Not at all familiar with the machine or the stump grinder but... The easiest way to tell what direction the wheel should rotate is by looking at the stump grinder teeth. The carbide MUST rotate with the cutting edge impacting the wood. Clockwise or counter clockwise don't matter as it's all in the tooth direction as it pertains to the cutting edge. My stump grinder uses Greenteeth (Green manufacturing) wearsharp, solid carbide teeth. 700 series.