Grease in swinging arm - take it apart or not ?

Throber said:

The Norton loses the swing arm oil immediately you put it in. Seem's to me not to be a good design.

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I do think that lubrication of the Commando S/A assembly is often misunderstood.

The sintered bronze "Oilite" bush material is extremely porous, and once saturated with oil, remains basically "self lubricating" over an extended period of time.

Periodic re-lubrication at the normal service intervals is intended to top-up the level of oil contained within the porous structure of the bushes (which occurs over a comparatively short period of time). The pivot assembly isn't intended to be an "oil bath", as it just isn't necessary.

From past discussions here, it does seem the S/A pivot assembly is far more likely to develop play due to the spindle becoming loose in the cradle tube rather than be caused by bush/spindle wear even when lubrication has been neglected.

Yes the bushes in the swing arm are oil absorbing but the amount of oil they should suck up could well be more than most people put in there when servicing. It takes a while for sufficient oil to get into the whole of the bush to make it work as intended. So many people have problems with those bushes, there has to be a better solution.
It's one thing to say that the owner should do their servicing as per the book but some people might do a lot of miles (oh the irony) on rough roads while others on smooth roads. Some owners may be big fat bastards with big fat riding partners on the back. The bike may have loads of accessories added too. Many variables, including slack chain, dragging rear brake, shot iso's, shot shocks. All these put stress on those bushes. Not to mention that they are too close together. On the Italian framed bikes the top shock mounts are further apart than the mount's on the swing arm, inducing twisting loads when cornering and when hitting big bumps.
A better method of keeping the oil in there should have, in my opinion, been designed into the bike.
It's a drag to have to disassemble the whole gestalt to repair the pivot parts. Foresight by the designer would have served us all a lot better.
I thought this site was about solutions for the problems encountered by owners of these beautiful bikes. Not to slag each other off for not towing the party line.
Maintaining an old Brit bike isn't as obvious to some people as it is to others. Helpful suggestions work better than 'ass holing' someone cause they didn't know something or other. We could all pick each other to bits and get no where. Wouldn't that be nice ! That's just what the British motor industry did to each other in house and look what it did to them.
It may be better to use anti-seize grease in there than oil.
My suggestion is to connect the drive chain oiler to the swing arm oil hole and let the stuff drip in there rather then on to the chain. May be the wrong oil but at least it gets something in there.
OK, give me your worst shot.

+1 and I like the attitude. I also like the chain oilier idea.
There are a few individuals that seem to endlessly drone on with their criticism of people and ideas. Enough is enough. Life is too short.

Throber said:

Yes the bushes in the swing arm are oil absorbing but the amount of oil they should suck up could well be more than most people put in there when servicing. It takes a while for sufficient oil to get into the whole of the bush to make it work as intended. So many people have problems with those bushes, there has to be a better solution.
It's one thing to say that the owner should do their servicing as per the book but some people might do a lot of miles (oh the irony) on rough roads while others on smooth roads. Some owners may be big fat bastards with big fat riding partners on the back. The bike may have loads of accessories added too. Many variables, including slack chain, dragging rear brake, shot iso's, shot shocks. All these put stress on those bushes. Not to mention that they are too close together. On the Italian framed bikes the top shock mounts are further apart than the mount's on the swing arm, inducing twisting loads when cornering and when hitting big bumps.
A better method of keeping the oil in there should have, in my opinion, been designed into the bike.
It's a drag to have to disassemble the whole gestalt to repair the pivot parts. Foresight by the designer would have served us all a lot better.
I thought this site was about solutions for the problems encountered by owners of these beautiful bikes. Not to slag each other off for not towing the party line.
Maintaining an old Brit bike isn't as obvious to some people as it is to others. Helpful suggestions work better than 'ass holing' someone cause they didn't know something or other. We could all pick each other to bits and get no where. Wouldn't that be nice ! That's just what the British motor industry did to each other in house and look what it did to them.
It may be better to use anti-seize grease in there than oil.
My suggestion is to connect the drive chain oiler to the swing arm oil hole and let the stuff drip in there rather then on to the chain. May be the wrong oil but at least it gets something in there.
OK, give me your worst shot.

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CNW has a modification for what you're talking about. Correction... I looked at their new website this evening and didn't see the service anymore.

