🏷️ Basic Information

Make:

GMC

Model:

Sierra HD 2500 / 3500 Pickup Truck

Model Variant:

HD (Heavy Duty)

Generation Code:

GMT900 (Second Generation)

Generation Years:

2007-2013 (GMT900 platform)

Platform Code:

GMT900

👋 Introduction

Segment:

Heavy Duty Pickup Truck

Target Audience:

Owners seeking to perform maintenance and repairs, professional mechanics, fleet managers

Competitors:

Ford F-Series Super Duty, Ram Heavy Duty (e.g., 2500/3500)

Manual Utility:

Comprehensive, factory-accurate information for efficient and correct repairs, cost savings on professional labor.

Technical Accuracy:

Same manual used by authorized service centers, ensuring accuracy and adherence to OEM specifications.

Ease Of Use:

Easy-to-read text, clear diagrams, step-by-step instructions.

📋 Manual Details

Covered Years:

2007, 2008, 2009

Covered Models:

Sierra HD 2500, Sierra HD 3500

Covered Trims:

All Trim Levels

Covered Configurations:

All Cab Styles (Regular, Extended, Crew), All Bed Lengths, All Drivetrains (2WD, 4WD)

Estimated Page Count:

Refer to official GM service manual for exact page count; typically 3000+ pages for complete factory service manuals covering multiple model years and configurations.

Manual Type:

Factory Service Repair Manual / Workshop Manual

Language:

English

Format:

PDF

📖 Manual Coverage

Powertrain:

Engine mechanical, fuel system, cooling system, exhaust system, lubrication system, ignition system, emissions control

Drivetrain:

Manual transmission, automatic transmission, transfer case, drive shafts, differentials, axles, hubs, CV joints

Chassis:

Suspension (front and rear), steering system, brake system (front and rear), ABS, electronic stability control (ESC)

Electrical:

Battery, charging system, starting system, lighting, instrument cluster, body control modules (BCM), power windows/locks, HVAC controls, audio system, trailer wiring

Body:

Body structure, doors, hood, tailgate, bumpers, interior trim, seating, glass, mirrors

HVAC:

Heating, ventilation, and air conditioning system diagnosis and repair

Maintenance:

Scheduled maintenance, fluid changes, filter replacements, lubrication, inspection points

Troubleshooting:

Diagnostic procedures, symptom analysis, component testing, wiring diagrams for fault finding

Repair:

Step-by-step disassembly, component replacement, assembly, and adjustment procedures

Diagnostics:

On-Board Diagnostics (OBD-II), diagnostic trouble codes (DTCs), system-specific diagnostic charts

Specifications:

Torque specifications, clearances, fluid capacities, electrical data, diagnostic parameters

Technical Data:

Wiring schematics, vacuum diagrams, component locations, overhaul procedures

Depth:

Comprehensive factory-level coverage, suitable for professional mechanics and advanced DIY enthusiasts. Includes complete disassembly and reassembly instructions.

📊 Manual Specifications

Format:

PDF

Printability:

Printable without restriction

Image Quality:

High-quality diagrams and images designed for clear display via Adobe PDF Reader

Binding Type:

Digital Download (PDF)

Paper Type:

N/A (Digital)

Delivery Method:

Instant Download via Link

⚙️ Engine Specifications

Engine Options:

2007-2009 models were typically equipped with robust V8 gasoline and Duramax diesel engines.

Gasoline Engine 1:

6.0L V8 Vortec (L96) - Power: Approx. 300-360 hp, Torque: Approx. 370-400 lb-ft. (Specific ratings may vary by year and configuration)

Gasoline Engine 2:

6.2L V8 Vortec (L92) - Power: Approx. 403 hp, Torque: Approx. 417 lb-ft. (Often found in higher trims or as an option)

Diesel Engine 1:

6.6L V8 Duramax Turbo-Diesel (LLY/LBZ/LMM) - Power: Approx. 300-365 hp, Torque: Approx. 520-765 lb-ft. (Specific ratings vary significantly by engine code and year, LMM is common for 07.5-09)

Engine Management:

Electronic Fuel Injection (EFI) / Common Rail Direct Injection (CRDI for Duramax)

Fuel Type:

Unleaded Gasoline (for V8 Vortec engines), Diesel Fuel (for Duramax engines)

Fuel Delivery:

Multi-port fuel injection (MPFI) for gasoline, high-pressure common rail system for diesel

🔧 Transmission

Transmission Options:

Manual and Automatic transmissions available, depending on engine and trim.

Manual Transmission:

6-speed manual (e.g., ZF6)

Automatic Transmission 1:

Allison 1000 6-speed automatic (Heavy Duty Automatic Transmission)

Automatic Transmission 2:

4-speed automatic (e.g., 4L70-E) often found with gasoline engines, though Allison is standard for Duramax.

Transfer Case:

Available with 2-speed electronic transfer case for 4WD models

📐 Dimensions

Wheelbase Options:

Various wheelbases available depending on cab and bed configuration (e.g., 143.5" for Crew Cab Short Bed, 167.9" for Crew Cab Long Bed, 173.9" for Regular Cab Long Bed).

