Technical Description
The John Deere 644H MH Wheel Loader is a heavy-duty machine designed for efficient material handling and loading applications. It is equipped with a turbocharged, aftercooled 6-cylinder 6081H engine delivering a gross power of 212 hp (158 kW) and a net power of 180 hp (134 kW) at 2200 rpm, featuring a 40% torque rise at 1300 rpm for strong performance under load. The machine’s bucket has a breakout force of 34,340 lbs (15,577 kg), with a heaped capacity of 4.5 cubic yards (3 cubic meters) and a struck capacity of 3.8 cubic yards (2 cubic meters). The bucket width is 10 feet (3 meters), allowing for robust material movement.
The loader’s hydraulic system includes a piston pump with a flow capacity of 74 gallons per minute (280 liters/min), operating at 3600 psi, achieving dump, raise, and lower cycle times of 1.2, 6, and 3 seconds respectively, ensuring fast load cycles. The operating weight is approximately 38,927 lbs (17,657 kg), with a static tipping load of 30,906 lbs (14,019 kg). Dimensions include a wheelbase of 10.5 feet (3 meters), a width over tires of 9.5 feet (3 meters), and a height to the top of the cab of 11.2 feet (3 meters).
Transmission is power shift with 4 forward and 3 reverse gears, allowing a maximum forward speed of 24 mph (39 kph) and a reverse speed of 16.4 mph (26 kph). The 24-volt electrical system is powered by a 55-amp alternator. Fuel capacity is 90 gallons (341 liters), with hydraulic fluid capacity at 31 gallons (117 liters), supporting extended operation in heavy-use conditions. Tire size is 23.5-25, and rear axle oscillation is 26 degrees to enhance maneuverability on uneven terrain. This loader balances power, capacity, and efficiency for diverse heavy construction tasks.
