If it was "banging" at hitting the limit(s) before it quit, I'd look for a gear engagement issue. In your second picture, the horizontal rod bevel gear appears to be backed away from the vertical bevel gear. It may just be the picture angle, but something like that would do just what you have described. If that bevel gear isn't fully seated against and engaged with the mating gear, check the allen set screw for looseness, and if it is not tight, back it off a little, pry the bevel gear up against the mating gear, and tighten the set screw. Then again, maybe that is just a roll pin and not a set screw? If so, what keeper holds it tight against the other gear?
But, if that banging was a gear hopping a cog, then eventually the two sides are way out of sync.
I'd check both sides while you are at it.
He who hesitates is not only lost, but miles from the next exit.