RA/Azimuth Gearmotor

Yep, those are the tensioner range adjustment screws for the RA drive. Unlike the declination axis, there is no pressure adjustment of the spring. Instead you're just adjusting the range of motion of the carrier. Loosening the black screw lets the worm gear ride deeper in the spur gear, while the set screw in the hole controls how far OUT of the teeth it can ride. While the declination axis can still skip teeth if too much force is applied, this screw prevents the RA axis from skipping teeth. However, it doesn't increase the spring pressure.