like previously stated, try 1/4 turn at a time, shouldn't need much to take the play out. It won't be perfect, but you can eliminate much play this way. I ended up turning mine in 1and 1/4 full turns before I got it were I was satisied, and this rebuilt box is only 2 years old with maybe 10km's on it. Its seems like I had to break in the rebuilt box and then set that screw. My play was getting pretty bad. I have in the past turned this too much and ended up with a tight spot in the turning, but back it off 1/4 turn and perfect. Good luck, don't be scared, just go1/4 turn at a time