Shortening axles

[stidnam]

So I am told that you can't shorten an axle and use the area where it tapers to recut the spline, you have to either use the section either side of it so you can shorten an axle say up to 30mm and then you have to shorten 70mm or more so that you are clear of this tapered bit.

Why is this so? Can't you just put it in a lathe and bring the tapered bit down to the right diameter and then cut the spline or is this tapered area weaker somehow?

Random axle pic for reference

[SillyCarS]

depending on how they are manufactured the splenes may have been formed through cold working (stronger due to more fractures in the lattice produced by rolling or forging)

any capable engineering show should be able to shorten them for you, im not sure about the specifics. they may weld material on and the machine it; EDIT: this is incorrect and has been confirmed below

with my diff i covered the splenes with grease and shoved it in the diff and saw how much i had to play with, as there will be excess. i found they were long enough to shorten 15mm on each side

[styler]

its simple, geta set of vernier calipers on to it and get some
diameters along the spline section. usually axles can be resplined a little
or a lot as you say, thats because often on axles the splines are
proud (ie above) the flat section they sit on. then that flat section
can also go for a bit along the shaft (if it exists), then you get the tapered section which goes from flat to full axle width. so if you cut your splines in the tapered section some part of them if not all will have a taper to it which makes for a weak spline if you are using the original spline diameter, if its a smaller spline it should be fine.

also you need a few mm for the cutting wheel to cut into as it makes
a mess at the start of the cut or something i believe and the wheels are 2 inch so for a full depth cut there will be quite a taper left from the wheel going into the axle towards the hub.

it is a pain to find axles to respline with the correct pcd and spigot size,
then bearings are also something to look at id / od and interchangability.

best to shorten a lot and get the full axle section resplined as long as the axle is through hardened which i believe most toyota axles are, just got to find a long anough axle to do that with the correct pcd, spigot and a bearing to suit the axle and diff.

talk to a diff shop / axle resplining place, they will probably ask
you to take in the axles and they can tell you if its possible to do it.

[LeeRoy]

The reason you can't do it is because the splines are rolled and not machined. Prior to this the whole area where the spline now resides would have been the same OD as the area which is tapered.

I would imagine the machines to roll splines would be either rare, or very expensive, hence the practice of resplining axles though machining, and therefore having that unworkable area on them.

[The Real Roadrunner]

leeroy is correct (good work my young apprentice).

the are knurled from the factory and then hardened.
if you measure the start of the machined section it will be about 1.?mm smaller than the spline, the knurling proceedure pushes in the valleys and the material moved causes the peaks of the spline.

99% of resplines are cut therefore you need to have the same diameter to start with as what the spline must be, unfortunately this means alot of factory toyota axles cant be shortened unless its by a large amount.

Cheers
Linden