VIDEO: John Deere reveals new 9000 Series self-propelled forager

Though the driveline of JD’s wide body foragers was future proofed from day one of design to handle more power, up to 1,250hp, a new gearbox and driveline was still required to handle the low-revving, high torque characteristics of the Liebherr power plant.

This has seen JD develop a whole new gearbox to transfer power from the engine to the chopping cylinder. Unlike Claas and Krone which mount their engines transversely, with power taken directly from a pulley to the chopping cylinder, Deere says its longitudinal engine layout affords the ability to match the engine better to the needs of the forager, via gearing. This means the engine can run in its ‘sweet spot’ and not a compromised higher rpm, though some would argue that the use of a gearbox actually saps a certain percentage of power itself.

In addition, the belt from the gearbox to the chopping cylinder is now a nine groove item, previously seven, as is the kernel processor drive.

Header drive has also been beefed up with a larger hydrostatic drive and fatter shaft dimeter and bearings.

To increase throughput, speed of the chopping cylinder for the top three models has increased to 1,350rpm at rated speed, previously 1,200. This puts it at an almost 1:1 ratio with the engine speed, during certain points in the rev range, and offers a 13 per cent throughput increase.

Claimed to offer better stone protection and set-up flexibility, though you might be a while setting it up, the forager’s multi-blade chopping cylinder availability extends to 40, 48, 56 and 64 knife options. Its shafts and bearings have been uprated, as has the crop accelerator’s, and it features more bracing within the cylinder. Complimenting this is a beefed up mounting for the sharpening mechanism.

Up front, Deere continues to stick with four compression rollers, rather than six as Krone and Fendt have done, citing it can still achieve the require crop compression and it affords much better access to the chopping cylinder, with the feed roller housing simply swinging out of the way. Feeder house frame is now thicker.

To match the power, JD’s 639 Premium grass pickup features reinforced tines, cam track and drive lines, along with ‘hard’ metal replaceable wearing parts around the throat and the edge of the auger’s flights. It also gets a split pickup reel, allowing a centre support bearing to be fitted.

Retaining the same wheelbase, the chassis has been slightly adapted. New engine mountings have been developed to offer a lower centre of gravity, while more space has been made for stronger drivelines. Deere says it experimented with mounting the engine transversely, but this raised the centre of gravity and required much more cooling. As it is, cooling capacity has only had to increase slightly, and the engine can be mounted right at the back of the forager for better balance.

A bit of re-jigging sees fuel tank capacity boosted to 1,500 litres, previously 1,100 litres. The new diesel tank design is evident by the new cab steps’ layout which now take on a spiral arrangement.

Wheel equipment sees 800 front tyres offer a transport width of 3.3m, while 900s push the forager out to 3.5m. At the rear, Michelin now offers IF 650/60 R34 tyres – previously, only Trelleborg did this size. This allows a higher load rating at lower pressures.

• John Deere has added a new top model to its 8000 Series narrow body foragers, designated the 8600, and not to be confused with the old wide body 8600 which is now the 9600. With 625hp, it offers a certain level of overlap within JD’s forager range, which now includes six, 8000 Series models from 380hp.
• Developed by JD-owned company Kemper, Deere has introduced a new maize header featuring six ‘large’ drums. The 12-row header is said to be suited to high yielding crops. It also folds for transport within 30 seconds.
• Finally, John Deere has extended its range of kernel processors by introducing the XStream KP model. Developed with the US-based company Scherer, it provides a large roll diameter of 250mm and 50 per cent roll speed differential, increasing processing intensity by 10 per cent at all cutting lengths, says the manufacturer. Kernel processor rolls are available with a standard saw tooth design on the Premium KP unit, and either the saw tooth or a new XCut design on the XStream KP, which features a spiral cut groove across the roll surface.