🏷️ Basic Information

Make:

Chevrolet

Model:

Corvette

Year:

1975

Engine Options:

350 cu in (5.7L) V8 (L48), 350 cu in (5.7L) V8 (LM1 - California)

Body Styles:

Coupé (ZPB - 2-door hardtop)

Vin Decode Base:

1Z37...

👋 Introduction

Positioning:

The 1975 Corvette represented a significant shift in the Corvette's evolution, moving towards greater comfort and compliance while retaining its sporting image, adapting to stricter emissions and safety regulations of the era.

Competitors:

Primary competitors included other American performance cars like the Ford Mustang, Pontiac Firebird Trans Am, and to a lesser extent, European sports cars of comparable price and performance.

Design:

Second generation (C3) Stingray styling, removable T-tops, fiberglass body.

Performance Focus:

V8 engine power, independent suspension for all wheels, rear-wheel drive.

Regulatory Compliance:

Features like catalytic converters and revised engine tuning to meet 1975 federal emissions standards.

📋 Manual Details

Covered Models:

All 1975 Chevrolet Corvette Models

Covered Engines:

350 cu in (5.7L) V8 (L48 and LM1)

Covered Transmissions:

3-speed Turbo Hydra-Matic Automatic, 4-speed Manual (Muncie M21/M22 - although less common in '75, manual transmissions were available)

Covered Trims:

All available trim levels

Estimated Pages:

800-1200

Type:

Workshop Repair Service Manual

Language:

English

Format:

PDF Download

📖 Manual Coverage

Engine Mechanical:

Engine assembly, disassembly, inspection, repair, troubleshooting of the 350 V8 (L48/LM1).

Engine Fuel System:

Carburetor (Rochester Quadrajet), fuel pump, fuel lines, fuel tank, emissions control systems (e.g., EGR, PCV).

Engine Ignition System:

Distributor, ignition coil, spark plugs, wiring, timing adjustment.

Cooling System:

Radiator, fan, water pump, thermostat, coolant hoses, heater core.

Lubrication System:

Oil pump, oil filter, oil pan, lubrication passages, oil pressure specifications.

Exhaust System:

Exhaust manifolds, catalytic converter (if applicable for year/region), mufflers, exhaust pipes.

Transmission Automatic:

Turbo Hydra-Matic 400 (THM400) service, overhaul, adjustments, troubleshooting, fluid specifications.

Transmission Manual:

4-speed manual transmission service, clutch, shifter linkage, fluid specifications.

Drivetrain:

Driveshaft, U-joints, differential, rear axle assembly, wheel bearings.

Suspension Front:

Independent front suspension components (control arms, ball joints, tie rods, steering knuckle), springs, shock absorbers, alignment specifications.

Suspension Rear:

Multi-link independent rear suspension (trailing arms, transverse spring, shock absorbers), alignment specifications.

Steering:

Power steering system (pump, hoses, steering gear), steering column, universal joints, tie rods, steering wheel.

Brakes Front:

Disc brake system (calipers, rotors, pads, master cylinder, brake lines, power assist/booster).

Brakes Rear:

Disc brake system (calipers, rotors, pads, parking brake mechanism).

Wheels Tires:

Wheel and tire specifications, bolt patterns, maintenance, troubleshooting.

Electrical System:

Battery, charging system (alternator), starting system (starter motor), ignition system, lighting, gauges, fuses, relays.

Body Exterior:

Body panel repair, alignment, doors, hood, T-tops, weatherstripping, bumpers, trim.

Body Interior:

Seating, upholstery, dashboard, gauges, door panels, carpeting, climate control system (HVAC).

Climate Control:

Heating, ventilation, air conditioning (HVAC) system operation, components, and service.

Electrical Accessories:

Power windows, power door locks, radio, power antenna, interior lighting, headlamp doors.

Routine Maintenance:

Oil changes, filter replacements, fluid checks and top-offs, spark plug replacement, belt inspection/replacement, tune-ups.

Troubleshooting Diagnostics:

Step-by-step diagnostic procedures for common and complex issues across all systems.

