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Indicator switch/horn push -Special Sports

Posted: Wed Dec 06, 2017 5:32 pm
by terryfrombury
Evening everyone,
I`m using the winter months to try to sort out the last couple of teething problems on the Special Sports. One of these problems is the failure of the semaphore indicator switch to self-cancel. It turns out that there is a bit too much wear in the slip ring which engages with the steering wheel, turns with it around the static switch unit, and pushes the little pieces which return the indicator lever to the central position. The Lucas part number is 323182.
I don`t suppose anyone has a less worn ring - or complete centre unit - do they?
Many ta`s
Terry from Bury

Re: Indicator switch/horn push -Special Sports

Posted: Wed Dec 06, 2017 8:41 pm
by Db n j
Terry, good to see you have nearly finished ! Goodness knows when we will meet up with our cars, especially since I now have to refit the cylinder head on the Duke.

As for your indicator switch, I don't think I can help. I did wonder if it's the same internal but as the conquest. (I see quite a lot of db18s with the later unit fitted. This may be easier to source)

Regards

Re: Indicator switch/horn push -Special Sports

Posted: Wed Dec 06, 2017 8:56 pm
by clevitt
Hi Terry,
Is this the part you are after?. Out of interest, where do see the wear that is causing the problem?
My own experience is that I am lucky to achieve a self cancellation success rate of 50%, right hand turns being better than left hand turns. I put this down to the limits of the technology of that time , as presumably the 1950s were early days for the use of self cancelling indicators in British cars?
image.jpeg
image.jpeg
Chris

Re: Indicator switch/horn push -Special Sports

Posted: Thu Dec 07, 2017 7:19 am
by qantasqf1
Terry, this cancelling ring should be securely fastened to the inner diameter of the steering wheel yoke by a chrome headed screw which threads through the yoke and engages a slotted nut fitted to the cancelling ring, the ring being slotted to allow for minor adjustment to centralise it. Given this, the cancelling ring shouldn’t slip at all, being positively retained, and although I’m loath to suggest is the retaining screw missing? FWIW sometimes the 2 brass (or aluminium) pawls of the trafficator switch itself can wear so the cam on the cancelling ring won’t trip it.
Steve

Re: Indicator switch/horn push -Special Sports

Posted: Thu Dec 07, 2017 11:01 am
by Simon Hyslop
I would hazard a guess that 1935 was the first year the self cancelling mechanical indicator switch came out. Austins I've had from 1935 had it and that's as early as I remember. At least one club I know of is looking at the possibility of 3D printing some of the trafficator switch components but again, if my memory is correct, the metal (some sort of pot metal or mazak) in the pre war units may, and I stress the" may" , be of somewhat better quality than the post war ones.

I wonder if a piece of shim steel, cut to size and araldited inside, might be of use ?

Re: Indicator switch/horn push -Special Sports

Posted: Thu Dec 07, 2017 1:57 pm
by terryfrombury
DSC_0094.JPG
DSC_0093.JPG
Bless Joe Lucas, though - you`ll see just how different this piece is from the one Chris posted. This piece is a die cast zinc item which is not screwed to the steering wheel boss. The notch on the outer edge (at the bottom of the lower photo) engages with a lug in the steering wheel boss.
The part which is worn is the shoulder within the piece, and I think in the upper picture you can just see how shiny it is where it is worn away.
Cheers
Terry

Re: Indicator switch/horn push -Special Sports

Posted: Thu Dec 07, 2017 5:05 pm
by Phillmore
They don't call Joe the Prince of Darkness for nothing :D

Re: Indicator switch/horn push -Special Sports

Posted: Thu Dec 07, 2017 7:06 pm
by ron.rsp
Lucas unit from 1938 EL24, on rewiring I found one side of the unit broken, I was fortunate to find this
replacement part!

Ron

Re: Indicator switch/horn push -Special Sports

Posted: Thu Dec 07, 2017 8:25 pm
by clevitt
Terry, if it will work with the other parts of your switch assembly, you are welcome to the circular part in my photo.
Chris

Re: Indicator switch/horn push -Special

Posted: Thu Dec 07, 2017 11:50 pm
by qantasqf1
Well now, Terry, fortune has smiled upon you. Rummaging through my extensive and comprehensive trafficator switch spares I retrieved a cancelling ring, pt . no. 323182 in bloody good nick - even the cam has no sign of wear. If you can’t source one in the UK it’s yours. I can post it to you if you email me your address.
stevemoore47@iprimus.com.au

Cheers from Oz.




quote=clevitt post_id=16615 time=1512678349 user_id=457]
Terry, if it will work with the other parts of your switch assembly, you are welcome to the circular part in my photo.
Chris
[/quote]
terryfrombury wrote: Wed Dec 06, 2017 5:32 pm Evening everyone,
I`m using the winter months to try to sort out the last couple of teething problems on the Special Sports. One of these problems is the failure of the semaphore indicator switch to self-cancel. It turns out that there is a bit too much wear in the slip ring which engages with the steering wheel, turns with it around the static switch unit, and pushes the little pieces which return the indicator lever to the central position. The Lucas part number is 323182.
I don`t suppose anyone has a less worn ring - or complete centre unit - do they?
Many ta`s
Terry from Bury