From the trucking backround, a live axle would be a driven axle.

So following that line of thinking, an IFS axle is still a driven axle or live axle.

 

I would have to agree that the live axle would be a driven axle so I think your origional use of it was exactly right.

Any IFS system would definitly NOT be a live axle as the term is used to differentiate BETWEEN an IRS/IFS and straight axle in the AUTOMOTIVE text, I don't know about the trucking nomenclature though.