The Chevrolet Silverado 3500 HD II (GMT900) Crew Cab Long Box, equipped with the 6.6-liter Duramax TD V8 engine producing 365 horsepower and paired with a 4WD SRW 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 passenger comfort. It was a key player in the competitive North American heavy-duty truck market, directly challenging offerings from Ford and Dodge (Ram).
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) 4WD 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 | 8.7 kg/Hp, 115.1 Hp/tonne |
| Weight-to-torque ratio | 3.5 kg/Nm, 282.2 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 | 3172 kg (6993.06 lbs.) |
| Max. weight | 4490 kg (9898.76 lbs.) |
| Max load | 1318 kg (2905.69 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 | 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 | The Internal combustion engine (ICE) drives the rear wheels permanently, and the front wheels are driven through an electrically or mechanically operated clutch if necessary. |
| Drive wheel | All wheel drive (4×4) |
| 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 | 265/70 R17; 225/75 R17 |
| Wheel rims size | 7J x 16; 7.5J x 17 |
INTRODUCTION
The Chevrolet Silverado 3500 HD II (GMT900) Crew Cab Long Box with the 6.6L Duramax diesel and Allison automatic transmission, produced between 2007 and 2010, represented a significant upgrade over its predecessors. Built on the GMT900 platform, this truck was designed to provide a blend of heavy-duty capability, improved ride quality, and enhanced interior features. The Crew Cab configuration offered expanded rear-seat space, making it suitable for both work and family use. This particular variant, with its potent diesel engine and automatic transmission, was positioned as a premium offering within the Silverado 3500 HD lineup, appealing to customers who needed substantial towing capacity and a comfortable driving experience.
Powertrain & Engine Architecture
At the heart of this Silverado 3500 HD lies the Duramax LMM 6.6-liter V8 diesel engine. This engine is a turbocharged, intercooled diesel featuring a common-rail fuel injection system. The LMM engine built upon the foundation of the earlier LBZ Duramax, incorporating a revised electronic control module (ECM) and improved exhaust gas recirculation (EGR) system to meet stricter emissions standards. The engine boasts a 16.8:1 compression ratio and utilizes an overhead valve (OHV) valvetrain. The Duramax LMM produces 365 horsepower at 3200 rpm and a substantial 895 lb-ft of torque at 1600 rpm. This torque output is crucial for heavy towing and hauling. The engine is mated to the Allison 1000 six-speed automatic transmission, known for its durability and smooth shifting. This transmission is specifically designed to handle the high torque output of the Duramax engine. The Allison transmission features electronically controlled shifting and a lock-up torque converter for improved fuel efficiency.
Driving Characteristics
The Silverado 3500 HD with the 6.6L Duramax and Allison automatic delivers a driving experience focused on capability and stability. While not a performance-oriented truck, the abundant torque provides strong acceleration, even when heavily loaded. The Allison transmission shifts smoothly and efficiently, contributing to a comfortable ride. Compared to the manual transmission options available on the Silverado 3500 HD, the automatic offers ease of use, particularly in stop-and-go traffic or when towing. However, some drivers may prefer the more direct control offered by a manual gearbox. The 6-speed Allison transmission provides well-spaced gear ratios, allowing the engine to operate within its optimal power band. The truck’s substantial weight and long wheelbase contribute to a stable and planted feel, even when carrying heavy loads. Steering is relatively precise, although it can feel somewhat heavy at low speeds.
Equipment & Trim Levels
The Silverado 3500 HD II Crew Cab Long Box with the Duramax diesel 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, navigation, and a power sunroof. The Crew Cab configuration provided ample space for five passengers, with a spacious rear seat. Optional extras included a trailer brake controller, a backup camera, and various appearance packages. The Long Box bed offered a generous 2170 liters (76.63 cubic feet) of cargo space.
Chassis & Braking
The Silverado 3500 HD features a robust chassis designed to withstand heavy loads. The front suspension utilizes an independent torsion bar setup with double wishbones, providing a comfortable ride and good handling. The rear suspension employs a traditional leaf spring design, offering excellent load-carrying capacity. Braking duties are handled by ventilated disc brakes on all four wheels, with ABS (Anti-lock Braking System) as standard. Front brakes measure 325x38mm, while rear brakes are 325x30mm. The truck’s substantial weight necessitates a powerful braking system to ensure safe stopping distances, especially when towing.
Market Reception & Comparison
The Silverado 3500 HD II with the Duramax diesel and Allison automatic was generally well-received by critics and consumers alike. It was praised for its powerful engine, smooth transmission, and comfortable ride. Fuel economy, while not a primary concern for heavy-duty truck buyers, was considered reasonable for a vehicle of this size and capability. Compared to the gasoline-powered Silverado 3500 HD models, the Duramax diesel offered significantly more torque and better fuel economy, albeit at a higher initial cost. Compared to the Ford Super Duty and Dodge Ram 3500, the Silverado 3500 HD was often seen as offering a good balance of capability, comfort, and value. The Duramax engine was consistently ranked among the best diesel engines in the heavy-duty truck segment.
Legacy
The Duramax LMM engine and Allison transmission combination proved to be exceptionally durable and reliable. Well-maintained examples of the 2007-2010 Silverado 3500 HD continue to be highly sought after in the used truck market. The LMM Duramax is known for its longevity and relatively low maintenance costs, making it a popular choice for buyers seeking a dependable heavy-duty truck. While some early LMM engines experienced issues with the EGR cooler, these problems were generally addressed through recalls and updates. Today, these trucks represent a sweet spot in the heavy-duty truck market, offering a proven powertrain and a comfortable driving experience at a reasonable price.
