HarvestersThe making of a John Deere Forage Harvester

The forage harvester is consid­ered a pres­tige product by many customers – powerful, tech­ni­cally sophis­ti­cated and config­ured down to the last detail. The factory in Zweibrücken is the only John Deere plant in the world that builds these machines. Here, the manu­fac­turing process begins with high-preci­sion welding work – and ends with a rolling giant.

Pre-Assem­bling the Forage Unit

At the heart of the forage harvester lies the cutter­head drum – housed within what’s known as the forage unit. Weighing around 550kg, it contains up to 64 blades and spins at up to 1,350 revo­lu­tions per minute. In a dedi­cated pre-assembly hall, this massive compo­nent is precisely welded and metic­u­lously balanced. Its produc­tion is a core in-house compe­tency, because even the slightest imper­fec­tion would impact chop­ping perfor­mance and quality.

Mounting the Radi­ator

A dedi­cated assembly area prepares the cooling package, which measures over two metres in height. This massive unit is essen­tial for reli­ably dissi­pating the intense heat gener­ated during harvesting oper­a­tions and for supplying the engine with clean, cool air. Each radi­ator is pre-assem­bled to order and then mounted onto the machine with millimetre preci­sion. Its exact posi­tion and align­ment are crit­ical to ensure an unob­structed airflow.

The Engine Enters the Scene

The biggest forage harvester model houses the most powerful engine currently used by John Deere – supplied by Lieb­herr. This power­house not only drives the vehicle but also delivers the force needed to chop massive volumes of harvested mate­rial in the forage unit. Instal­la­tion is carried out with the utmost preci­sion – because in the field, power without control is not an option.

Mounting the Cab

The cab arrives pre-assem­bled from the John Deere plant in Bruchsal, Germany. In Zweibrücken, it is mounted onto a specially designed welded frame. This connec­tion requires a deli­cate touch and tech­nical support from lifting equip­ment. Once in place, the cab is fully wired, connected, and inte­grated into the machine’s elec­trical system – the forage harvester is taking shape.

The Kernel Processor

Another key compo­nent is the kernel processor. During maize harvesting, it ensures that every single kernel is cracked open so its nutri­ents can be more easily absorbed later. Two toothed rollers rotate against each other at different speeds. The harvested mate­rial is processed in the narrow gap between them, which is just a few millime­tres wide. Preci­sion is crit­ical here, to unlock the full energy poten­tial of the corn. The gap is adjusted manu­ally or elec­tri­cally, requiring the utmost care.

The Filling Station

Filling is carried out auto­mat­i­cally – tailored to the specific machine config­u­ra­tion. Various fluids and oils are precisely measured and filled. The system inde­pen­dently detects how much oil, hydraulic fluid, or coolant is required. Sensors and control tech­nology ensure that each medium is deliv­ered to the correct loca­tion in the exact amount needed.

The “Marriage”

In a central stage of the assembly process, the forage unit is joined with the major compo­nents – including the main frame and drive­train. This phase is known as the “marriage”. It marks the moment when indi­vidual parts come together to form a complete machine. From this point on, the forage harvester begins to func­tion as a single entity.

Commis­sioning and Testing

After­wards, the commis­sioning process begins in a sound-proofed area. Systems are tested, pres­sure levels are checked, and initial cali­bra­tions are carried out. Special atten­tion is given to the hydraulic units, as even the slightest devi­a­tions can nega­tively affect perfor­mance and safety. Expe­ri­enced employees monitor every detail and digi­tally docu­ment all test results.

Final Assembly and Quality Check

The final steps include fitting cameras, mirrors, and large decals, followed by a compre­hen­sive func­tion­ality test. The final inspec­tion is carried out by expe­ri­enced special­ists who know exactly what to look for. Each machine under­goes a thor­ough 45-minute test run on the in-house test track – only then is it approved for delivery.

Ready for the Field

At the end of the line stands a forage harvester capable of filling an entire truck trailer with chopped crop in just two minutes – precisely cali­brated, indi­vid­u­ally equipped, and ready to deliver peak perfor­mance in the field. A tech­nical master­piece – proudly built in Zweibrücken.