Part of the John Deere Repair Manuals.
Looking for a John Deere JD646 technical manual PDF you can actually trust? This 309-page factory technical manual (OEM TM-1073) walks you through the whole JD646 Compactor: engine, fuel system, power train, steering, brakes, and loader hydraulics. Inside you get the full machine electrical schematic with numbered wiring charts, wire colors and routing, hydraulic circuit diagrams for the loader and the power steering with pressure testing and diagnosis, and exploded views that show exactly how every assembly comes apart. Troubleshooting charts run from the basic engine through the Robert Bosch injection nozzles to the transmission and differentials. Set engine oil pressure between 40 and 55 psi, torque the rocker arm clamp cap screws to 55 ft-lbs, and pull the camshaft gear cap screw to 85 ft-lbs. Forum threads won't rebuild your differential. Bookmarked and keyword-searchable; open it on any device and take it straight to the machine.
What's Inside This Manual
| System | Pages | Key Topics |
|---|---|---|
| General | 7-30 | Predelivery, Delivery, And After-Sale Services, Tune-Up and Adjustment, Lubrication, Compactor Separation, Specifications |
| Engine | 31-68 | Diagnosis, Basic Engine, Engine Lubrication, Speed Control Linkage, Engine Cooling |
| Fuel System | 69-90 | System Diagnosis; Tank, Filters and Transfer Pump; Air Intake System; Fuel Injection Pump; Robert Bosch Injection Nozzles |
| Electrical System | 91-130 | Charging Circuit, Starting Circuit, Gauges and Switches, Wiring Diagrams |
| Power Train | 131-196 | Damper Assembly and Drive Shafts, Axle Assemblies, Differentials, Transmission Assembly, System Diagnosis |
| Power Steering and Brake Systems | 197-252 | General Information, Testing and Diagnosis; Hydraulic Pump; Filters, Oil Cooler and Accumulators; Steering System; Brake System |
| Hydraulic System | 253-286 | Reservoir and Filters, Return-to-Dig Valve, Cylinders, Control Valve, Hydraulic Pump |
| Miscellaneous Components | 287-309 | Frames, Buckets, Multi-Purpose Bucket, Demolition Wheels |
Every system also includes specifications and special tools.
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| Rocker arm clamp cap screws | 55 ft-lbs | p. 39 |
| Camshaft thrust plate cap screws | 20 ft-lbs | p. 41 |
| Engine oil pressure | 40 - 55 psi | p. 51 |
| Oil filter bypass valve spring free length | 3-3/8 in. | p. 66 |
| Air cleaner primary element replacement interval | 1 year | p. 76 |
| Intake manifold pressure | 12 to 15 psi | p. 78 |
| Battery voltage | 12 volts | p. 100 |
| Battery BCI group | 30H | p. 100 |
| Alternator through bolts torque | 50 to 60 in-lbs | p. 107 |
| Starting circuit relay 5/16 inch terminal nuts torque | 35 in-lbs | p. 127 |
| Rear output flange nut torque | 600 to 700 lb-ft (814 to 949 N-m) | p. 169 |
