🏷️ Basic Information

Make:

Mazda

Model:

RX-4

Model Years Covered:

1975

Chassis Code:

LA2

Engine Code Prefix:

12A

👋 Introduction

Historical Context:

The Mazda RX-4 represented Mazda's continued commitment to the rotary engine in the mid-1970s, offering a sporty and distinctive alternative in the compact and mid-size segments.

Key Competitors:

Competed against a range of domestic and import sedans, coupes, and hatchbacks, including models from Toyota, Datsun, Honda, Ford, Chevrolet, and Chrysler.

Distinguishing Features:

Rotary engine, unique styling, optional advanced features for its time, sporty handling characteristics.

Manual Utility:

An indispensable resource for owners and mechanics seeking to maintain, diagnose, and repair the 1975 Mazda RX-4, covering all critical systems in detail.

📋 Manual Details

Coverage Scope:

Complete official service and repair

Model Variants Covered:

All models and all engines

Estimated Page Count:

Refer to actual manual for exact count

Manual Type:

Service and Repair Manual

Language:

English

Format:

PDF

📖 Manual Coverage

Engine:

Rotary engine (12A) - principles, disassembly, assembly, troubleshooting, diagnostics

Fuel System:

Carburetion (e.g., Hitachi, Nikki), fuel pump, fuel lines, emission controls

Ignition System:

Distributor, ignition coils, spark plugs, timing adjustments

Cooling System:

Radiator, water pump, thermostat, hoses, coolant specifications

Lubrication System:

Oil pump, oil passages, oil specifications, oil filter replacement

Transmission:

Manual and Automatic transmission - overhaul, fluid specifications, torque specifications

Drivetrain:

Driveshafts, U-joints, differential, axle seals

Suspension:

Front and rear suspension components, shock absorbers, springs, bushings, alignment specifications

Steering:

Steering column, steering gear, power steering system (if equipped), components, fluid

Brakes:

Front and rear disc/drum brakes, brake master cylinder, wheel cylinders, brake lines, fluid specifications, bleeding procedures

Electrical System:

Battery, alternator, starter motor, wiring diagrams, lighting, fuses, relays, switches

Body And Chassis:

Body panel removal/installation, interior trim, glass, doors, hinges, latches, body repair principles

Heating And Air Conditioning:

HVAC system components, refrigerant handling (if applicable), controls, diagnosis

Emission Control Systems:

PCV system, exhaust gas recirculation (EGR), thermal reactors, catalytic converters (depending on market), emission testing procedures

Maintenance Procedures:

Oil changes, filter replacements, spark plug service, fluid level checks, belt adjustments, lubrication points

Troubleshooting Guides:

System-specific diagnostic flowcharts, symptom-based troubleshooting

Repair Procedures:

Detailed step-by-step instructions for component removal, disassembly, inspection, repair, and reassembly

Overhaul Procedures:

Complete engine and transmission rebuild instructions

Wiring Diagrams:

Comprehensive electrical system wiring schematics

Diagnostic Procedures:

Tools and techniques for diagnosing faults

Torque Specifications:

Detailed torque values for critical fasteners across all systems

Clearances And Tolerances:

Specifications for internal engine clearances, bearing tolerances, etc.

Depth Of Coverage:

Comprehensive, from basic maintenance to complete engine rebuilds and system overhauls

Diagnostic Focus:

Detailed troubleshooting steps and diagnostic flowcharts for common and uncommon issues

Component Level Detail:

In-depth coverage of individual component disassembly, inspection, and repair

📊 Manual Specifications

File Type:

PDF

Searchability:

Searchable text (typically)

Image Resolution:

High-resolution scans, suitable for printing

Binding Type Digital:

N/A (Digital format)

Paper Type Digital:

N/A (Digital format)

⚙️ Engine Specifications

Engine Type:

Two-rotor Wankel Rotary

Engine Code:

12A

Displacement Cc:

1146 cc (nominal)

Displacement Ci:

69.9 ci (nominal)

Rotor Housing Design:

Epitrochoid

Horsepower Gross:

Approx. 90-100 hp (varies by market and emissions equipment)

