Positioning:
The 1968 Corvette was a significant evolution of the Sting Ray, offering increased performance and refined styling. This manual targets owners and mechanics seeking in-depth technical knowledge for maintenance and restoration.
Comparative Advantage:
This workshop manual provides more detailed technical information than a typical owner's manual, bridging the gap between basic user guidance and factory service bulletins.
Manual Features:
Extensive diagrams, troubleshooting flowcharts, torque specifications, and step-by-step repair instructions.
Engine:
Full Engine Overhaul, Tune-up, Lubrication, Cooling System, Fuel System, Exhaust System, Ignition System, Emissions Control (where applicable)
Transmission:
Manual Transmission (Muncie 4-speed), Automatic Transmission (Turbo Hydra-Matic 3-speed), Clutch System, Driveshaft, U-Joints
Brakes:
Hydraulic System, Disc Brakes (Front), Drum Brakes (Rear), Parking Brake, Master Cylinder, Wheel Cylinders, Brake Lines and Hoses
Suspension Steering:
Front Independent Suspension (Coil Springs, Control Arms, Ball Joints), Rear Independent Suspension (Trailing Arms, U-Joints), Steering Gearbox, Power Steering System, Wheel Alignment
Electrical:
Wiring Diagrams, Battery, Charging System (Alternator), Starting System (Starter Motor), Ignition System Components, Lighting System, Gauges and Instruments, Horn, Wiper System, Radio System
Body Chassis:
Frame, Body Panels, Doors, Hood, Trunk, Bumpers, Glass, Interior Trim, Seat Belts, Convertible Top Mechanism, Weatherstripping
Maintenance:
Oil Change, Filter Replacement, Spark Plug Replacement, Fluid Level Checks, Lubrication Points, Belt Adjustments, Air Filter Replacement
Troubleshooting:
Diagnostic Charts, Symptom-Based Troubleshooting for Engine, Electrical, and Mechanical Issues
Repair:
Engine Rebuild, Transmission Rebuild, Brake System Overhaul, Suspension Component Replacement, Electrical Component Repair/Replacement, Body Panel Repair
Disassembly Assembly:
Step-by-step instructions for component removal and reinstallation with torque specifications
Depth:
Comprehensive; suitable for professional mechanics and advanced DIY enthusiasts. Covers detailed diagnostics and rebuild procedures.
Engine Code:
L46 (350/300 hp), L36 (427/390 hp), L68 (427/390 hp Tri-Power), L71 (427/435 hp Tri-Power), L88 (427/430 hp - Special Order)
Displacement:
350 cubic inches (5.7 Liters) and 427 cubic inches (7.0 Liters)
Horsepower:
Ranges from 300 hp (350 CI) to 435 hp (427 CI Tri-Power)
Torque:
Varies by engine; e.g., 360 lb-ft for L46 (350/300hp)
Carburetion:
Single 4-barrel carburetor (e.g., Rochester Quadrajet for 350), Tri-Power (3x2-barrel carburetors) for L68/L71 427 models
Fuel Type:
Unleaded gasoline (required due to unleaded fuel introduction)
Bore X Stroke 350:
4.00 in x 3.48 in
Compression Ratio 350:
10.25:1 (L46)
Oil Capacity:
5 US quarts (4.7 Liters) with filter (typically)
Standard Transmission Base:
Muncie SM465 4-Speed Manual
Optional Transmission:
Turbo Hydra-Matic 350 (3-speed Automatic)
Clutch Type:
Single dry plate, diaphragm spring (for manual)
Automatic Features:
Torque converter, column or floor shift linkage
Muncie 4 Speed Ratios:
Typical ratios: 2.20, 1.71, 1.31, 1.00 (Low gears vary slightly by application)
Crash Test Data:
No standardized NHTSA or IIHS crash test data available for this era. Safety features were basic.
Active Safety Features:
Four-wheel hydraulic disc brakes (standard front, optional rear), dual-circuit brake system.
Passive Safety Features:
Lap and shoulder belts (standard for 1968), padded dashboard, energy-absorbing steering column.
Oil Change Interval:
Typically every 3,000 miles or 6 months, though older engines may benefit from more frequent changes.
Tune Up Interval:
Spark plugs, points, and condenser every 10,000 - 15,000 miles.
Transmission Fluid Change:
Manual: Inspect regularly, drain/refill as needed (e.g., 30,000 miles). Automatic: Change fluid and filter every 24,000 miles.
Engine Oil Type:
API SF or SG classification, SAE 10W-30 or 10W-40 recommended for general use. Consider higher zinc content for flat-tappet camshafts.
Coolant Type:
Ethylene glycol-based antifreeze with distilled water (50/50 mix). Check owner's manual or manual for specific fill types.
Brake Fluid Type:
DOT 3 or DOT 4 hydraulic brake fluid.
Transmission Fluid Manual:
GL-4 Gear Oil (e.g., 80W-90)
Transmission Fluid Automatic:
Dexron-III (or equivalent)
Common Wear Items:
Ball joints, tie rod ends, wheel bearings, U-joints, clutch components, carburetor tuning, aging rubber seals and hoses.
Electrical Gremlins:
Corrosion in wiring connectors, failing voltage regulators, and worn electrical contacts are common in vehicles of this age.
Engine Specific Notes:
The 427 Big-Block engines can be prone to overheating if cooling systems are not meticulously maintained. L88 engines require specific high-octane fuel and careful engine management.
Frame Rust:
Inspect frame and birdcage for rust, especially in areas exposed to moisture. Body panel alignment can also be an issue due to age and potential previous repairs.
Chevrolet Legacy:
Chevrolet, founded in 1911, has a long history of producing reliable and performance-oriented vehicles. The Corvette, introduced in 1953, is America's premier sports car.
Corvette C3 Introduction:
The third generation (C3) Corvette debuted in 1968, featuring radical new 'Mako Shark' styling. The 1968 model year was the first year of the C3 generation.
1968 Distinguishing Features:
First year for the C3 body style. Introduced the T-top coupe. Retained side-pipe exhaust for some models. Iconic Coke-bottle styling.
Production Volume 1968:
28,566 units
Manufacturing Location:
St. Louis, Missouri, USA
Model Recognition:
The 1968 Corvette is widely recognized as a classic American sports car and is highly sought after by collectors and enthusiasts. While specific awards for the 1968 model year itself are rare, the C3 generation as a whole is celebrated for its design and performance evolution.
Performance Ratings:
Highly regarded for its performance capabilities, especially models equipped with the 427 engines, offering supercar-level acceleration for its time.
