The GMC Sierra 3500HD III, produced between 2007 and 2010, represented a significant evolution in GMC’s heavy-duty truck lineup. Part of the GMT900 generation, this iteration of the Sierra 3500HD was designed to cater to the demands of serious work and towing, offering a robust platform and powerful engine options. The Crew Cab Long Box configuration, paired with the 6.6-liter Duramax turbodiesel V8 engine producing 365 horsepower and 895 lb-ft of torque, and a six-speed Allison automatic transmission, positioned this truck as a premium offering within the 3500HD range, aimed at customers needing substantial capability and a comfortable cabin. This particular variant, often referred to as a “DRW” (Dual Rear Wheel) model, further enhanced its towing and hauling capacity.
Technical Specifications
| Brand | GMC |
| Model | Sierra 3500HD |
| Generation | Sierra 3500HD III (GMT900) Crew Cab Long Box |
| Type (Engine) | 6.6 Duramax TD V8 (365 Hp) 4WD DRW Automatic |
| Start of production | 2007 |
| End of production | 2010 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Pick-up |
| Seats | 5 |
| Doors | 4 |
| Fuel Type | Diesel |
| Weight-to-power ratio | 9.1 kg/Hp, 109.4 Hp/tonne |
| Weight-to-torque ratio | 3.7 kg/Nm, 268.2 Nm/tonne |
| Power | 365 Hp @ 3200 rpm |
| Power per litre | 55.3 Hp/l |
| Torque | 895 Nm @ 1600 rpm, 660.12 lb.-ft. @ 1600 rpm |
| Maximum engine speed | 3450 rpm |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | Duramax LMM |
| Engine displacement | 6599 cm3, 402.7 cu. in. |
| Number of cylinders | 8 |
| Engine configuration | V-engine |
| Cylinder Bore | 103 mm, 4.06 in. |
| Piston Stroke | 99 mm, 3.9 in. |
| Compression ratio | 16.8:1 |
| Number of valves per cylinder | 4 |
| Fuel injection system | Diesel Commonrail |
| Engine aspiration | Turbocharger, Intercooler |
| Valvetrain | OHV |
| Engine oil capacity | 9.5 l, 10.04 US qt | 8.36 UK qt |
| Coolant | 24 l, 25.36 US qt | 21.12 UK qt |
| Kerb Weight | 3337 kg, 7356.83 lbs. |
| Max. weight | 5171 kg, 11400.1 lbs. |
| Max load | 1834 kg, 4043.28 lbs. |
| Trunk (boot) space – maximum | 2170 l, 76.63 cu. ft. |
| Fuel tank capacity | 129 l, 34.08 US gal | 28.38 UK gal |
| Permitted trailer load with brakes (12%) | 5897 kg, 13000.66 lbs. |
| Length | 6572 mm, 258.74 in. |
| Width including mirrors | 2436 mm, 95.91 in. |
| Height | 1934 mm, 76.14 in. |
| Wheelbase | 4242 mm, 167.01 in. |
| Front track | 1742 mm, 68.58 in. |
| Rear (Back) track | 1897 mm, 74.69 in. |
| Ride height (ground clearance) | 233 mm, 9.17 in. |
| Drivetrain Architecture | All wheel drive (4×4). ICE drives rear wheels, front wheels engaged via clutch. |
| Number of gears and type of gearbox | 6 gears, automatic transmission Allison |
| Front suspension | Independent torsion bar, double wishbone |
| Rear suspension | Rigid axle suspension, Leaf spring |
| Front brakes | Ventilated discs, 325×38 mm |
| Rear brakes | Ventilated discs, 325×30 mm |
| Assisting systems | ABS (Anti-lock braking system) |
| Steering type | Cone worm with recirculation balls |
| Tires size | 265/75 R16; 265/70 R17; 225/75 R17 |
| Wheel rims size | 6.5J x 17; 7J x 16; 7.5J x 17 |
INTRODUCTION
The 2007-2010 GMC Sierra 3500HD Crew Cab Long Box, equipped with the 6.6-liter Duramax diesel and Allison automatic, was a workhorse designed for demanding tasks. Built on the GMT900 platform, this generation represented a significant step forward in heavy-duty truck refinement. The Crew Cab configuration offered increased passenger space, making it suitable for both work and family use, while the long box provided ample cargo capacity. The Dual Rear Wheel (DRW) setup, signified by the presence of two wheels on each rear axle, dramatically increased stability and payload capacity, making it ideal for hauling heavy trailers and equipment. This variant sat at the top end of the 3500HD lineup, offering the highest towing and payload ratings.
