Norton commando 750 1972 Camshaft bush and washers

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chiccogarz

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Hi there,

I have a norton commando 750 1972 #205000 and I am redoing the engine as well as the entire motorbike :P :P . It came rusty and dirty and there is a lot to do.
Since I am working on the engine, I would like to ask you something about the bushes of the camshaft. My motorbike fits (as I disassembled it) a plain bush on the timing side. Then, there are two washers one internal and one external between the case and the chain gear. These two tabbed washers 06-2601 having thie peg that goes in a hole in the crank case (time side).

Now, I have been suggested to get away with these washers and fit a bush that is not plain. My question are:

1) which is the number of this bush: 06-3020 ?
2) which bush should I fit on the drive side of the camshaft ? the same 06-3020 or another one like the plain one I have on now ?
3) which washer should I fit in the time side between the gear and the case instead of the tabbed one (06-2601) ?

Thank you very much in advance!!!
 
Just for fun, I was reading the Norton Service Sheets a couple of days ago. I know, I need to get a life. You want to look at Service Sheet 77, called 1972 Camshaft and Bushes.Text appended below.
Stephen Hill

New type camshaft bushes with oil groove are
introduced for 1972. To suit these, camshafts
are being produced without the figure of eight
oil groove which was a feature of previous camshafts.
Whilst we shall continue to stock the
bushes and camshafts of the previous type for
spares purposes, all concerned are alerted to the
danger of using a 1972 non-grooved camshaft in
pre-1972 non-grooved bushes, which would result
in oil starvation and possible engine damage. 1972
camshaft bushes are of smaller outside diameter than
previous camshaft bushes and as a result, it is not
possible to fit later bushes to an earlier crankcase.
No harm would result from using a grooved camshaft
in a grooved bush if this should prove necessary
at anytime,
Ensure that the correct years parts are ordered
when replacement camshafts or camshaft bushes
are required and on fitting recheck that either
the camshaft journals or bushes have lubrication
grooves.
February 1972
 
The bronze tabbed washers should be done away with because they can/do crack on the outside of the bend whhere the factory bloke took the pliers to bend the tabs over. The potential exists to have a tab fall off/apart and drop into the works/oil pump. Yes you can fit a later type bush to the timing side and no washer(s) will be required. Scrolling marks for oil supply must exist either on the cam end or if unscrolled cam being used then the new bush itself. The new bush will need to be reemed to fit after it's placement in the T.S. casehole. for a nice fit for the cam.
 
I have been switching all mine over to needle bearings and quick change cam kits.

The needle bearings fit with little machining on the LH side and a bit more for the carrier on the RH side.
On the plus side cam removal dosn't require splitting the cases.

Norton commando 750 1972 Camshaft bush and washers
 
chiccogarz said:
Hi there,

Then, there are two washers one internal and one external between the case and the chain gear. These two tabbed washers 06-2601 having thie peg that goes in a hole in the crank case (time side).
Click to expand...

Whoo! Wait a minute here. Two tabbed washers?

Let's back up a litte, then move on.

There is no washer between the case and the cam gear in the timing chest. This gear will ride against the shoulder on the cam shaft.
Again, NO WASHER HERE!

Now let's go inside the case.
You can eliminate the tabbed washer (the only one used) by going with the 06-3020 on the timing side. The shoulder is, of course, on the inside. On the drivers side you can use either the 06-2600, even though it is scrolled, or the 06-5425.

The thrust washer 06-1086 is still required with the pointy side toward the middle and the wider flat side against the shoulder of the 06-3020 cam bushing.
 
hold on! really?

My norton fits two tabbed washers of the same kind.
Here, it is as it was when I started to disassemble the engine.




Norvil Motorcycle says that I need two of them!

Could anyne give me a confirmition???
 
Only by memory as I recall my Crazy Combat 72 had 2 of the potentionally problematic tabbed washers. One on each side of the T.S. case casting. And yes they were cracked at the bend-over locator tabs. But it was 15 or so years back when I tossed it/them in disgust.
 
My genuine manual part no. 063419 states: "On the later engines there are 2 thrust washers with tabs engaging to holes in the crankcase ". This is what I recall.
 
chiccogarz said:
hold on! really?

My norton fits two tabbed washers of the same kind.
Here, it is as it was when I started to disassemble the engine.




Norvil Motorcycle says that I need two of them!

Could anyone give me a confirmition???
Click to expand...

Yes, please someone chime in here.
Norvil Motorcycle said this or just someone "at" Norvil Motorcycles. Did they explain why they are different all the manuals? Is there in issue particular to your machine that you are not explaining or are not aware of?

Quite frankly, I cannot see how a tabbed washer between the cam sprocket and the case would allow for the rest of the assembly to be completed. This would surely misalign the intermediate gear. Not to mention, the cam sprocket running up against this second tabbed washer, which of course is stationary, might generate a little heat and fail, but that is a moot point cause assemble completion would not be possible.

I may be totally off my rocker here, but some one show me where it calls for "2" 06-2601's.
Not to mention, show me a picture of a washer of any kind between the cam sprocket and the case.
This might make some sense on how so many tab washers fail. They added one on the wrong freaking side. "Duh, I wonder what that hole's for?"
 
