This might provide the answer to the OP Question. During the shock absorber extension two internal cams become engaged to ensure the wheel centering before landing gear retraction. (MECAER nose landing gear only). After take-off, with weight of helicopter OFF the gear, a double acting spring (located on the rear side of nose cylinder outer case), recenter the nose wheel before landing gear retraction. (MAGNAGHI nose landing gear only). Copied from 109 engineer type rating training course notes