Steering Arm routine bring up

[Steve Jones]

I always present my car for scrutineering with the steering arm clean and polished, but there is no requirement to do so. I've been competing for almost 40 years and I'm not aware of a scrutineer ever having looked at my steering arm.

The steering arms on my Trials Chummy and my Ulster used for Hillclimbs and Sprints are both repro items from David Cochrane but a scrutineer wouldn't know that. Both are painted and I've never known them to be specifically inspected despite both cars having been scrutineered many, many times. I've never seen steering arms on other Sevens being specifically inspected either. Maybe the specific inspection is a 750MC thing? I've never competed at any of their events.

Steve

[Alan]

Steve just to make you happy, I will look at your steering arm next time I scrutineer you.

Seriously, I'm not suggesting that replacement steering arms aren't a good thing. I use them, in the same way as I wouldn't build a new engine without a replacement crankshaft. However, to regale newcomers with tales of disaster centred on these components is inappropriate and not helpful in my opinion.

[Steve Jones]

Steve just to make you happy, I will look at your steering arm next time I scrutineer you.

Seriously, I'm not suggesting that replacement steering arms aren't a good thing. I use them,  in the same way as I wouldn't build a new engine without a replacement crankshaft. However, to regale newcomers with tales of disaster centred on these components is inappropriate and not helpful in my opinion.

Agree 100%.

A lot of us have used our Sevens to excess and beyond over many years and one thing that's consistently proved is that they're tough little beggers. Yes, things do break sometimes and that's inevitable given the age of many of the components but, most of the time, they don't. Keep an eye on everything, obviously, and keep up with the maintenance and, as Ruairidh says, '...don't worry about it, just use it'. 

If you read David Cochrane's paper on his replacement steering arms (on his web site) you'll see that I'd had a metallurgical analysis of a steering arm carried out out some years earlier. Why doesn't matter but we used a steering arm of mine that had a significant crack showing on the inside radius such that it was scrap. As part of the process we decided to fix the scrap arm in the vice and break it. No matter how we tried we never managed it (and we tried VERY hard). We ended up cutting it into two with a disc. 

Notwithstanding that, of course I'd never use a steering arm that displayed any form of fracturing but the experience did lead to the conclusion that they are, perhaps, tougher than they look. Austin quality even............!! 

Steve

[David Cochrane]

I have been keeping track of actual failures of steering arms since a friend of mine (Nigel Coulter) had one break in c.2003. I now have a total of 55 recorded failures, i.e. ones for which I have a name and details (edited to include the 3 failures I didn't know about that are mentioned in this thread). 55 is quite a large handful!

David

[Ruairidh Dunford]

Very interesting.

If my maths is correct the total recorded failures represents 0.55% of remaining cars and 0.022% of total production - I have used conservative figures of 10000 and 250000 respectively.

This is to be taken seriously but not pandemic - in my opinion.

[Nick Salmon]

I am reading Michael Collins' fascinating biography 'Carry the Fire'. He relates that a Saturn V rocket with command and lunar modules attached amounts to over 5 million separate components. They worked on the expectation that 99.9% of these components would work perfectly. Leaving just 0.1% or 5,000 to malfunction. Of course they had no idea which 5,000 that might be...

[Phil Kingdom]

When you start looking into ( common ) parts failures on vehicles you could write a book on the subject, Austin 7 steering arms and brake rod, Triumph Herald and Morris Minor trunions, Land Rover 80 inch steering boxes to say nothing about rust in important places. There are not many vehicles that do not have a fault common to them, as long as the owners are aware of the inherent problems and keep them in check there should be no problem avoiding disasters.

[Bob Culver]

Many of the responses leave me incredulous.
Either the topic is publicised or not.
To discreetly shelve it would be irresponsible. If anyone got hurt would batter my conscience.
My original post hardly sensationalised the topic.
I dunno about the UK but in this over regulated country a fatality from a steering arm would likely bring legislation far more counter to Sevens and the old car movement generally than any cautions expressed by me.
The arm in my car broke at 60,000 miles. Sevens were bread and butter for wreckers at the time and they had masses of parts. Yet my father had to trudge around many city firms before eventually finding a replacement ...(which later proved to be cracked.) I doubt if most had been sold to replace ones which then non enthusiast owners had observed to be merely cracked.
 
With long mechanical association with most older cars a formidable list of known failures can eventually be compiled.
When I started on my Seven as a teenager I wish someone had regaled with the list. Amongst other things it would have avoided a broken crank and wrecked engine 3,000 miles after a rebuild, hub oil leaks, clutch slip, broken kingpin etc etc.
For decades I ran a Jowett car as everyday transport. If regaled with the list at the outset at least one  gearbox re rebuild, two engine re rebuilds and a wrecked crankcase, and many awkward in situ component replacements  would likely have been avoided.
 
It is indisputable that compared  to many others and particularly moderns, Sevens are relatively fragile, unreliable and dangerous. As with riding motor bikes, the fun is attended with some heightened risk. But some risks can be avoided.
 
Our local RSA (a social Club open to all) has a vintage TQ Seven based speedway  car on display in the foyer. I can see a crack in the painted steering arm....

[Zetomagneto]

Many of the responses leave me incredulous.
Either the topic is publicised or not.
To discreetly shelve it would be irresponsible. If anyone got hurt would batter my conscience.
My original post hardly sensationalised the topic.
I dunno about the UK but in this over regulated country a fatality from a steering arm would likely bring legislation far more counter to Sevens and the old car movement generally than any cautions expressed by me.
The arm in my car broke at 60,000 miles. Sevens were bread and butter for wreckers at the time and they had masses of parts. Yet my father had to trudge around many city firms before eventually finding a replacement ...(which later proved to be cracked.) I doubt if most had been sold to replace ones which then non enthusiast owners had observed to be merely cracked.
 
With long mechanical association with most older cars a formidable list of known failures can eventually be compiled.
When I started on my Seven as a teenager I wish someone had regaled with the list. Amongst other things it would have avoided a broken crank and wrecked engine 3,000 miles after a rebuild, hub oil leaks, clutch slip, broken kingpin etc etc.
For decades I ran a Jowett car as everyday transport. If regaled with the list at the outset at least one  gearbox re rebuild, two engine re rebuilds and a wrecked crankcase, and many awkward in situ component replacements  would likely have been avoided.
 
It is indisputable that compared  to many others and particularly moderns, Sevens are relatively fragile, unreliable and dangerous. As with riding motor bikes, the fun is attended with some heightened risk. But some risks can be avoided.
 
Our local RSA (a social Club open to all) has a vintage TQ Seven based speedway  car on display in the foyer. I can see a crack in the painted steering arm....

A well maintained Seven cannot be fragile and dangerous

[Ian Williams]

Hypocritical at the very least!