🏷️ Basic Information

Make:

Mazda

Model:

RX-4

Year:

1975

Chassis Code:

LA2

Engine Code:

12A (Rotary)

👋 Introduction

Original Market:

Entry-level sports coupe and sedan, positioned as an affordable and stylish performance alternative, particularly appealing for its rotary engine technology.

Competitors:

Datsun 240Z/260Z, Toyota Celica, Ford Capri (in some markets), smaller European sports coupes.

Unique Selling Points:

Unique rotary engine technology (Wankel), sporty styling, good handling for its class, relatively affordable performance.

Purpose:

To provide technicians and owners with the definitive guide for maintaining, diagnosing, and repairing the 1975 Mazda RX-4.

📋 Manual Details

Overall Coverage:

Comprehensive Service and Repair

Repair Scope:

All models and all repairs A-Z

Estimated Pages:

Varies by specific print edition, typically 500+ pages for a complete factory service manual.

Type:

Factory Service Manual / Workshop Manual

Language:

English

Format:

Likely printed paper, potential for digital (PDF) versions for sale.

📖 Manual Coverage

Engine:

Rotary Engine (12A) - Disassembly, Assembly, Reassembly, Timing, Sealing, Lubrication, Cooling, Fuel Injection/Carburetion (depending on specific market/spec), Ignition, Emissions Control.

Transmission:

Manual Transmission (likely 4-speed and 5-speed options), Automatic Transmission (if applicable) - Overhaul, Adjustment, Fluid Specifications, Shifter Linkage.

Drivetrain:

Rear Axle, Driveshaft, U-Joints, Differential - Inspection, Lubrication, Repair.

Suspension:

Front Suspension (Independent, likely MacPherson struts), Rear Suspension (Live Axle, likely leaf springs or coil springs) - Component Inspection, Bushing Replacement, Shock Absorber/Strut Replacement, Alignment Specifications.

Steering:

Steering Gearbox (likely recirculating ball), Power Steering System (if equipped) - Adjustment, Repair, Fluid Types, Tie Rod Ends, Ball Joints.

Brakes:

Front Disc Brakes, Rear Drum Brakes (common for the era) - Pad/Shoe Replacement, Rotor/Drum Machining, Caliper/Wheel Cylinder Overhaul, Brake Fluid Specifications, Bleeding Procedures, Parking Brake System.

Electrical:

Battery, Alternator, Starter, Ignition System (Points/Condenser or early electronic), Lighting System, Gauges, Wiring Diagrams, Fuses, Relays, Switches, Wiper System, Horn.

Fuel System:

Carburetor(s) (likely Hitachi/Mikuni), Fuel Pump, Fuel Lines, Fuel Tank - Cleaning, Adjustment, Jetting, Diaphragm Replacement.

Cooling System:

Radiator, Water Pump, Thermostat, Hoses, Fan - Flushing, Replacement, Antifreeze Specifications.

Exhaust System:

Manifold, Pipes, Muffler, Catalytic Converter (if applicable for the market) - Inspection, Replacement.

Body And Chassis:

Frame, Body Panels, Doors, Hood, Trunk, Bumpers, Glass, Seals - Adjustment, Repair, Rust Prevention, Trim.

Interior:

Seats, Dashboard, Upholstery, Headliner, Trim - Removal, Installation, Repair.

Maintenance:

Oil Changes, Filter Replacements, Spark Plug Gap/Replacement, Tune-ups, Lubrication Points, Brake Adjustments, Tire Rotation, Coolant Flushes.

Diagnostics:

Troubleshooting charts for common symptoms, Electrical diagnostics, Engine performance issues, Brake system faults, Suspension noises.

Repair:

Engine rebuilding, Transmission overhauls, Brake component replacement, Suspension and steering linkage repair, Body panel replacement, Electrical component repair/replacement.

Adjustment:

Carburetor idle and mixture, Ignition timing, Clutch adjustment, Parking brake adjustment, Door and window alignment.

Specification Data:

Torque specifications for all fasteners, Engine clearances, Fluid capacities, Tire pressures, Alignment angles.

Depth:

Complete rebuild procedures, detailed diagnostic flowcharts, component-level repair instructions.

Audience:

Professional Technicians, Enthusiast Mechanics

📊 Manual Specifications

Digital Format:

Searchable PDF (if available), high-resolution scans.

Print Quality:

Professionally printed with clear diagrams and text (original). High-quality reproduction for aftermarket.

Binding:

Original manuals often saddle-stitched or perfect bound. Reprints typically perfect bound or coil bound for durability.

Paper Type:

Durable, high-quality paper stock to withstand shop use.

⚙️ Engine Specifications

Engine Type:

Two-Rotor Rotary (Wankel)

Engine Code:

12A

Displacement:

1146 cc (approx. 70 cubic inches)

Horsepower:

Approximately 100-110 hp (net, depending on market and specific configuration)

Torque:

Approximately 115-125 lb-ft (net, depending on market and specific configuration)

Fuel Delivery:

Dual Barrel Carburetor (e.g., Hitachi or Mikuni)

Fuel Type:

Unleaded Gasoline (91 Octane or higher recommended)

Ignition Type:

Distributor-based, points and condenser ignition (or early electronic ignition variants)

Oil Type Recommendation:

API SF or SG rated, SAE 10W-30 or 20W-50 (specific recommendations in manual, often oil-cooled rotary specific).

