This complete gearbox assembly drives the cutterbar on a grain-harvester header. It replaces the original drive unit and mounts at the existing points without modification. The gearbox is specified for headers up to 6.6 meters in width. It uses ZVL ball bearings and NTN needle bearings to handle the loads of intensive harvesting. The housing and internal components are machined to match the original geometry, which keeps vibration low and maintains alignment of the knife-drive system. Before operation, fill the gearbox with 0.85 liters of SAE 85W-90 API-GL5 gear oil. The kit includes the housing, eccentric shaft, fork, bearings, seals, and mounting hardware needed for a complete replacement.