🏷️ Basic Information

Make:

Mazda

Model:

RX3

Year:

1975

Chassis Code:

S102A (Coupe), S124A (Sedan), S132A (Wagon)

👋 Introduction

Market Position:

The 1975 Mazda RX3 was a significant model for Mazda, particularly in introducing their rotary engine technology to a wider global audience. It was positioned as a stylish and sporty compact car, often appealing to enthusiasts seeking an alternative to conventional piston engines.

Competitive Analysis:

Competed against other compact sporty cars of the era such as the Toyota Corolla, Datsun 710, and Ford Pinto. Its primary differentiator was the unique rotary (Wankel) engine, offering a smooth and high-revving experience.

Key Features:

Rotary Engine (unique selling proposition), RWD platform, stylish coupe, sedan, and wagon body styles, relatively affordable entry into sporty motoring.

Engine Type Distinctiveness:

The rotary engine offers a high power-to-weight ratio and smooth operation compared to piston engines of similar displacement.

📋 Manual Details

Coverage Areas:

Engine, Emission Control System, Lubricating System, Cooling system, Fuel system, Electrical System, Clutch, Transmission, Propeller Shaft, Steering, Brakes, Suspension, Body, and more.

Page Count:

Estimated 500+ pages (typical for factory service manuals of this era)

Manual Type:

Factory Service & Repair Manual

Manual Classification:

Comprehensive workshop manual, designed for professional technicians and advanced DIY enthusiasts.

Language:

English

Format:

PDF Download

📖 Manual Coverage

Systems Covered:

Engine Mechanical, Engine Electrical, Fuel System (including carburetion), Ignition System, Lubrication System, Cooling System, Emission Control Systems (relevant to 1975 standards), Clutch System, Manual Transmission (4-speed and 5-speed), Automatic Transmission (optional), Driveshaft, Rear Axle, Steering System, Front Suspension, Rear Suspension, Brake System (disc front, drum rear), Electrical Components (lighting, wipers, horn, instrumentation), Body and Chassis, Interior Trim, HVAC System (if equipped).

Procedures Included:

Routine Maintenance, Scheduled Maintenance, Troubleshooting of Common Problems, Component Removal and Installation, Component Disassembly and Reassembly, Adjustment Procedures, Torque Specifications, Wiring Diagrams, Vacuum Diagrams, Diagnostic Procedures, Overhaul Procedures, Component Testing, Wheel Alignment Specifications, Brake Bleeding Procedures, Clutch Adjustment, Engine Tune-Up.

Body Repair:

Basic body repair procedures, panel alignment, trim removal and installation, glass replacement guidance.

Technical Depth:

Comprehensive, covering everything from basic fluid changes and tune-ups to complete engine rebuilds, transmission overhauls, and detailed electrical system diagnostics. Includes step-by-step instructions and detailed diagrams for most workshop procedures.

Diagnostic Procedures:

Includes specific diagnostic flowcharts and troubleshooting guides for common drivability issues and electrical faults.

Diagrams Included:

Detailed wiring diagrams, vacuum schematics, exploded views of components, torque sequence diagrams.

📊 Manual Specifications

File Format:

PDF

Searchable Text:

Likely includes searchable text within the PDF, aiding in quick information retrieval.

Print Quality:

Digital PDF, quality of original factory documentation.

Binding Type:

Not Applicable (Digital Download)

Paper Type:

Not Applicable (Digital Download)

Compatibility:

Compatible with all versions of Windows & Mac.

Requirements:

Adobe PDF Reader.

⚙️ Engine Specifications

Primary Engine:

Mazda 13B Rotary (Two-Rotor Wankel)

Displacement:

1.3 Liters (79.1 cu in)

Horsepower:

Approx. 110-125 HP (varies by market and specific engine tune, e.g., US models often had lower output due to emissions)

Torque:

Approx. 117-135 lb-ft

Fuel System:

Twin Downdraft Carburetor (e.g., Hitachi SH20 or similar).

Fuel Type:

Unleaded gasoline (typically 91 octane or higher recommended for optimal performance and longevity).

Rotor Design:

Apex seals, side seals, corner seals.

Lubrication System:

Wet sump, oil cooler often integrated.

Ignition System:

Distributor-based, dual ignition coils (one per spark plug per rotor housing for optimal combustion timing).

Emissions Control:

Air injection system, exhaust gas recirculation (EGR), thermal reactor (depending on market). Manual provides specific details on these systems.

