Yes, the wobble box is fixed, unless it has gotten loose some time and worn the holes larger.If you find you are way out of register , it may be the cutter bar has wear in the support arms where they pivot.
Thanks Steve I haven't taken the wobble box loose yet It is nice and tight and hated to losen it up till i heard a little more about the sickle timing. the sections are a half inch off from the center of the gaurd . Im back in my neighbors combine so was going towork on mine whenit rains. thanks again