Commercial-grade 2002 John Deere 644H wheel loader engineered for high-volume aggregate, material handling, and earthmoving applications. Solid mechanical configuration ready for production Powered by a reliable John Deere 6.8L diesel engine, this 644H starts up easily and delivers strong breakout force. The fully enclosed cab keeps the operator comfortable through long shifts, while the heavy-duty 4WD drivetrain cuts through soft ground and heavy stockpiles without bogging down.