2007-2010 Chevrolet Silverado 3500 HD II (GMT900) Crew Cab Long Box 6.6 Duramax TD V8 (365 Hp) 4WD DRW Automatic

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 a 4WD and 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 comfortable, crew cab interior. This model was primarily aimed at the North American market, where heavy-duty trucks are essential for both commercial and personal use, particularly in industries like agriculture, construction, and ranching.

Technical Specifications

INTRODUCTION

The Silverado 3500 HD II, specifically this Crew Cab Long Box configuration with the Duramax diesel and Allison automatic, was introduced as part of the GMT900 series, a comprehensive redesign of Chevrolet’s heavy-duty truck lineup. The GMT900 platform aimed to improve upon the previous generation in terms of capability, comfort, and refinement. This particular variant was positioned as a premium offering, appealing to customers who needed the robust towing capacity of a 3500-series truck but also desired the space and convenience of a crew cab. Production spanned from 2007 through 2010, with the LMM Duramax engine being a key feature during this period.

Powertrain & Engine Architecture

At the heart of this Silverado 3500 HD II lies the Duramax LMM 6.6-liter V8 diesel engine. This engine is a turbocharged, overhead valve (OHV) design, utilizing 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, contributing to both power and fuel economy. The Allison 1000 series 6-speed automatic transmission was specifically designed to handle the high torque output of the Duramax engine. This transmission featured a lock-up torque converter for improved efficiency and durability. The engine’s longitudinal mounting and rear-wheel-drive base, coupled with the electronically controlled 4WD system, provided excellent traction and control in various conditions.

Driving Characteristics

The 365 horsepower and 895 lb-ft of torque delivered by the Duramax engine, combined with the Allison automatic, resulted in a truck capable of impressive towing and hauling. While not as quick as lighter-duty Silverado models, the 3500 HD II offered substantial pulling power, making it ideal for transporting heavy loads. The Allison transmission’s six gears allowed for a relatively wide range of ratios, optimizing both acceleration and fuel efficiency. Compared to the 6.0L gasoline V8 option, the Duramax provided significantly more torque at lower RPMs, making towing less strenuous on the engine. Compared to other Duramax variants, like those with higher horsepower ratings in later years, this version prioritized torque delivery for work applications over outright speed. The automatic transmission, while convenient, didn’t offer the same level of control as a manual transmission, but it simplified operation for a wider range of drivers.

Equipment & Trim Levels

The Crew Cab configuration provided ample space for passengers, making it suitable for both work and family use. Standard features typically included air conditioning, power windows and locks, and a basic audio system. Higher trim levels, such as LT and LTZ, added features like leather upholstery, heated seats, a premium audio system, and navigation. Optional extras included a sunroof, upgraded wheels, and various towing packages. The interior design was functional and durable, reflecting the truck’s work-oriented nature. The long box provided a generous cargo bed for hauling materials.

Chassis & Braking

The Silverado 3500 HD II featured a robust chassis designed to withstand heavy loads. 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 good balance of ride comfort and load-carrying capacity. Braking duties were handled by ventilated disc brakes on all four wheels, with ABS as standard equipment. The dual rear wheel (DRW) configuration further enhanced stability and load capacity. Stabilizer bars were incorporated to reduce body roll during cornering.

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 exceptional, was considered reasonable for a truck of its size and capability. Compared to the gasoline-powered Silverado 3500 HD models, the Duramax diesel offered significantly better fuel economy and towing performance. The Duramax/Allison combination was often seen as a superior choice for those who frequently towed heavy loads. However, the diesel engine came with a higher initial cost and potentially higher maintenance expenses.

Legacy

The Duramax LMM engine, found in this Silverado 3500 HD II, has proven to be a durable and reliable powertrain. While some early LMM engines experienced issues with the fuel injectors, these were largely addressed through updates and revisions. Today, well-maintained examples of this truck are still common on the used car market, and they continue to be valued for their towing and hauling capabilities. The GMT900 platform laid the groundwork for future generations of Chevrolet heavy-duty trucks, and the Duramax diesel remains a popular choice for those who need a powerful and reliable work truck. The Allison transmission is also highly regarded for its durability and performance.