NCLights,
The first thing to do is take the servo wheel off of the servo and see if you can move the rod freely to it's full travel. If not, find where it is rubbing. Maybe just bending the rod slightly will help.

Put the servo back on and try again. If the servo tries to turn further than the control surface can move, then you're pushrods are in the wrong holes. Use the outermost hole on the control surface. If it still tries to move too far, move the rod inward at the servo end.

Some servos just like to buzz. If it only does this at mazimum stick movement, it's not a problem. You won't be keeping the stick there anyway.

Tom