Torque Gross:

Approx. 100-110 lb-ft (varies by market and emissions equipment)

Carburetor Type:

Single or Two-barrel downdraft carburetor (e.g., Hitachi, Nikki) - specific types detailed in manual

Fuel Type:

Unleaded gasoline (premium recommended)

Fuel Pump Type:

Mechanical

🔧 Transmission

Transmission Type Standard:

4-speed Manual Transmission

Transmission Type Optional:

3-speed Automatic Transmission

Transmission Fluid Type:

Dexron II (or equivalent) for automatic; GL-4 gear oil for manual. Specifics in manual.

Clutch Type:

Dry single plate (manual transmission)

📐 Dimensions

Wheelbase In:

Approx. 98.2 inches

Length In:

Approx. 170.5 inches

Width In:

Approx. 65.0 inches

Height In:

Approx. 53.0 inches (coupe)

Curb Weight Lbs:

Approx. 2400-2600 lbs (varies by body style and equipment)

Gross Vehicle Weight Rating Lbs:

Refer to VIN plate or manual

Trailer Towing Capacity:

Not specified by manufacturer for this model.

🛡️ Safety Features

Crash Test Data:

No formal NHTSA or IIHS ratings available for this era; consult manual for structural integrity information.

Braking System:

Front Disc, Rear Drum standard; potential for 4-wheel disc on some higher trims/markets.

Parking Brake:

Mechanical, rear wheel

Seat Belts:

Standard lap and shoulder belts (front), lap belts (rear)

Steering Column:

Collapsible steering column for improved impact absorption.

💡 Technology Features

Audio System:

Factory AM/FM radio, optional AM/FM/8-track player. Manual may cover basic troubleshooting.

ABS:

Anti-lock Braking System not available on this model.

Cruise Control:

Optional on some higher trim levels. Manual will cover its operation and basic troubleshooting.

Power Windows Locks:

Optional on higher trims. Manual covers electrical systems for these features.

🔧 Maintenance

Oil Change Interval Miles:

Typically 3,000 miles (refer to manual for exact specification)

Spark Plug Replacement Miles:

Refer to manual; rotary plugs have specific intervals.

Transmission Fluid Change Miles:

Typically 20,000-30,000 miles. Specifics in manual.

Engine Oil Type:

API SF or SG rated oil, SAE 10W-30 or 10W-40. Crucially, rotary engines require oil injection into the fuel or intake manifold for apex seal lubrication. Manual will detail this system and oil type (e.g., specific rotary pre-mix or injection oil).

Coolant Type:

Ethylene Glycol based antifreeze (50/50 mix with distilled water). Manual will specify capacity and type.

Brake Fluid Type:

DOT 3 or DOT 4.

Rotary Engine Apex Seals:

Wear or failure of apex seals is a common concern in older rotary engines, leading to loss of compression and power. Proper maintenance and oiling are critical.

Carbon Buildup:

Carbon deposits can accumulate in the rotor housings and exhaust ports, requiring periodic cleaning or decarbonization.

Carburetor Issues:

Carburetors can become gummed up or misadjusted over time, affecting idle and performance.

Thermal Reactor Maintenance:

Early emission control systems like thermal reactors require specific maintenance and can be prone to failure or clogging.

📚 Vehicle History

Mazda Rotary Legacy:

Mazda's pioneering and persistent development of the Wankel rotary engine, starting with the Cosmo.

Predecessors:

Mazda R100 (Rotary Coupe), Capella Rotary.

Successors:

Mazda RX-7 (first generation SA/FB).

Production Years:

1972-1977 (RX-4 designation largely for export markets, internally known as the Luce AP in Japan).

Production Locations:

Japan

🏆 Awards & Recognition

General Reputation:

Praised for its innovative rotary engine and sporty driving dynamics, establishing Mazda's reputation for unique engineering.

Consumer Reports Historical:

Reviews from the era often highlighted its performance and unique engine, but also noted potential maintenance complexities associated with rotary engines.

Manual Certification:

Official Mazda factory service manual, representing the highest standard of technical documentation for the vehicle.