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. The “II” designation signifies a mid-cycle refresh of the GMT900 platform, introducing updated styling and improved features compared to the initial 2007 models.
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) 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 | 8.8 kg/Hp, 114.1 Hp/tonne |
| Weight-to-torque ratio | 3.6 kg/Nm, 279.7 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 | 3200 kg (7054.79 lbs.) |
| Max. weight | 5171 kg (11400.1 lbs.) |
| Max load | 1971 kg (4345.31 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 | 1897 mm (74.69 in.) |
| Ride height (ground clearance) | 233 mm (9.17 in.) |
| Drivetrain Architecture | Rear wheel drive. Internal Combustion engine. |
| 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 | 225/75 R17 |
| Wheel rims size | 6.5J x 17 |
INTRODUCTION
The 2007-2010 Chevrolet Silverado 3500 HD II Crew Cab Long Box with the 6.6L Duramax diesel and Allison automatic transmission was a workhorse designed for serious tasks. Built on the GMT900 platform, this truck was aimed at customers needing substantial towing and payload capacity, such as contractors, ranchers, and those frequently hauling heavy equipment. The Crew Cab configuration offered increased passenger space compared to the standard cab models, making it suitable for both work and family use. This particular variant, with its robust diesel engine and automatic transmission, represented a premium offering within the Silverado 3500 HD lineup.
Powertrain & Engine Architecture
At the heart of this Silverado 3500 HD lies the Duramax LMM 6.6-liter turbocharged diesel V8 engine. This engine is a significant evolution of the previous LBZ Duramax, featuring a redesigned combustion chamber and improved fuel injection system. The LMM utilizes a common-rail direct injection system, delivering fuel at extremely high pressures for optimized combustion efficiency and reduced emissions. The engine produces 365 horsepower at 3200 rpm and a substantial 895 lb-ft of torque at 1600 rpm. The valvetrain employs an overhead valve (OHV) configuration, known for its durability and simplicity. The Allison 1000 series 6-speed automatic transmission is specifically designed to handle the high torque output of the Duramax engine. This transmission features a lock-up torque converter for improved fuel efficiency and a heavy-duty cooling system to prevent overheating under demanding conditions. The transmission’s gear ratios are optimized for both towing and everyday driving, providing a balance of power and efficiency.
Driving Characteristics
The Silverado 3500 HD II with the Duramax/Allison combination delivers a driving experience focused on capability rather than outright speed. The immense torque available from low engine speeds allows for effortless towing and hauling, even with heavy loads. While not a sports truck, the 365 horsepower provides adequate power for merging onto highways and maintaining speed on inclines. The Allison transmission shifts smoothly and predictably, contributing to a comfortable driving experience. Compared to the 6.0L gasoline V8 offered in the Silverado 3500 HD, the Duramax diesel provides significantly more torque and better fuel economy, especially when towing. However, the diesel engine is noticeably louder and produces more vibration than the gasoline counterpart. Compared to manual transmission equipped Duramax models, the Allison automatic offers convenience and ease of use, but some drivers may prefer the greater control offered by a manual gearbox.
Equipment & Trim Levels
The Silverado 3500 HD II Crew Cab Long Box with the Duramax/Allison powertrain typically came well-equipped, though specific features varied depending on the trim level (Work Truck, LT, LTZ). Standard features generally included air conditioning, power windows and locks, a CD player, and cloth upholstery. Higher trim levels, such as the LTZ, added features like leather upholstery, heated seats, a premium sound system, and chrome exterior trim. Optional extras included a navigation system, a sunroof, and various towing packages. The Crew Cab configuration provided ample space for five passengers, with a spacious rear seat offering comfortable seating for adults. The Long Box bed offered a generous 76.63 cubic feet of cargo space.
Chassis & Braking
The Silverado 3500 HD II features a robust chassis designed to withstand heavy loads. The front suspension utilizes an independent torsion bar setup with double wishbone components, providing a comfortable ride and good handling. The rear suspension employs a traditional leaf spring design, optimized for load-carrying capacity. Braking duties are handled by ventilated disc brakes on all four wheels, providing ample stopping power. An Anti-lock Braking System (ABS) is standard. Due to the truck’s weight and intended use, rear brakes were often smaller in diameter than the front brakes. The steering system utilizes a cone worm with recirculation balls, providing a solid and predictable steering feel.
Market Reception & Comparison
The Silverado 3500 HD II with the Duramax/Allison combination was generally well-received by critics and consumers alike. It was praised for its exceptional towing and hauling capabilities, comfortable ride, and refined interior (especially in higher trim levels). Fuel economy was considered good for a heavy-duty truck, particularly when compared to gasoline-powered alternatives. However, some critics noted the higher price tag compared to other trucks in the segment. Compared to the Ford Super Duty and Ram Heavy Duty trucks of the same era, the Silverado 3500 HD offered a competitive combination of power, capability, and refinement. The Duramax/Allison combination was often considered a superior powertrain to the gasoline engines offered by competitors.
Legacy
The Duramax LMM engine and Allison transmission pairing in the 2007-2010 Silverado 3500 HD II have proven to be remarkably durable and reliable. These trucks continue to be popular on the used car market, commanding relatively high prices due to their reputation for longevity and capability. While some maintenance items, such as the fuel injectors and turbocharger, may require attention after high mileage, the core powertrain is generally considered robust. The GMT900 platform, and specifically this Duramax/Allison configuration, established a strong foundation for future generations of Chevrolet heavy-duty trucks, solidifying the Silverado’s position as a leading contender in the full-size truck segment.