Powertrain & Engine Architecture
The heart of this Sierra 3500HD is the Duramax LMM 6.6-liter V8 diesel engine. This engine utilized a common-rail direct fuel injection system, delivering fuel at extremely high pressure for improved combustion efficiency and reduced emissions. The LMM featured a variable geometry turbocharger (VGT) and an intercooler to maximize power and torque output. The engine’s valvetrain employed an overhead valve (OHV) configuration, known for its simplicity and durability. The Allison 1000 six-speed automatic transmission was specifically designed to handle the immense torque produced by the Duramax engine. This transmission featured a lock-up torque converter for improved fuel efficiency at highway speeds and a heavy-duty cooling system to prevent overheating under strenuous conditions. The engine’s robust construction and advanced technologies contributed to its reputation for reliability and longevity.
Driving Characteristics
The 365 horsepower and 895 lb-ft of torque delivered by the Duramax engine and Allison transmission provided impressive performance, even when heavily loaded. While not designed for outright speed, the truck offered strong acceleration and effortless towing capability. The Allison transmission’s six gears allowed for a wide range of ratios, optimizing engine speed for both fuel efficiency and power delivery. Compared to the gasoline-powered versions of the Sierra 3500HD, the Duramax diesel offered significantly more torque at lower RPMs, making it ideal for hauling heavy loads and navigating challenging terrain. Compared to other Duramax variants, like those with slightly less power, this 365hp version offered a noticeable increase in pulling power, making it a favorite among those who frequently tow large trailers. The DRW configuration further enhanced stability, reducing body roll and providing a more confident driving experience, especially when towing.
Equipment & Trim Levels
The Crew Cab Long Box 3500HD typically came standard with features like air conditioning, power windows and locks, and a basic audio system. Higher trim levels, such as the SLT and Denali, added luxury features like leather upholstery, heated seats, a premium audio system, and navigation. Optional extras included a sunroof, rear-seat entertainment system, and various towing packages. The interior design focused on functionality and durability, with comfortable seating and easy-to-use controls. The spacious Crew Cab provided ample room for passengers, making long trips more comfortable.
Chassis & Braking
The Sierra 3500HD’s chassis was designed for heavy-duty use, featuring a robust frame and heavy-duty suspension components. The front suspension utilized an independent torsion bar and double wishbone setup, providing a comfortable ride and good handling. The rear suspension employed a rigid axle with leaf springs, offering excellent load-carrying capacity. Braking duties were handled by ventilated disc brakes on all four wheels, providing ample stopping power even when heavily loaded. An Anti-lock Braking System (ABS) was standard, enhancing safety and control. The DRW configuration significantly increased the truck’s stability and braking performance.
Market Reception & Comparison
The 2007-2010 GMC Sierra 3500HD with the Duramax diesel and Allison automatic received positive reviews from critics and owners alike. It was praised for its powerful engine, smooth transmission, and impressive towing and hauling capabilities. Fuel economy, while not exceptional, was considered reasonable for a heavy-duty truck of its size and capability. Compared to other trucks in its class, such as the Ford Super Duty and Ram 3500, the Sierra 3500HD was often seen as offering a good balance of power, refinement, and reliability. The Duramax engine’s reputation for longevity and low maintenance costs also contributed to its popularity.
Legacy
The Duramax LMM engine and Allison transmission combination proved to be exceptionally durable, and many of these trucks remain on the road today with high mileage. While some maintenance items, such as the fuel injectors and turbocharger, may require attention over time, the powertrain is generally considered to be very reliable. The 2007-2010 Sierra 3500HD continues to be a popular choice in the used truck market, particularly among those seeking a capable and dependable work truck. Its strong resale value reflects its reputation for quality and longevity. The GMT900 platform laid the groundwork for future generations of GMC heavy-duty trucks, continuing a legacy of robust performance and dependability.
