A complete main transmission assembly contains 30–50 parts, sourced from different factories. If you want to shorten your procurement cycle, Maikeyier may be your ideal partner. We supply replacement harvester mechanical gearboxes, covering tracked and wheeled harvesters — travel main transmissions, auxiliary transmissions, and header drive gearboxes, threshing drum drive gearboxes, unloading auger drive gearboxes, cleaning fan drive gearboxes, and other working component gearboxes. We support matching by OEM part number and also provide aftermarket replacement parts.
Combine Harvester Gearbox Assembly Components
A Combine Harvester Gearbox Assembly includes the mechanical Gearbox Housing, Transmission Gears, Transmission Shafts, Transmission Bearings, Gear Shift Components, and Seals & Gaskets.
Gearbox Housing
The housing supports internal transmission parts and provides mounting space for gears, bearings, and the lubrication system. Maikeyier offers cast iron, ductile iron, cast steel, or other suitable materials.
| Product | Function |
| Gearbox Housing | Supports internal transmission parts, provides mounting space, withstands working loads |
| Gearbox Cover | Closes the top or side of the housing, dustproof and leak-proof, facilitates inspection |
| Bearing Housing | Fixes bearings, ensures shaft positioning and rotational accuracy |
| Inspection Cover | Facilitates inspection of internal gears, bearings, and lubrication status |
Transmission Gears
Gears transmit torque through mutual engagement and are important parts for speed adjustment in mechanical gearboxes. When selecting, key parameters such as tooth count, module, tooth profile, pressure angle, material, and heat treatment requirements must be verified.
| Product | Function |
| Transmission Gear | Transmits torque through engagement, converts speed and torque |
| Drive Gear | Receives input power, drives the driven gear |
| Driven Gear | Receives power from the drive gear, outputs to the next stage |
| Reverse Gear | Changes power transmission direction, enables reverse travel |
| Gear Set | Matched set for completing a specific gear ratio |
Transmission Shafts
Transmission shafts support gears and transmit torque. Shaft diameter, length, spline parameters, shoulder dimensions, and mounting positions affect service life and unit price.
| Product | Function |
| Input Shaft | Receives engine or previous stage power input |
| Output Shaft | Outputs shifted power to subsequent transmission mechanisms |
| Countershaft | Changes gear ratio and rotation direction, enables multiple gears |
| Splined Shaft | Transmits torque through splines, facilitates shift sleeve sliding engagement |
Transmission Bearings
Gearbox bearings support rotating shafts, withstand working loads, and reduce friction. The type, size, load capacity, and lubrication requirements of each bearing must match the harvester.
| Product | Function |
| Ball Bearing | Supports rotating shafts, withstands radial loads, reduces friction |
| Tapered Roller Bearing | Withstands combined radial and axial loads, suitable for heavy-duty shaft systems |
| Needle Roller Bearing | Suitable for space-restricted locations, withstands radial loads |
Gear Shift Components
For gearboxes with mechanical shifting, the shift mechanism is responsible for changing gears or changing the power transmission path.
| Product | Function |
| Shift Fork | Moves the shift sleeve to achieve gear switching |
| Shift Shaft | Supports the shift fork and transmits shifting action |
| Shift Sleeve | Works with the splined shaft to engage and disengage gears |
| Detent Mechanism | Positions gears, prevents jumping out or disengagement |
Seals & Gaskets
Harvester seal specifications must match shaft diameter, mounting bore diameter, width, speed, lubricant, and operating temperature. They are mainly used to reduce lubricant leakage and prevent dust, moisture, and other contaminants from entering the housing.
| Product | Function |
| Transmission Oil Seal | Prevents lubricant leakage along the rotating shaft, blocks external contaminants |
| O-Ring | For static sealing, prevents oil leakage from joint surfaces |
| Gasket | Seals housing joint surfaces, prevents oil leakage and contaminant ingress |
Functions of the Combine Harvester Gearbox Assembly
Speed change: Changes the harvester’s travel speed.
Power transmission: Transmits engine power to subsequent transmission mechanisms.
Gear shifting: Achieves different gear switching according to the structure.
Changing travel direction: Some gearboxes use a reverse mechanism for forward and reverse.
Adapting to working conditions: Enables the machine to adapt to field operations, transport, and different ground conditions.
Combine Harvester Gearbox Assembly Supplier
Maikeyier adheres to manufacturing + supply chain to provide global Kubota, Yanmar, Lovol, and FMWorld agricultural parts wholesalers and retailers with high-quality, multi-category one-stop procurement services. Customers can complete gearbox assemblies, undercarriage parts, cutting parts, and threshing parts in one order.
