If you are starting to notice that one side of you x-axis arm does not stay in place, you may need to tighten one of the Nylon Nutblock holding up the arm. This will show you how to adjust the tension of the nutblocks installed on your gMax.
Be careful not to over tighten the nutblock. This will make it so the motor can not turn the LEAD screw and you will start to get binding issues in your z-axis. Start with small adjustments and moving the z-axis in between.