Split clutch push rod?

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Madnorton said:
I would have thought that as well, but it seems to be the worst lubricated bearing in the box.
Click to expand...

In all the time I've been using this forum I don't recall anyone reporting a problem with that particular bearing (unlike the layshaft D/S bearing), and I still don't agree that oil won't find its way through it and onto the lifter mechanism.
 
The commando gearbox if filled to the lower level of the level plug (ie plug removed) the lower shaft is a bit over half submerged in oil. The teeth of all the rotating lower gears pick up the oil and start to jam it into the teeth of the upper shaft. This is how the double floating bushes get oil by being jammed through the holes between the teeth of the bushed gear.
If anyone thinks the oil does not "get around"...then make and install a clear plastic cover to see if any oil gets splashed about. It should be easily visable.
I think the oil does get around and up to the LH bearing... otherwise about 5000 people would not have felt a need to buy one of my clutch rod seals. In 1988, I knew for fact certain that after less than 5 minutes of doing a break-in run on the centerstand that within a half hour cool off I had gear oil running down the face of my clutch diaphragm.
I no longer argue over this issue...believe what ever makes you happy :mrgreen:
 
After 5 mins! some rate of oil transfer, better go and check my gearbox oil level, I bet it is where it is when I last checked it about 700 miles ago - no change. A lot of owners know LH bearing takes a pounding, but they also find the RH bearing pretty shot also.
 
Madnorton said:
A lot of owners know LH bearing takes a pounding, but they also find the RH bearing pretty shot also
Click to expand...

Did DD mean RH bearing?

I've had it happen (smelt the gear oil on the clutch) and I'm sure the box was not overfilled so there must be more to it.

So, what's your theory on how oil from an overfilled box would get into the pushrod tunnel, taking into account there's no 'splash' in the outer case and for the oil level to be high enough to reach it, the box would have to be filled to the gearbox inspection port.

Anyone else here found a worn RH mainshaft bearing that looked as if it had suffered from a lack of lubrication?
 
There is certainly more to it, does it happen - yes it does, we know how it can be stopped, but we don't fully know the reason why it occurs otherwise it would be easy to design out and prevent from happening. Those like Ashman, myself and many others do not suffer this issue. DD may have sold in the region of 5000 seal kits for this purpose, but that is a relatively a small number considering how many Commando's were made, just under 10% it maybe believed, but there maybe as many again owners who just live with it, add in all those gearboxes AMC made and fitted to many other makes and Norton models since '57 including the race cars, pre 65 trials etc and it is not the norm.

I would suggest that the issue does not solely lie with just one item, oil levels, the clutch operating arm, clutch operating body and any mix of tolerances for the components may allow it to happen, first the oil has to get there, then it has to to travel along the rod.

I remember something somewhere about checking the gearbox vent is clear, but this alone would not prevent it from happening.

From the numbers, unless an owner knows his gearbox suffers with this issue, then it would seem strange to fit something to prevent a problem that may not affect them.

Next time my inner cover is off I will take some measurements of all those parts and compare them against the AMC drawings.
 
I am also free of this issue. Although there is a solution to those the who suffer from this, it is still a mystery as why it effects some and not others. I do not believe fluid level or fluid type are a particular causes. Although over filling may be an obvious contributor, corrections to levels may not always resolve it.

Anyhow, be thankful if you are excluded from the infliction or follow the needed corrections if you are not.

Peace!
 
Yes Les, sorry did mean RH bearing.
To visualize the volume of oil needed to slip and drag I visualize 8 drops on the outer friction plate (4 each side), 6 on the second plate, 4 on the third plate and 2 on the fourth. We all know the most oil is at the outer end. That's 20 drops which is .4 grams (yes I measured on lab scales) which is well under 1/4 tea spoon....yes I poured it into my 1/4 teaspoon. Like to see some one tell me when 1/4 teaspoon has leaked out of their gearbox by looking IN the gearbox inspection cover. LOL :roll: :?:
Yet... pour it on the clean concrete floor under my new belt drive with no outer primary cover after a 5 minute break in run and anyone who is not blind can see it.....I did.
 
Madnorton said:
There is certainly more to it, does it happen - yes it does, we know how it can be stopped, but we don't fully know the reason why it occurs otherwise it would be easy to design out and prevent from happening.
Click to expand...

As far as I'm concerned the DD mod. does prevent it from happening (RGM also has their own version) so nothing further needs to be designed out as it would only be replacing one modification with another.


