The Allis-Chalmers D-21, produced from 1963 to 1967, is a robust heavy-duty agricultural tractor designed for demanding farm work. Known for its significant pulling power and hydraulic capacity, the D-21 features a reliable inline 6-cylinder diesel engine and a durable constant mesh transmission. Its construction emphasizes longevity and versatility, allowing it to operate a wide array of implements. This tractor was a key competitor in the agricultural market, recognized for its solid engineering and ability to perform under strenuous conditions, making it a favored choice for farmers and agricultural businesses. This comprehensive Workshop Service Manual provides in-depth guidance for the maintenance, repair, and troubleshooting of the Allis-Chalmers D-21 Tractor. It covers all major systems, including detailed procedures for the engine, transmission, hydraulics, electrical systems, chassis, and power take-off. The manual includes step-by-step instructions for disassembly, overhaul, and reassembly, along with diagnostic procedures, adjustment guidelines, and testing protocols. This resource is essential for owners, mechanics, and technicians seeking to ensure the optimal performance and longevity of their D-21 tractor through accurate and thorough service practices. 🏷️ Basic Information Identification Make: Allis-Chalmers Model: D-21 Product Type: Service Manual / Repair Manual Manual Title: Allis Chalmers Model D-21 Tractor WSM Service Manual Repair PDF Download 👋 Introduction Market Position Segment: Heavy-duty agricultural tractor. Target User: Farmers, agricultural businesses, tractor restorers, mechanics specializing in vintage farm equipment. Competitive Analysis Comparison: Competed with other heavy-duty tractors from manufacturers like John Deere, International Harvester, and Ford during its production era. Key Features Power: Designed for heavy draft work, offering significant pulling power and hydraulic capacity for its time. Durability: Known for robust construction and reliability in demanding agricultural conditions. Versatility: Capable of operating a wide range of implements, including plows, cultivators, mowers, and loaders. 📋 Manual Details Coverage Areas Primary Coverage: Complete service, repair, troubleshooting, and maintenance of the Allis-Chalmers Model D-21 Tractor. Page Count Estimated Page Count: Extensive (specific count not provided, but implied as comprehensive for a WSM). Manual Type Type: Workshop Service Manual (WSM) Language Language: English Format Format: PDF Download 📖 Manual Coverage Systems Covered Engine: Detailed breakdown, overhaul, timing, fuel system, lubrication, cooling, ignition, and starting systems. Transmission: Service, repair, and adjustment of the transmission, clutch, and associated driveline components. Hydraulics: Repair and maintenance of the hydraulic system, including pump, cylinders, control valves, and fluid lines. Electrical: Wiring diagrams, troubleshooting for lighting, starting, charging, and accessory systems. Chassis: Front axle, steering, rear axle, brakes, and suspension system service. Power Takeoff: PTO engagement, operation, and repair of both independent and transmission-driven PTOs. Cooling System: Radiator, fan, thermostat, water pump, and coolant specifications and maintenance. Fuel System: Carburetor (if applicable), fuel pump, filters, injection system troubleshooting and repair. Procedures Included Maintenance: Scheduled maintenance intervals, lubrication charts, fluid changes, filter replacements. Troubleshooting: Diagnostic procedures, symptom-based troubleshooting guides, common problem identification. Repair Overhaul: Step-by-step instructions for complete disassembly, inspection, repair, and reassembly of all major components. Adjustment: Alignment, linkage adjustments, brake adjustments, clutch adjustments, and PTO adjustments. Testing: Diagnostic tests, performance checks, and calibration procedures for various systems. Technical Depth Depth: Comprehensive, covering basic maintenance to complete engine and transmission rebuilds. Diagnostics: Advanced diagnostic procedures and schematics for electrical and hydraulic systems. 📊 Manual Specifications File Format Format: PDF (Portable Document Format) Searchability: Likely text-searchable, assuming a high-quality scan or digital original. Print Quality Quality: Professional quality, in-depth. Binding Type Binding: N/A (Digital Download) Paper Type Paper: N/A (Digital Download) ⚙️ Engine Specifications Primary Engine Make Model: Allis-Chalmers 3400 Series (typically a six-cylinder diesel). Configuration: Inline 6-cylinder, naturally aspirated diesel. Displacement: Approximately 301 cubic inches (4.9 Liters) - specific displacement may vary slightly by exact engine variant. Bore X Stroke: Refer to manual for exact dimensions. Typical for this era would be around 3.875" x 4.375". Performance Horsepower Rated: Estimated 65-75 PTO horsepower (exact figures depend on engine tuning and specific model year). Torque Rated: Significant torque for heavy draft applications, specific figures available in manual. Fuel System Fuel Type: Diesel Injection System: Typically Roosa Master or similar rotary injection pump system. Cooling System Type: Water-cooled Lubrication System Type: Pressurized, forced lubrication with oil pump and filter. 🔧 Transmission Standard Type: Constant Mesh Transmission (CMT) with multiple forward and reverse gears. Gear Count: Likely 8 forward speeds and 2 reverse speeds, or similar configuration. Optional Features: Optional features might include a differential lock, creeper gears, or power adjust rear wheels depending on configuration. Features Clutch: Dual-stage or single-stage dry clutch for transmission and independent PTO engagement. Final Drive: Heavy-duty spur gear final drives. Fluid Specifications Transmission Oil Type: Refer to manual for specific API GL-4 or GL-5 lubricant specifications and viscosity grade (e.g., SAE 80W-90 or 90). 📐 Dimensions Exterior Length: Refer to manual for exact dimensions; typically around 140-150 inches. Width: Refer to manual for exact dimensions; typically around 70-80 inches at rear wheels....