The GMC Sierra 3500HD IV (GMTK2XX) Crew Cab Long Box, specifically equipped with the 6.6-liter Duramax Turbo Diesel V8 engine producing 445 horsepower and paired with an Allison automatic transmission, represents a significant iteration in GMC’s heavy-duty truck lineage. Produced from 2017 to 2019, this variant occupied a premium position within the Sierra 3500HD lineup, targeting buyers requiring substantial towing and hauling capabilities alongside a comfortable, well-equipped cabin. It was part of the fourth generation of the Sierra/Silverado HD trucks, known as the GMTK2XX platform, which brought substantial improvements in strength, refinement, and technology compared to its predecessors.
Technical Specifications
| Brand | GMC |
| Model | Sierra 3500HD |
| Generation | Sierra 3500HD IV (GMTK2XX) Crew Cab Long Box |
| Type (Engine) | 6.6 Duramax TD V8 (445 Hp) DRW Automatic |
| Start of production | 2017 |
| End of production | 2019 |
| Powertrain Architecture | Internal Combustion engine |
| Body type | Pick-up |
| Seats | 5 |
| Doors | 4 |
| Fuel Type | Diesel |
| Weight-to-power ratio | 7.9 kg/Hp, 127.1 Hp/tonne |
| Weight-to-torque ratio | 2.8 kg/Nm, 352.5 Nm/tonne |
| Power | 445 Hp @ 2800 rpm |
| Power per litre | 67.4 Hp/l |
| Torque | 1234 Nm @ 1600 rpm (910.15 lb.-ft. @ 1600 rpm) |
| Engine layout | Front, Longitudinal |
| Engine Model/Code | Duramax L5P |
| Engine displacement | 6604 cm3 (403 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 | 16:1 |
| 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 | 29.7 l (31.38 US qt | 26.13 UK qt) |
| Kerb Weight | 3501 kg (7718.38 lbs.) |
| Max. weight | 5908 kg (13024.91 lbs.) |
| Max load | 2407 kg (5306.53 lbs.) |
| Trunk (boot) space – maximum | 2162 l (76.35 cu. ft.) |
| Fuel tank capacity | 136 l (35.93 US gal | 29.92 UK gal) |
| Permitted trailer load with brakes (12%) | 9072 kg (20000.34 lbs.) |
| Length | 6563 mm (258.39 in.) |
| Width including mirrors | 2438 mm (95.98 in.) |
| Height | 1976 mm (77.8 in.) |
| Wheelbase | 4259 mm (167.68 in.) |
| Front track | 1748 mm (68.82 in.) |
| Rear (Back) track | 1906 mm (75.04 in.) |
| Minimum turning circle (turning diameter) | 17 m (55.77 ft.) |
| Drivetrain Architecture | Rear wheel drive |
| Number of gears and type of gearbox | 6 gears, automatic transmission Allison |
| Front suspension | Coil spring, Double wishbone, Transverse stabilizer |
| Rear suspension | Rigid axle suspension, Leaf spring |
| Front brakes | Ventilated discs, 355×40 mm |
| Rear brakes | Ventilated discs, 355×40 mm |
Introduction
The 2017-2019 GMC Sierra 3500HD Crew Cab Long Box with the 6.6L Duramax diesel and Allison automatic transmission was a cornerstone of GMC’s heavy-duty truck offerings. Built on the GMTK2XX platform, it represented a move towards increased capability, refinement, and technology. This particular configuration was aimed at customers who needed a powerful truck for demanding tasks like hauling large trailers, construction work, or commercial applications, but also desired a comfortable and spacious interior for daily driving. The “DRW” designation indicates a Dual Rear Wheel configuration, further enhancing its towing and payload capacity.
Powertrain & Engine Architecture
At the heart of this Sierra 3500HD lies the Duramax L5P 6.6-liter turbocharged diesel V8 engine. This engine is a testament to modern diesel technology, featuring a cast iron block, aluminum cylinder heads, and a robust rotating assembly. The L5P utilizes a common-rail direct fuel injection system, delivering fuel at extremely high pressures for optimized combustion and efficiency. The turbocharger, coupled with an intercooler, provides increased air intake, boosting power and torque. The engine’s overhead valve (OHV) valvetrain, while traditional, is known for its durability and reliability. The Allison 1000 Series 6-speed automatic transmission is specifically designed to handle the immense torque output of the Duramax engine. This transmission features electronically controlled shifts and a lock-up torque converter for improved fuel economy and responsiveness. The Allison is renowned for its durability and smooth operation, making it a preferred choice for heavy-duty applications.
Driving Characteristics
The combination of the 445 horsepower and 910 lb-ft of torque delivered by the Duramax engine and the Allison transmission results in a driving experience that is both powerful and refined. While not as quick off the line as gasoline-powered trucks, the Sierra 3500HD excels in situations requiring substantial pulling power. The Allison transmission’s gear ratios are optimized for towing, providing ample torque in lower gears and efficient cruising in higher gears. Compared to the 6.0L gasoline V8 option, the Duramax offers significantly more torque, making it the preferred choice for heavy hauling. Compared to the 6.6L Duramax in earlier generations, the L5P offered a noticeable increase in horsepower and torque, improving overall performance. The DRW configuration provides enhanced stability when towing heavy loads, minimizing sway and improving control.
Equipment & Trim Levels
The Crew Cab Long Box configuration offered a spacious interior with seating for five passengers. Standard features typically included air conditioning, power windows and locks, a rearview camera, and a basic infotainment system. Higher trim levels, such as the SLT and Denali, added features like leather upholstery, heated and ventilated seats, a premium sound system, navigation, and advanced safety technologies. Optional extras included a sunroof, upgraded wheels, and various towing packages. The interior design focused on functionality and durability, with comfortable seating and easy-to-use controls.
Chassis & Braking
The Sierra 3500HD’s chassis is built for strength and durability. The frame is fully boxed and constructed from high-strength steel. The front suspension utilizes coil springs and a double wishbone design, while the rear suspension employs a traditional leaf spring setup. The DRW configuration features a wider rear axle for increased stability. Braking duties are handled by ventilated disc brakes on all four wheels, providing ample stopping power even when hauling heavy loads. An Anti-lock Braking System (ABS) is standard, enhancing safety and control. The steering system utilizes a recirculating ball mechanism, providing a solid and predictable feel.
Market Reception & Comparison
The 2017-2019 GMC Sierra 3500HD with the Duramax diesel and Allison automatic received generally positive reviews from automotive critics. It was praised for its powerful engine, smooth transmission, comfortable ride, and impressive towing capabilities. Fuel economy, while typical for a heavy-duty diesel truck, was considered competitive. Compared to the Ford Super Duty and Ram 3500, the Sierra 3500HD was often seen as offering a good balance of capability, refinement, and value. The Duramax engine’s reputation for reliability was a significant selling point, although diesel engines generally require more expensive maintenance than gasoline engines.
Legacy
The Duramax L5P engine and Allison transmission pairing has proven to be exceptionally reliable, and well-maintained examples continue to command strong resale values in the used truck market. The GMTK2XX platform Sierra 3500HD is considered a robust and capable truck, capable of providing years of dependable service. The combination of power, towing capacity, and interior comfort makes it a popular choice for both personal and commercial use. While newer generations of the Sierra 3500HD offer even more advanced technology and features, the 2017-2019 model remains a highly regarded and capable heavy-duty truck.
