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John Deere 644 G-Tier Mid-Size Wheel Loader

Model Photo

644 G-Tier

  • Net Power: 169 kW (227 hp) at 1,800 rpm
  • Operating Weight: 17 934–18 205 kg (39,537–40,135 lb.)
  • Bucket Capacity: 3.1–3.2 m3 (4.00–4.25 cu. yd.)



Comfortable and straightforward cab design

View of operator’s station View of operator’s station
View of foot pedals from the seat View of foot pedals from the seat

The cab on the 644 G was designed to provide different levels of comfort to operators, depending on the machine application. It is also set up to ensure that operation of the machine is straightforward with easy-to-access machine settings and features.


  • With a standard mechanical seat or optional air-ride suspension seat, you’re able to choose the seat suspension that matches your average operating conditions.
  • Floor storage area on the left side of the seat means storing lunch boxes or personal items is easy and out of the way of foot pedals or controls.
  • Joystick controls, foot pedals, and sealed-switch module have all been ergonomically placed to ensure maximum comfort.
  • A high-definition and adjustable monitor includes built-in abilities to view diagnostic trouble codes.




Service and support capabilities you’ve come to expect from John Deere

Hinged doors open on both sides of the machine for daily, ground level access and service Hinged doors open on both sides of the machine for daily, ground level access and service
John Deere Connected Support™ capabilities monitor key machine data John Deere Connected Support™ capabilities monitor key machine data

The 644 G is backed by John Deere’s world-class dealer network that provides warranty support and maintenance and has the parts on the shelf needed to allow maximum uptime. Attributes related to servicing and supporting the 644 G are no different than those experienced today on all other pieces of John Deere equipment.


  • All daily service points including fuel fill are conveniently grouped on the left side of the machine at ground level for easy access.
  • Hinged doors provide wide-open access to the engine, the cooling system, and other components.
  • John Deere Connected Support™, JDLink™, Service ADVISOR™ Remote, and Expert Alerts are all tools that enable sharing of real- time machine data and alerts so fleet managers and dealers can view codes and data before dispatching a technician to a jobsite, which increases uptime and lowers costs.

Proven and reliable major components that enable maximum reliability and durability

John Deere PowerTech™ 6.8-L (415-cu in.) engine John Deere PowerTech™ 6.8-L (415-cu in.) engine

Built on over 50 years of experience producing and supporting wheel loaders, the 644 G features a high commonality of components found in other John loaders that are designed and tested to meet John Deere standards including the engine, transmission, and axles.


  • The John Deere PowerTech 6.8-L (415-cu in.) engine is designed to improve cooling and provide high cylinder and piston ring durability.
  • John Deere Teammate V axles contain pressure-lubed input bearings and brake discs that enhance cooling and extend component life, which helps lower total cost of ownership.
  • Extended service intervals lower the cost of maintenance over the entire life of the machine.
  • Auto Idle and Auto Shutdown reduce engine speed or turn the off completely after a period of inactivity to save fuel and warranty hours.


Operate with ease with user-friendly controls

Operator’s view of the controls from the seat Operator’s view of the controls from the seat

The 644 G controls were designed with operators of all skill sets in mind. The simple setup and functionality mean you can start putting the machine to work quicker and easier.


  • Pilot controls on the 644 G are intuitive to operate and are familiar to both novice and experienced operators.
  • Automatic shifting of the transmission occurs on the fly to enhance ease of operation
  • Optional front differential lock provides additional traction in muddy or softer ground conditions.
  • In-cab adjustable boom height kickout, return to carry, and return-to-dig can be easily activated from the convenient sealed switch module (SSM), speeding production in repetitive applications.
  • Clutch cut-off allows for the delivery of full engine power to the hydraulics when crowding a pile and using the brakes, which increases cycle times and productivity. A sensor integrated into the brake pedal cues the cut-off in the transmission to occur during braking so that operators don’t have to press a button to disengage the transmission.


Engine Manufacturer John Deere
Engine Model PowerTech PVS 6068H
Emission Rating EPA Tier 4 / EU Stage V
Displacement, ltr (Inches³) 6.8 (414)
Rated Speed, rpm 1800
Engine Output - Net, kW (hp) 169 (227)
Torque, Nm (lbf / ft) 981 (724)
Transmission Type Powershift
Front Differential Type Open
Rear Differential Type Open
Tire size - Standard 23.5 R25
Service Brake - Type Wet Disc
Service Brake - Actuation Hydraulic
Parking Brake - Type Wet Multi Disc


Height - Over Cab, mm (ft/in) 3460 (11 ft 4 in)
Wheelbase, mm (ft/in) 3260 (10 ft 8 in)
Ground clearance, mm (inches) 422 (16.6)
Width Over tires - Std, mm (ft/in) 2777 (9 ft 1 in)
Height - Pivot Pin, mm (ft/in) 4130 (13 ft 7 in)
Reach - At 2130mm 45° Dump, mm (ft/in) 1630 (5 ft 4 in)


Fuel Tank, ltr (gallons (US)) 300 (79.3)
Hydraulic Tank, ltr (gallons (US)) 100 (26.4)
Heaped Capacity, m³ (yd³) 3.1 (4)
Breakout - Bucket, kgf (lbf) 14462 (31883)
Ride Control System Optional
Pump Type Piston
Pump Flow - 1, lt/min (gallons (US) / min) 330 (87)
System Pressure, bar (PSI) 231 (3350)


Operating Weight, kg (lbs) 17934 (39537)