Throber said:

Yes the bushes in the swing arm are oil absorbing but the amount of oil they should suck up could well be more than most people put in there when servicing.

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Oilite can absorb approximately 15-25% (depending on type) of its volume, and a rough calculation of the bush volume would mean a dry bush is capable of absorbing around 2cc of oil.

Throber said:

It takes a while for sufficient oil to get into the whole of the bush to make it work as intended. So many people have problems with those bushes, there has to be a better solution.

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I don't know who those many people are? They certainly don't post on this forum.

The sintered bronze does wick up oil reasonably quickly.
From this (one drop of oil placed on a bush)


To this...the oil drop completely absorbed in 12 minutes, although it was a drop of SAE50 oil rather than EP 140 we are talking minutes to maybe an hour or so, for the oil to soak into the bush and not days, weeks, or months.

Throber said:

It's one thing to say that the owner should do their servicing as per the book but some people might do a lot of miles (oh the irony) on rough roads while others on smooth roads. Some owners may be big fat bastards with big fat riding partners on the back. The bike may have loads of accessories added too. Many variables, including slack chain, dragging rear brake, shot iso's, shot shocks. All these put stress on those bushes. Not to mention that they are too close together.

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That is perhaps outlining a worst case scenario, I seriously doubt the vast majority of Commandos fall into that category and, as we know from the recent mileage poll, most of our members here do a comparatively low yearly mileage (less than 1,000 miles) and are far more likely to over-maintain their Commandos relative to the actual mileage they do. But I'm sure some will have covered many thousands of miles without the bushes requiring attention.

Throber said:

A better method of keeping the oil in there should have, in my opinion, been designed into the bike.
It's a drag to have to disassemble the whole gestalt to repair the pivot parts.

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So, how many times have you had to replace Commando S/A bushes because of wear?

Alternative methods of lubricating the pivot have been suggested in the past, however when I asked members how often they needed to change worn bushes-suddenly it all went quiet!

Throber said:

Foresight by the designer would have served us all a lot better.

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I think it's unfair to blame the designers as they didn't always get the last say, that was often down to the penny-pinchers, for instance, if the designers had had the last say, then Commandos would have had vernier Isos. from the beginning.

Throber said:

I thought this site was about solutions for the problems encountered by owners of these beautiful bikes.

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Yes, in many ways it is, and I'm glad you said "problems encountered" as many of us are unlikely to have encountered any such problem.

Throber said:

...Some owners may be big fat bastards ...OK, give me your worst shot.

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So Throber, What have you got against us big fat bastards ? ...................................Just kidding, I look forward to seeing photos of your chain oiler mod. Cj

Cj, I'm a little over weight, I have nothing against fat bastards. One just left my place on his brand new BMW 6 cylinder tourer he bought today. Fell of it when parking it outside my kitchen window. Oh dear !
L.A.B, I have to replace my swing arm bushes and shaft because the previous owner, a fat bastard and engineer, greased the thing instead of oiling it. The shaft rusted so badly that the rust impregnated into the drive side bush and bonded to the bush. The bush was turning in the swing arm. I never owned a new Commando for long enough to have to do anything serious to it. They, 3 of them, all crapped out early in their life and I got rid of them, two under warranty. Not that I know every one who owns a Commando world wide but I know of many cases where the swing arm bushes have needed to be replaced. It was a well known weak spot back when they were new, everybody bitched about the swing arm bushing wearing out. You think that when oil is put into the pivot it gets all over the bush surfaces. Not sure I'd agree with that. It seem to flood out as fast as it is pumped in. On this site there are photos of many rebuilt Commandos that were once in very poor condition. I would be surprised if those bikes didn't need new bushes. I bet all of them were replaced. There are questions here on how to service the bushes too. On other sites there are people with bush problems. One of the issues with the bush is that the surface metal of the shaft can impregnate into the bush and do quite a bit of damage to the whole arrangement. I guess that is down to no oiling by owners. Sure, the people on this site would more likely look after their bikes than previous owners did. It is fair to say that most Norton's were subject to neglect and abuse during their life, we are all fixing the mess. Some survived well but most were scrapped. The designer is responsible for his design. Can you prove that the bean counters told the designer to skimp on the swing arm pivot ? Can you prove that all owners have and will service their swing arm's as per the book ? Ever ? Smart owners will but not so the great unwashed. Have a pint on me mate !

