🏷️ Basic Information

Make:

Mazda

Model:

RX-4

Year:

1974

Product Name:

1974 Mazda RX-4 Service and Repair Manual

Chassis Codes:

LA2

Engine Codes:

Mazda 12A (Rotary)

👋 Introduction

Market Segment:

Compact sports coupe/sedan, positioned as a stylish and performance-oriented vehicle with unique rotary engine technology.

Key Competitors:

Datsun 240Z, Toyota Celica, Ford Capri, various European sporty coupes of the era.

Unique Selling Proposition:

Mazda's revolutionary Wankel rotary engine, offering a compact, smooth, and high-revving alternative to conventional piston engines. Distinctive styling.

Technician Grade Info:

Exact same manual used by dealership technicians, providing unparalleled accuracy and completeness for maintenance, diagnosis, and repair.

Specificity:

Vehicle-specific information, not generic repair data, ensuring correct procedures and specifications for the 1974 RX-4.

📋 Manual Details

Coverage Scope:

All models and all repairs A-Z

Page Count:

Detailed, extensive (specific page count not provided in product info, but described as comprehensive for technicians)

Manual Type:

Factory Service Manual / Repair Manual

Language:

English

Format:

Print (implied by technician use and comprehensive nature)

📖 Manual Coverage

Engine Systems:

Rotary engine (12A), lubrication, cooling, fuel injection (if applicable for 1974, though carburetors were more common), ignition, exhaust, emissions control

Transmission Systems:

Manual transmission, automatic transmission (if equipped), clutch, drivetrain, driveshafts, rear axle

Chassis Systems:

Suspension (front and rear), steering system, braking system (hydraulic, disc/drum configurations), wheels, tires

Electrical Systems:

Wiring diagrams, charging system (alternator), starting system, lighting, instrumentation, accessories, fuses, relays

Body And Trim:

Body panels, doors, glass, interior trim, bumpers, chassis lubrication points

Maintenance Procedures:

Routine checks, fluid changes, filter replacements, lubrication, tune-ups

Diagnostic Procedures:

Troubleshooting guides, symptom-based diagnostics, specific repair procedures for common faults

Repair Procedures:

Engine rebuilds, transmission overhauls, brake caliper service, electrical component replacement, body repair techniques

Adjustment Procedures:

Ignition timing, carburetor adjustments, clutch adjustment, brake shoe adjustment

Diagnostic Level:

Advanced diagnostics, component testing, specifications for troubleshooting

Rebuild Level:

Complete engine and transmission rebuild procedures, component disassembly and reassembly with torque specifications

Specification Detail:

Comprehensive technical data, including tolerances, clearances, pressures, and electrical specifications

📊 Manual Specifications

File Format Type:

Print

Print Quality:

High-quality factory printing (assumed)

Binding Type:

Stapled or perfect bound (typical for factory manuals)

Paper Type:

Durable, glossy or matte paper stock (typical for workshop manuals)

⚙️ Engine Specifications

Engine Type:

Rotary (Wankel)

Engine Code:

Mazda 12A

Displacement:

1146 cc (equivalent rotary displacement)

Rotor Housing Shape:

Epitrochoid

Horsepower:

Approx. 100-110 hp (SAE Gross) depending on specific tuning and market.

Torque:

Approx. 110-120 lb-ft (SAE Gross) depending on specific tuning and market.

Redline:

Approx. 7000 RPM

Fuel Delivery:

Two downdraft carburetors (e.g., Hitachi, Mikuni)

Fuel Type:

Unleaded gasoline (required for emissions equipment, though leaded was still prevalent)

Ignition Type:

Distributor-based, dual ignition system (two spark plugs per rotor housing)

Cooling Method:

Water-cooled (with recirculating oil for apex seals)

Oil Type:

Specific rotary engine oil blend (e.g., SAE 20W-50, often with API SF or SG rating, depending on manual specification). Crucial for apex seal lubrication. Manual will specify exact type and quantity.

Oil Capacity:

Approx. 5-6 quarts (including oil cooler and filter). Exact specification in manual.

🔧 Transmission

Type:

4-speed manual

Type:

3-speed automatic (e.g., Mazda 'JATCO' 3N71B)

Clutch Type:

Single dry plate (for manual)

Transmission Fluid Type:

Dexron II or equivalent automatic transmission fluid (for automatic); Gear oil GL-4 SAE 80W-90 for manual. Manual will specify exact type and capacity.