Someone here. My Crazy is 208018 and I recall she used a plain bush on timing side ,the necessary (chamferred to clear tach drive) thrust washer then the locator washer(s) each side of the casting. The actual bushing hole in case was smaller than previous bushings plus there is another very small hole nearby to put the tab(s) into to "locate" and prevent spinning about freely. My solution was to fit a lipped (right word ?) t.s. bushing with that lip facing the gear side. Fit was good and yes I was concerned about the gear rubbing against bush there but after tightening down sprocket nut all was goodly. Mike of Walridge provided me with the lipped bush after some conversation. Off your rocker thread for the future.
 
Norton commando 750 1972 Camshaft bush and washers


This is a picture of my motorbike when it was disassemble. To be honest, the gears were in line and there was no sign of rubbing or unusual worning around the case or gear. I believe, there should be two washers as mentioned before.

Norvil says that two are required in the description of the component in the list.

Does anyone know more about why I do have two washers and someone as pete has one?
 
Ok, that's a picture of one all right. But what I was looking for was a picture in a manual or something along those lines.

These damn bikes really screw me up sometime with shit like this.

Bare with me here.
Your picture makes sense for one reason that i can think of. The picture shows this washer loose and sort of dangling on the cam. If the washer slips over the od of the cam sprocket, allowing the sprocket to go through it and butt up against the cam as it should, then this washer may be acting as a shim to adjust camshaft end play.
Yes? No? Maybe?

It just so happens that I have some excess camshaft end play and if someone can truly validate this intention rather than vaguely recalling something from the past, then I just may keep my 2 PowerArc unit around for a while.

I will be add the hydraulic chain tensioner and chain from the comnoz and this would be an opportunity to make this adjustment.

Honestly, I do not know exactly how I would adjust camshaft end play. Maybe that is what we are seeing here.

So, again, let call upon the "professionals". :?
 
pete.v said:
It just so happens that I have some excess camshaft end play and if someone can truly validate this intention rather than vaguely recalling something from the past, then I just may keep my 2 PowerArc unit around for a while.
Click to expand...


pete.v said:
So, again, let call upon the "professionals".
Click to expand...

Mick Hemmings specifically mentions the need for the second, outer thrust washer in his NOC Heavyweight Twin Engine Restoration DVD.

Mick Hemmings:

".....on the 750 engines, that are 200000 engine number, they have, a bronze thrust washer inside the crankcase next to this [the chamfered washer] and also, one on the outside, this is because the camshaft bush is plain, without a shoulder on-so it needs something to support the cam....."
Click to expand...

Mick goes on to say that the tabs should be cut off the thrust washers, or preferably that he prefers to replace the bush with the shouldered type.
 
Should we assume that nothing came from the factory with this second washer or the other way around? And if it isn't in our motors is it because the rebuilder from previous owners failed to put it in there simply because the didn't read Mick notes?

Anyone going by the book is living on the edge of assumption.
LAB, good info yet I hunger for more reasoning and examples of intended application.
We're getting closer to the truth.

I wonder when Mick speak of supporting the camshaft, is he speaking of positioning as in endplay?
 
The idea was the tab broke of , fed through the oil feed , got in the pump gears , and Jammed Them .

This ensured thered be Nortons parked up for people to sort out for decades to come .

REMOVE the tags .
 
Someone non-professional vaguely chiming in again. From the I.N.O.A. Tech Digest : The first non-grooved cam bushings ,in '72 ,were not machined from a solid piece, but 'wrapped' construction -that is,the bushing was rolled into a tube from flat stock, with separate thrust washers. Reliability problems with the thrust washers occured; this was fixed with a later solid on-piece bush design, used on 73 750's and all 850's. Any '72 from S/N 2049-on should be checked; any bushings using separate thrust washers should be converted to 850 style bushings.
 
pete.v said:
Should we assume that nothing came from the factory with this second washer or the other way around? And if it isn't in our motors is it because the rebuilder from previous owners failed to put it in there simply because the didn't read Mick notes?
Click to expand...

Pete,
As far as the 850 goes, I think they may have come from the factory that way. The 850 parts list doesn't show a second washer, 06-1086. And it does show them calling for the 06-3020 bushing. Anyway you slice it, there isn't anything between the sprocket and the crankcase. I'm going to be going in there for the chain adjuster soon too and have a look. I think it's been like this for as long as I've had the bike, 67,000mi. I think I could have used Mr. Hemmings' lessons, engine and trans. It's never too late :oops:

http://www.oldbritts.com/1973_g1.html

http://www.oldbritts.com/1973_g5.html
 
rpatton said:
I think I could have used Mr. Hemmings' lessons, engine and trans. It's never too late :oops:
Click to expand...
I am certainly not adverse to the idea, particularly if it solves a cam end play issue. I was thinking that i would have to split the case to take care of this, so I am really quite pleased this has come about.

I am assuming comnoz is on the road somewhere, hopefully not riding shotgun in a pickup truck. I hope he has some definitive answers relating to this discussion.
 
I just had a look at the MkIII parts lists and they have a pair of the 06-5428 bushings on the timing side. So I should have been saying Pre-MkIII 850 on all the issues I mentioned before. One more reason for MkIII envy. I hear there's some of them in crates somewhere going cheap :D
 
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