Throber said:

I have to replace my swing arm bushes and shaft because the previous owner, a fat bastard and engineer, greased the thing instead of oiling it. The shaft rusted so badly that the rust impregnated into the drive side bush and bonded to the bush. The bush was turning in the swing arm.

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Yes, problems with the S/A assembly are invariably caused by somebody filling the pivot with grease and/or neglect.
The fact that the bushes and spindle of your 40 year old Commando require replacement due to corrosion doesn't exactly surprise me-especially as you'd said in a previous thread that it had been parked up for 20 years.

Throber said:

I never owned a new Commando for long enough to have to do anything serious to it. They, 3 of them, all crapped out early in their life and I got rid of them, two under warranty.

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That makes me wonder why you bought yet another Commando?

Throber said:

Not that I know every one who owns a Commando world wide but I know of many cases where the swing arm bushes have needed to be replaced. It was a well known weak spot back when they were new, everybody bitched about the swing arm bushing wearing out.

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So what's changed? I've been a member of this forum for several years, and during that time, I know that posts concerning worn bushes have been comparatively rare when compared to some other Commando "ailments", and most reported S/A pivot bush problems appear to be the result of either somebody filling it with grease, or from basic neglect.

Throber said:

You think that when oil is put into the pivot it gets all over the bush surfaces. Not sure I'd agree with that. It seem to flood out as fast as it is pumped in.

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I don't think it needs to "get all over the bush surfaces" as the oil travels through the porous structure of the Oilite, the photos I posted shows how the Oilite readily absorbs oil and it does so quite rapidly, as I see it, there's no need to supply oil directly to the working surface of the bush or be concerned about any excess oil leaking out.

Throber said:

The designer is responsible for his design. Can you prove that the bean counters told the designer to skimp on the swing arm pivot ?

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I can't prove it, no more than you can prove otherwise, and I don't think it was necessarily always the case that designers were *told to do so, only that once a design left the drawing board I would expect it to be passed to the engineers and penny-pinchers to fight over, the result of which may not always have been quite what the designer intended, the Vernier Isos. not used at the beginning of Commando production being a prime example.

Throber said:

Can you prove that all owners have and will service their swing arm's as per the book?

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I think I can prove many don't-judging by the number of "grease"-filled pivots we hear about, but that's hardly the fault of the design. If the designer was guilty of anything then it was assuming that the owner/mechanic would follow the service routine and not "know better" by filling the pivot with grease.

*(Although Bert Hopwood gives several accounts of that in his book, as he certainly had to alter his original Norton Dominator twin and Lightweight twin designs because the bean-counters at Norton considered certain aspects of the designs to be too expensive to produce as it would have involved the purchase of new tooling.
Many of his other Norton/BSA/Triumph designs were also shelved as they were considered too expensive to produce. See "Whatever Happened To The British Motorcycle Industry" by Bert Hopwood )

L.A.B : Stop.
Just stop this shit right there mate. I don't want to go down that road that way with anyone here or else where.
Get a grip, have a day out and enjoy life.
Let's be friends instead
OK mate !

I will post photos of my fecked swing arm pivot and bushes when I get time. It isn't a good look !

Throber said:

L.A.B : Stop.
Just stop this shit right there mate. I don't want to go down that road that way with anyone here or else where.
Get a grip, have a day out and enjoy life.
Let's be friends instead
OK mate !

I will post photos of my fecked swing arm pivot and bushes when I get time. It isn't a good look !

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I took mine apart this winter to validate its condition after a rebuild 2 years ago. New orings and some 140w oil, just like 2 years ago. In a couple more years I should have another $5.00 saved up to do it again.

I suggest you go down this road.

OK Mr pvisseriii. I will do regular servicing on my bike once it is rebuilt. Just like the good book says. Logical to me to service frequently all parts of any machine. But I am going to figure out some kind of improvement on the swing arm pivot and bushes just for the hell of it. May be make it a rigid rear end and extend the forks. I got the Hi-Rider seat and bars already. Open megaphone pipes and Maltese cross tail light. Might put a VW Beetle motor in there just to get some attention, supercharged of course. Lots o chrome too. Chick magnet !

