Specification sheet Wheel Loader Ref john-deere-644j-z-bar-wheel-loader

John Deere 644J Z-Bar

The John Deere 644J Z-Bar is a wheel loader with an operating weight of 40,150 lb (18,212 kg), a 185 hp engine, and a 4.25 yd³ (3.2 m³) bucket.

✓ QA-verified — every figure checked for unit consistency, physical possibility, and class plausibility; failures withheld →
Operating weight
40,150lb
18,212kg
Engine power
185hp
138kW
Net Power
Bucket capacity
4.25yd³
3.2m³

Where it sits in its classpercentile · small wheel loaders

Among 439 small wheel loaders (22,000–45,000 lb), the John Deere 644J Z-Bar sits above the median for its class:

  • Operating weight 40,150 lb heavier than 85% (n=439)
  • Engine power 185 hp more powerful than 67% (n=408)
  • Bucket capacity 4.3 yd³ larger-bucket than 85% (n=387)

Scale drawingdrawn to scale · mm

3400B434C8050A
Side elevation
3400B2875D
Front elevation

01 Engine Specification

Number Of Cylinders 6
Engine Make 2240
Engine Model 6068H
Net Power 185hp 138kw
Power Measured @ 2200rpm
Max Torque 749lb ft 1016Nm
Displacement 414cu in 6.8L
Torque Measured @ 1400rpm
Aspiration Turbocharged charge air cooled
Torque Rise 55%

02 Operational Specification

Operating Weight 40150lb 18212kg
Fuel Capacity 93gal 352L
Hydraulic System Fluid Capacity 31gal 117L
Engine Oil Fluid Capacity 6.5gal 24.5L
Cooling System Fluid Capacity 7.8gal 29.5L
Transmission Fluid Capacity 7.1gal 26.5L
Front Axle/Diff Fluid Capacity 5.9gal 22L
Rear Axle/Diff Fluid Capacity 5.9gal 22L
Static Tipping Weight 34379lb 15594kg
Turning Radius 18ft in 5490mm
Operating Voltage 24V
Alternator Supplied Amperage 80amps
Rear Axle Oscillation 26degrees
Tire Size 23.5 R25

03 Transmission Specification

Transmission Type Automatic powershift
Number Of Forward Gears 4
Number Of Reverse Gears 3
Max Speed - Forward 22mph 35.4km/h
Max Speed - Reverse 15.5mph 25km/h

04 Hydraulic System Specification

Relief Valve Setting 3600psi 24800kPa
Pump Flow Capacity 68gal/min 257L/min
Raise Time 6.2sec
Dump Time 1.4sec
Lower Time 3sec
Pump Type Variable axial piston

05 Bucket Dimensions

Dump Clearance At Max Raise 9.67ft in 2950mm
Bucket Capacity - Heaped 4.25yd3 3.2m3
Bucket Capacity - Struck 3.7yd3 2.8m3
Bucket Width 9.5ft in 2895.6mm
Breakout Force 34407lb 153kN

06 Dimensions Dimensions

Ground Clearance 1.42ft in 434mm
Length With Bucket On Ground 26.42ft in 8050mm
Width Over Tires 9.43ft in 2875mm
Height To Top Of Cab 11.17ft in 3400mm
Wheelbase 10.5ft in 3200mm
Hinge Pin - Max Height 13.58ft in 4140mm
Reach At Max Lift And Dump 3.67ft in 1120mm

Method. Figures are manufacturer reference specifications, not measurements. Every value is checked for unit consistency, physically possible magnitude, and plausibility for its equipment class before publication; figures that fail any check are withheld rather than shown, and figures reconstructed from related data are marked above. Imperial and metric figures are reproduced as published, except where a note states otherwise.