2 hours ago
The Origins of Diamond T and Reo
Diamond T and Reo were two iconic American truck manufacturers with roots stretching back to the early 20th century. Diamond T was founded in 1905 by C.A. Tilt in Chicago, known for its stylish and durable trucks. Reo, established by Ransom E. Olds in 1904 after his departure from Oldsmobile, focused on reliable commercial vehicles. Both brands earned reputations for quality and innovation, supplying trucks for civilian and military use through the Great Depression and World War II.
By the late 1950s, both companies were absorbed into White Motor Corporation, which merged them into Diamond Reo Trucks in 1967. This merger aimed to consolidate engineering and production while preserving brand heritage. The resulting trucks combined Diamond T’s rugged design with Reo’s mechanical reliability, creating a line of Class 8 vehicles that appealed to long-haul and vocational operators.
The Collapse and Rebirth of Diamond Reo
Despite strong brand loyalty and innovative models like the C-116 Giant, Diamond Reo struggled financially. In 1974, the company filed for bankruptcy. A year later, Loyal Osterlund and Ray Houseal, based in Harrisburg, Pennsylvania, acquired the rights to the Diamond Reo name and tooling. Their facility, originally a dealership and service center, became the new production site for a reborn Diamond Reo—now operating under the name Giant Trucks.
The revived company focused on building the C-116 Giant, a heavy-duty conventional truck powered by Cummins diesel engines. Production was modest, with only 131 units built in 1978. However, the trucks were known for their durability and customizability, often used in concrete mixing, dump hauling, and specialized vocational roles.
A construction firm in New Jersey ran a fleet of Deutz-powered Giant mixers throughout the 1980s. These trucks were praised for their simplicity and resistance to overheating, even in congested urban environments. Mechanics often joked that “you couldn’t kill a Giant,” a testament to their overbuilt frames and straightforward engineering.
Giant Trucks and the Osterlund Era
Under Osterlund’s leadership, Giant Trucks continued to produce Diamond Reo-branded vehicles into the 1990s. The Harrisburg plant was expanded to handle up to 10 trucks per day, though actual output remained closer to two units daily. Each truck was built to order, with options for Caterpillar or Cummins engines, Eaton or Allison transmissions, and Dana or Meritor axles.
The company’s approach was artisanal rather than industrial. Trucks were tailored to customer specifications, often incorporating parts from Navistar, Autocar, and other manufacturers. The Autocar steel cab was a common feature, paired with Diamond Reo’s signature long-nose hood and heavy-duty frame rails.
In 1985, the company introduced the T-Line series, blending vintage styling with modern components. These trucks were marketed as vocational workhorses, ideal for municipal fleets, construction firms, and independent haulers. The T-Line offered multiple hood lengths and cab configurations, with glider kits available for rebuild projects.
Transition to T-Line and Final Years
After Osterlund’s retirement, a group of former employees continued production under the name Diamond Vehicle Solutions LLC. The company operated into the early 2010s, manufacturing parts and assembling trucks under the T-Line brand. These vehicles retained the Diamond Reo aesthetic but were branded independently.
In 2015, T-Line Trucks & Chassis announced plans to resume production of Class 6, 7, and 8 trucks, focusing on vocational applications. The new models were inspired by Diamond T and Diamond Reo heritage, offering made-to-order builds and glider kits. However, full-scale production never materialized, and the brand faded from the market.
Meanwhile, in Australia, Daysworth International revived the Diamond Reo name for terminal tractors, making the brand officially Australian. Though unrelated to the Osterlund operation, this move kept the Diamond Reo legacy alive in a new form.
Stories from the Field
In Pennsylvania, a Diamond Reo Giant was spotted in 2020 serving as a sign truck on the state turnpike. Despite its age, the truck remained operational, a testament to the build quality of the Osterlund era. Its air-cooled Deutz engine still fired reliably, and its frame showed minimal corrosion.
In Michigan, a collector restored a 1980s Giant mixer with original Diamond Reo badging. The restoration included a rebuilt Cummins NTC-290 and a fresh coat of metallic blue paint. The truck now appears at vintage truck shows, drawing admiration from enthusiasts who remember the brand’s heyday.
Conclusion
The connection between Diamond Reo and Osterlund’s Giant Trucks is a story of resilience, craftsmanship, and brand loyalty. From bankruptcy to boutique production, the Diamond Reo name survived through the dedication of a small team in Harrisburg. Their trucks, built with pride and precision, continue to roll decades later—proof that heritage and hard work can outlast even the toughest market conditions.
