I've no idea what this 'stem end' is you're talking about,or what you mean by "adjust the brake on the bigger side with the smaller adjustment button". If either of the adjustment knobs will only turn in one direction,that would mean the pad is at the outer limit of its range. I'm guessing maybe the caliper is mounted off center and maybe the pad retention spring is broken?

The pics you posted are for tearing the caliper apart for servicing,not adjusting it. Please post pictures of the actual brake. Try to get one looking down into the caliper so we can see how the rotor is positioned in the caliper.