An overload clutch (10) for a rotating agitation member (11) for a surface cleaning machine includes a clutch member (12) connected to the agitation member (11) to rotate therewith, a coupling member (20) rotatable relative to the clutch member (12), and a torque lever (40) having an end pivotally mounted to the coupling member (12). The other end of the torque lever (40) is biased to engage with the clutch member (12) such that the agitation member (11) is rotated together with the coupling member (20) when a torque load from the agitation member (11) is not greater than a preset level. The torque lever (40) pivots outward away from the clutch member (12) and disengages from the clutch member (12) to disconnect the torque lever (40) from the clutch member (12) when the torque load from the agitation member (11) is greater than the preset level.