I still have a conceptual problem with the re-index issue. If the tension on a torsion bar is able to keep the a-arm at height X. Why would more tension be needed if you detach the torsion bar, move the a-arm to a new position Y, and re-apply the same initial tension? The weight of the vehicle hasn't changed, and isn't that what the t-bar is resisting? (I do understand how this would be needed if the t-bars are just adjusted and not re-indexed).
Can anyone clarify this?