1994-2012 JOHN DEERE 644K Z-BAR WHEEL LOADER

Technical Description

The John Deere 644K Z-Bar is a mid-size wheel loader powered by a Tier III certified 6.8L six-cylinder turbocharged diesel engine delivering 232 horsepower at 1,700 rpm with 55% torque rise, producing 1,062 Nm of torque. This machine features a variable axial piston pump supplying 81.9 gallons per minute of hydraulic flow at 3,650 psi system pressure, enabling impressive performance with a 15,378 kg (33,903 lb.) breakout force and 12,879 kg (28,393 lb.) tipping load. The loader accommodates bucket capacities ranging from 3.1 to 3.2 cubic meters with maximum 45-degree dump clearance of 2.91 meters using the standard Z-bar linkage. Operating at 18,160 kg (40,036 lbs.), the 644K delivers responsive cycle times—5.5 seconds for raising, 1.4 seconds for dumping, and 3 seconds for lowering—supporting efficient material handling operations. The countershaft powershift transmission provides four forward and three reverse gears, with maximum speeds of 22.8 mph forward and 15.5 mph reverse, while maintaining a compact 18.3-foot turning radius. Measuring 26.8 feet long with 9.5-foot width over tires and 13.4-foot maximum hinge pin height, the loader offers excellent maneuverability in confined spaces. Standard tire equipment consists of 23.5 R25 units with 26-degree rear axle oscillation, complemented by a 352-liter fuel capacity and comprehensive fluid system capacities supporting extended operational periods in demanding material handling and construction applications.