Overall Length:

Varies significantly with configuration, typically ranging from 230" to 266".

Overall Width:

Approx. 79.9" (excluding mirrors)

Overall Height:

Approx. 77.4" - 78.9" (depending on configuration and suspension)

Bed Length Options:

Standard Bed (approx. 78.8 inches), Long Bed (approx. 97.8 inches)

Curb Weight:

Ranges from approximately 6,000 lbs to over 7,500 lbs depending on configuration.

Gvw Range:

2500 models typically range from 9,500 lbs to 10,000 lbs GVWR. 3500 models range from 9,900 lbs to 14,000+ lbs GVWR.

Max Payload:

Can exceed 5,000 lbs for appropriately equipped 3500 models.

Max Towing Capacity:

Can exceed 16,000 lbs for 3500 models with proper configurations (e.g., dually, diesel, gooseneck hitch).

🛡️ Safety Features

NHTSA Crash Tests:

Refer to NHTSA records for specific year and configuration. Generally performed well for its class but may vary.

Braking System:

Four-wheel disc brakes, Anti-lock Braking System (ABS)

Stability Control:

Available StabiliTrak electronic stability control system

Traction Control:

Standard traction control system

Airbags:

Driver and front passenger airbags, available side-impact airbags.

Seatbelts:

Three-point seatbelts with pretensioners

Structure:

High-strength steel frame and body structure

💡 Technology Features

Audio System:

Available Bose premium audio, CD player, satellite radio, auxiliary input. Higher trims may have navigation.

Display:

Optional integrated touch-screen display for navigation and infotainment.

Towing Features:

Integrated trailer brake controller, trailer sway control, tow/haul mode for transmission, available integrated trailer mirrors.

Parking Assistance:

Available rear parking assist sensors.

Phone Integration:

Available Bluetooth connectivity for hands-free calling on some models/trims.

🔧 Maintenance

Oil Change Interval:

Typically every 5,000-7,500 miles for gasoline, or 10,000-15,000 miles for Duramax diesel with synthetic oil, or as indicated by the oil life monitoring system.

Air Filter Replacement:

Every 30,000-45,000 miles or as needed based on driving conditions, more frequently for diesel.

Fuel Filter Replacement Diesel:

Crucial for Duramax; typically every 15,000-25,000 miles. Refer to manual for specific LLY/LBZ/LMM requirements.

Coolant Flush:

Initial fill might be Dex-Cool extended life; subsequent flushes typically every 5 years or 100,000 miles.

Engine Oil Gasoline:

SAE 5W-30, API SN/SN Plus, GM dexos1™ Gen 2 (or equivalent compatible specification). Check owner's manual for exact specification.

Engine Oil Diesel:

SAE 15W-40 or 5W-40 (synthetic), API CJ-4 or CK-4, meeting GM specifications for Duramax. Always use diesel-specific oil.

Transmission Fluid Automatic:

Dexron VI for most GM transmissions, including Allison 1000. Verify with manual.

Transmission Fluid Manual:

GL-4 or GL-5 gear oil, specific viscosity (e.g., 75W-90 or 80W-90). Check manual.

Coolant:

GM specified orange coolant (Dex-Cool), a 50/50 mix of antifreeze and distilled water.

Brake Fluid:

DOT 3 or DOT 4. Check reservoir cap or manual.

Duramax Diesel Lmm:

Potential for injector issues, emissions system (DPF, EGR) related problems, glow plug issues, although generally robust.

Gasoline Engines:

Possible issues with AFM/DOD lifters (if equipped), intake manifold gaskets, or valve cover leaks on some Vortec engines.

Drivetrain:

Rear differential pinion seal leaks, transfer case issues on higher mileage units.

Suspension Steering:

Wear in ball joints, tie rod ends, and steering components due to heavy duty use. Possible steering wheel vibration.

Electrical:

Body control module (BCM) issues, intermittent electrical gremlins, HVAC blower motor resistor failure.

📚 Vehicle History

Brand:

GMC (General Motors Truck Company)

Specialization:

Long history of producing trucks, SUVs, and commercial vehicles.

Sierra Nameplate:

The Sierra nameplate has been used by GMC for its full-size pickup trucks since 1999, replacing the C/K series.

Gmt900 Platform:

The GMT900 platform, introduced for the 2007 model year, represented a significant redesign with improved styling, interior, and chassis dynamics over its GMT800 predecessor.

Hd Distinction:

HD (Heavy Duty) models are specifically designed for increased towing and payload capacities, featuring reinforced frames, heavy-duty suspensions, and more powerful engine/transmission options compared to standard Sierra models.

Production Location:

Assembled in North America (e.g., Fort Wayne, Indiana; Oshawa, Ontario).

🏆 Awards & Recognition

Previous Generation Awards:

While specific awards for the 2007-2009 HD models are less commonly cited, the Sierra HD line generally maintained a strong reputation in professional reviews for capability and durability.

Consumer Reports:

Specific ratings vary by year and powertrain. Generally praised for towing/hauling, but some reports on reliability for certain components exist.

Emisiones Standards:

Compliant with EPA emissions standards for the respective model years.