Some of you may have heard about this simple treatment to prolong the life of your axles, but if not, I will attempt to describe how to modify them. This treatment is based on the premise that if the axle is able to twist, it is less likely to shear off at the end of the splined section – as often happens. I have used them with much success in the past.

If you measure the small width of the axle at the bottom of the spline grooves, you will have a measure of the weakest part of the axle. So rather than leave this as the only part of the axle to have this small section to carry the load, you machine down another larger section to also be of the same diameter, and if it is long enough it will twist rather than break. Therefore put the axle in a lathe and machine down a length of section of 6 times this diameter – eg a six inch (150mm plus) section in the centre of the axle length to the ‘root diameter’ of the base of the splines, and then taper this back up to the large diameter closer to the splines and flange at the other end. Of course, hardened Dufor axles are even better to do this with, and re-hardening of them afterward can be beneficial as well.

Axles will then last much, much longer, than standard ones, and are probably suitable for most mildly tuned road Spridgets. Full Race engines however will need fully fabricated and expensive so – called ‘Unbreakable’ axles (based on early Holden axles which are then pressed and keyed into a fabricated ‘Hat’ on the end).

Happy Spriting,

John Fowler.