Bush Hog EZ80 Gearbox Assembly For Rotary Cutter Genuine OEM #00791057BH

Replace a failed or worn gearbox and restore full cutting performance to your Bush Hog rotary cutter with this Genuine OEM EZ80 Gearbox Assembly (Part #00791057BH). The EZ80 designation identifies this as Bush Hog’s 80 HP rated right-angle gearbox assembly — precision-engineered and factory-built to exact Bush Hog specifications to deliver reliable, full-rated power transfer from the tractor PTO to the blade spindle assembly on compatible Bush Hog rotary cutter models.

What the Gearbox Assembly Does:
The rotary cutter gearbox is the central power transmission component of the entire cutter system. It receives input rotation from the tractor PTO shaft through the driveline, changes the angle of rotation 90 degrees from horizontal input to vertical output, and steps up the blade shaft speed through its internal bevel gear set to deliver the blade tip speed required for effective cutting performance. Different sizes of rotary cutters have different gearboxes in order to provide the proper blade tip speed at the tractor’s rated PTO RPM. The EZ80 gearbox is rated to handle up to 80 horsepower of continuous PTO input — making it appropriate for mid-to-heavy-duty rotary cutter applications where significant cutting power and vegetation-clearing capacity are required. 

Why Genuine OEM Matters for Gearbox Replacement:
Only Bush Hog cutters are equipped with Bush Hog designed gearboxes — and for good reason. Bush Hog’s OEM gearboxes are engineered to the exact mounting bolt pattern, output shaft spline specification, gear ratio, and input shaft configuration of the specific cutter model. Aftermarket gearboxes may claim compatibility but can introduce subtle dimensional or ratio differences that affect blade tip speed, mounting stability, and long-term bearing life. The genuine OEM gearbox assembly is the only replacement that is guaranteed to restore the cutter to its original factory-designed cutting performance and service life. 

Critical Gearbox Replacement Considerations:
Rotary cutter gearboxes come in both clockwise (CW) and counterclockwise (CCW) output rotation variants, and in multiple gear ratios and HP ratings. Make sure you get the rotation right — some gearbox model numbers are available in both CW and CCW rotation. Always verify the following before ordering a replacement gearbox:

• HP rating — must match or exceed the cutter’s rated requirement
• Input shaft diameter and type (smooth bore or splined) and size (1-3/8″ or 1-3/4″)
• Output shaft spline count, diameter, and taper specification
• Gear ratio — must match the original for correct blade tip speed
• Output rotation direction (CW or CCW when viewed from below)
• Mounting bolt pattern — hole count, diameter, and bolt circle dimension

Signs Your Gearbox Assembly Needs Replacement:

• Gearbox oil leaking from input or output shaft seals or housing seams
• Loud grinding, knocking, or rattling from the gearbox during operation
• Excessive heat at the gearbox housing during or after operation
• Blade spindle rotating rough, binding, or with noticeable vibration
• Metal particles in the gearbox oil at service — internal gear or bearing damage
• Catastrophic failure — gear tooth breakage, bearing collapse, or housing cracking
• Gearbox housing cracked from rock or stump strike impact

Key Features:

• Genuine Bush Hog OEM gearbox assembly — not aftermarket
• EZ80 designation — 80 HP rated for mid-to-heavy-duty rotary cutter applications
• Bush Hog designed gearbox engineered to exact OEM mounting, ratio, and shaft specifications 
• Factory-correct output shaft spline specification for direct blade carrier/stump jumper installation
• Complete assembly — ready to install with no additional internal components required
• Backed by Bush Hog’s industry-leading gearbox warranty on compatible models

Gearbox Service Note:
Before installing a new gearbox, always fill to the correct oil level with the manufacturer-specified gear oil grade. Ensure gearbox oil level is correct and the oil appears clean, not milky — a milky appearance indicates water contamination requiring immediate attention. Always inspect the driveline, shear bolt hardware, and slip clutch at the time of gearbox replacement.

Compatibility:
This EZ80 gearbox assembly fits select Bush Hog rotary cutter models that use the 80 HP rated EZ80 gearbox configuration. Always confirm fitment using your Bush Hog model and serial number — found on the equipment identification plate on the frame — and cross-reference against your unit’s parts manual to verify this is the correct gearbox assembly for your specific cutter model, PTO RPM, and rotation direction.

Part Details:

• Part Number: 00791057BH
• OEM Brand: Bush Hog
• Part Description: EZ80 Gearbox Assembly
• HP Rating: 80 HP
• Application: Select Bush Hog Rotary Cutter Models
• Condition: New / Genuine OEM