There is a scissors gear (sub-gear) on the driven gear of the camshaft for the compact DOHC which serves to reduce gear noise associated with changes in torque. The sub-gear is pushed toward the rotational direction by the spring at all times and the scissors gear reduces the backlash of the gear by meshing with the drive gear, in order to prevent the noise. Backlash Backlash is the gap between the gear contact surfaces and due to this tolerance in the design and assembly, wear and seizure are prevented.