Engine Repair:

Engine overhaul, piston/ring replacement, bearing replacement, cylinder head repair, valve jobs, timing chain/gear replacement.

Transmission Repair:

Transmission rebuild, clutch replacement, seal replacement, torque converter service.

Brake System Service:

Brake pad/rotor replacement, caliper overhaul, master cylinder replacement, bleeding procedures, power booster testing/replacement.

Suspension Steering Repair:

Replacement of ball joints, tie rods, control arms, bushings, shock absorbers, steering gear rebuild.

Electrical System Repair:

Alternator/starter testing and replacement, wiring harness repair, component diagnosis (e.g., power windows, lights).

Body Panel Replacement:

Procedures for body panel removal, installation, and alignment.

Climate Control Service:

Refrigerant handling (if applicable for the era), component replacement (blower motor, heater core, A/C compressor).

Emissions Control Service:

Adjustment and service of emissions control components.

Depth:

Comprehensive rebuild and diagnostic procedures

Detail Level:

Detailed component disassembly, assembly, specifications, and torque values.

Diagnostic Charts:

Likely includes diagnostic flowcharts and symptom-based troubleshooting guides.

Special Tools:

Mentions necessary special tools for specific procedures.

📊 Manual Specifications

Digital Format:

PDF

Searchability:

Likely text-searchable for quick information retrieval.

Printability:

Typically printable for workshop use.

Image Resolution:

Variable, but generally clear for diagrams and illustrations in professional manuals.

Binding:

N/A (Digital PDF)

Paper:

N/A (Digital PDF)

⚙️ Engine Specifications

Displacement Standard:

350 cubic inches (5.7 Liters)

Engine Code Standard:

L48

Configuration:

V8, Overhead Valve (OHV)

Bore X Stroke:

4.00 in x 3.48 in (101.6 mm x 88.4 mm)

Compression Ratio Standard:

8.0:1

Horsepower Standard:

165 hp @ 4000 rpm (gross), ~145 net HP

Torque Standard:

255 lb-ft @ 2400 rpm (gross), ~220 net lb-ft

Horsepower California:

175 hp @ 4000 rpm (gross), ~155 net HP (LM1 engine)

Torque California:

265 lb-ft @ 2400 rpm (gross), ~230 net lb-ft (LM1 engine)

Fuel Delivery:

Rochester Quadrajet 4-barrel carburetor (Model 17057208 for L48, 17057218 for LM1)

Fuel Type:

Unleaded gasoline

Emissions Controls:

Catalytic converter, EGR (Exhaust Gas Recirculation), Air Injection Reactor (AIR) system, Positive Crankcase Ventilation (PCV).

🔧 Transmission

Type:

3-speed Turbo Hydra-Matic Automatic (THM400)

Type:

4-speed Manual Transmission (Muncie M21/M22)

Automatic Gear Ratios:

1st: 2.48, 2nd: 1.48, 3rd: 1.00, Reverse: 2.08

Manual Gear Ratios:

M21: 1st: 2.20, 2nd: 1.66, 3rd: 1.28, 4th: 1.00, Reverse: 2.21 (approximate, may vary slightly)

Automatic Fluid Type:

Dexron II Automatic Transmission Fluid (ATF)

Manual Fluid Type:

GM Synchromesh or equivalent (e.g., SAE 80W-90 GL-4 gear oil)

📐 Dimensions

Length:

194.7 inches (4945 mm)

Width:

70.8 inches (1798 mm)

Height:

47.8 inches (1214 mm)

Wheelbase:

98.0 inches (2489 mm)

Front Track:

59.7 inches (1516 mm)

Rear Track:

61.4 inches (1560 mm)

Curb Weight Approx:

3,725 - 3,920 lbs (1690 - 1778 kg)

Gross Vehicle Weight Rating:

Approx. 4,500 lbs (2041 kg)

Cargo Volume:

Approx. 5.3 cu ft (rear compartment)

🛡️ Safety Features

NHTSA Crash Test Results:

NHTSA testing protocols were different in 1975; direct comparisons to modern ratings are not applicable. However, the C3 Corvette featured significant safety advancements for its time.

Brakes:

Four-wheel power disc brakes (standard).

