I wouldn’t. Only on the first time when putting in new bushings. For a ride height change, don’t have to jack it up much, just enough to take some of the weight off the adjuster bolts.. tires would still be on the ground..
Depends on how much lowering is going to occur. For less than a 1/2” I probably wouldn’t bother.
But for more than a 1/2” with rubber bushings, absolutely. The lower control arm pivot nuts should be loosened and then torqued again at the new ride height. It’s just like the initial install, you want the bushing neutral at ride height. If you’re lowering more than a 1/2” then you should also be adjusting the bump stops heights to recenter the suspension travel around the new ride height, and if you’ve got rubber LCA bushings the bushing needs to be “reset” so it doesn’t twist too far in one direction.
Whether or not it’s the initial install or not is irrelevant, the reason the LCA pivots are tightened at ride height is so they don’t tear with too much suspension travel in one direction. If you substantially change the ride height they should be re-torqued at the new height.
And if you change the ride height by any significant amount up or down you’ll need a new alignment too.
This does not work. If the ride height is changed and the car is lowered off of jack stands the friction of the tires once they hit the ground when it’s can keep the suspension from reaching its true height. “Jouncing” won’t fully settle the car, the tires need to roll on the ground so the suspension will reach its true ride height.
