AG400 Torsion Bar Alignment

Torsion bar? Are you talking the torque arms on top of the diff or the flat bars that attach between the axle and the centre hanger between the diffs?

 

I haven't looked at the AG400 suspension in a while but from what I remember there are shims that adjust the torque arms on the top of the diff. Those hold the axle centred and at the proper angle. I wouldn't mess with their alignment because you could mess up the pinion angles and cause all kinds of driveline vibrations. I would recommend taking it to an alignment shop and have them inspect the bushings and suspension components before performing an alignment.