John Deere 6020, 6120, 6220, 6320, 6420, 6420S, 6520 and 6620 Tractors Repair Manual (TM4750)

What's Covered in This Manual

This is the Repair Technical Manual (TM4750, dated 01OCT02) covering eight John Deere tractors - the 6020, 6120, 6220, 6320, 6420, 6420S, 6520 and 6620 - plus the SE variant of six of those models (6020, 6120, 6220, 6320, 6420, and 6520), published by John Deere's European office, Werke Mannheim. It's the repair half of a three-manual set: the companion TM4741 covers Operation and Tests, and TM4726 covers Diagnostics, across this same model range (with the Op & Test manual actually extending slightly further, to the 6920S).

This European-published manual offers a genuine choice of five different transmissions across the lineup, and gives each one its own complete section: SyncroPlus, Power Reverser, AutoPowr/IVT (a continuously variable design), and PowrQuad/PowrQuad Plus/AutoQuad, each with full removal, shift control, and transmission rebuild procedures. Front-wheel drive comes through either the AS/MS Series axle (CTM4687) or the 700 Series axle (CTM4820), each with its own separate component reference for deep axle work.

Depending on model and emissions tier, these tractors could carry mechanical fuel injection (CTM207) or one of several electronic fuel injection levels (Level 1 through Level 12, each with its own CTM reference), reflecting the production run spanning multiple emissions regulation changes. Beyond the engine and fuel system, the manual covers the complete electrical system, drive systems (front-wheel drive clutch, differential, PTO options), hydrostatic steering and brakes including air brakes for tractors so equipped, and the hydraulic system with both standard and PFC (pressure/flow compensated) pump options. For anyone maintaining one of these eight tractor models or their SE variants, this manual has the complete factory procedures for the specific engine, transmission, and axle combination on that machine.

Table of Contents

• Section 05/10 - Safety and General Information - safety measures, specifications, tune-up
• Section 20 - Engine - engine removal and installation, repair
• Section 30 - Fuel, Air Intake, Cooling and Exhaust - speed control linkage, fuel system, cooling
• Section 40 - Electrical System - connectors, wiring harnesses, charging, monitoring systems
• Section 50/51/53/55 - Transmissions - SyncroPlus, Power Reverser, AutoPowr/IVT, PowrQuad/AutoQuad
• Section 56 - Drive Systems - front-wheel drive clutch, differential, PTO, front implement drive
• Section 60 - Steering and Brakes - hydrostatic steering, rear brakes, handbrake, air brakes
• Section 70 - Hydraulic System - controls, hydraulic pump, PFC system, valves