Steering:

Power steering (standard).

Seatbelts:

Three-point lap and shoulder belts.

Steering Column:

Collapsible steering column.

Body Construction:

Reinforced frame and fiberglass body construction.

Windshield:

Laminated safety glass windshield.

Fuel System Protection:

Underbody fuel tank for improved crash protection.

💡 Technology Features

Audio System:

Typically AM/FM radio, often with an optional 8-track player or cassette deck. Speaker placement varied.

Gauges Instruments:

Full complement of analog gauges including speedometer, tachometer, oil pressure, coolant temperature, fuel level, and voltmeter. Warning lights for various systems.

Cruise Control:

Optional feature available on some models.

Connectivity Features:

None in the modern sense; primarily mechanical and basic electrical systems.

🔧 Maintenance

Oil Change:

Every 3,000 miles or 6 months (typical for the era).

Oil Filter Change:

Every oil change.

Air Filter Change:

Every 15,000 miles or 12 months, or as needed based on driving conditions.

Spark Plug Replacement:

Every 20,000 - 30,000 miles (typical).

Transmission Fluid Change Auto:

Every 24,000 miles or 24 months.

Transmission Fluid Change Manual:

Every 30,000 miles or 36 months.

Brake Fluid Change:

Every 24,000 miles or 24 months.

Coolant Change:

Every 24,000 miles or 24 months.

Engine Oil:

SAE 10W-30 or 10W-40 (depending on ambient temperature). Consult manual for precise recommendations, especially concerning API service classification (e.g., SF or SE).

Engine Oil Capacity:

5 quarts (4.7 L) with filter.

Coolant:

50/50 mixture of ethylene glycol antifreeze and distilled water.

Power Steering Fluid:

GM Power Steering Fluid or Dexron II ATF.

Brake Fluid:

DOT 3 brake fluid.

Fiberglass Body:

Delamination, cracking, and stress fractures in fiberglass body panels, especially around wheel wells and front/rear bumpers. T-top seals can degrade, leading to leaks.

Chassis Corrosion:

While fiberglass, the underlying steel frame and components are susceptible to rust and corrosion, particularly in humid or road-salt-prone climates.

Engine Performance Emissions:

Reduced power output compared to earlier C3 models due to emissions controls and lower compression ratios. Carburetor tuning can be sensitive. Potential issues with vacuum leaks in the emissions system.

Suspension Wear:

Wear in ball joints, bushings, and tie rod ends is common due to age and mileage, affecting handling and alignment.

Electrical Aging:

Aging wiring harnesses can lead to intermittent electrical issues. Gauges and instrument cluster components can fail. Headlight door actuator mechanisms are a common failure point.

Cooling System:

Radiator leaks, water pump failures, and thermostat sticking can lead to overheating.

Exhaust System:

Catalytic converter replacement may be required if clogged or damaged. Exhaust manifolds can develop cracks.

📚 Vehicle History

Chevrolet Legacy:

Chevrolet has a long history of performance and innovation, with the Corvette being its flagship sports car since its introduction in 1953.

C3 Generation:

The 1975 model is part of the third generation (C3) Corvette, which ran from 1968 to 1982. The C3 generation is characterized by its iconic 'Mako Shark' styling.

1975 Changes:

Key changes for 1975 included the mandatory inclusion of a catalytic converter (making it the first year for this on the Corvette), the elimination of the optional dual-exhaust system (to reduce backpressure and meet emissions), and a reduction in horsepower due to emissions controls and lower compression ratios. The 1975 also marked the last year for a manual transmission option until 1984, and the last year for the large-block 454 V8 engine.

Production Numbers:

Total 1975 Corvette production: 38,467 units (approximate).

Production Locations:

St. Louis, Missouri, USA

🏆 Awards & Recognition

Model Prestige:

The Corvette has consistently been recognized as an American sports car icon, representing performance, style, and technological advancement throughout its history.

Performance Reviews:

Contemporary reviews highlighted its distinctive styling and comfortable ride for a sports car, though often noted the power compromises made for emissions compliance.

Safety Certifications:

Met all federal safety and emissions standards for 1975.