Madnorton said:
DD may have sold in the region of 5000 seal kits for this purpose, but that is a relatively a small number considering how many Commando's were made, just under 10% it maybe believed,
Click to expand...

A valid point but only if you can tell us how many Commandos survive today, and I think you have to agree 5000 is a significant amount and probably a great deal more than the RH mainshaft bearings you've sold to Commando owners? :wink:

Madnorton said:
add in all those gearboxes AMC made and fitted to many other makes and Norton models since '57 including the race cars, pre 65 trials etc and it is not the norm.
Click to expand...

However, the oil used in AMC boxes then would have been an SAE motor oil and not so different to the oil in the primary, not EP gear oil as used in the Commando.
 
dynodave said:
To visualize the volume of oil needed to slip and drag I visualize 8 drops on the outer friction plate (4 each side), 6 on the second plate, 4 on the third plate and 2 on the fourth. We all know the most oil is at the outer end. That's 20 drops which is .4 grams (yes I measured on lab scales) which is well under 1/4 tea spoon....yes I poured it into my 1/4 teaspoon. Like to see some one tell me when 1/4 teaspoon has leaked out of their gearbox by looking IN the gearbox inspection cover. LOL :roll: :?:
Click to expand...

Agreed, it isn't a significant amount, but can be enough to contaminate at least some of the friction surfaces.
 
A teaspoon of oil in 5 mins of running that is a lot, agree this amount would not be noticed missing from the gearbox level. After an hours running you certainly would based on that volume obtained in 5 mins.

As for Commandos made, I would suggest that there are easily ten times the amount of seal kits sold - they keep many dealers in the UK and abroad in business , they would not all survive on just 5 figures. It is believed that somewhere in the region of 50 - 55,000 were manufactured. How many exist now, who knows but I bet a large proportion of those made exist but not used regularly as many owners have more than one Commando, some own many more. Sadly, the UK registration system is open to abuse so I bet some even have clones under one set of records and insurance.

The seal kit stops the oil coming out of the mainshaft, so yes it achieves the aim of stopping the oil getting into the clutch - the better method would be to stop it getting in the the pushrod in the first instance where it is not supposed to be, there must be way.
 
Madnorton said:
As for Commandos made, I would suggest that there are easily ten times the amount of seal kits sold - they keep many dealers in the UK and abroad in business , they would not all survive on just 5 figures. It is believed that somewhere in the region of 50 - 55,000 were manufactured.
Click to expand...

No idea what that has to do with the number of DD seals sold as no-one suggested they'd been fitted to practically all (surviving) Commandos, however.........

Madnorton said:
How many exist now, who knows but I bet a large proportion of those made exist but not used regularly as many owners have more than one Commando, some own many more. Sadly, the UK registration system is open to abuse so I bet some even have clones under one set of records and insurance.
Click to expand...

In other words, you don't know, same as the rest of us, but I'd guess not much more than around half survive, with less than that number in regular use, so I don't think 5,000 seals is such "a relatively small number" after all.


Madnorton said:
the better method would be to stop it getting in the pushrod in the first instance where it is not supposed to be, there must be way.
Click to expand...

What then keeps the pushrod lubricated within the mainshaft?
I think the best solution so far is the clutch-side seal as it allows lubrication to reach the pushrod without the oil getting to the clutch. I don't see how shifting the seal to the other end of the mainshaft would improve on that.
 
Re: Split clutch push rod?update

So far have new push rod plus the o-ring seal nut but decided to check stack height
Original fibre 0.656" + steel plates 0.318" + pressure plate 0.109" = 1.083" so 89 thou low

The bronze hi torque 0.6275" + steel plates 0.318" + press plate 0.109" = 1.052" so 120 thou low.
Steel plates are 2@ 0.08 & 2 @ 0.79
Bronze plates 0.126 - 1 thou diff less in 3 plates
Both pressure plates 0.109" the one fitted with bronze plates badly scored.

Am I missing something here bronze plate bought from rgm July 2015 bike traveled less than 100 miles
Thanks for previous input
Think I might phone RGM
Cheers BBM
 
Re: Split clutch push rod?update

Bigbossmonty said:
Original fibre 0.656"
Click to expand...



Can you just confirm that's five fibre plates?
Your 850 would have had a five (bronze) plate and thin (0.227") pressure plate clutch, originally. The original 750 clutch had four (0.145") fibre friction plates, three plain and a thick (0.347") pressure plate, however, there are "five-fibre plate" clutch kits around and these have thinner friction plates.




