Ned,
The very old A/Ss used beam axles with leaf springs, or so I've gathered from
reading the mail here and on the Vintage list. Starting in the 60s or
thereabouts, they went to a 'torsion spring' axle.

You're right that it APPEARS to be a simple solid axle, bolted securely to the
frame, but if you look closely, you'll see a short 'arm' on the end that carries
the spindle. You'll notice that the spindle is NOT in line with the axle beam,
but is either ahead of it or behind it. That little arm is attached to a
spring-steel bar that goes through the hollow tube (what looks like a solid beam
to you) and is mounted in rubber. I'm personally unclear on whether the rubber
or the steel bar is the actual spring, but it's not important at the moment. The
point is that the axle is pretty complicated, and certain precautions must be
adhered to when working around it/them.

Jacking in the middle of the axle beam would almost certainly damage it. Think
about it: if you have a single-axle trailer, nearly the entire weight is on that
hollow tube and it's very likely to bend it. If you place your jack under the
frame attachment point, it's much less likely to hurt anything.
 

Ned Hall wrote:

> >As I understand the problem, jacking on the axle, if your '58 has the
> >torsion axle, could warp the axle alignment.
> >I am not sure about the axle arrangement on a '58.
>
> Well, it APPEARS to be a simple solid axle. How would I recognize a torsion
> axle?
>
> n