This double gear transmits drive from the reel-drive system to the reel itself. It sits in the gear train between the hydraulic motor output and the reel shaft, converting rotational speed and torque to match the required reel speed for crop handling. A worn or damaged gear causes slip or irregular reel rotation, leading to uneven feeding of crop material into the header auger. This component is machined to the original tooth profile and bore tolerance, ensuring it meshes correctly with the mating gears without requiring shimming or modification. On installation, verify that the gear is fully seated on the shaft and that the retaining hardware is torqued to specification.