Meet The John Deere 644K Hybrid Loader

JD_644K Hybrid_6 The new 644K Hybrid Wheel Loader (Insert QR Code)from John Deere is now available for contractors looking to lower owning and operating costs. The 644K Hybrid uses two sources of energy: diesel and electric. It captures regenerated energy as it’s being created and uses it to power the machine.

“The 644K Hybrid is a result of our dedication to integrating the best technology available to better the industry and provide our customers superior uptime and productivity, while lowering daily operating costs,” said Andrew Kahler, engine and driveline product marketing manager, John Deere Construction & Forestry.

The 644K Hybrid is equipped with a John Deere PowerTech™ 6.8-L IT4/Stage IIIB engine that runs at an operator-selected constant speed from 900 to 1,800 rpm. The hybrid boasts a net 229 hp and is equipped with all the key features of the conventional John Deere K-Series Wheel Loader line.

The machine’s hybrid technology delivers performance that is equal to or better than the conventional 644K, depending on the application. The engine’s constant operating speed maintains continuous hydraulic flow at all times, which  delivers crisp hydraulic responsiveness and reduces cycle times. The electric motor smoothly delivers torque resulting in fluid operation and a smoother ride. As a result, the 644K Hybrid delivers optimal performance for novice and experienced operators alike.

“With fuel prices on the rise, the 644K Hybrid can reduce fuel consumption up to 25 percent, helping contractors lower their dailyJD_644K Hybrid_1 operating costs,” said John Chesterman, global product marketing manager for 4WD loaders, John Deere Construction & Forestry. “But there is so much more to the 644K than fuel-efficiency. The hybrid’s features make it easy to control, virtually becoming an extension of the operator.”

Another benefit of the hybrid design is noise reduction on the jobsite. Since the engine runs at a constant speed instead of increasing and decreasing speed as the machine is worked, the engine noise is continuous and therefore less noticeable to both the operator inside the cab and bystanders outside.

During operation, a simplified, PowerShift™, countershaft-style transmission maintains smooth shifting for added productivity whether the operator is stockpiling, truck loading or ramp climbing. The 644K Hybrid has four operating speed ranges, but no reverse gear or clutches as direction changes are performed by the electric motor. An integrated, spring-applied, hydraulically released wet-disc park brake requires reduced maintenance and increased machine uptime.

Like conventional K-Series Loaders, a Sealed Switch Model (SSM) gives fingertip control of keyless start and 24 other machine functions. New to the SSM are engine speed adjust and coast control. The coast control feature allows the operator to enable dynamic braking through the SSM, reducing mechanical brake wear.


Four main components pace the 644K’s electric-drive technology – the generator, inverter, motor and brake resistor.


The generator is brushless and converts the rotational energy from the engine into three-phase alternating current (AC) electrical energy. It can also be driven as a motor to use recycled energy to drive hydraulics and save fuel.

The inverter is a solid-state electronic system designed for reliability, durability, and long life. The water-cooled inverter delivers electrical energy to the motor as demanded by the operator.

The single electric motor is also brushless for added reliability and converts three-phase (AC) back to rotational energy and torque. The motor replaces the job of a torque convertor, but can also work as a generator to recycle energy back into the system.

JD_644K Hybrid_2The water-cooled brake resistor passively consumes energy whenever the power electronics actively control its circuit and is only needed to consume excess recycled energy.

Fleet managers, owners or operators looking to get the most out of their equipment can rely on John Deere WorkSight™, the most comprehensive, easy-to-use suite of technology available for increasing uptime and productivity while lowering operating costs. JDLink™ monitoring provides real-time machine utilization and health data, plus location info. Fleet Care proactively suggests maintenance to  prevent costly downtime. Service ADVISOR™ Remote enables the John Deere dealer to read diagnostic codes, record performance data, and even update software without a trip to the jobsite. Integrated payload weighing is also available and enables operators to monitor load data and optimize machine utilization.

644K Specifications

Engine Emission Level IT4/ Stage III B
Displacement 6.8L (415 cu. in.)
Net Peak Power hp (kW) 229 (171)
Transmission Type Hybrid-electric drive
SAE Operating Weight lb. (kg) 40,436 (18,341)
Tipping Load – Straight lb. (kg) 31,061 (14,089)
Tipping Load – Full Turn lb. (kg) 26,992 (12,243)

For more information, visit John Deere at

Leave a Reply

Your email address will not be published. Required fields are marked *


This site uses Akismet to reduce spam. Learn how your comment data is processed.