Yes, that is also very likely if the bolt turns! You can obtain a new spacer or with the alternator on the bench, grind the head off the bolt and as much of the shaft inside the adjuster slot, grind the opposite threaded end off the bolt and as much of the shaft inside the adjuster bracket. Then you can lever the alternator and the spacer out of the bracket, the remaining bolt shaft can then be removed from the spacer much easier in a vise and reused. You've got to get the old bolt and spacer out even if you had a new bolt and spacer.