Historical Context:
The Allis-Chalmers D-21 was a powerful, high-horsepower tractor designed for heavy-duty agricultural work, competing in a market segment dominated by larger articulated tractors and robust conventional models.
Key Competitors:
During its production era, the D-21 Series II would have competed with models from John Deere (e.g., 4020, 4320), International Harvester (e.g., 806, 1206), and Case (e.g., 930, 1030).
Tractor Features:
Known for its robust construction, powerful engine, and advanced (for its time) power shift transmission, making it suitable for plowing, cultivation, and heavy draft operations.
Manual Benefit:
This WSM is essential for owners and mechanics to maintain, diagnose, and repair the D-21 Series II effectively, ensuring longevity and optimal performance of a valuable vintage tractor.
Primary Coverage:
Comprehensive service, repair, and maintenance for the Allis-Chalmers D-21 Series II Tractor
Engine Coverage:
Detailed engine overhaul, diagnostics, and component repair
Transmission Coverage:
Service and repair of power shift transmission and final drives
Hydraulic System Coverage:
Repair and maintenance of the hydraulic pump, control valve, and cylinders
Electrical System Coverage:
Wiring diagrams, component testing, and troubleshooting for the electrical system
Estimated Page Count:
Varies by specific manual edition, typically 300-500 pages for a full WSM
Manual Type:
Workshop Service Manual (WSM) / Service Repair Manual
Engine Systems:
Engine overhaul, cooling system, lubrication system, fuel system, ignition/starting system (if applicable for diesel ignition), exhaust system
Drivetrain Systems:
Clutch, power shift transmission, PTO (Power Take-Off) system, differential, final drives, axle assemblies
Hydraulic Systems:
Hydraulic pump, control valve, cylinders (3-point hitch, external hydraulics), hydraulic fluid reservoir and filters, power steering system
Electrical Systems:
Starter, alternator/generator, battery, lighting system, instrumentation, wiring diagrams
Braking Systems:
Service brakes (internal expanding shoe type), parking brake, brake pedal and linkages
Steering Systems:
Mechanical steering, hydraulic power steering components
Chassis And Body:
Frame, fenders, operator's platform, drawbar, hitches
Maintenance Procedures:
Lubrication charts, fluid change intervals, filter replacement, greasing points, pre-operation checks
Repair Procedures:
Step-by-step disassembly, assembly, inspection, and repair of all major components
Troubleshooting Guides:
Systematic diagnostic procedures for common issues and fault finding
Tune Up Procedures:
Engine tune-up specifications and adjustments
Special Tool Requirements:
Identification and usage of specialized tools required for repairs
Depth Of Coverage:
In-depth, professional-level repair and overhaul procedures, suitable for mechanics and experienced owners
Engine Make:
Allis-Chalmers
Engine Model:
Allis-Chalmers 3500 Mark II
Displacement:
301 cubic inches (4.93 Liters)
Configuration:
Inline 6-cylinder
Gross Horsepower:
Approximately 103 HP (76.8 kW) at rated governed speed
Drawbar Horsepower:
Approximately 85 HP (63.4 kW)
Torque:
Not explicitly stated in common literature, but substantial for its class.
Injection System:
Roosa-Master rotary injection pump (typical for this era)
Fuel Filter Part Number:
Refer to manual for specific AC or aftermarket equivalents (e.g., Wix 33323, Baldwin BF7736 may be compatible).
Cooling System Type:
Water Cooled
Coolant Capacity:
Refer to manual, approximately 18 quarts (17 liters).
Coolant Type:
Ethylene Glycol based antifreeze (e.g., 50/50 mix with distilled water)
Oil Type:
API CD or CE rated Diesel Engine Oil, SAE 15W-40 recommended for general use (check manual for specific viscosity based on temperature).
Oil Capacity:
Refer to manual, approximately 10 quarts (9.5 Liters) with filter change.
Oil Filter Part Number:
Refer to manual for specific AC or aftermarket equivalents (e.g., Wix 51042, Baldwin B2).
Transmission Type:
Allis-Chalmers Power Shift (4 forward and 4 reverse speeds)
Optional Transmission:
None typically offered for the D-21 Series II; Power Shift was standard.