Coolant Type:

Ethylene Glycol based antifreeze (50/50 mix with distilled water recommended)

🔧 Transmission

Transmission Type:

4-speed Manual Transmission

Transmission Type:

3-speed Automatic Transmission (optional)

Clutch Type:

Dry single plate, hydraulically operated (manual)

Manual Transmission Fluid:

GL-4 SAE 75W-90 or 80W-90 gear oil (specific Mazda recommendation should be verified in manual).

Automatic Transmission Fluid:

Dexron III or equivalent (specific Mazda recommendation should be verified in manual).

📐 Dimensions

Body Styles:

2-door Coupe, 4-door Sedan, 5-door Station Wagon

Wheelbase:

Approx. 98.4 inches (2499 mm)

Length:

Approx. 167.1 inches (4244 mm) for Coupe/Sedan

Width:

Approx. 64.2 inches (1631 mm)

Height:

Approx. 52.6 inches (1336 mm) for Coupe

Curb Weight:

Approx. 2300-2600 lbs (1043-1179 kg), depending on body style and equipment.

Gross Vehicle Weight Rating:

Refer to vehicle data plate; typically around 3200-3500 lbs.

Wheel Bolt Pattern:

4x110mm

Tire Sizes:

Commonly 175/70R13 or 185/70R13, depending on trim level and wheel size.

🛡️ Safety Features

Crash Test Era:

Vehicles from 1975 were not subject to modern standardized crash testing (e.g., NHTSA, IIHS). Safety features were basic.

Brakes:

Front Disc, Rear Drum. Dual-circuit hydraulic system.

Steering:

Recirculating ball steering system, potentially with optional power assist.

Seat Belts:

Lap belts standard, shoulder belts available/optional on some models.

Windshield:

Laminated safety glass.

Body Structure:

Reinforced passenger compartment, crumple zones were rudimentary compared to modern standards.

💡 Technology Features

Audio System:

Basic AM/FM radio, potentially with an 8-track player or cassette adapter for aftermarket units. Speaker count typically 2-4.

Features:

No electronic driver assistance features like ABS, traction control, or airbags. Focus is on mechanical systems.

Features:

No modern connectivity features (Bluetooth, USB, etc.).

Air Conditioning:

Optional factory or dealer-installed air conditioning system, common for higher trims.

Power Features:

Power steering was often optional. Power windows and door locks were rare or limited to very high-end trims/specific markets.

🔧 Maintenance

Oil Change Interval:

Every 3,000-5,000 miles or 6 months, whichever comes first (verify in manual).

Tune Up Interval:

Every 12,000-15,000 miles or annually (includes spark plugs, points, condenser, filter checks).

Coolant Flush Interval:

Every 2 years or 30,000 miles.

Engine Oil Capacity:

Approx. 5.0-5.5 US quarts (4.7-5.2 Liters) with filter change (verify in manual).

Coolant Capacity:

Approx. 7.0-7.5 US quarts (6.6-7.1 Liters) (verify in manual).

Brake Fluid Type:

DOT 3 or DOT 4 (verify in manual).

Washer Fluid:

Standard automotive windshield washer fluid.

Rotary Apex Seals:

Wear of apex seals is a common concern in rotary engines; proper lubrication and avoiding 'lugging' the engine are critical. Manual details seal replacement.

Carburetor Tuning:

Carburetors can require frequent adjustment due to wear or environmental factors. Manual provides detailed tuning procedures.

Ignition System Maintenance:

Points and condenser require periodic inspection and adjustment/replacement. Manual covers this.

Rust And Corrosion:

Typical for vehicles of this era, particularly in areas exposed to salt. Manual may offer guidance on undercoating or rust repair.

Cooling System Maintenance:

Importance of regular flushing and inspection of hoses and radiator for optimal rotary engine operation. Manual details this.

📚 Vehicle History

Mazda Heritage:

Mazda has a long history of producing innovative vehicles, with a particular focus on rotary engine technology starting with the Cosmo.

Rx4 Introduction:

The RX-4, known as the 'Rotor' in Japan, was introduced in 1972 as a successor to the R100 (Familia Rotary). It represented Mazda's commitment to rotary power in a larger, more refined package.

Rx4 Facelift Updates:

The 1975 model year represents a significant update, often referred to as the 'Series II' or 'facelift' for the RX-4, featuring revised styling (e.g., quad headlights, new grille, updated interior).

Production Years:

1972-1978 (globally)

Manufacturing Locations:

Japan (Mazda factories)

Rotary Perception:

The RX-4 helped solidify Mazda's reputation for rotary performance, although it also faced challenges related to fuel economy and emissions in various markets.

🏆 Awards & Recognition

Rotary Pioneering:

Mazda's commitment to rotary technology itself earned significant industry recognition and innovation awards over the years.

Performance Reviews:

Contemporary automotive reviews often praised the RX-4 for its unique engine character, agile handling, and distinctive styling.