Test it Out: Mack Defense Begins Production Vehicle Testing Phase with Armored M917A3
Mack Defense Shows Off Heavy Dump Truck
Based on the commercially available Mack Granite model, the Mack Defense HDT is part of the previously announced firm-fixed price $296 million contract with the U.S. Army to be fulfilled over seven years.

Mack Defense will feature a production M917A3 Heavy Dump Truck (HDT) at the Association of the United States Army (AUSA) 2022 Annual Meeting and Exposition in Washington, D.C.
Photo: Mack Trucks
Mack Defense will feature a production M917A3 Heavy Dump Truck (HDT) at the Association of the United States Army (AUSA) 2022 Annual Meeting and Exposition, Oct 10-12, at the Walter E. Washington Convention Center in Washington, D.C.
Based on the commercially available Mack Granite model, the Mack Defense HDT is part of the previously announced firm-fixed price $296 million contract to be fulfilled over seven years that the Army awarded Mack Defense in 2018. Mack Defense began production of the HDT vehicle in 2021 at the Mack Experience Center in Allentown, Pennsylvania.
This will be the first time that a production version of the Mack HDT is on display at AUSA and is one of many the U.S. Army is purchasing and fielding to the Army, Army Reserve and the National Guard.
“We are proud to publicly show a production version of the Mack M917A3 HDT for the first time at AUSA,” said David Hartzell, president of Mack Defense. “The response has been very positive, and we look forward to continuing to build these trucks to meet the U.S. Army’s demanding operational requirements with a modified commercial-based vehicle.”
Getting to Know the Mack Defense M9173A HDT
When it comes to specifications, this heavy-duty defense truck has what the military needs:
GVW: 94,500 lbs.
Wheel Configuration: 8x8
Frame: 300mm X 90mm X 11.1mm with steel reinforcement frame
Wheelbase: 243"
Platform: 230"
Mack Defense optimized the M917A3 HDT to meet the current performance needs of the U.S. Army, but included modularity in the design, to more easily adapt to evolving requirements. Mack Defense engineers added heavier-duty rear axles and all-wheel drive, while increasing the suspension travel and ride height to create a heavy dump truck capable of meeting the demanding payload and mobility requirements set forth by the U.S. Army HDT program.
Powered by a Mack 13.0L MP8 440, the truck achieves 440 hp at 1,660 lb.-ft. of torque.
The HDTs are a key component in construction and maintenance missions for infrastructure assets, such as airfields, roadways, landing strips, supply facilities and motor pools.
Built on the Mack Granite, the HDT model is a modern truck equipped with state-of-the-art technology, such as an anti-lock braking system (ABS), back-up camera, blind spot sensors, and inclinometer to ensure safe dump operations.
The Granite model is user-friendly, more comfortable and safer to operate than past models used by the Army, which is key to the Army’s investment in the new HDTs. The Granite HDTs and assembly processes were inspected by the government’s quality auditors to ensure expectations were met or exceeded.
Prefer to watch? Check out this video for more details on the Mack Defense M917A3 Heavy Dump Truck:
Mack Defense is a member of AUSA, which has a vision to be the premier voice for American soldiers. AUSA is committed to building the best professional and representative association for the U.S. Army. More than 30,000 attendees visited AUSA in 2021, with 700 exhibitors representing 100 countries from around the world.
Looking Back
Mack Defense began producing Heavy Dump Trucks (HDT) at the Mack Experience Center in June of 2021, following an investment of $6.5 million to create a dedicated production line at the facility. Not stopping there, the automaker partnered with TenCate Advanced Armor USA to provide a force protection system for the Mack Granite-based M917A3 Heavy Dump Truck (HDT) and other Mack Defense vehicle platforms.
The truckmaker was originally awarded a $296 million firm-fixed price contract to be fulfilled over seven years. In August of 2022, the U.S. Army placed an order for 144 more trucks from Mack Defense.
Want to stay up to date on all of the Work Truck news, updates from Mack Defense and more? Register today for Bobit Connect for your secure and easy way to access your favorite content.
More Vehicle Research

Recalls You Need to Know About in August 2026
If you have Altec, Autocar, Chrysler, Daimler Truck, Ford, Heil, International, Orange EV, Paccar, Shyft Group, Volvo Trucks, or Wabash vehicles in your fleet, you should check these important recalls issued by the National Highway Safety Administration.
Read More →
DTNA to Close Portland Facility, Move Manufacturing to the Carolinas
Daimler Truck North America will shift production of the Western Star X-series, Freightliner eCascadia, and Freightliner eM2 from its Portland, Oregon, manufacturing facility to its manufacturing operations in the Carolinas.
Read More →
Kenworth T880: Powertrain & Customization Options
Vocational fleets often require trucks tailored to specific applications, and the Kenworth T880 is designed with flexibility in mind. In this video walkaround, Rachel Woods explains how the T880 can be configured to support a broad range of industries and operational requirements.
Read More →
Electrification Incentives: The Acquisition Windfall Fleets Can't Miss
Discover how fleets can use tax credits, grants, rebates, and vouchers to dramatically reduce electric truck and charging infrastructure costs—before today’s funding disappears.
Read More →
Top 50 Executive Fleets
It is that time of year again! Time for the 2026 list of the Top 50 Executive Fleets, presented by Automotive Fleet and Volvo as part of its annual Fleet 500. Download now to see this year's list of companies!
Read More →
Back at Star Nation for a Closer Look at Western Star Trucks and the People Behind Them
Work Truck returned to Western Star’s Star Nation Experience for another hands-on look at the trucks, technology, and operator community behind the brand.
Read More →The Top 300 Commercial Fleets
The Top 300 Commercial Fleets: See the List
Read More →
Mack Defense Receives Additional Order for 115 Heavy Dump Trucks Under U.S. Army’s M917A3 Program
The latest order of 115 Heavy Dump Trucks (HDTs) from Mack Defense for the National Guard is part of the $47-million order from the U.S. Army approved in the 2026 National Defense Appropriations Act.
Read More →
Rizon Introduces Service Combo Body, Increases Electric Truck Applications
Rizon now offers a combo service body that combines lockable storage and a spacious cargo bed in a single zero-emission vehicle. The body supports unique options including cranes, ladder racks, generators, lift gates, and work lighting for a wide range of vocational applications.
Read More →


