🏷️ Basic Information Identification Make: GMC Model: Sierra 3500 Year: 2004 Codes Platform: GMT800 Chassis Code: GMT880 👋 Introduction Market Position Target Audience: Do-it-yourselfers (DIYers) and professional automotive technicians Competitive Analysis Advantage Over Print: More convenient, less expensive, instant access, searchable Key Features Access Method: Online, web-browser based Data Accuracy: Factory-derived, accurate information Cost Savings: Enables significant cost savings on vehicle repairs 📋 Manual Details Coverage Areas Primary Coverage: Service and Repair Secondary Coverage: Maintenance, Diagnostics, Troubleshooting Page Count Estimated Pages: Extensive (Software-based, not fixed page count) Manual Type Type: Digital Service and Repair Manual Language Language: English Format Format: Software Application (Web-based Access) 📖 Manual Coverage Systems Covered Engine: All gasoline and diesel engine variants Drivetrain: Transmission (automatic and manual), Transfer case, Axles, Driveshafts Suspension: Front and rear suspension components, shocks, struts, springs, steering linkage Brakes: Brake system hydraulics, ABS, Parking brake, Rotor and pad replacement Electrical: Wiring diagrams, Fuse box locations, Lighting, Gauges, Body control modules (BCM) HVAC: Heating, Ventilation, and Air Conditioning system components and service Body: Body panels, Doors, Glass, Seats, Interior trim, Bumpers Procedures Included Maintenance: Oil changes, Filter replacements, Fluid checks and changes, Spark plug replacement Repair: Component removal and installation, Overhaul procedures, Component replacement Diagnostics: Troubleshooting guides, Diagnostic trouble codes (DTCs), Symptom-based diagnostics Technical Depth Depth: Factory-level detail, suitable for professional technicians and advanced DIYers Troubleshooting Approach: Comprehensive, step-by-step diagnostic flowcharts and procedures 📊 Manual Specifications File Format Access Method: Web Browser Access via Internet Connection Print Quality Image Resolution: High-resolution diagrams and illustrations Binding Type Binding: N/A (Digital Format) Paper Type Paper Type: N/A (Digital Format) Licensing Licensing Status: Officially Licensed Data Source: OE (Original Equipment) Materials Access Duration Access Period: 1 Year with discounts for renewal Compatibility Device Compatibility: PC, Laptop, Smartphone, Tablet ⚙️ Engine Specifications Primary Engine Engine Options: 6.0L Vortec V8 (LQ4), 8.1L Vortec V8 (7400 V8), 6.6L Duramax V8 Turbo-Diesel (LLY) Performance 6.0L Vortec V8 Horsepower: Approx. 300-325 hp (depending on configuration) 6.0L Vortec V8 Torque: Approx. 360-370 lb-ft (depending on configuration) 8.1L Vortec V8 Horsepower: Approx. 340 hp 8.1L Vortec V8 Torque: Approx. 455 lb-ft 6.6L Duramax Lly Horsepower: Approx. 310 hp 6.6L Duramax Lly Torque: Approx. 525 lb-ft Fuel System Gasoline Injection: Sequential Fuel Injection (SFI) Diesel Injection: High-pressure common rail (HPCR) injection system 🔧 Transmission Standard Transmission Options: 4-speed automatic (4L80-E, Allison 1000), 5-speed manual (NV4500) Optional Optional Transmission: 5-speed automatic (Allison 2000/2400 for specific applications) Features Allison Transmission Features: Heavy-duty design, Tow/Haul mode, Electronic controls 📐 Dimensions Exterior Body Styles: Regular Cab, Extended Cab, Crew Cab Bed Lengths: 6.5 ft Fleetside, 8 ft Fleetside Wheelbase Options: 133.0 in (Regular Cab), 143.5 in (Extended Cab), 153.0 in (Crew Cab - standard bed), 167.5 in (Crew Cab - long bed) Weights Gvwr Range: 9,900 lbs to 11,400 lbs (depending on configuration and axle ratio) Curb Weight Range: Approx. 5,800 lbs to 7,000 lbs 🛡️ Safety Features Ratings NHTSA Rollover Resistance: Generally good for its class, specific ratings vary by configuration Active Features ABS: Standard Anti-lock Braking System (ABS) Towing Features: Integrated trailer brake controller wiring, Tow/Haul mode Passive Features Airbags: Driver and front passenger airbags Seatbelts: Three-point safety belts with pretensioners 💡 Technology Features Infotainment Audio Options: AM/FM Stereo with CD player, Cassette player (optional), Premium Bose sound system (optional) Driver Assistance Cruise Control: Standard cruise control Trailer Towing Prep: Available heavy-duty trailering package including hitch receiver, wiring harness, and upgraded cooling. 🔧 Maintenance Service Intervals Oil Change Interval: Every 3,000-5,000 miles or 3-6 months, or per oil life monitor system. Transmission Fluid Change: Every 45,000-60,000 miles for heavy-duty use, or as per manual. Fluid Specifications Engine Oil Gasoline V8: API Service SG, SH, SJ, SL, SM; SAE 5W-30 (or viscosity recommended by oil life monitor) Engine Oil Diesel Duramax: API CI-4/CJ-4 or equivalent; SAE 15W-40 or 5W-40 synthetic for extreme cold. Coolant: GM DEX-COOL (Orange) extended life coolant or equivalent. Transmission Fluid Auto: Dexron III/VI for 4L80E, Allison TES 295 for Allison transmissions. Known Issues Duramax Lly Injector Issues: Potential injector harness chafing and injector performance issues. Exhaust Manifold Cracks: Common on early 6.0L Vortec engines due to heat cycles. Rear Main Seal Leaks: Can occur on higher mileage vehicles, especially with manual transmissions. 📚 Vehicle History Brand Heritage Brand Identity: GMC is a division of General Motors focused on trucks and commercial vehicles. Model Evolution Generation: Part of the second generation of the redesigned Sierra (GMT800 series, 1999-2006) Production Manufacturing Locations: Fort Wayne Assembly (Indiana), Oshawa Car Assembly (Ontario, Canada) 🏆 Awards & Recognition Recognitions Overall Truck Awards: The Sierra line consistently received praise for its towing and hauling capabilities.