🏷️ Basic Information

Make:

Chevrolet

Model:

C3500

Year:

1991

Chassis Code:

GMT400

👋 Introduction

Target Audience:

DIY mechanics, independent repair shops, C3500 owners seeking to maintain or repair their vehicle.

Comparison To Print:

More convenient, accessible, and often more cost-effective than traditional printed manuals.

Licensing:

Officially licensed, OE (Original Equipment) derived materials.

Access:

Full year of access included, with discounts for renewal.

📋 Manual Details

Coverage Scope:

Comprehensive Service and Repair

Estimated Page Count:

Varies by specific model and options; typical factory manuals for this era are extensive, often exceeding 1000 pages.

Type:

Service and Repair Manual Software

Language:

English

Format:

PDF Download (Digital)

📖 Manual Coverage

Engine Mechanical:

Yes (including diagnosis, overhaul, component testing)

Engine Electrical:

Yes (ignition, fuel injection, starting, charging systems)

Transmission:

Yes (automatic and manual, diagnosis, repair, fluid service)

Drivetrain:

Yes (drive axles, universal joints, differentials)

Suspension:

Yes (front and rear suspension, steering components, alignment)

Brakes:

Yes (hydraulic system, ABS (if equipped), disc and drum brake service)

Steering:

Yes (power steering system, steering column, linkage)

Electrical System:

Yes (wiring diagrams, lighting, accessories, fuses, relays)

Heating Ventilation Air Conditioning:

Yes (HVAC system diagnosis and repair)

Body And Chassis:

Yes (body panel removal, interior trim, structural components)

Diagnostic Procedures:

Yes (troubleshooting guides, fault code interpretation (OBD-I))

Scheduled Maintenance:

Yes (oil changes, filter replacements, tune-ups)

Repair Procedures:

Yes (step-by-step guides for component replacement and overhaul)

Troubleshooting:

Yes (systematic diagnosis of common and uncommon problems)

Component Testing:

Yes (diagnosing the health of individual parts)

Wiring Diagram Interpretation:

Yes (detailed schematics for electrical systems)

Depth:

In-depth (covering everything from routine maintenance to major overhauls and diagnostics)

📊 Manual Specifications

Compatibility:

PC, Laptop, Smartphone, Tablet (requires web browser and internet connection)

Resolution:

High-resolution digital images and text (optimised for screen viewing and printing)

Binding:

N/A (Digital Download)

Paper:

N/A (Digital Download)

⚙️ Engine Specifications

Engine Options:

4.3L V6 (VIN 'Z'), 5.0L V8 (VIN 'H'), 5.7L V8 (VIN 'K'), 7.4L V8 (VIN 'F')

Horsepower Range:

Approximately 160 HP (4.3L V6) to 230 HP (7.4L V8)

Torque Range:

Approximately 230 lb-ft (4.3L V6) to 360 lb-ft (7.4L V8)

Injection Type:

Throttle Body Injection (TBI) for V6 and 5.0L/5.7L V8; Multiport Fuel Injection (MPI) for 7.4L V8 (likely).

🔧 Transmission

Manual Transmission:

NV4500 5-speed manual (optional on some models, especially heavier duty).

Automatic Transmission:

TH400 3-speed automatic, 4L60 4-speed automatic, 4L80E 4-speed automatic (depending on engine and GVWR).

Overdrive:

Available on 4L60 and 4L80E transmissions for improved fuel economy.

📐 Dimensions

Body Styles:

Regular Cab, Extended Cab, Chassis Cab.

Wheelbase Options:

Varies significantly by configuration (e.g., 117.5" for standard cab, longer for extended cabs and chassis cabs).

Gvwr:

Ranges from approximately 6,000 lbs to over 10,000 lbs depending on configuration and options.

🛡️ Safety Features

Crash Test Data:

Limited official NHTSA/IIHS ratings for this specific year and model. Trucks of this era generally lacked the advanced safety structures of modern vehicles.

ABS:

Anti-lock Braking System (ABS) was optional on rear-wheel-drive models and standard on some four-wheel-drive configurations.

Airbags:

Driver-side airbag was typically optional or not available on this model year.

💡 Technology Features

Audio System:

Factory AM/FM radio with cassette player, optional CD player. Basic analog gauges.

Cruise Control:

Optional.

Onboard Diagnostics:

OBD-I (On-Board Diagnostics, First Generation) system. Troubleshooting relies on diagnostic codes accessed via jumper or specialized scanner.

🔧 Maintenance

Oil Change:

Typically every 3,000-5,000 miles or 3-6 months, depending on driving conditions. Check manual for specific recommendations based on oil type.

Transmission Fluid:

Check every 15,000 miles, change every 30,000-60,000 miles depending on transmission type and usage.

Spark Plugs:

Typically replaced every 30,000-60,000 miles, depending on plug type (conventional, platinum).

Engine Oil:

API SJ or SL rated oil, viscosity typically 5W-30 or 10W-30 depending on ambient temperature. Check manual for exact specs.

Coolant:

Ethylene Glycol based coolant (green) with a 50/50 mix with distilled water. Ensure proper freeze protection.

Brake Fluid:

DOT 3 brake fluid.

Automatic Transmission Fluid:

Dexron-III (or equivalent) for 4L60/4L80E; Dexron-II for TH400. Check manual for precise type.

Common Problems:

Rocker arm wear (especially on 5.7L L05), intake manifold gasket leaks, rear main seal leaks, ABS sensor issues, HVAC blend door actuator failure.

Rust Prone Areas:

Cab corners, rocker panels, bed floor, frame rails, especially in areas with road salt.

📚 Vehicle History

Legacy:

Chevrolet has a long and distinguished history in the pickup truck market, with the C/K series being a foundational line.

Generation:

The 1991 C3500 is part of the third generation of Chevrolet C/K trucks, known as the GMT400 platform, which debuted in late 1987 for the 1988 model year.

Manufacturing Plant:

Various GM plants in North America, including Fort Wayne, Indiana and Oshawa, Ontario.

🏆 Awards & Recognition

Industry Accolades:

While specific awards for the 1991 model are not widely documented, the GMT400 platform was generally well-received for its comfort, ride quality, and modern styling compared to previous generations of GM trucks.