John Deere 8120, 8220, 8320, 8420, 8520 Tractors Repair Manual (TM1970 and TM1980)

Table of Contents
Section 10—General Information
Group 05—Safety
Group 10—General Information
Section 20—Engine
Group 00—Component Removal and Installation
Group 05—Engine Repair
Section 30—Fuel and Cooling Systems
Group 05—Diesel Fuel System
Group 10—Air Intake System
Group 15—Engine Cooling System
Group 20—Coolers and Air Conditioning Condenser
Section 40—Electrical
Group 05—Connectors
Group 10—Wiring Harness Routings
Group 15—Charging Circuit
Group 20—Starting Circuit
Group 25—Relays, Fuses, Solenoids, and Switches
Group 30—Monitoring Systems and Sensors
Group 35—Armrest Control
Group 40—Implement and Accessory Connectors
Group 45—Convenience and Accessory Components
Section 50—Power Shift Transmission
Group 00—Component Removal and Installation
Group 05—Miscellaneous Repair
Group 10—Transmission
Section 56—Drive Systems
Group 00—Component Removal and Installation
Group 05—Rear Differential and Input Quill
Group 10—Final Drives
Group 15—Rear PTO
Group 20—Hydraulic Pump Drive
Group 25—MFWD Clutch
Group 30—Drivelines
Section 57—MFWD Axles
Group 00—Component Removal and Installation
Group 05—Final Drives
Group 10—Axle Housing
Group 15—Differential
Group 20—Input Gear Train
Group 25—Oscillation
Group 30—Secondary Brake
Section 58—INDEPENDENT LINK SUSPENSION™ Axle
Group 00—Component Removal and Installation
Group 05—Controls
Group 10—Final Drives
Group 15—Drive Shafts
Group 20—Brakes
Group 25—Differential
Group 30—Steering
Group 35—Suspension
Section 60—Steering and Brakes
Group 05—Steering Column
Group 10—Steering Control Assembly
Group 15—Steering Cylinders
Group 20—Brake Valve
Group 25—Brake Components
Group 30—Trailer Brakes
Section 70—Hydraulics
Group 00—Component Removal and Installation
Group 05—Hydraulic System Repair and Cleanup
Group 10—Tandem Hydraulic Pump (Steering-Brakes- Charge)
Group 15—Secondary Hydraulic Pump (Hitch-SCV)
Group 20—Filter Bypass
Group 25—Hitch Valve, Selective Control Valves, and Couplers
Group 30—Hitch
Section 80—Miscellaneous
Group 05—Hood
Group 10—Front Axle (Two-Wheel Drive)
Group 15—Wagon and Pick-Up Hitch
Section 90—Operator Station
Group 00—Component Removal and Installation
Group 05—Heating, Ventilating, and Air Conditioning (HVAC)
Group 10—Air Conditioning System
Group 15—Air Suspension Seat
Group 20—ACTIVE SEAT™
Group 25—Armrest
Group 30—Cab Door and Windshield
Section 99—Dealer Fabricated Tools
Group 05—Fabricated Tools
Technical manuals are divided in two parts: repair and diagnostics. Repair sections tell how to repair the components. Diagnostic sections help you identify the majority of routine failures quickly.
This manual was planned and written for the Service Department; its place is in the shop. Use the manual whenever in doubt about correct maintenance procedures. Use it as a text book for training new Service Department personnel who are unfamiliar with John Deere Tractors.
Daily use of this Service Manual as a guide in overcoming service problems will reduce error and costly delay to a minimum and as-sure you the best in finished service work. In many instances your customer’s confidence in your work will be improved when he sees you using the Service Manual. He knows you are following approved maintenance procedures and making proper adjustments. There is no guess-work when you use the manual.