The friction drive system, used on many of our self-propelled snow throwers and some of our other self-propelled devices, operates on the principles of two intersecting circles (or drive disks) positioned at right angles to each other.

In a practical example, imagine two discs (dinner plates, coins etc...) positioned with one horizontal and one vertical and having the vertical disc positioned standing with its bottom edge centered over the exact center of the horizontal disc. If the horizontal disc is rotated the vertical disc in the exact center position should remain stationary. Now begin to rotate the horizontal disc clockwise at a constant rotational speed, slowly move the vertical disc to the left. The horizontal disc should begin to rotate and as you move it slowly from center. The farther to the left of center the disc is moved, the faster it should rotate. This increase in vertical disc rotational speed will occur even if the horizontal disc remains at a constant rotational speed. Now slowly move the vertical disc to the right of center. As the vertical disc passes the center position and moves to the right of center, the rotational direction of the vertical disc will reverse and rotate the opposite direction. This rotation will also increase in speed as the vertical disc is moved towards the right edge. All of this while the horizontal disc remains at a constant clockwise speed and rotational direction.

This is how a friction drive system changes wheel drive speed and direction, while the augers and engine use the same drive mechanism that maintains a constant and fixed rotational direction and speed. To adjust the NEUTRAL position on your wheel drive system the rubber coated friction drive wheel must be positioned at the exact center of the friction drive plate when the shift lever is placed in the NEUTRAL position. Please refer to your operators manual or service manual on how to do this adjustment for your particular model.