Bigbossmonty said:
+ pressure plate 0.109"
Click to expand...

I get the feeling you are measuring the pressure plate at the edge and not the full height, which should be around 0.227" so if you are using the dynodave data your stack height measurement will be wrong.

http://atlanticgreen.com/clutchpak.htm
 
Re: Split clutch push rod?update

L.A.B. said:
Bigbossmonty said:
Original fibre 0.656"
Click to expand...



Can you just confirm that's five fibre plates?
Your 850 would have had a five (bronze) plate and thin (.227") pressure plate clutch, originally. The original 750 clutch had four (.145") fibre friction plates, three plain and a thick (.347") pressure plate, however, there are "five-fibre plate" clutch kits around and these have thinner friction plates.




Bigbossmonty said:
+ pressure plate 0.109"
Click to expand...


I get the feeling you are measuring the pressure plate at the edge and not the full height, which should be around .227" so if you are using the dynodave data your stack height measurement will be wrong.

http://atlanticgreen.com/clutchpak.htm
Click to expand...

Just checked in the box 4 fibre plates 0.161,0.162,0.168,and 0.165 respectively.
Both pressure plates 0.109 at teeth and 0.232 in centre.
Using centre size would take stack height to 1.178 then if missing plate detailed below it would be 1.258"
I have checked RGM kit 050008 there should be a thin back plate 80 thou thick I might not have removed this so will look tomorrow but that still leaves approx 40 thou low what would an acceptable differance in actual stack height and spec stack height many thank in advance?
BBM
 
Re: Split clutch push rod?update

Bigbossmonty said:
Just checked in the box 4 fibre plates 0.161,0.162,0.168,and 0.165 respectively.
Click to expand...

OK, well, the four standard (0.145") friction plate clutch assembly would normally have three plain plates and 'thick' 0.347" pressure plate.


Bigbossmonty said:
I have checked RGM kit 050008 there should be a thin back plate 80 thou thick I might not have removed this so will look tomorrow
Click to expand...

I just checked 050008 and I think what you are seeing as a "back plate" is the additional HS0746 plain plate required to make up the 5-friction (+ 4 plain) clutch, as the narrower HS0746 plain plates can be used with the bronze hi-torque plates.

http://www.rgmnorton.co.uk/buy/clutch-p ... mm_853.htm


Bigbossmonty said:
but that still leaves approx 40 thou low what would an acceptable difference in actual stack height and spec stack height many thank in advance?
Click to expand...

You also need to know the depth of the clutch drum to find the right stack height.

However, there is an easier way, and what I suggest you do, is fit the full clutch stack into the drum, adjust the diaphragm spring to flat using the spring compressor, then fit the spring and large spring retaining circlip and without releasing the spring compressor, measure the distance between the spring and the circlip (using stacked feelers etc.) whilst holding the spring against the stack. That distance will be the amount the stack height is "low" from the "flat spring" position.
Reducing the distance (by increasing stack height) will lighten clutch action, but at the expense of clamping force, so the eventual stack height may be a compromise and the optimum setting can differ between individual clutches.
 
Hey Big Boss,

After reading your posts on Triplesonline for years, nice to see you here! (I'm Don W on that one) Good luck with your Commando!
 
Bigbossmonty said:
Should have said size of stack is bronze plates 0.125 thick so stack at edge would be 0.628 + 0.318+0.109+.08= 1.135" or 28.83mm.

At centre Press Plate 0.232 so stack height 1.258" or 32mm!
Click to expand...


But why are you adding 0.08"?

The stack is: 5 friction + 4 plain + 1 pressure plate. So, 1.258" minus 0.080" would be 1.178". Which is close to the dynodave measurement of 1.172".


Bigbossmonty said:
Still have to look for missing plate the 0.08 size above!
http://www.rgmnorton.co.uk/buy/bronze-c ... es_855.htm
Click to expand...

I don't think there is a missing plate and in any case, you don't need it if the stack height is 1.178" without it?.
The RGM conversion kit in the link contains one extra plain plate to convert a 4+3 four-plate clutch to a 5+4 five plate clutch.

BRONZE CLUTCH CONVERSION. CONSISTING OF:

063741 - BRONZE CLUTCH PLATE X5
063768 - STEEL PRESSURE PLATE X1
HS0746 - STEEL CLUTCH PLATE X1
Click to expand...
 
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