📐 Dimensions

Wheelbase:

Approx. 98.4 inches (2500 mm)

Length:

Approx. 168.5 inches (4280 mm)

Width:

Approx. 65.4 inches (1660 mm)

Height:

Approx. 51.6 inches (1310 mm)

Curb Weight:

Approx. 2200-2400 lbs (1000-1100 kg) depending on body style and equipment.

Wheel Size:

13-inch or 14-inch steel wheels with hubcaps.

Tire Sizes:

Commonly 175/70R13, 185/70R13, or 185/70R14. Manual will confirm original equipment sizes.

Bolt Pattern:

4x114.3 mm (4x4.5 inches)

🛡️ Safety Features

Crash Test Data:

Limited official crash test data available for this era and specific model from major agencies. Manual will focus on mechanical safety systems.

Braking System:

Front disc brakes, rear drum brakes. Dual hydraulic circuits for safety. Manual details system checks and service.

Steering System:

Recirculating ball steering. Manual covers linkage checks, adjustment, and fluid replacement (if power steering equipped).

Seat Belts:

Lap and shoulder belts (front), lap belts (rear) as standard equipment. Manual covers inspection and adjustment.

Body Structure:

Unitized body construction with integrated safety cage elements.

💡 Technology Features

Audio System:

Basic AM/FM radio with analog tuning, potentially with a single speaker. Manual covers removal, installation, and basic troubleshooting of radio components.

Gauges And Instruments:

Analog gauges for speedometer, tachometer (rotary engines have unique tachometer characteristics), fuel level, coolant temperature, and oil pressure. Manual details instrument cluster removal and repair.

Vintage Tech:

Minimal connectivity features typical of the era. Focus is on mechanical and electrical systems for operational integrity.

🔧 Maintenance

Oil Change:

Typically every 3,000 miles or 3 months. Manual will provide precise recommendations, especially considering rotary engine oil consumption.

Spark Plug Replacement:

Refer to manual for specific mileage. Rotary engines use specific spark plug types and require precise gap settings.

Filter Replacement:

Oil filter: With every oil change. Air filter: Per manual recommendations (e.g., every 12,000-15,000 miles).

Timing Belt Chain:

Rotary engines do not have traditional timing belts or chains; they use internal timing gears. Manual will cover inspection of rotating elements and associated components.

Engine Oil:

Specific rotary engine oil blend, SAE 20W-50 (likely). Refer to manual for exact API rating and quantity.

Coolant:

Ethylene glycol-based antifreeze, 50/50 mix with distilled water. Manual will specify type and capacity.

Brake Fluid:

DOT 3 or DOT 4 hydraulic brake fluid. Manual will specify type and capacity for the reservoir.

Transmission Fluid:

Manual: GL-4 SAE 80W-90 gear oil. Automatic: Dexron II or equivalent ATF. Manual will specify exact type and capacity.

Rotary Engine Apex Seals:

Wear on apex seals is a common concern in high-mileage rotary engines, leading to loss of compression and power. The manual details diagnostic procedures and replacement.

Carburetor Issues:

Carburetors can require frequent adjustment and rebuilding due to their complexity and sensitivity to fuel quality and intake air conditions. Manual provides adjustment and overhaul procedures.

Oil Consumption:

Rotary engines naturally consume some oil as part of their lubrication system. Excessive consumption may indicate seal wear. Manual explains normal vs. abnormal consumption.

Cooling System Overheating:

Overheating can be an issue if the cooling system (radiator, water pump, thermostat) is not maintained. The manual details inspection and replacement of cooling system components.

📚 Vehicle History

Mazda Rotary Development:

Mazda's commitment to the Wankel rotary engine began in the 1960s, leading to innovations like the Cosmo and R100, culminating in the RX series.

Predecessors:

Mazda R100 (Familia Rotary)

Successors:

Mazda RX-5 (SA22C, later RX-7)

Production Years:

1972-1977

Manufacturing Location:

Japan

Available Styles:

Coupe, Sedan, Hardtop Coupe

🏆 Awards & Recognition

Rotary Engine Recognition:

The Wankel rotary engine itself received considerable attention and awards for innovation during its development and early adoption by Mazda.

Period Reviews:

The RX-4 was generally well-received for its unique powertrain, sporty handling, and stylish design in period reviews. Specific awards are less common than overall positive critical reception.