John Deere Product Details
644 P-Tier
Electrohydraulic (EH) Controls
Electrohydraulic (EH) controls provide enhanced functionality, allowing operators to customize machine operations. This includes soft hydraulic stops and programmable joystick buttons. These features empower operators with increased productivity across various jobsite tasks.
Payload Weighing Systems
SmartWeigh delivers dynamic weighing without slowing down the job—no workflow interruption or boom reset needed. Easily viewed on the onboard monitor and integrated with the John Deere Operations Center, it’s available as a factory or field‑installed option.
Vision and Detection Systems
Active jobsites present many operational challenges, including multiple machines, crew members, and bystanders. The John Deere Advanced Vision System (AVS), SmartDetect™, and SmartDetect Assist™ can help enhance operator awareness to confidently navigate busy work areas.
Description: 644 P-Tier
Key Specs
| Net Peak Power At Rated RPM (ISO 9249) | 249 hp |
| Net Peak Torque At Rated RPM (ISO 9249) | 783 lb-ft |
Engine
| Manufacturer | John Deere |
| Model | PowerTech™ PSS 6068 |
| Non-Road Emission Standards | EPA Final Tier 4/EU Stage V |
| Cylinders | 6 |
| Valves Per Cylinder | 4 |
| Displacement | 415 cu in. |
| Net Peak Power At Rated RPM (ISO 9249) | 249 hp |
| Gross Peak Power At Rated RPM (ISO 9249) | 260 hp |
| Net Peak Torque At Rated RPM (ISO 9249) | 783 lb-ft |
| Gross Peak Torque At Rated RPM (ISO 9249) | 811 lb-ft |
| Net Torque Rise | 58 % |
| Fuel System (Electronically Controlled) | High-pressure common rail |
| Lubrication | Full-flow spin-on filter and integral cooler |
| Aspiration | Series turbocharged, charge air cooled |
| Air Cleaner | Under-hood, dual-element dry type, restriction indicator in cab monitor for service |
Cooling
| Fan Drive Type | Hydraulically driven, proportionally controlled, fan aft of coolers |
Electrical And Lighting
| System Type | 24 volt with 100-amp alternator |
| Battery Voltage | 24 V |
| Number Of Batteries | 2 |
| Battery Capacity Per Each | 950 CCA |
| Standard Alternator Rating | 100 amp |
| Optional Alternator Rating | 140 amp |
Transmission System
| Type | Countershaft-type PowerShift™ |
| Torque Converter | Single stage, single phase |
| Shift Control | Electronically modulated, adaptive, load and speed dependent |
| Operator Interface | Steering-column or joystick-mounted F-N-R and gear-select lever; Quick-Shift button on hydraulic lever |
| Shift Modes | Manual/auto (1st–D or 2nd–D); Quick-Shift button with two selectable modes: kick-down or kick-up/down; and four clutch cutoff settings |
Maximum Forward Travel Speeds (Standard 5-Speed With Lockup Torque Converter)
| Tire Size Used To Measure Travel Speeds | 23.5 R 25 |
| Range 1 | 4.4 mph |
| Range 2 | 7.5 mph |
| Range 3 | 12.7 mph |
| Range 4 | 15.3 mph |
Axles And Brakes
| Final Drives | Heavy-duty inboard-mounted planetary |
| Standard Differentials Front | Hydraulic locking |
| Standard Differentials Rear | Conventional |
| Optional Differentials Front | Dual locking |
| Optional Differentials Rear | Dual locking |
| Service Brakes (ISO 3450) | Hydraulically actuated, inboard sun-shaft mounted, oil cooled, self adjusting, single disc |
| Parking Brake (ISO 3450) | Automatic spring applied, hydraulically released, driveline mounted, oil cooled, multi disc |
Wheels And Tires
| Tread Width On Standard Tires | 85.4 in. |
| Width Over Tires On Standard Tires | 113.2 in. |
Serviceability
| Fuel Tank (With Lockable Cap) Refill Capacity | 92.6 gal. |
| Cooling System Refill Capacity | 47 qt |
| Diesel-Exhaust Fluid (DEF) Refill Capacity | 19.5 qt |
| Engine Oil With Vertical Spin-On Filter Refill Capacity | 28.5 qt |
| Transmission Reservoir With Vertical Filter Refill Capacity | 6 gal. |
| Axle Oil Without Coolers (Front And Rear, Each) Refill Capacity | 5.75 gal. |
| Hydraulic Reservoir With Filter Refill Capacity | 27.8 gal. |
| Parking Brake Oil (Wet Disc) Refill Capacity | 22 oz. |
Hydraulic System And Steering
| Pump Type And System (Loader And Steering) | Variable-displacement, axial-piston pump; closed-center, pressure-compensating system |
| Rated RPM | 2250 rpm |
| System Pressure At Max Rated Flow | 1000 psi |
| Max Rated Flow At Rated RPM | 82 gpm |
| System Relief Pressure (Loader And Steering) | 3650 psi |
| Loader Controls | Two-function valve; joystick control or fingertip controls; hydraulic-function enable/disable; optional 3rd- and 4th-function valve with auxiliary lever |
| Steering Type (ISO 5010) | Power, fully hydraulic |
| Steering Articulation Full Arc Angle | 80 degrees |
| Steering Articulation Angle Each Direction | 40 degrees |
| Turning Radius (Measured To Centerline Of Outside Tire) | 18.5 ft, in. |
| Hydraulic Raise Cycle Time | 5.3 seconds |
| Hydraulic Dump Cycle Time | 1.4 seconds |
| Hydraulic Lower (Power Down) Cycle Time | 3.8 seconds |
| Hydraulic Total Cycle Time | 10.5 seconds |
