Do you need an alignment after replacing the upper control arms? The need for calibration after lowering the car is not the same as replacing the upper arm. If you're just replacing your upper arm, you shouldn't worry about alignment unless your old arm is badly worn and has significant play.

Does replacing control arm affect alignment?

Even though the parts are "basically" the same, they are not exact. Newer parts will be tighter than old (less deflection and no wear), so will put the alignment into a different position. The only thing you are going to cause by not getting the alignment done is worn out tires.

Does control arm bushing affect alignment?

steering problems: worn control arm bushings can greatly affect a vehicle's alignment. this can make the car hard to steer, or give it vague, wandering steering. bad control arm bushings can also make a car pull to one side.