Komatsu D31E-20, D31P-20, D31PL-20, D31PLL-20, D31P-20A, D31S-20, D31Q-20, D37E-5, D37P-5A Shop Manual
Komatsu Models Covered & Key Technical Specifications
Models: D31E-20, D31P-20, D31PL-20, D31PLL-20, D31P-20A, D31S-20, D31Q-20, D37E-5, D37P-5A
Sub-models / Variants: E-series, P-series, PL-series, PLL-series, S-series, Q-series
Model Years: 1997
Serial Numbers: D31E-20 (42001–42714+), D31P-20 (45001–47617+), D31PL-20 (45001–47617+), D31PLL-20 (45001–47654+), D31P-20A (45001–47617+), D31S-20 (41001–42184+), D31Q-20 (41001–42184+), D37E-5 (3001–3731+), D37P-5A (3001–3661+)
Technical Data:
- Engine: Komatsu 6D95L-1 (D31 models), S4D102-1 (D37/D31 variants)
- Engine Type: 4-cycle, water-cooled, in-line vertical, direct injection
- Transmission: Hydroshift planetary gear type, 3-speed forward/reverse
- Max. Engine Power: 52.2 kW / 70 HP (D31), 59.6 kW / 79.9 HP (D37)
- Steering System: Dry-type, multiple-disc clutch with PPC actuation
- Operating Weight: 5,060 kg to 7,700 kg depending on model and configuration
- Hydraulic Pump: Gear type (SAL(2)-036 or SAR(2)-045 models)
- Max. Hydraulic Pressure: 17.2 MPa {175 kg/cm²}
- Coolant Capacity: 22 Liters
Komatsu Manual Features & Content Preview
- Covers 1997 Komatsu D31E, D31P, D31PL, D31PLL, D31S, D31Q, D37E, and D37P series bulldozers, including all 20-series and 5-series variants
- Original OEM publication SEBM001007, dated May 1997
- Features 671 pages of technical specifications, component logic, and factory workshop documentation structures
- Includes 12 electrical wiring diagrams and hydraulic system schematics
- Contains over 40 reference tables for standard tightening torques and lubrication capacities
Component and System Logic
Understanding the operational mechanics of the Komatsu D31 and D37 series is critical for accurate diagnostics. This factory publication breaks down the entire powertrain architecture. You get detailed functional explanations of the engine, damper, Hydroshift transmission, and steering clutch assemblies. How exactly do the modulating valve, steering control, and work equipment hydraulics interact? The text maps out these system dependencies clearly. During the inspection of disassembled parts, these subsections provide the exact logic needed to verify component integrity. Working on heavy earthmoving equipment naturally carries inherent risks. Always verify pressure readings and load limits against these official charts before initiating any testing procedures to ensure shop safety.
Technical Reference and Specification Highlights
Precise data eliminates guesswork on the shop floor. The documentation delivers extensive tables for every variant, detailing operating weights, blade capacities, and track configurations. Engine specifications explicitly list rated horsepower at 2,350 or 2,500 rpm for both the 6D95L-1 and S4D102-1 powerplants. For reassembly, mechanics can rely on cataloged torque values covering standard metric bolts, split flange bolts, and O-ring boss connectors. Fluid capacities are clearly defined. You will find the D31 series transmission oil capacity documented at 13 to 16 liters, while the final drive takes exactly 9.5 liters on the D31E, D31S, and D31Q models. Standard pump configurations require a hydraulic system pressure set strictly at 17.2 MPa. These figures serve as the definitive baseline for all maintenance routines on the undercarriage, powertrain, and hydraulic assemblies.
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