gear Clutch Issue


Furthermore, the smaller picture that shows the arm which receives the clutch cable must have pressure on it from the ball behind it, which the pressure is received by the push rod, mine as I'm looking at it isn't even moving the front rolling washer, or whatever it is, that is directly in front of the arm unless I'm putting manual pressure on it. No way to check if this is correcting the issue or not..
 
Deets55 said:
Not to get of topic, but is that a modified shifter rubber or did you buy it that way. I had to use a piece of rubber hose in order to clear my boots.
Click to expand...

Just the standard rubber, filed-down.
 
sturrubiarte said:
Furthermore, the smaller picture that shows the arm which receives the clutch cable must have pressure on it from the ball behind it, which the pressure is received by the push rod, mine as I'm looking at it isn't even moving the front rolling washer, or whatever it is, that is directly in front of the arm unless I'm putting manual pressure on it. No way to check if this is correcting the issue or not..
Click to expand...

In that case, there may be no alternative other than to remove the gearbox outer cover and strip out the lifter mechanism?


https://www.oldbritts.com/gearbox_d.html

https://www.oldbritts.com/gearbox_a.html

Perhaps somebody fitted the wrong size operating ball (part 040031, item [32])?
http://www.nortonmotors.de/ANIL/Norton% ... 08&Part=32

Or, the roller sleeve (040065 item [37]) could be missing?
http://www.nortonmotors.de/ANIL/Norton% ... 09&Part=37

Or, the pushrod could be too short?
 
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