I don't know of a simple command to change the distance between an axis title and the axis itself.
What I do is, instead of using the GrADS default title commands (eg draw title or draw ylab), I typically set a string characteristic and draw the string explicitly. The disadvantage is that one has to use more than 1 line to accomplish drawing labels and the such:
set strsiz width <width> set string color <justification <thickness <rotation>>> draw string xpos ypos string
A more concret example:
ga-> set strsiz 0.14 ga-> set string 1 r 2 0 ga-> draw string 10.25 1.0 my_x_title ga-> set string 1 r 2 90 ga-> draw string 0.2 7.25 my_y_title
Line1. Setting the string character size by changing the width
Line2. Choose a right justified white string with width 2 and no rotation
Line3. Draw X-axis title
Line4. The same as above, but rotate 90deg counterclockwise
Line5. Draw Y-axis title