Diamond T and Reo were two iconic American truck manufacturers with roots stretching back to the early 20th century. Diamond T was founded in 1905 by C.A. Tilt in Chicago, known for its stylish and durable trucks. Reo, established by Ransom E. Olds in 1904 after his departure from Oldsmobile, focused on reliable commercial vehicles. Both brands earned reputations for quality and innovation, supplying trucks for civilian and military use through the Great Depression and World War II.
By the late 1950s, both companies were absorbed into White Motor Corporation, which merged them into Diamond Reo Trucks in 1967. This merger aimed to consolidate engineering and production while preserving brand heritage. The resulting trucks combined Diamond T’s rugged design with Reo’s mechanical reliability, creating a line of Class 8 vehicles that appealed to long-haul and vocational operators.
The Collapse and Rebirth of Diamond Reo
Despite strong brand loyalty and innovative models like the C-116 Giant, Diamond Reo struggled financially. In 1974, the company filed for bankruptcy. A year later, Loyal Osterlund and Ray Houseal, based in Harrisburg, Pennsylvania, acquired the rights to the Diamond Reo name and tooling. Their facility, originally a dealership and service center, became the new production site for a reborn Diamond Reo—now operating under the name Giant Trucks.
The revived company focused on building the C-116 Giant, a heavy-duty conventional truck powered by Cummins diesel engines. Production was modest, with only 131 units built in 1978. However, the trucks were known for their durability and customizability, often used in concrete mixing, dump hauling, and specialized vocational roles.
A construction firm in New Jersey ran a fleet of Deutz-powered Giant mixers throughout the 1980s. These trucks were praised for their simplicity and resistance to overheating, even in congested urban environments. Mechanics often joked that “you couldn’t kill a Giant,” a testament to their overbuilt frames and straightforward engineering.
Giant Trucks and the Osterlund Era
Under Osterlund’s leadership, Giant Trucks continued to produce Diamond Reo-branded vehicles into the 1990s. The Harrisburg plant was expanded to handle up to 10 trucks per day, though actual output remained closer to two units daily. Each truck was built to order, with options for Caterpillar or Cummins engines, Eaton or Allison transmissions, and Dana or Meritor axles.
The company’s approach was artisanal rather than industrial. Trucks were tailored to customer specifications, often incorporating parts from Navistar, Autocar, and other manufacturers. The Autocar steel cab was a common feature, paired with Diamond Reo’s signature long-nose hood and heavy-duty frame rails.
In 1985, the company introduced the T-Line series, blending vintage styling with modern components. These trucks were marketed as vocational workhorses, ideal for municipal fleets, construction firms, and independent haulers. The T-Line offered multiple hood lengths and cab configurations, with glider kits available for rebuild projects.
Transition to T-Line and Final Years
After Osterlund’s retirement, a group of former employees continued production under the name Diamond Vehicle Solutions LLC. The company operated into the early 2010s, manufacturing parts and assembling trucks under the T-Line brand. These vehicles retained the Diamond Reo aesthetic but were branded independently.
In 2015, T-Line Trucks & Chassis announced plans to resume production of Class 6, 7, and 8 trucks, focusing on vocational applications. The new models were inspired by Diamond T and Diamond Reo heritage, offering made-to-order builds and glider kits. However, full-scale production never materialized, and the brand faded from the market.
Meanwhile, in Australia, Daysworth International revived the Diamond Reo name for terminal tractors, making the brand officially Australian. Though unrelated to the Osterlund operation, this move kept the Diamond Reo legacy alive in a new form.
Stories from the Field
In Pennsylvania, a Diamond Reo Giant was spotted in 2020 serving as a sign truck on the state turnpike. Despite its age, the truck remained operational, a testament to the build quality of the Osterlund era. Its air-cooled Deutz engine still fired reliably, and its frame showed minimal corrosion.
In Michigan, a collector restored a 1980s Giant mixer with original Diamond Reo badging. The restoration included a rebuilt Cummins NTC-290 and a fresh coat of metallic blue paint. The truck now appears at vintage truck shows, drawing admiration from enthusiasts who remember the brand’s heyday.
Conclusion
The connection between Diamond Reo and Osterlund’s Giant Trucks is a story of resilience, craftsmanship, and brand loyalty. From bankruptcy to boutique production, the Diamond Reo name survived through the dedication of a small team in Harrisburg. Their trucks, built with pride and precision, continue to roll decades later—proof that heritage and hard work can outlast even the toughest market conditions.
