John Deere 9RX: Record-breaking power in the biggest tractor

There’s no mistaking the 9RX. From the moment you walk up to it, the scale is staggering – and that’s before you discover it holds a record breaking 1,200mm drive idler, the largest John Deere has ever fitted to a tractor.

Throw in the 18-litre JD18X engine which can put out up to 913hp, and up to 636-litres/min hydraulic capacity, it becomes immediately clear that this is a machine built to dominate large-scale cultivations. 

Hosting the world’s biggest tractor

Nestled in the Trent Valley near Newark, Staythorpe Farming is a vast, family-run operation. Run by a dedicated team led by father and son, John and Tom, the farm spans 1,500ha of cereals and 550ha of potatoes, with a further 1,500ha of maize supporting their on-site digesters. The farm’s approach blends generational experience with a keen eye for modernisation – and their choice of machinery reflects that. 

This year, like many others across the country, has been tough. Yield expectations have taken a hit, with the farm’s light land producing well below average.

Where they’d usually expect around 9t/ha from wheat, the 2025 harvest is struggling to reach 7t/ha. The quality, however, has remained high – with high quality milling wheat flowing into the sheds. 

With 42 irrigators running since April, plus 258 reels of drip tape deployed, water management has dominated the season.

The team has already invested in several winter-fill reservoirs and relies heavily on the adjacent River Trent, which allows flooding across 1,500 acres in winter. But the pressure on water resources continues to mount. 

To adapt, they introduced cover cropping across the entire potato rotation – something they weren’t doing at all only five years ago. Staythorpe Farming’s director, Tom Burnett said that cover cropping had been effective at preserving soil moisture and structure for them. Grazing sheep on the covers adds another benefit, keeping the system tight and functional all year-round. 

The farm now employs 12 full-time staff, rising to 18 at peak times, all within a 25-mile radius. While Staythorpe’s scale is impressive, what stands out is their deliberate approach to data and precision.

HarvestLab yield data and protein mapping is in place, and each load from the combine is directed into separate sheds based on protein content, setting up an intelligent winter blending strategy to maximise returns. 

9RX in action 

When you’re pulling heavy cultivators across hundreds of hectares of light, drought-prone land, you need a tractor that can deliver brute strength without leaving a mark.

Apparently, that job can fall to John Deere’s new 9RX – a 34.8-tonne tracked beast that somehow manages to tread lightly, thanks to some intelligent engineering. Under the bonnet is the 18-litre JD18X engine, co-developed with Liebherr.

A focus on serviceability

Despite the size, another defining feature of the engine is the lack of an AdBlue system. The system instead relies on an efficient injection pattern and EGR to meet emissions targets.

All-in-all, John Deere says this is a simpler system – and that that simplicity extends throughout the machine, with a strong focus on serviceability. 

One of the standout features is the daily service centre – a neat panel on the side of the tractor where operators can check engine oil, refill fuel and air filters, access the ECU and even reach air conditioning components, all from ground level.

The side guards are lighter than on previous models and attach with rubber clips rather than bolts, allowing for tool-free access. 

Cooling has also been upgraded with a massive front grille and a hydraulic fan that automatically reverses flow every 15 minutes to keep dust at bay. The result is a tractor designed to run harder for longer and with fewer headaches. 

Down at the track level, the 9RX runs on 30in width belts with either 6,500 or 3,500 tensile strength options. The 1,200mm drive idler is the largest John Deere has ever fitted to a machine, and extra bottom idlers help distribute the tractor’s considerable weight.

Despite its size, ground pressure is impressively low – just 0.58kg/cm2 – keeping compaction to a minimum. 

Suspension is handled by a new four-post cab system mounted on wishbones with springs in each corner. It’s a mechanical system, not hydraulic, and it delivers a surprisingly smooth ride.

Inside, the new CommandView 4 Plus cab offers 15% more floor space and 20% better right-hand visibility compared to previous models.

The exhaust and air intake are also offset diagonally, hiding them behind the front pillars and opening up visibility even more. From the driver’s seat, the operator has a clear view of the drawbar and pin, making hitching up big implements far less of a guessing game. 

Power reaches the ground through the new e21 PowerShift transmission, delivering 21 forward and 11 reverse gears. This is paired with a hydraulics system offering flow rates of up to 636-litres/min.

The unit on show was fitted with the mid-range 424-litres/min pump, with 200-litres/min available to implements. Hydraulic oil for the implement system is now stored separately from the drivetrain, pushing service intervals up to 4,000 hours. 

At the rear, operators will find six SCVs – three high flow and three standard – delivering up to 180-litres/min per coupler.

Tombstone weights on the rear of the demonstrator machine added nearly 700kg in rear ballast, with a 1,080kg saddle weight up front. There’s even a provision for fast-fill. With the right pump, the 1,500-litres fuel tank can be filled in under four minutes.

Despite its scale, the 9RX keeps its transport width to under 3m, and the turning circle is just 0.4m wider than the smaller 640. It’s a machine built for big jobs, but with the refinement in place to make those jobs easier.  

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