🏷️ Basic Information

Make:

Chevrolet

Model:

Corvette

Year:

1975

Engine Type:

350ci V8

Vin Start Digit:

1Z87

Factory Engine Code:

LM1 (350ci V8)

👋 Introduction

Positioning:

The 1975 Corvette represented a significant evolution in the C3 generation, focusing on comfort and refined performance following the oil crisis and stringent emissions regulations. This model year marked the end of the convertible option and continued the transition towards more contemporary automotive design and engineering.

Competitors:

Key competitors in the sports car segment for 1975 included the Ford Mustang (particularly higher performance variants), the Pontiac Firebird/Trans Am, and various European sports cars like the Jaguar E-Type (though in its final years) and Porsche 911.

Value Proposition:

This workshop manual is an indispensable tool for any owner or restorer of the 1975 Corvette. It provides the most accurate and detailed factory-level information for diagnosis, repair, and maintenance, ensuring the vehicle is kept in optimal condition or restored to its original specifications.

Diagnostic Focus:

Emphasis on practical, hands-on troubleshooting and repair procedures essential for maintaining a classic vehicle.

📋 Manual Details

All Models Trims Engines:

Yes

Transmission Types Covered:

All (Manual and Automatic)

Estimated Page Count:

Comprehensive (typically 500+ pages for factory service manuals)

Type:

Workshop Repair Service Manual

Language:

English

Format:

PDF Download

📖 Manual Coverage

Engine Mechanical:

Engine overhaul, internal component inspection and repair, cylinder head assembly, piston and connecting rod installation, crankshaft and bearing service, oil pump and lubrication system.

Fuel System:

Carburetor (Quadrajet) specifications, adjustments, and overhaul. Fuel pump, fuel lines, and fuel tank service.

Ignition System:

Distributor service, ignition timing, spark plug specifications, coil and wiring diagnostics.

Cooling System:

Radiator, water pump, thermostat, fan, and coolant specifications. Overheating diagnosis and repair.

Exhaust System:

Exhaust manifold, pipes, mufflers, and catalytic converter (if applicable for export/specific markets) replacement and repair.

Transmission Manual:

Muncie SM465 (if applicable, though less common in Corvettes) or other contemporaneous manual transmissions; clutch service, transmission overhaul, gearshift linkage adjustment.

Transmission Automatic:

Turbo Hydramatic 350 (THM350) specifications, adjustments, overhaul procedures, and fluid service.

Drivetrain:

Driveshaft, universal joints, rear axle assembly, differential service, and half-shaft inspection.

Suspension Front:

Independent front suspension service, ball joint replacement, control arm bushings, coil spring replacement, shock absorber installation, steering knuckle service.

Suspension Rear:

Independent rear suspension service, transverse leaf spring replacement, trailing arm bushings, shock absorber installation.

Brakes:

Front and rear brake system diagnosis and repair, power brake booster service, master cylinder replacement, brake caliper and pad replacement, brake rotor service, parking brake adjustment.

Steering:

Power steering system service, steering gearbox overhaul and adjustment, tie rod end replacement, steering column service.

Electrical System:

Battery service, charging system (alternator, voltage regulator), starting system (starter motor), lighting system, ignition switch, fuses, wiring diagrams, instrument cluster service, power windows, power locks (if equipped).

Body Exterior:

Door panel removal, hood latch service, bumper alignment, exterior trim removal and installation, glass replacement.

Body Interior:

Seat removal and installation, dashboard disassembly, carpet replacement, headliner service.

HVAC:

Heater core replacement, blower motor service, air conditioning system (if equipped) component identification and basic service, ducting inspection.

Scheduled Maintenance:

Detailed service intervals for oil changes, filter replacements, fluid checks, and tune-ups.

Troubleshooting:

System-specific diagnostic charts, symptom-based troubleshooting guides for common driveability issues, electrical gremlins, and mechanical failures.

Disassembly Reassembly:

Step-by-step instructions for component removal, disassembly, inspection, repair, and reassembly for major vehicle systems.

Diagnostic Procedures:

Guidance on using diagnostic tools (where applicable for the era), checking for vacuum leaks, electrical circuit testing, and engine performance analysis.

Adjustment Procedures:

Precise instructions for adjusting carburetor idle speed and mixture, ignition timing, clutch pedal free play, and parking brake.

Specifications Tolerances:

Critical torque specifications, factory clearances, wear limits, and measurement procedures for all major components.

Depth:

Comprehensive, covering everything from basic fluid checks and filter changes to complete engine and transmission overhauls, and detailed electrical system diagnostics.

Target Audience:

Professional mechanics, experienced DIY enthusiasts, and restorers.

📊 Manual Specifications

PDF Quality:

High-resolution scans for clarity, typically searchable text if OCR processed.

Printable:

Yes, designed to be printed for workshop use.

Original Binding:

Typically perfect bound or spiral bound for workshop manuals.

Original Paper Type:

Heavy-duty paper stock, often glossy or semi-gloss, designed for durability in a shop environment.

