Part of the John Deere Repair Manuals.
Arguments about whether a 640D power train is worn out or simply out of adjustment end at a test port, and TM1441, the 438-page John Deere 640D technical manual PDF covering both the 640D and 648D skidders, is where those tests live. Wiring diagrams trace the starting, charging, parking brake and secondary steering circuits back to the battery. The hydraulic section takes the main pump, stroke control valve, surge relief valve and steering crossover relief valve from theory through diagnosis to a pressure test, and the winch closes things out the same way. Pressurize the cooling system to 69 kPa (0.7 bar) (10 psi) when you are chasing a leak, and retire a transmission pump that will not make 42 L/min (11.0 gpm) new. Most breakdowns happen with nobody around for you to ask. Bookmarked and text searchable, it points at the failed part before you phone in the order.
What's Inside This John Deere 640D Skidder & 648D Grapple Skidder Manual
| System | Pages | Key Topics |
|---|---|---|
| General Information | 7-38 | Safety Information, General Specifications, Torque Values, Fuels and Lubricants |
| Operational Checkout Procedure | 39-62 | Gauges, Indicators, Hourmeter, Park Brake Indicator, Control Lever, Linkages, Neutral Start Switch, Speed Control |
| Engine Operation and Tests | 63-110 | Theory of Operation, Diagnostic Information, Adjustments, Tests |
| Electrical Operation and Tests | 111-170 | Batteries, Starting Circuit, Starting Motor, Charging Circuit, Alternator, Parking Brake, Secondary Steering Circuit, Gauges |
| Power Train Operation and Tests | 171-294 | Theory of Operation, Diagnostic Information, Adjustments, Tests |
| Hydraulic System Operation and Tests | 295-401 | Main Hydraulic Pump, Stroke Control Valve, Hydraulic Charge Pump, Surge Relief Valve, Hydraulic Manifold, System Relief Valve, Steering Valve, Steering Crossover Relief Valve |
| Miscellaneous Components (Winch) Operation and Test | 402-438 | Theory of Operation, Diagnostic Information, Adjustments, Tests |
Quick Reference Specifications
| Specification | Value | Page |
|---|---|---|
| Blade lift cylinders (2) rod diameter | 1.75 in. (44.5 mm) | p. 20 |
| Blade lift cylinders (2) bore | 4.00 in. (101.6 mm) | p. 20 |
| Cooling System Test Pressure | 69 kPa (0.7 bar) (10 psi) | p. 102 |
| Transmission Pump Minimum Flow (New Pump) | 42 L/min (11.0 gpm) | p. 242 |
| Transmission Pump Minimum Flow (Used Pump) | 41 L/min (10.0 gpm) | p. 242 |
| Rod length adjustment | 6.4 mm (0.25 in.) | p. 235 |
| Slow idle adjustment | 800 ± 50 rpm | p. 89 |
| Intake Valve Lift | 11.68-12.45 mm (0.460-0.490 in.) | p. 97 |
| Crankshaft End Play (Not To Exceed) | 0.38 mm (0.015 in.) | p. 98 |
| Engine Oil Pressure (Slow Idle) | 100 kPa (1.0 bar) (15 psi) minimum | p. 101 |
| Fuel Transfer Pump Pressure (Minimum) | 15-30 kPa (0.15-0.3 bar) (2-4 psi) | p. 103 |