Harvester Gearbox Assembly for Sale
- Travel main transmission
- Travel auxiliary transmission
- Header drive gearbox
- Threshing drum drive gearbox
- Unloading auger drive gearbox
- Cleaning/fan drive gearbox
- Straw chopper drive gearbox
- Gearbox housing and end cover
- Gear pairs and shaft parts
- Shift forks and synchronizer assemblies
- Gearbox bearings and harvester oil seals
Gearbox Assembly Specifications
| Item | Description |
| Product Type | Replacement mechanical gearbox / Aftermarket replacement |
| Matching Method | OEM part number, drawing, sample |
| Compatible Brands | Kubota, Yanmar, Lovol, World, etc. |
| Housing Material | Cast iron / Ductile iron / Cast steel (per design) |
| Gear Material | 20CrMnTi, 40Cr and other alloy steels (per design) |
| Shaft Material | 45#, 40Cr (per design) |
| Bearing Type | Deep groove ball, tapered roller, needle roller (per design) |
| Seal Type | Oil seal, O-ring, gasket (per design) |
| Packaging | Export wooden case / Pallet |
| Order Type | Sample / Bulk / Mixed lot / Full container |
Process
- Material selection: Select alloy steel for gears and shafts according to load and working conditions.
- Forging: Forging blanks to ensure metal flow lines and strength of gear blanks and shafts.
- Machining: CNC turning and milling of shafts, housings, and mounting interfaces.
- Hobbing/shaping: Machining gears according to module and tooth profile requirements.
- Heat treatment: Carburizing, quenching, tempering to obtain surface hardness and core toughness.
- Gear/shaft grinding: Tooth surface grinding and shaft diameter grinding to ensure dimensional accuracy and smooth engagement.
- Assembly: Install shafts, gear pairs, bearings, seals, and shift mechanisms into the housing.
- Testing and inspection: Rotation test, backlash check, air tightness test, dimensional inspection before packaging.
Combine Harvester Gearbox Assembly Price
The price of a Combine Harvester Gearbox Assembly ranges from $300 to $10,000+, affected by multiple factors such as model and structural complexity, housing material, gear material and heat treatment, bearing brand and grade, shift mechanism type, OEM vs. aftermarket, etc. Leave us a message with your harvester brand and gearbox requirements to get a free quotation!
Combine Harvester Gearbox Assembly vs HST vs HMT vs Power Shift
Several components in a harvester gearbox assembly are easily confused: Gearbox, HST, HMT, etc. Mechanical gearboxes use gear pairs for speed change; HST uses a variable hydraulic pump + motor for speed change. Tracked harvesters generally use a combined solution — HST for stepless speed change, mechanical auxiliary transmission for field/road gear switching.
| Comparison Item | Mechanical Gearbox | HST Hydrostatic | HMT Hydraulic-Mechanical | Power Shift |
| Transmission medium | Gears and shafts | Hydraulic oil | Hydraulic + mechanical | Wet clutch |
| Speed change method | Stepped (2–6 gears) | Stepless | Stepless | Stepped (shift under load) |
| Shift operation | Manual lever/clutch | Pedal or handle | Handle | Shift under load |
| Forward/reverse | Gear engagement | Single handle forward/reverse | Single handle | Shift under load |
| Transmission efficiency | High (90–95%) | Medium (75–85%) | High (85–92%) | High |
| Controllability | Average | Good, precise inching | Good | Good |
| Wet soft fields | Deep mud easy to stall | Strong low-speed high torque | Strong | Good |
| Fault symptoms | Hard shifting, abnormal noise, broken teeth | Weak, high oil temperature, deviation | Both | Slipping, shift shock |
| Unit cost | Low | High | Highest | Medium-high |
| Maintenance focus | Oil level, oil seals | Oil quality, oil temperature, filter | Both | Clutch plates |
Maikeyier One-Stop Harvester Parts Supply
In addition to Combine Harvester Gearbox Assembly, we supply complete harvester parts, achieving one supplier and one-time solution for all harvester parts needs.
Travel Transmission
- Travel main transmission
- Travel auxiliary transmission
- Drive axle assembly
- Final drive / side reducer
- Working Component Drive Gearboxes
Header drive gearbox
- Threshing drum drive gearbox
- Unloading auger drive gearbox
- Cleaning/fan drive gearbox
- Straw chopper drive gearbox
Gearbox Internal Parts
- Gear pairs
- Shaft parts
- Bearings
- Oil seals and O-rings
- Shift forks and synchronizers
Track Undercarriage System
- Drive sprocket
- Idler wheel assembly
- Track roller assembly
- Carrier roller
- Harvester rubber track
Looking for a harvester mechanical gearbox? Maikeyier supplies replacement mechanical gearboxes and gearbox assemblies, serving agricultural parts wholesalers, dealers, retailers, and importers. Contact us for a free quotation!