The Chevrolet Silverado 2500 HD II (GMT900) Crew Cab Standard Box, equipped with the 6.6-liter Duramax TD V8 engine producing 365 horsepower and paired with an automatic transmission, represents a significant iteration in Chevrolet’s heavy-duty truck lineage. Produced from 2007 to 2010, this variant occupied a key position in the 2500 HD lineup, catering to buyers needing substantial towing and hauling capacity without sacrificing interior space and comfort. It was part of the GMT900 platform generation, a substantial redesign for Chevrolet’s heavy-duty trucks, focusing on increased strength, improved refinement, and enhanced capability.
Technical Specifications
| Brand | Chevrolet |
| Model | Silverado 2500 HD |
| Generation | Silverado 2500 HD II (GMT900) Crew Cab Standard Box |
| Type (Engine) | 6.6 Duramax TD V8 (365 Hp) 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 kg/Hp, 125.4 Hp/tonne |
| Weight-to-torque ratio | 3.3 kg/Nm, 307.5 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 | 2911 kg (6417.66 lbs.) |
| Max. weight | 4173 kg (9199.89 lbs.) |
| Max load | 1262 kg (2782.23 lbs.) |
| Trunk (boot) space – maximum | 1718 l (60.67 cu. ft.) |
| Permitted trailer load with brakes (12%) | 5897 kg (13000.66 lbs.) |
| Length | 6094 mm (239.92 in.) |
| Width including mirrors | 2032 mm (80 in.) |
| Height | 1958 mm (77.09 in.) |
| Wheelbase | 3886 mm (152.99 in.) |
| Front track | 1744 mm (68.66 in.) |
| Rear (Back) track | 1676 mm (65.98 in.) |
| Ride height (ground clearance) | 243 mm (9.57 in.) |
| Minimum turning circle (turning diameter) | 15.6 m (51.18 ft.) |
| Drivetrain Architecture | Rear wheel drive |
| 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 |
| Tires size | 245/75 R16; 265/75 R17 |
| Wheel rims size | 6.5J x 16; 7.5J x 17 |
INTRODUCTION
The 2007-2010 Chevrolet Silverado 2500 HD II Crew Cab with the 6.6L Duramax diesel and Allison automatic transmission was a workhorse designed for demanding tasks. Positioned as a mid-to-high range offering within the 2500 HD lineup, it bridged the gap between the gasoline-powered engines and the more expensive, fully-loaded trims. The GMT900 platform brought a significant overhaul to the Silverado HD series, improving structural rigidity, interior space, and overall refinement compared to its predecessor. This generation aimed to provide a comfortable and capable truck for both commercial and personal use, particularly for those needing to tow large trailers or haul heavy loads.
Powertrain & Engine Architecture
At the heart of this Silverado variant lies the Duramax LMM 6.6-liter V8 diesel engine. This engine is a turbocharged, overhead valve (OHV) design featuring a common-rail direct fuel injection system. The LMM represented an evolution of the previous LBZ Duramax, incorporating a more efficient turbocharger and improved engine management software. The common-rail system allowed for precise fuel delivery, optimizing combustion and maximizing power and efficiency. The engine produced 365 horsepower at 3200 rpm and a robust 895 lb-ft of torque at 1600 rpm.
The engine is mated to the Allison 1000 six-speed automatic transmission, renowned for its durability and ability to handle high torque loads. This transmission was specifically designed for heavy-duty applications and featured a lock-up torque converter for improved fuel economy at highway speeds. The Allison transmission’s gear ratios were optimized to provide strong acceleration and efficient cruising, even when towing heavy loads. The transmission also featured a tow/haul mode, which adjusted shift points to better manage trailer weight and reduce transmission temperatures.
Driving Characteristics
The Silverado 2500 HD with the Duramax/Allison combination delivered a driving experience focused on capability and control. While not a sports truck, the ample torque of the Duramax engine provided strong acceleration, even with a substantial load. The Allison transmission shifted smoothly and predictably, contributing to a comfortable ride. Compared to the gasoline-powered Silverado 2500 HD models, the diesel offered significantly more low-end torque, making it ideal for towing and hauling. Compared to the 8.1L gasoline V8, the Duramax offered superior fuel economy, especially under load. Against other Duramax variants, like those with manual transmissions, the automatic offered convenience and ease of use, though some performance was sacrificed. The automatic transmission’s gear ratios were tuned for work, prioritizing pulling power over outright speed.
Equipment & Trim Levels
The Crew Cab configuration provided spacious seating for five passengers, making it a comfortable option for families or work crews. Standard equipment typically included air conditioning, power windows and locks, a CD player, and cloth upholstery. The Silverado 2500 HD II offered various trim levels, with the Duramax/Allison combination often found in LT and LTZ trims. LT models added features like chrome exterior trim, upgraded interior materials, and a premium sound system. LTZ trims further enhanced the luxury with leather upholstery, heated seats, and additional convenience features. Optional extras included a navigation system, a sunroof, and a rear-seat entertainment system.
Chassis & Braking
The Silverado 2500 HD II featured a fully boxed frame, providing a solid foundation for heavy-duty use. The front suspension utilized an independent torsion bar setup with double wishbones, while the rear suspension employed a traditional leaf spring design. This combination provided a balance of ride comfort and load-carrying capacity. Braking duties were handled by ventilated disc brakes on all four wheels, with ABS (Anti-lock Braking System) as standard equipment. The rear brakes were slightly smaller in diameter than the front brakes to optimize braking performance and cost. The truck’s robust chassis and braking system were designed to handle the substantial weight of the vehicle and its potential payloads.
Market Reception & Comparison
The 2007-2010 Chevrolet Silverado 2500 HD with the Duramax diesel and Allison automatic received generally positive reviews. Critics praised its powerful engine, smooth transmission, and comfortable ride. The truck was recognized as a capable workhorse, well-suited for towing and hauling. Fuel economy was considered good for a heavy-duty truck, although it still lagged behind lighter-duty pickups. Compared to the Ford Super Duty and Ram Heavy Duty trucks of the same era, the Silverado 2500 HD was often seen as offering a good balance of capability, comfort, and value. The Duramax/Allison combination was particularly well-regarded for its reliability and longevity.
Legacy
The Duramax LMM engine and Allison transmission pairing in the Silverado 2500 HD II have proven to be remarkably durable and reliable. These trucks continue to be popular in the used market, commanding relatively high prices due to their reputation for longevity and capability. Properly maintained examples can easily exceed 200,000 miles. Common maintenance items include regular oil changes, fuel filter replacements, and coolant flushes. While the LMM Duramax is generally considered a robust engine, potential issues can include injector failure and turbocharger wear. Overall, the 2007-2010 Chevrolet Silverado 2500 HD II Crew Cab with the 6.6L Duramax and Allison automatic remains a highly sought-after truck for those needing a powerful and dependable heavy-duty workhorse.
