The Chevrolet Silverado 3500 HD II (GMT900) Crew Cab Long Box, equipped with the 6.6-liter Duramax Turbo Diesel V8 engine producing 365 horsepower and paired with an Allison automatic transmission, represents a significant iteration in Chevrolet’s heavy-duty truck lineage. Produced from 2007 to 2010, this variant occupied a premium position within the GMT900 generation, catering to buyers requiring substantial towing and hauling capabilities combined with a degree of comfort and refinement. It was a key player in the competitive American heavy-duty truck market, directly challenging offerings from Ford and Dodge.
Technical Specifications
| Brand | Chevrolet |
| Model | Silverado 3500 HD |
| Generation | Silverado 3500 HD II (GMT900) Crew Cab Long Box |
| Type (Engine) | 6.6 Duramax TD V8 (365 Hp) SRW 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 | 8.3 kg/Hp, 120.5 Hp/tonne |
| Weight-to-torque ratio | 3.4 kg/Nm, 295.5 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 | 3029 kg (6677.8 lbs.) |
| Max. weight | 4445 kg (9799.55 lbs.) |
| Max load | 1416 kg (3121.75 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 | 1931 mm (76.02 in.) |
| Wheelbase | 4242 mm (167.01 in.) |
| Front track | 1742 mm (68.58 in.) |
| Rear (Back) track | 1676 mm (65.98 in.) |
| Ride height (ground clearance) | 233 mm (9.17 in.) |
| Minimum turning circle (turning diameter) | 16.8 m (55.12 ft.) |
| Drivetrain Architecture | Rear wheel drive. Internal Combustion engine (ICE) drives the rear wheels. |
| 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; 225/75 R17 |
| Wheel rims size | 7J x 16; 7.5J x 17 |
INTRODUCTION
The 2007-2010 Chevrolet Silverado 3500 HD II Crew Cab Long Box, powered by the 6.6L Duramax diesel and Allison automatic, was a cornerstone of Chevrolet’s heavy-duty truck offerings. Built on the GMT900 platform, this generation represented a significant step forward in terms of capability, refinement, and interior space compared to its predecessors. The Crew Cab configuration, combined with the long bed, provided a compelling blend of passenger comfort and cargo capacity, making it popular with both commercial users and individuals needing a powerful and versatile truck. This specific configuration, with the Duramax/Allison pairing, was positioned as a premium offering, appealing to those who prioritized performance and durability.
Powertrain & Engine Architecture
At the heart of this Silverado 3500 HD lies the Duramax LMM 6.6-liter turbocharged diesel V8. This engine, a product of a joint venture between General Motors and Isuzu, was renowned for its robust construction and impressive torque output. The LMM featured a common-rail fuel injection system, delivering highly pressurized fuel directly into the cylinders for optimized combustion. The engine utilized an overhead valve (OHV) valvetrain, a design choice favored for its simplicity and durability. A variable geometry turbocharger and intercooler further enhanced performance and efficiency. The Allison 1000 series 6-speed automatic transmission was specifically designed to handle the immense torque produced by the Duramax engine. This transmission featured electronically controlled shifting and a lock-up torque converter, contributing to smooth operation and improved fuel economy. The Allison’s durability was a key selling point, known for its ability to withstand the stresses of heavy towing and hauling.
Driving Characteristics
The 365 horsepower and 895 lb-ft of torque delivered by the Duramax/Allison combination translated into impressive real-world performance. While not as quick accelerating as gasoline-powered trucks, the Silverado 3500 HD excelled in situations requiring substantial pulling power. The Allison transmission’s six gears allowed for a wide range of ratios, optimizing engine speed for both towing and highway cruising. Compared to the 6.0L gasoline V8 offered in the Silverado 3500 HD, the Duramax provided significantly more low-end torque, making it far more capable when towing heavy loads. Compared to the 1.9L TDI versions, the Duramax offered a much higher towing capacity and overall power. The automatic transmission, while convenient, did result in a slight reduction in fuel economy compared to the available manual transmission, but the trade-off in ease of use was often considered worthwhile by many drivers.
Equipment & Trim Levels
The Silverado 3500 HD II Crew Cab Long Box with the Duramax/Allison powertrain typically came well-equipped, even in its base trim. Standard features included air conditioning, power windows and locks, a CD player, and cloth upholstery. Higher trim levels, such as the LT and LTZ, added features like leather upholstery, heated seats, a premium sound system, and navigation. Optional extras included a sunroof, rear-seat entertainment system, and various towing packages. The Crew Cab configuration offered ample space for five passengers, making it a comfortable option for families or work crews. The long bed provided a generous cargo area, further enhancing the truck’s versatility.
Chassis & Braking
The Silverado 3500 HD featured a robust chassis designed to withstand the stresses of heavy-duty use. The front suspension utilized an independent torsion bar and double wishbone setup, providing a comfortable ride and good handling. The rear suspension employed a traditional leaf spring design, optimized for load-carrying capacity. Braking duties were handled by ventilated disc brakes on all four wheels, providing ample stopping power. An Anti-lock Braking System (ABS) was standard equipment. The rear axle ratios varied depending on the specific configuration, influencing both towing capacity and fuel economy. Stabilizer bars were included to reduce body roll during cornering.
Market Reception & Comparison
The Duramax/Allison-equipped Silverado 3500 HD received generally positive reviews from automotive critics. It was praised for its powerful engine, smooth-shifting transmission, and comfortable ride. Fuel economy, while not exceptional, was considered acceptable for a truck of its size and capability. Compared to the Ford Super Duty and Dodge Ram HD trucks of the same era, the Silverado 3500 HD was often seen as offering a good balance of performance, refinement, and value. Reliability was generally good, although some owners reported issues with the emissions control system, particularly the particulate filter.
Legacy
The Duramax LMM engine and Allison transmission pairing have proven to be remarkably durable and reliable powertrains. Well-maintained examples of the 2007-2010 Silverado 3500 HD continue to command strong prices in the used car market. The engine’s longevity and the transmission’s robustness make it a popular choice for buyers seeking a capable and dependable heavy-duty truck. The GMT900 platform, while superseded by newer generations, remains a respected and capable platform, and the 6.6L Duramax continues to be a popular engine choice in Chevrolet and GMC trucks today, albeit in updated and refined forms. The combination of power, durability, and comfort has cemented this Silverado 3500 HD variant’s place as a significant truck in Chevrolet’s history.
