John Deere 644 P-TIER wheel loader is a mid-size articulated loader designed for material handling, aggregate, construction, and site preparation applications. It features a powerful diesel engine, hydrostatic or power shift drivetrain depending on configuration, and a Z-bar loader linkage for efficient bucket breakout and loading performance. The 644 P-TIER includes a spacious operator cab, integrated controls, and visibility-focused design for productive operation in demanding environments. Common attachments and bucket options support versatility across loading, stockpiling, and truck loading tasks. The model is part of John Deere's P-TIER wheel loader lineup, built for durability, service access, and consistent cycle performance.
General Specifications
John Deere 644 P-TIER Wheel Loader General Specifications specifications
Bucket Capacity
4.0–4.75 - Starting 2025
Engine Power
249 (186) - Starting 2024
Engine Power Net
249.00 hp (185.68 kw) - Starting 2025
Engine type
Deere PowerTech PSS 6068 - Starting 2024
Max Dump Height
9.40 ft (2.87 m) - Starting 2025
Operating Weight
41,246–42,913 - Starting 2025
OperatingWeight
41,246–42,913 - Starting 2026
Axles And Brakes
John Deere 644 P-TIER Wheel Loader Axles And Brakes specifications
John Deere 644 P-TIER Wheel Loader Cooling specifications
Fan Drive Type
Hydraulically driven, proportionally controlled, fan aft of coolers - Starting 2026
Electrical And Lighting
John Deere 644 P-TIER Wheel Loader Electrical And Lighting specifications
Battery Capacity Per Each
950.0 CCA - Starting 2026
Battery Voltage
24.0 v - Starting 2026
Number Of Batteries
2 - Starting 2026
Optional Alternator Rating
140.0 amp - Starting 2026
Standard Alternator Rating
100.0 amp - Starting 2026
System Type
24 volt with 100-amp alternator - Starting 2026
Engine
John Deere 644 P-TIER Wheel Loader Engine specifications
Air Cleaner
Under-hood, dual-element dry type, restriction indicator in cab monitor for service - Starting 2026
Aspiration
Series turbocharged, charge air cooled - Starting 2026
Cylinders
6 - Starting 2026
Displacement
415.00 cu in (6,800.65 cu cm) - Starting 2026
Fuel System (Electronically Controlled)
High-pressure common rail - Starting 2026
Gross Peak Power At Rated RPM (ISO 9249)
260.00 hp (193.89 kw) - Starting 2026
Gross Peak Torque At Rated RPM (ISO 9249)
811.00 lbs ft (1,099.55 nm) - Starting 2026
Lubrication
Full-flow spin-on filter and integral cooler - Starting 2026
Manufacturer
John Deere - Starting 2026
Net Peak Power At Rated RPM (ISO 9249)
249.00 hp (185.68 kw) - Starting 2026
Net Peak Torque At Rated RPM (ISO 9249)
783.00 lbs ft (1,061.59 nm) - Starting 2026
Net Torque Rise
58.0 % - Starting 2026
Non-Road Emission Standards
EPA Final Tier 4/EU Stage V - Starting 2026
Valves Per Cylinder
4 - Starting 2026
Hydraulic System And Steering
John Deere 644 P-TIER Wheel Loader Hydraulic System And Steering specifications
Hydraulic Dump Cycle Time
1.4 s - Starting 2026
Hydraulic Lower (Power Down) Cycle Time
3.8 s - Starting 2026
Hydraulic Raise Cycle Time
5.3 s - Starting 2026
Hydraulic Total Cycle Time
10.5 s - Starting 2026
Loader Controls
Two-function valve; joystick control or fingertip controls; hydraulic-function enable/disable; optional 3rd- and 4th-function valve with auxiliary lever - Starting 2026
Max Rated Flow At Rated RPM
82.00 gpm (310.37 lpm) - Starting 2026
Pump Type And System (Loader And Steering)
Variable-displacement, axial-piston pump; closed-center, pressure-compensating system - Starting 2026
Rated RPM
2250.0 rpm - Starting 2026
Steering Articulation Angle Each Direction
40.0 degrees - Starting 2026
Steering Articulation Full Arc Angle
80.0 degrees - Starting 2026
Steering Type (ISO 5010)
Power, fully hydraulic - Starting 2026
System Pressure At Max Rated Flow
1000.0 psi - Starting 2026
System Relief Pressure (Loader And Steering)
3650.0 psi - Starting 2026
Turning Radius (Measured To Centerline Of Outside Tire)
18.5 ft, in. - Starting 2026
Key Specs
John Deere 644 P-TIER Wheel Loader Key Specs specifications
Net Peak Power At Rated RPM (ISO 9249)
249.00 hp (185.68 kw) - Starting 2026
Net Peak Torque At Rated RPM (ISO 9249)
783.00 lbs ft (1,061.59 nm) - Starting 2026
Maximum Forward Travel Speeds (Standard 5-Speed With Lockup Torque Converter)
John Deere 644 P-TIER Wheel Loader Maximum Forward Travel Speeds (Standard 5-Speed With Lockup Torque Converter) specifications
Range 1
4.40 mph (7.08 kph) - Starting 2026
Range 2
7.50 mph (12.07 kph) - Starting 2026
Range 3
12.70 mph (20.44 kph) - Starting 2026
Range 4
15.30 mph (24.62 kph) - Starting 2026
Tire Size Used To Measure Travel Speeds
23.5 R 25 - Starting 2026
Serviceability
John Deere 644 P-TIER Wheel Loader Serviceability specifications
Axle Oil Without Coolers (Front And Rear, Each) Refill Capacity
5.75 gal (21.76 l) - Starting 2026
Cooling System Refill Capacity
47.0 qt - Starting 2026
Diesel-Exhaust Fluid (DEF) Refill Capacity
19.5 qt - Starting 2026
Engine Oil With Vertical Spin-On Filter Refill Capacity
28.5 qt - Starting 2026
Fuel Tank (With Lockable Cap) Refill Capacity
92.60 gal (350.49 l) - Starting 2026
Hydraulic Reservoir With Filter Refill Capacity
27.80 gal (105.22 l) - Starting 2026
Parking Brake Oil (Wet Disc) Refill Capacity
22.0 oz. - Starting 2026
Transmission Reservoir With Vertical Filter Refill Capacity
6.00 gal (22.71 l) - Starting 2026
Transmission System
John Deere 644 P-TIER Wheel Loader Transmission System specifications
Operator Interface
Steering-column or joystick-mounted F-N-R and gear-select lever; Quick-Shift button on hydraulic lever - Starting 2026
Shift Control
Electronically modulated, adaptive, load and speed dependent - Starting 2026
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 - Starting 2026
Torque Converter
Single stage, single phase - Starting 2026
Type
Countershaft-type PowerShift™ - Starting 2026
Wheels And Tires
John Deere 644 P-TIER Wheel Loader Wheels And Tires specifications
Tread Width On Standard Tires
85.40 in (216.92 cm) - Starting 2026
Width Over Tires On Standard Tires
113.20 in (287.53 cm) - Starting 2026
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