Jaguar Mark IV trafficator

Well it does happen to all of us at some time the driver side trafficator has finally decided it does not want to work any longer. It has been working perfectly since restoration some 7 years ago but the plastic is now so brittle along with the die cast pivot re-enforcemet and considering it’s age, it is no wonder it has broken right at the pivot point.

Any suggestions as to where I may find a complete unit or if anyone has one/two gathering dust and no longer wanted, I am willing to exchange some flat stacking stuff. Home town is Brisbane, Queensland, Australia. The vehicle in question is a 1948 Jaguar 3.5 L sedan.



Paul Beck Vintage Supplies has a complete unit, or you can buy just the plastic arm or the stainless steel backing arm.
I don’t know, is there is more than one size of these?

I think the Paul Beck ones are for SF80 and are only 7.25" long from the pivot. The MkIV should be more like 8" long.


There are many different models of these created over the few decades of manufacture, to suit different mounting arrangements. The coupe had the more common shorter ones but the saloons have the rare longer ones. Worcester Classic Spares (UK) does an overhaul service as listed in their spares catalogue but it is very expensive. I think they are reconditioned using whatever old parts are salvaged from wherever. These longer ones were used on many of the bigger cars of the day but for some reason parts replacements have not been supported by the after-market trade. I think hens teeth are more common. A colleague had one with a broken arm with a piece missing. I had a broken arm from a short one and cut a piece from it and glued it in as repair. The colour doesn’t match too well, but at least it is complete and working.


According to the parts catalogues, '36-'37 cars all used SF45/17C, but the arm is not listed separately; '38-39 cars all used SF54G; while '40 and Mark IVs used SF55L or SF55J. All used the same arm 531854. But Mark V used SF34N with arm 539239.
I guess we should try to delineate the differences and identifying characteristics of all these.


You might try Ian Mullins in Melbourne. He used to do a ni e job in repairing them. He’ll be at the border run, which I think is about a week away.
Remember there were two wiring systems 2 or 3 wire and you need a trafficator compatible with your car’s system

Hi all.

Thanks for all the replies, it is appreciated. It appears that I was barking up the wrong tree, it should have been the SF-55L or J. Mine have the flat chrome strip on the top, screw in one end & hooking around the the pivot at the other. Hen’s teeth seem to be easier to find. Yes Peter,
Worchester do have rebuilt units & they are quite expensive but it is for a pair. Ed, I did not think of ringing Ian will do first thing tomorrow morning,

Once again thanks for the response & information, it is appreciated

Regards to all Neil

If you think MKIV trafficators are rare, try finding SS1,
Although I did see what appeared to be. Them on a Ford Poplar.
Quite different to OHV cars

Thanks for that screen shot, Peter.
The arm on my '38 measures 8-1/2" and I presume it is a SF54 model.
Assuming Lucas followed the same practice as with their other products, the suffix letter denotes a minor developmental change and was not necessarily recorded/updated in the SS/Jaguar parts books.
One of my plastic arms has the number 539941 and the other has no number at all.

Just a note about function. The earth return for the bulb is taken through the chromed cover, then via its sliding contact with the housing at the knuckle. Several points of hope and glory that need careful checking. The other problematic contact is the power supply through the finger spring which supports the bulb. I usually tin the circular tip contact to reduce the chance of future oxidisation breaking the circuit, and most springs have suffered some age-related corrosion. The bulb upper end point contact under the arm cover must be kept clean too and I often smear a little vaseline on the surface after polishing.

There are now LED festoons marketed to fit these arms and apparently perform well. I am not sure if they fit easily, or are a tight fit - not desirable. There is no heat from these, which will help preserve the plastic. They are available in self-flashing configuration too, which will save fiddling around with a split circuit, but they will flash at their own rate, not matching the flasher. Not an operational deficiency in my mind.