🏷️ Basic Information Identification Make: GMC Model: Sierra Year: 2008 Codes Platform: GMT900 👋 Introduction Market Position Segment: Full-size pickup truck Brand Perception: GMC positions the Sierra as a premium, professional-grade truck. Competitive Analysis Key Competitors: Ford F-150, Dodge Ram 1500, Toyota Tundra Key Features Powertrain Options: Available with multiple V8 engine options and robust chassis for towing and hauling. Interior Design: Focus on comfort, durability, and integrated technology for the driver. 📋 Manual Details Coverage Areas Primary Coverage: Owner's Information and Operation Secondary Coverage: Basic Maintenance, Safety, and Features Page Count Estimated Page Count: Approximately 400-500 pages (typical for this model year) Manual Type Type: Owner's Manual Language Language: English Format Digital Format: PDF (Portable Document Format) 📖 Manual Coverage Systems Covered Powertrain: Engine operation, fuel system, lubrication, cooling, exhaust (general information) Chassis: Braking system, steering system, suspension system (basic operation and checks) Electrical: Lighting systems, instrument cluster, entertainment systems, climate controls, power outlets Body: Locks and security, seating and safety restraints, windows, mirrors, doors Procedures Included Operation: Starting and operating the vehicle, using vehicle controls and features Maintenance: Fluid checks (oil, coolant, brake fluid), tire pressure checks, filter replacement (air), battery maintenance Safety: Understanding safety restraints, child seat installation guidance, reporting safety defects (US) Troubleshooting: Instrument cluster warning lights and indicators, basic customer assistance procedures Technical Depth Depth: Owner-level understanding and basic operation/maintenance 📊 Manual Specifications File Format Compatibility: Requires PDF reader (e.g., Adobe Acrobat Reader, Foxit Reader) Print Quality Quality: Digital PDF from original factory manual, ensuring high fidelity Binding Type Binding: N/A (Digital Download) Paper Type Paper Type: N/A (Digital Download) ⚙️ Engine Specifications Primary Engine Engine Code: LMG (4.8L Vortec V8) Displacement: 4.8 Liters (293 cubic inches) Configuration: V8, Overhead Valves (OHV), 2 valves per cylinder Horsepower: Approx. 295 hp @ 5600 RPM Torque: Approx. 305 lb-ft @ 4600 RPM Secondary Engine Engine Code: LY5 (5.3L Vortec V8) Displacement: 5.3 Liters (327 cubic inches) Configuration: V8, Overhead Valves (OHV), 2 valves per cylinder, with Active Fuel Management (AFM) Horsepower: Approx. 315 hp @ 5200 RPM Torque: Approx. 338 lb-ft @ 4400 RPM Tertiary Engine Engine Code: LC8 (6.0L Vortec V8 - typically for heavy-duty models) Displacement: 6.0 Liters (364 cubic inches) Configuration: V8, Overhead Valves (OHV), 2 valves per cylinder Horsepower: Approx. 355 hp @ 5400 RPM Torque: Approx. 380 lb-ft @ 4200 RPM Fuel System Injection: Electronic Fuel Injection (EFI) Fuel Information Fuel Type: Unleaded Gasoline (87 octane or higher recommended) 🔧 Transmission Standard Transmission Type: 4-Speed Automatic (4L60-E based, typically for 4.8L and 5.3L) or 6-Speed Automatic (6L80-E, typically for 5.3L and 6.0L) Optional Transmission Type: 6-Speed Manual (less common in this generation, typically for specific configurations) Features Drive Type: Rear-Wheel Drive (RWD) or Four-Wheel Drive (4WD) Fluid Specifications Automatic Transmission Fluid: Dexron VI (GM P/N 88861017 or equivalent) 📐 Dimensions Exterior Wheelbase: Varies by configuration (e.g., approx. 143.5 inches for Crew Cab short bed) Weights Curb Weight: Varies significantly by configuration, typically 4,500 - 5,500 lbs. 🛡️ Safety Features Ratings NHTSA Front Driver Side: 5-Star (2008 model year) NHTSA Front Passenger Side: 5-Star (2008 model year) NHTSA Side Driver: 5-Star (2008 model year) NHTSA Side Passenger: 5-Star (2008 model year) NHTSA Rollover: 4-Star (2008 model year) Active Features ABS: Standard Anti-lock Braking System Traction Control: StabiliTrak Electronic Stability Control (may vary by trim/option) Passive Features Airbags: Driver and front passenger airbags, available side-impact airbags Seat Belts: 3-point height-adjustable front seat belts with pretensioners, rear seat belts 💡 Technology Features Infotainment Audio System: AM/FM stereo with CD player, auxiliary input jack. Optional Bose premium audio, satellite radio, and in-dash 6-disc CD changer. Navigation: Available factory-installed navigation system with touch-screen interface. Driver Assistance Parking Assist: Available rear parking assist sensors. Connectivity Remote Start: Available factory-installed remote vehicle starter system. Bluetooth: Available Bluetooth hands-free calling system (RPO code UPF). 🔧 Maintenance Service Intervals Engine Oil And Filter: Every 7,500 miles or 12 months (using synthetic oil and GM filter). Refer to manual for specific oil life monitoring system guidance. Tire Rotation: Every 7,500 miles Air Filter Replacement: Inspect every 15,000 miles, replace as needed. Replace if dirty. (Part Number likely varies by engine, e.g., ACDelco A1890C for 5.3L) Cabin Air Filter: Inspect annually, replace as needed. (Part Number likely varies, e.g., ACDelco CF10168) Coolant Replacement: First change at 5 years or 100,000 miles, then every 2 years or 50,000 miles thereafter. Fluid Specifications Engine Oil: SAE 5W-30 Synthetic (GM specification: dexos1 Gen 2 or equivalent) Engine Coolant: GM P/N 12346014, Orange Long Life (50/50 mix with distilled water) Brake Fluid: DOT 3 (GM P/N 12377974 or equivalent) Power Steering Fluid: GM P/N 12345874 or equivalent Known Issues Active Fuel Management Lifter Noise: Some AFM-equipped 5.3L engines can develop lifter noise due to AFM system operation. Regular oil changes with correct oil are critical. Transmission Hard...