⚙️ Engine Specifications

Engine Code:

LM1

Displacement:

350 cubic inches (5.7 Liters)

Configuration:

V8, OHV (Overhead Valve)

Horsepower Net:

165 hp @ 4,000 rpm ( SAE Net rating, significantly impacted by emissions controls)

Torque Net:

265 lb-ft @ 2,000 rpm (SAE Net)

Carburetor:

Rochester Quadrajet 4-barrel

Fuel Type:

Unleaded Regular (87 octane minimum, as mandated by federal regulations)

Coolant Type:

GM Delco-Remy recommendation: 50/50 mix of ethylene glycol antifreeze and clean water.

Oil Type Capacity:

SAE 10W-40 or 10W-30 recommended; 5 US quarts (4.7 Liters) with filter change.

Ignition Timing Initial:

Typically 4 degrees BTDC (Before Top Dead Center) at idle, with vacuum advance connected.

🔧 Transmission

Transmission Type:

Turbo Hydramatic 350 (THM350) 3-speed automatic was standard on most models. A 4-speed manual transmission (e.g., Muncie M21/M22 variants were phased out or less common, with some potentially using Saginaw variants) was optional but increasingly rare.

Optional Transmission:

4-speed Manual Transmission

Automatic Transmission Fluid:

Dexron III (or equivalent specification of the era) for THM350. Capacity: approximately 10 US quarts (9.5 Liters) for a full refill.

Manual Transmission Fluid:

GL-4 gear oil, typically SAE 80W-90. Capacity varies by specific transmission model.

📐 Dimensions

Length:

Approximately 190.5 inches (4839 mm)

Width:

Approximately 70.8 inches (1798 mm)

Height:

Approximately 48.0 inches (1219 mm)

Wheelbase:

98.0 inches (2489 mm)

Curb Weight:

Approximately 3,358 - 3,641 lbs (1523 - 1652 kg), depending on options.

Gross Vehicle Weight Rating:

Not typically specified as a distinct GVWR for sports cars of this era, but generally around 4,000 lbs (1814 kg).

🛡️ Safety Features

Crash Test Data:

Official NHTSA crash test data for 1975 models is limited and not directly comparable to modern standards. However, the C3 Corvette featured a strong chassis and body structure for its time.

Braking System:

Standard power-assisted front disc brakes and rear disc brakes. Optional power steering.

Seatbelts:

Standard 3-point seatbelts (lap and shoulder).

Steering Column:

Collapsible steering column for improved impact protection.

💡 Technology Features

Audio System:

Factory AM/FM radio, often with an 8-track tape player option. Speaker configurations varied but typically included front and rear speakers.

Cruise Control:

Optional cruise control system available on some models.

Power Steering:

Standard on most models to aid maneuverability.

Connectivity Features:

No modern electronic connectivity features (Bluetooth, USB, etc.). Communication relies on analog systems.

🔧 Maintenance

Oil Change Interval:

Every 3,000 miles or 6 months, whichever comes first. However, classic car best practices often suggest more frequent changes (e.g., 2,500 miles) if used for short trips or under strenuous conditions.

Tune Up Interval:

Every 12,000 miles or 12 months, including spark plug replacement, distributor cap and rotor inspection, ignition timing adjustment, and carburetor adjustment.

Transmission Fluid Change:

Automatic: Every 24,000 miles or 24 months. Manual: Check and top off as needed, change every 48,000 miles or 48 months.

Brake Fluid:

DOT 3 or DOT 4 hydraulic brake fluid.

Power Steering Fluid:

GM Power Steering Fluid (or Dexron II/III compatible fluid).

Carburetor Problems:

Rochester Quadrajet carburetors can be prone to leaks from the choke housing, accelerator pump diaphragm failures, and clogged idle circuits, requiring regular cleaning and adjustment.

Fiberglass Body Issues:

Fiberglass body panels can develop stress cracks, especially around stress points like wheel wells and door openings. Imperfect repairs can lead to delamination.

Electrical Gremlins:

Aging wiring harnesses, faulty grounds, and deteriorating insulation can lead to intermittent electrical problems, particularly with lighting, ignition, and accessories.

Suspension Wear:

Worn ball joints, tie rod ends, and control arm bushings are common, leading to poor steering and alignment issues.

Frame Corrosion:

While the Corvette chassis is robust, age and climate can lead to rust and corrosion, especially in areas exposed to road salt and moisture. The frame should be inspected regularly.

📚 Vehicle History

Chevrolet Legacy:

Chevrolet, a division of General Motors, has a long history of producing popular and performance-oriented vehicles since its founding in 1911. The Corvette, introduced in 1953, is its flagship sports car and an iconic American automotive symbol.

C3 Generation Timeline:

The third-generation (C3) Corvette, introduced in 1968, was known for its 'Mako Shark' inspired styling. The 1975 model year falls towards the end of the C3's significant redesigns, with the introduction of catalytic converters (for US market) and revised bumper systems to meet federal regulations. The 1975 model year was the last year for the convertible body style.

Production Volume 1975:

Approximately 38,460 Corvettes were produced for the 1975 model year.

Manufacturing Location:

Bowling Green, Kentucky, USA.

🏆 Awards & Recognition

Automotive Icon Status:

The 1975 Corvette, as part of the C3 generation, is widely recognized as a significant American sports car and a collectible classic. It continues to be celebrated for its distinctive styling and performance capabilities of its era.

Collector Car Value:

Consistently ranks as a desirable collector car, with values influenced by condition, originality, and specific options.