Power Take Off:
Live PTO (540/1000 RPM), mechanically driven
Transmission Fluid Type:
Refer to manual. Typically Allis-Chalmers Type 2 or equivalent UTF (Universal Tractor Fluid) or TDTO (Transmission Drive Train Oil) meeting specified viscosity and friction properties.
Transmission Fluid Capacity:
Refer to manual, includes transmission, hydraulic system, and final drives. Approximate total capacity: 16 gallons (60.5 Liters).
Wheelbase:
Approx. 90 inches (2286 mm)
Length:
Approx. 145 inches (3683 mm) without front weights
Width:
Varies with tire size, approx. 70-80 inches (1778-2032 mm) at rear axle
Height To Exhaust:
Approx. 90 inches (2286 mm)
Operating Weight:
Approx. 10,000 - 11,500 lbs (4536 - 5216 kg) depending on configuration
Drawbar Pull Capacity:
Significant, designed for heavy draft work
Three Point Hitch Category:
Category III
Hydraulic Lift Capacity:
Refer to manual, typically in the range of 3500-4500 lbs at the link ends.
Safety Features Era:
As per 1960s/early 1970s standards; basic safety features, emphasis on operator skill and awareness.
Braking System Type:
Internal expanding shoe type, foot pedal operated, with provision for trailer brake actuation.
Parking Brake Type:
Hand-lever operated, mechanically locking brakes.
Operator Platform:
Open operator station with fenders and guards. ROPS (Roll Over Protection Structure) and seat belts were not standard equipment for this model's original production but can be retrofitted.
Lighting:
Basic front and rear lights for road use (if equipped).
Infotainment System:
N/A - This is a tractor from the 1960s/1970s; no infotainment or entertainment systems were present.
Driver Assistance Features:
N/A - Basic operator controls; no electronic driver assistance systems.
Connectivity Options:
N/A - No electronic connectivity features.
Power Shift Transmission:
A significant technological advancement for its time, allowing shifting between gears without using the clutch pedal, thus increasing productivity.
Hydraulic System:
Advanced closed-center hydraulic system (typical for Series II) providing responsive and precise control for implements.
Engine Oil Change Interval:
Refer to manual; typically 250 hours or annually for older diesel engines.
Transmission Hydraulic Fluid Change Interval:
Refer to manual; typically 500-1000 hours, or annually.
Air Filter Service:
Service as needed based on operating conditions; check daily. Typically dry element type.
Transmission Hydraulic Fluid Spec:
Allis-Chalmers Type 2 or equivalent. Consult manual for exact viscosity and API rating.
Engine Coolant Spec:
50% Ethylene Glycol and 50% distilled water with appropriate corrosion inhibitors for heavy-duty diesel engines.
Common Wear Points:
Power shift clutch packs, hydraulic pump wear, PTO clutch engagement, final drive seals, and steering components.
Electrical System Reliability:
Older wiring harnesses can degrade, leading to intermittent issues. Alternator/generator charging system can require periodic checks.
Maintenance Recommendations
Importance Of Lubrication:
Regularly greasing all specified points is critical to prevent wear on kingpins, tie rods, PTO shaft, and hitch components.
Fuel System Care:
Proper fuel filtration and bleeding of air from the system are essential for diesel engine operation.
Brand History:
Allis-Chalmers was a prominent American manufacturer of agricultural and construction machinery, known for its innovative designs, particularly its distinctive 'Persian Orange' paint scheme.
D Series Lineage:
The D-21 was the flagship model in Allis-Chalmers' D-Series tractor line, succeeding models like the D-19, offering increased power and advanced features for large-scale farming.
Production Years:
The D-21 was produced from approximately 1963 to 1969. The Series II designation indicates later production runs with updates.
Manufacturing Location:
Likely manufactured at Allis-Chalmers' tractor plant in West Allis, Wisconsin, USA.
Tractor Awards:
Specific awards for the D-21 Series II are not widely documented. Its success was measured by its performance and market acceptance as a powerful row-crop and general-purpose tractor.
Industry Recognition:
Allis-Chalmers tractors of this era were generally well-regarded for their power, durability, and innovative features, contributing to the brand's strong reputation in the agricultural sector.
