Adding to its line-up of high horsepower 9R series wheeled and 9RT series twin-track tractors, John Deere is to introduce its first four-track tractor.

Four models make up the new 9RX series, ranging from 470 to 620hp. Features include integrated AutoTrac guidance, a full powershift 18-speed transmission and specifically developed high capacity hydraulics.

Power for the 9RX series comes from either a John Deere PowerTech PSS 13.5-litre engine (9470RX and 9520RX models) or a 15-litre Cummins QSX15 engine (9570RX and 9620RX models).

To keep up engine response and maximise torque curves, the Deere motor uses series turbos, one of which is a variable geometry turbo (VGT). The Cummins engine has a similar approach, but just makes do with a VGT. Other benefits of VGTs include increased low rpm torque, quicker response to load, increased peak torque and improved fuel economy, says Deere.

Both engine makes comply to Stage 4 emissions levels.

Like its 9R/9RT siblings, the four-track tractors are available with the firm’s e18, full powershift transmission.
The transmission can be controlled in one of three modes; manual, custom or automatic. In the latter two modes the tractor’s Efficiency Manager system allows automatic control of the engine and transmission. This essentially lets the operator select a target speed, leaving the tractor to work out the optimum engine revs and gear ratio based on loads exerted on the powertrain.

Unlike the firm’s twin track machines, drive to the tracks is positive using lugs on the inside of the belts and a large diameter drive sprocket.
Interestingly, the track units use one less set of mid-rollers compared to a certain red coloured competitor’s machine. Deere says this reduces vertical shock loadings up through the drive axle, which occurs when a mid-roller is positioned directly in-line with a drive axle.

In addition, the front idler is raised 20mm (0.78inch) higher than the two mid rollers allowing the tractor to climb over obstacles, says the manufacturer, and reduce track belt vibration. Similarly, the rear idler is raised 10mm (0.39inch) higher than the two mid rollers.

Track belts are available in 762mm and 914mm (30inch and 36inch) widths.

A redesigned hydraulic system for the 9RX includes up to eight double acting spool valves and delivers a standard 220 litres per minute of flow, or an optional 435 litres per minute of flow.

Via two parallel hydraulic systems (one optional), the spools can be split into two banks offering a bank of high flow, low pressure spools and a bank of low pressure, high flow spools.
A 9,072kg rear linkage can also be specified, as can a 1,000rpm pto.

All 9RX tractors are equipped with a cab suspension system, which is fully automatic and requires no operator adjustmen.

Similar to Deere’s other large tractors, the CommandView 3 cab on the 9RX features the same layout and operating logic, along with a 40 degree swiveling seat and leather seat option.

Via the Generation 4 touch screen CommandCenter, all major tractor functions can be set-up, along with access to guidance systems and job documentation.