Hmm, interesting...
Thanks for checking around, I sincerely appreciate it.
For the backlash adjustment, I don't think this particular machine is the same as you describe, but I will take another look at it tomorrow.
It sounds much easier to take the worm out from the thrust bearing end. I can see how that works- because the thrust bearing is made to be replaced, so it's easier to take out. Whereas the other worm bearing, (closest to brake end of the worm), doesn't generally need replacing, since it doesn't operate under as much end-play stress as the thrust bearing. So the brake end bearing is probably pressed in, which explains why the worm didn't budge, under tension applied from the brake end.
Unfortunately, this machine is facing the wall, so taking the worm out through the back end, (thrust bearing end), isn't a practical option. I wanted to swap in a good (but used) worm, because this worm is somewhat pitted. I don't want the pitting to wear away a good ring gear.
