the steering arms are part of the lower balljoint, so putting spacers between them and the spindle effectively shortens the tierod length, thus toe out occurs. [i'm talking rear steer, factory setup] in other words, the steering arm must physically be pushed inward to bolt up to your tierod assembly when you didn't alter your tierod length after you used the spacers. the tierod needs to be lengthened to get the toe back where it should be.