What am I doing wrong?
Re: What am I doing wrong?
How tight is the clearance between pinion gears and bull gears? Maybe they are binding a bit; although I don't know why that would make noise on down stroke but not up. I'm wondering if the babbitt in the 752 big gear bearing is slightly off center. If so, you could try flipping the gears 180°(so the current left gear is now on the right, and vice versa) and see if that makes a difference.
