Market Position:
Heavy-duty pickup truck segment, targeting commercial and consumer users requiring significant towing and hauling capabilities.
Competitors:
Ford F-Series Super Duty, Ram Heavy Duty (2500/3500)
Key Features:
Robust build, powerful engine options, high towing and payload capacities, extensive customization options, reliable heavy-duty components.
Coverage Years:
2007, 2008, 2009
Models Covered:
All Sierra HD 2500, Sierra HD 3500, all configurations (2WD/4WD, Cab types, Bed lengths)
Engine Coverage:
All gasoline and diesel engines offered for these model years
Transmission Coverage:
All manual and automatic transmissions offered
Estimated Page Count:
Thousands (exact count not specified, but 'complete' implies extensive)
Manual Type:
Workshop Service Repair Manual
Delivery Format:
Downloadable Digital File (PDF)
Accessibility:
Printable, Viewable on PC, MAC, Tablets, Smartphones
Systems Covered:
Engine, Drivetrain, Suspension, Steering, Brakes, Electrical System, HVAC, Body & Frame, Fuel System, Exhaust System, Cooling System, Emission Controls, Interior Components, Exterior Components, Diagnostics, Troubleshooting
Procedures Included:
Routine Maintenance, Scheduled Servicing, Major Repairs, Component Rebuilds, Diagnostics, Troubleshooting, Wiring Diagrams, Component Removal & Installation, Torque Specifications, Fluid Capacities, Specifications Tables
Technical Depth:
Comprehensive: Covers basic maintenance to advanced diagnostics and complete overhaul procedures.
Engine Option 1:
6.0L V8 Vortec L76/L96
6.0L Vortec L76 L96 Displacement:
5967 cc
6.0L Vortec L76 L96 Horsepower:
Approx. 350-365 hp (varies slightly by year/specific model)
6.0L Vortec L76 L96 Torque:
Approx. 375-380 lb-ft (varies slightly by year/specific model)
Fuel System Type:
Electronic Fuel Injection (EFI)
Engine Option 2:
6.6L V8 Duramax LMM Turbo-Diesel
6.6L Duramax Lmm Displacement:
6599 cc
6.6L Duramax Lmm Horsepower:
Approx. 365 hp
6.6L Duramax Lmm Torque:
Approx. 725 lb-ft
Turbocharger System:
Variable Geometry Turbocharger (VGT)
Emission Controls:
Diesel Particulate Filter (DPF), Diesel Oxidation Catalyst (DOC), Exhaust Gas Recirculation (EGR)
Standard Transmission Gasoline:
6-Speed Allison 1000 (Heavy Duty Automatic)
Optional Transmission Gasoline:
6-Speed Allison 1000 (Heavy Duty Automatic) - *Note: Manual transmissions were rare or unavailable in HD models during this period.*
Standard Transmission Diesel:
6-Speed Allison 1000 (Heavy Duty Automatic)
Allison 1000 Fluid Spec:
Dexron VI or equivalent approved fluid (refer to manual for precise specification)
Transmission Features:
Tow/Haul mode, driver-selectable gear range control (Grade Braking capability in some configurations)
Wheelbase Options:
Approximately 143.5 inches (Regular Cab, Short Bed), 153.7 inches (Extended Cab, Short Bed), 167.6 inches (Regular Cab, Long Bed), 172.0 inches (Extended Cab, Long Bed), 177.7 inches (Crew Cab, Long Bed)
Bed Length Options:
Standard Bed (approx. 78.8 inches), Long Bed (approx. 97.8 inches)
Gvw Range:
Gross Vehicle Weight Rating (GVWR) ranges from approximately 10,000 lbs to over 12,300 lbs depending on configuration and axle rating.
Curb Weight:
Varies significantly by configuration, typically starting around 6,000 lbs and increasing with cab size, engine, and drivetrain.
NHTSA Ratings:
NHTSA ratings for this generation vary by specific configuration; generally good for frontal and side impact, but subject to model year and specific testing protocols. Refer to NHTSA archives for detailed reports.
Active Safety Features:
Anti-lock Braking System (ABS), Traction Control System (TCS), StabiliTrak Electronic Stability Control (available on some models/trims)
Passive Safety Features:
Front airbags, available side-impact airbags, available seat-mounted airbags, reinforced frame construction, daytime running lamps.
Infotainment System:
Base AM/FM stereo with CD player, optional: Bose premium audio system, touch-screen navigation system (DVD-based), auxiliary input.
Driver Assistance Features:
Cruise control, rear parking assist (optional on some trims), trailer brake controller integration.
Connectivity Features:
Auxiliary audio input jack, available Bluetooth hands-free calling (depending on trim and options).
Oil Change Interval:
Gasoline: 7,500 miles or 6 months. Diesel: 5,000-10,000 miles or 6 months (depending on severe vs. normal use, and specific oil type - refer to manual).
Air Filter Replacement:
Inspect every 15,000 miles, replace as needed or at 30,000 miles. Severe use may require more frequent replacement.
Fuel Filter Replacement Diesel:
Replace every 15,000 to 25,000 miles (critical for Duramax longevity, refer to manual for precise interval).
Engine Oil Gasoline Spec:
SAE 5W-30 Synthetic (API SN, SM, or ILSAC GF-5 certified). Capacity approx. 6 quarts.
Engine Oil Diesel Spec:
SAE 15W-40 Synthetic Heavy Duty Diesel Engine Oil (API CJ-4 or CK-4). Capacity approx. 10-12 quarts depending on engine.
Coolant Spec:
Dex-Cool (GM P/N 12346990 or equivalent orange silicate-free coolant). Capacity approx. 15-17 quarts.
Known Issues Duramax Lmm:
Potential issues with EGR cooler failures, injector issues, DPF clogging if not driven properly (e.g., short trips without regeneration cycles), glow plug issues.
Known Issues 6.0 Vortec:
Head gasket issues, intake manifold gasket leaks, occasional ignition coil failures.
Known Issues General:
Front suspension wear (ball joints, tie rods) under heavy use, brake wear, potential electrical gremlins (typical for vehicle electronics of this era).
Brand Heritage:
GMC (General Motors Company) has a long history of producing trucks and commercial vehicles, known for durability and capability.
Model Evolution Gmt900:
The GMT900 platform represented a significant update for GM's heavy-duty trucks, introducing updated styling, improved interiors, enhanced powertrains (especially the Duramax diesel), and increased towing/hauling capacities compared to its GMT800 predecessor.
Production Location:
Fort Wayne, Indiana, USA; Oshawa, Ontario, Canada (for some GM trucks).
Model Recognition Duramax:
The 6.6L Duramax diesel engine consistently received praise for its power, torque, and durability within the heavy-duty segment.
Model Recognition General
Model Recognition General:
The GMC Sierra HD line generally performed well in consumer satisfaction surveys for its capability and robustness in its class.