Engine Mounting:

Engine and transmission mounted as a single unit with rubber isolation mounts.

0 60 Mph:

Approx. 9-11 seconds (depending on transmission and driver).

🔧 Transmission

Standard Transmission:

4-speed Manual

Optional Transmission:

3-speed Automatic (less common)

Features:

Rear-wheel drive, synchromesh on all forward gears.

Gear Ratios:

Specific gear ratios for 4-speed and optional 3-speed automatic are detailed in the manual.

📐 Dimensions

Wheelbase:

Approx. 95.5 inches

Length:

Approx. 162.8 inches (Coupe)

Width:

Approx. 63.2 inches

Height:

Approx. 52.6 inches (Coupe)

Track Width Front:

Approx. 52.2 inches

Track Width Rear:

Approx. 51.6 inches

Curb Weight:

Approx. 2,100 - 2,300 lbs

Gross Vehicle Weight Rating:

GVWR specified in manual, typically around 3,000 lbs.

🛡️ Safety Features

Safety Ratings:

Not rated by modern standards; typical safety features for the era.

Active Features:

Front Disc Brakes, Rear Drum Brakes, Limited-slip differential (optional on some performance variants).

Passive Features:

Lap belts, padded dashboard, crumple zones (early development).

💡 Technology Features

Infotainment System:

Basic AM/FM radio, possibly with cassette player (optional, depending on trim and market). No advanced infotainment features.

Driver Assistance Features:

None. This era predates modern driver assistance technologies.

Connectivity Options:

None. No Bluetooth, USB, or auxiliary inputs.

🔧 Maintenance

Service Intervals:

Oil changes every 3,000 miles or 3 months. Spark plug inspection/replacement every 15,000 miles. Apex seal inspection and lubrication (specific procedures in manual). Regular lubrication of suspension and steering components.

Spark Plug Type:

Specific rotary spark plug types (e.g., NGK) and gap specifications detailed in manual. Dual plugs per rotor housing.

Engine Oil Type:

API SF/SG, SAE 10W-30 or 10W-40 (check manual for exact specifications, specific rotary engine oil additives may be recommended).

Coolant Type:

Ethylene Glycol based coolant, typically a 50/50 mix with distilled water. Check manual for specific capacity.

Transmission Fluid Type:

Dexron II or equivalent (for automatic), Gear Oil SAE 75W-90 or 80W-90 GL-4 for manual.

Brake Fluid Type:

DOT 3

Known Issues:

Apex seal wear (leading to loss of compression), rotor housing wear, oil seal failures, carburetor tuning difficulties, potential for overheating if cooling system is not meticulously maintained, electrical gremlins typical of older vehicles.

Carburetor Idiosyncrasies:

Diaphragms in carburetors are prone to failure over time, affecting fuel delivery and idle quality.

Special Tools:

Rotary compression tester, specialized seal installation tools, timing light, carburetor synchronization tools.

Engine Tuning Procedures:

Detailed procedures for setting ignition timing, idle speed, and carburetor mixture adjustments.

Brake System Maintenance:

Front disc pad replacement, caliper service, rear drum shoe adjustment and replacement, brake fluid flushing.

Engine Oil Capacity:

Approx. 5.2 US quarts (with filter). Check manual for exact capacity.

Cooling System Capacity:

Approx. 7.0 US quarts. Check manual for exact capacity.

📚 Vehicle History

Brand Heritage:

Mazda's history is deeply intertwined with the development of the Wankel rotary engine, a technology few manufacturers pursued due to its complexity and unique characteristics. The RX series cemented Mazda's reputation for engineering innovation.

Model Evolution:

The RX3 (S102/S124/S132) succeeded the RX2 and was part of Mazda's early rotary-powered passenger car line-up, which also included the RX4 and later the RX7. It represented an evolution in styling and refinement over its predecessors.

Design Philosophy:

Mazda's commitment to rotary power as a viable alternative to conventional piston engines drove the development and refinement of the RX3.

Production Years:

1971-1978 (RX3 designation primarily used until 1977, then phased into Mazda 818/Mizer in some markets)

Manufacturing Locations:

Japan

Motorsport History:

The RX3 platform was successful in various forms of motorsport, particularly in touring car racing and rallying, showcasing the durability and performance potential of the rotary engine.

🏆 Awards & Recognition

Recognitions:

While specific awards for the 1975 RX3 are not widely documented, it received critical acclaim for its innovative rotary engine and sporty performance, contributing to Mazda's growing reputation in the automotive industry.