Slasher, rotary cutter, mower, tiller, irrigation pump and post-hole drives in bevel, parallel-shaft and worm configurations — engineered to take 540 RPM tractor power and turn it into the torque, speed and direction your implement actually needs.
An agricultural gearbox sits at the implement input, between the PTO driveline and the working components. It does three things at once — it changes shaft direction (most often turning horizontal PTO input into vertical or transverse output), it multiplies or reduces speed through a calculated ratio, and it provides a sealed oil-bath environment for hardened gear teeth that would otherwise wear out in months under field dust and shock loading.
Our catalogue covers the full spectrum: slasher and rotary cutter gearboxes (the largest category, used on every paddock-mowing tractor in Australia), through mower, tiller, irrigation pump, post-hole and forage drives, all the way to OEM-pattern replacements for discontinued machinery. Every gearbox ships with traceable metallurgical certificates, dimensional inspection data, and oil-fill from the factory.
Agricultural gearboxes are designed around the implement, not around abstract series numbers. We organise our catalogue the same way Australian dealers and farmers actually shop for them.
The biggest single category in any Australian gearbox catalogue. Right-angle bevel drives that take 540 RPM input and deliver to a vertical or transverse blade carrier. Cast iron housings, hardened-and-ground bevel gears, large-volume oil baths.
Disc mower input gearboxes (right-angle bevel feeding the mower bed) and drum mower drives (parallel-shaft units between input and rotor stack). Engineered for the high speeds and dust loading typical of grass and lucerne mowing.
Two-stage reduction designs that take 540 RPM and reduce it dramatically for the slow, high-torque rotation of tilling tines. Multi-speed shifters available on heavy-duty units to match different soil conditions and tractor power outputs.
Vertical right-angle drives that step up 540 RPM tractor input to the higher pump-shaft speeds typical of centrifugal irrigation pumps. Heavy-duty thrust bearings handle the axial load from belt-driven pump configurations and hose-reel main drives.
High-reduction drives for post-hole augers, fencing tools and earth augers — turning fast PTO input into the slow, hammering torque that bores into hard ground. Worm and double-bevel reductions both available, with shear-bolt protection options.
Built to original equipment manufacturer drawings — replacement gearboxes for discontinued machinery, new-build supply for Australian implement OEMs, and bespoke ratio packages for one-off engineering builds. Match by part number, sample, or photo.
Walk any Australian dealership lot and 80 percent of the agricultural gearboxes you see will be right-angle bevel-gear units. There's a structural reason for that — the implement geometry forces the answer:
Service factor is the multiplier applied to nominal input power to estimate the actual peak load a gearbox will see. Specifying it correctly is the difference between a gearbox that runs five seasons and one that fails in five hundred hours. The maths is simple — getting the answer right is not:
Click any gearbox below for full specification, ratio options, mounting dimensions and an enquiry button. Need an OEM-pattern unit not listed? Send us the part number, the worn gearbox sample, or your implement model — virtually any pattern can be matched.
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Looking for the matching tractor-side driveline? Browse our complete PTO shafts and drivelines range — gearbox-and-driveline kits supplied as matched assemblies on request.
Cross-reference your implement to the typical input speed, ratio, output type and torque range. Use this as a starting point — actual selection should account for tractor power, working environment and service factor.
| Application | Typical Input | Common Ratio | Output Style | Torque Range |
|---|---|---|---|---|
| Slasher / Rotary CutterBevel | 540 RPM, 1-3/8 6-spline | 1:1, 1:1.46, 1:1.93 | Vertical 1 inch keyed | 600 to 1,800 Nm |
| Disc / Drum MowerBevel | 540 / 1000 RPM | 1:1.78, 1:2 step-up | Smooth or splined | 400 to 1,200 Nm |
| Rotary TillerBevel + Reducer | 540 RPM, 1-3/8 6-spline | 1:1, 1:1.46 plus 2nd stage | Side-driven splined | 800 to 2,500 Nm |
| Power HarrowBevel + Reducer | 540 / 1000 RPM | 1:2 to 1:4 reduction | Side-flange to rotor train | 600 to 2,000 Nm |
| Round / Square BalerBevel | 540 / 1000 RPM | 1:1, 1:1.46 | Splined or flanged | 1,000 to 3,000 Nm |
| Forage HarvesterHeavy Duty | 1000 RPM, 21-spline | 1:1, 1:1.46 | Flange coupling | 1,500 to 4,000 Nm |
| Irrigation PumpStep-Up | 540 RPM, 1-3/8 6-spline | 1:2, 1:2.5, 1:3 step-up | Vertical pump shaft | 200 to 800 Nm |
| Post-Hole DiggerReducer | 540 RPM, 1-3/8 6-spline | 2:1, 3:1 reduction | Square / hex output | 600 to 1,500 Nm |
| Manure SpreaderMixed | 540 RPM, 1-3/8 6-spline | 1:1, 1:1.46, 2:1 mix | Multiple outputs | 500 to 1,800 Nm |
Eight equipment sectors where our gearboxes ship as direct-replacement units and as new-build OEM supply.
Single, multi-rotor and offset slashers — the dominant gearbox application in Australia.
Hay and lucerne mowers, conditioner drives, mower-conditioner combination units.
Rotary tillers, rotavators, power harrows, single-spike and double-spike rotor trains.
Round baler input drives, square baler ram inputs, forage harvester chopper inputs.
Centrifugal irrigation pump drives, hose-reel main drives, transfer pump packages.
Fencing post-hole drives, earth augers, soil sampling augers, tree-planting augers.
Silage defacer drives, feed mixer auger gearboxes, round bale unroller drives.
Manure spreader vertical and horizontal beater drives, slurry tanker pump gearboxes.
Working through these in order avoids the most common selection mistakes. If anything is unclear, send your details and our drive engineers will recommend a part number.
Tractor PTO speed (540 or 1000 RPM), shaft size (1-3/8 or 1-3/4 inch), spline count (6 or 21). Photograph the tractor PTO stub end-on if uncertain — counting splines from a photo is reliable.
What output speed does the implement actually need? Mowers want step-up (output faster than input), tillers want reduction (output slower than input). Calculate the ratio from input RPM and required output RPM.
Multiply nominal tractor PTO power by the service factor for your application — 1.25 light, 1.5 to 1.75 moderate, 2.0 to 2.5 heavy shock, 2.75 to 3.0 severe. Choose a gearbox rated above the result.
Cast iron for shock-loaded duty, aluminium acceptable for light steady duty. Specify lip seals plus dust shields for irrigation and slurry environments. Confirm mounting flange dimensions match implement.
Around 40 percent of the gearboxes we ship are to OEM patterns — replacements for discontinued machinery, new-build supply for Australian implement manufacturers, and one-off custom ratios for specialty engineering builds. Our OEM service includes:
You can read more about our manufacturing capability and quality systems on the about Ever-power Australia page.
A gearbox sits in the middle of the drive train. Browse the upstream and downstream components that complete a typical Australian implement, all from the same factory and matched to the same ISO 9001 quality system.
Send us your implement type, tractor PTO power, required output RPM and working environment — our engineering team replies with a verified specification, recommended ratio, applied service factor and a transparent quote. Or browse our full catalogue and request samples on specific gearboxes.
