We tend to think that cracked steering arms are a result of old age or perhaps damage over the years. But Arthur Waite told me that when his 1928 AGP Super Sports chassis arrived in Melbourne from Longbridge, the steering arms were highly polished, presumably to enable an eye to be kept on the arms. He added that this was standard procedure on Austin Twelves from new. Re the diagonal bracing idea - our Bob Booth (unfortunately now deceased) produced some many years ago. They may not have prevented cracking, but even if the arm broke, it all still held together with his design. Cheers, Bill

Location: Euroa, Victoria

Arms also crack at the shoulder tight radius/step, but the usual place is usally more advanced!
The shoulder must seat all around and definitely not primarily on the centreline, and the nut tight to pretension.
Prewar particularly, polishing was the stock way of forestalling fatigue, so key engine and other parts of racing cars likely to have been treated. Now recoginised as much inferior to shot peening etc.
I have seen the likes of the bracket fitted before new arms available. Would certainly help in the event of a failure. But many may not notice until bracket also failed!

Location: Auckland, NZ

anyone checking there steering arms for cracks.

Should also check around the the eye that the ball fits into.

I've had a couple in the past that haven't just cracked, but have then been brassed back together.


Around 15 years ago, I had saved up all the different cracked arms. Some 32 in total. That I had crack tested. To do an article for the club.

Stoopidly I lent them out to another club member around the country on the request that they were doing a talk on this matter at there local club meet.

They never came back, I heard they were sold back out into the public.

" you know who you are "

Never again.

Tony.

Location: Huncote on the pig

I was out early this morning and had a look at the arm on an axle that came with the last unfinished project I bought. It looks new. A slightly heavier casting and it's much heavier where the ball fits in. Also when I fitted it to my car I noticed it saith at a lower angle.

Location: Ireland

A7 Components offer different arms for standard and sports or special cars, so choose the right one for your application. If you bought a 'kit of parts' you get what the seller chose, and you don't know without looking carefully whether it is an old one possibly modified or a good new type item, probably the latter in your case.

Location: just north of Cambridge

The obvious difference between the original arm and the A7Components arms is the radius of the bend where the arm turns through 90 degrees. The original arm radius is much tighter.
See: http://www.a7c.co.uk/steering-arms.php

Big seven arms sometimes get fitted as well, though not the best idea unless you alter the drag link too.

Location: NZ

The one fitted now is definitely a new one. Looks like it is designed for a sports axle too

Location: Ireland