Block it up where it will turn freely and you can get close by rotating it and counting. Turn the yoke straight up and down and mark one end. Then mark the top of the brake drum you will turn on the top side. Count how many times the pinion turns, per one turn of the brake drum. 3 and a quarter turns would be close to 3.23, 3 and a half turns, 3.55, 2 3/4 turns, 2.76....etc. Hope that helps.