Throber,

love your sarcasm

seriously, well done

hello all. good to be alive.

xbacksideslider said:

Usually the pins, and not the bushings, wear because the bushings pick up grit that is harder than the pin. So, to escalate the war between materials of dissimilar hardness, hard chrome the pin, now the bushings might wear.

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i have a non factory pin and bushings. the pin wore in the cradle and was reamed out .007 oversize. this ended any use of factory parts. i made oversize pin and bushings to suit. the pin was made size for size and required a little bit of force to fit into the cradle.(draw bolt and nut, nickel anti seize).Size for size cannot be assembled by hand. the pin was nitrided and had surface hardness around 60 rockwell C. the bush was made from leaded gun metal, LG2. after many years both pin and bush were worn, pins a bit more then bush..

I thought factory pins were hard chromed. i cant believe the factory pin is supplied with a surface hardness of about 35 RockwellC or round about.

the clearence between pin and bushings was half a thou. 30 weight EP oil and wicking was used. the big hole in spindle was filled with a large wick and small wicks led into the small holes in spindle. no leaks and very slow wear. re lubing was a bit of a procedure though not at all troublesome.

we could go on forever about this but it really is not that complicated. there are many ways to skin a cat.

for those who see insurmountable problems with bushes, you could always go the whole hog and modify to needle rollers, though this to me is using a sledge hammer to crack a nut.

I think that when the swing arm is repaired then that is the best fit it is going to be. All downhill from thereon.

in summary, keep the pin a good fit with the cradle. keep the bush to pin clearence to a minimum. use wicks and light weight oil.by whatever method keep oil in there. then enjoy riding.

PS does anyone have info on factory tolerances, eg: pin to cradle and fitted clearence between pin and bush. Being sintered bushes and being mass produced, the clearences and fits would tend to be on the generous side. I would love to know the factory specs for the pin to cradle . I reckon it may be a surprise and on the generous side.

I tried nylon auslon bushes with nitrided pin once but the pin wore and not the bushes

best wishes to all
Bradley

B.Rad said:

I thought factory pins were hard chromed. i cant believe the factory pin is supplied with a surface hardness of about 35 RockwellC or round about.

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The latest genuine spindles are hard chrome plated.: http://www.andover-norton.co.uk/Pirate%20Parts.htm

B.Rad said:

for those who see insurmountable problems with bushes, you could always go the whole hog and modify to needle rollers, though this to me is using a sledge hammer to crack a nut.

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Needle rollers aren't necessarily the answer for the reasons stated in this previous thread: swingarm-questions-t15428-15.html#p188926
I've seen needle rollers used in this application on various other (Japanese) bikes and can't say I was impressed, as the rollers often wear flats on the pin due to the limited amount of bearing rotation so they don't seem to last long even when kept properly lubricated.

B.Rad said:

does anyone have info on factory tolerances, eg: pin to cradle and fitted clearence between pin and bush.

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I expect Joe (ZFD) would have access to that information.

Almost every motorcycle has this problem, typically it's the pin that wears, not the bushings, go oversize and you're done.

Yeah, the pin/cradle on the pre-'74 bikes is an issue but easily fixed.

So...what's the best deal?....never sieze and redo every so often?

Snakepit said:

So...what's the best deal?....

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EP140

Snakepit said:

So...what's the best deal?....never seize and redo every so often?

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No "never seize". Presoak the bushings in nice fresh 140w and fresh o-rings. Anti (never) seize may contaminate the porosity of the bushings. Unless you're doing teardowns after every AHRMA event, then just follow the manual.

Ok...I have new bushings and spindle coming. Will 90 be ok if I can't find 140?

Snakepit said:

Ok...I have new bushings and spindle coming. Will 90 be ok if I can't find 140?

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The smallest amount of straight 140 I have found is a 5 gallon unit.

I thought of dividing it up in 4oz bottle and have 160 service doses. At 5 bucks pop I could do pretty well. But its just not worth the trouble.

I really don't think the SA takes any more than that I went ahead with 90/140 and it has done well. If it does seep, it is very little. Yes, i know it will act like 90w but it must be a liile thicker

I thought of checking with a truck or tractor service center to see if they will let me drainoff the residual from a hose from their container. I shouldn't need any more than that.