Steven190 says : It does not matter if the spindles are on or not.
PST marketing manager says:The upper and the lower control arms should be attached the spindle.
Half dozen of one, six of the other. It doesn’t really matter most of the time, but it can depend on what components you’re using.
The bars are easier to install with just the lower control arm. This is especially true if you’re installing aftermarket bars, sometimes powder coated components make the torsion bar install harder and it’s helpful not to have all the other stuff attached so you can be sure nothing is binding up. Sometimes removing the bump stops isn’t all that easy if you haven’t replaced them already, stuff likes to rust. And aftermarket torsion bars sometimes require different LCA positions that can be more challenging than with the stock torsion bars. So it can depend on the diameter of the bars as really large torsion bars use a non-stock offset.
On the flip side, the spindle is usually easier to install without the torsion bars installed. Stuff moves around easier. And depending on what strut rods you’re using, you may need to install those before the LCA’s are all the way forward with the torsion bars fully installed. Nothing worse than finishing your install only to realize the LCA won’t slide back far enough to install the strut rod.
