Hope you see this post.
No joy. The video makes is look easy, and it should be. I loosened the 3mm and 5/64" screws to make sure the worm was seated firmly against the main RA gear, before I tackled the real apparent problem of the worm itself moving back and forth (i.e. left and right), where the real slop was.
Got the worm nicely seated against the main gear and turned the pulley gearing and everything was nice and smooth and not binding.
So, next step was to tighten the worm using a coin as in the video. No go...that is in there so tight that it cannot be loosened or tightened. I tried using a pair of pliers holding the coin (a dime) and tried to loosen or tighten, just to break it free...the coin bent. So, tried a penny, same thing.
At this point I am a loss. I put everything together and I still have the same backlash/slop in RA totaling about 1/4" total - 1/8" in either direction, which is not acceptable.
The video made it look so simple and, honestly, it should have been, but turning the screw to get the worm from shifting left and right (i.e. the RA slop) seems frozen in place. Is there a tool that may work better than a coin?