John Deere 803MH Tracked Harvester – Specs, Parts & Service Overview

Description:

The John Deere 803MH Tracked Harvester is a purpose-built forestry machine designed for full-tree harvesting and processing in tough terrain. With a powerful Final Tier 4 engine, a robust swing system, and exceptional boom control, the 803MH is optimized for productivity and durability in mechanized logging operations. Whether paired with a Waratah processing head or other harvesting attachment, this machine excels in soft soils, steep grades, and remote logging applications.

Key Specifications:

• Engine: John Deere PowerTech™ PSS 6068, 6.8L 6-cylinder turbocharged diesel (Final Tier 4)

• Horsepower: 255 HP (190 kW)

• Operating Weight: Approx. 67,000 lbs (varies by head and boom configuration)

• Undercarriage Type: Forestry-grade, heavy-duty tracks with leveling system

• Fuel Capacity: 132 gallons

• DEF Capacity: 6.5 gallons

• Boom Reach: Up to 32 ft (varies with head and boom option)

• Hydraulic Oil Capacity: 78 gallons

Hydraulic System:

• Type: Load-sensing, pressure-compensated, dual-circuit

• Pump Flow: Up to 140 GPM

• System Pressure: Up to 5,500 PSI

• Functions: Swing, boom, felling/processing head, leveling, travel

Performance Features:

• Exceptional leveling system for stability on steep slopes

• Boom float and return-to-cut functions for faster cycle times

• JDLink™ remote diagnostics and monitoring

• Comfortable, pressurized cab with climate control and touchscreen TimberMatic™ H-16 controls

• Built-in rear entry and LED lighting for improved visibility and safety

Maintenance Essentials & Replacement Parts:

• High-wear items include: processing head hoses, boom and stick cylinder seal kits, track roller assemblies, and swing motor seal kits

• Engine, DEF, and hydraulic filter kits should be serviced every 250 hours

• Undercarriage parts: sprockets, rollers, idlers, and track tension cylinders

• Common electronics repairs: cab sensor harnesses, boom angle sensors, and monitor interface cables

Common Issues and Fixes:

• Swing hesitation or drift: Usually due to worn rotary manifold seals or pressure drop in swing circuit

• Boom float not engaging: Often caused by joystick command delay or solenoid valve issue

• DEF derate or emissions code: Clean DEF injector, check tank heater and replace sensors as needed

• Cab leveling malfunction: Inspect leveling cylinder sensors and check hydraulic fluid level

Pro Tip:

The John Deere 803MH serial number is typically located on the main frame near the cab access point and also stamped on the engine tag. Always confirm serial number when ordering boom, engine, or hydraulic components.