Heavy Duty Trucking Logo
MenuMENU
SearchSEARCH

T-Line, Successor to Diamond T, Plans Return to Market

Exclusive — Diamond Specialty Vehicles LLC hopes to begin producing Class 6, 7 and 8 trucks, tractors and glider kits, mostly for vocational use, later this year, promising quality and simplicity.

Tom Berg
Tom BergFormer Senior Contributing Editor
Read Tom's Posts
May 13, 2015
T-Line, Successor to Diamond T, Plans Return to Market

Instruments and controls will use hard wiring to ensure simplicity and reliability, the company says. Photo: Diamond Specialty Vehicles LLC

4 min to read


T-Line’s aluminum cab, built by a body maker in Wisconsin, can be altered for specialty applications. Photo: Diamond Specialty Vehicles LLC

T-Line Trucks & Chassis, a low-volume business that evolved from the old Diamond T and Diamond Reo operations, plans a return to production later this year. Its principals promise quality and simplicity through sound design, methodical assembly and use of hard-wired electrical circuitry.

Barring any further financial, legal or operational snags, which partners Joe Whitman and Bruce Fylstra have previously seen, the company, Diamond Specialty Vehicles LLC, hopes to begin producing Class 6, 7 and 8 trucks and tractors, mostly for vocational use.

Ad Loading...

Glider kits and complete "made to order" trucks, using a proprietary aluminum cab, are described on the company’s website, www.tlinetrucks.com. Powertrain offerings include Cummins diesels and Power Systems International gasoline and alternative-fuel engines, along with Eaton and Tremac manual transmissions, Allison automatics, and Dana Spicer and Meritor axles.

Whitman was chief engineer for Osterlund Inc., builder of Diamond Reo and Giant trucks from the late 1970s to the mid ‘90s. He continued producing Diamond T-brand trucks, mostly for export to South America, until 2000. Then he sold T-Line trucks for domestic and foreign customers until 2010, when a dispute with a contract assembler intervened.

He continued selling parts to support in-service vehicles here and abroad until 2013. Since then he’s been working on reviving the business. More recently, Fylstra, a veteran truck salesman, invested in the venture and is handling sales, marketing and dealer development. A parts stocking and distribution agreement has already been arranged with a known logistics firm.

Ad Loading...

“We’ll probably start with glider kits because people are having a lot of trouble with the modern engines and their exhaust equipment,” Whitman said. “There’s a lot of opportunity there.”

 Simplicity is the watchword with the electrical system.

Instruments and controls will use hard wiring to ensure simplicity and reliability, the company says. Photo: Diamond Specialty Vehicles LLC

“We’re going to all hard wiring,” Fylstra said. “None of this multiplexing, and no fiber optics. You’ll still be able to change a light bulb in your dash. We’re cutting out all the redundancy -- no multiple fuse blocks; there’ll be one fuse box that everything will go into. ”

High-strength Domex steel from Sweden will go into T-Line frames, which will be powder-coated before air and electrical lines are strung. Because volume will be relatively low, assembly will be unlike any truck products now on the market.

“They’ll be stall-built by a team of two or three guys,” Fylstra said. “We can be more efficient this way because you can do it right and not be rushed by a moving assembly line.”

Ad Loading...

The aluminum cab is assembled from structural members and panels so it can be altered for specialty uses – high or low roofs, and added length for stowage or sleeper space, he said. The windshield consists of two pieces of mostly flat glass that will fit on either side. A body maker in Wisconsin has built more than a dozen cabs and is ready to produce more.

The T-Line aluminum cab could directly replace International S-series steel cabs, which often are damaged by rust, and that could be a side business, Fylstra thinks. Whitman said he used the S cabs in the last 10 years of production, until Navistar stopped making them.

Gliders and complete vehicles might be assembled by a contract manufacturer, but the partners prefer to set up their own facility, hopefully around Hershey, Pa., where the company is headquartered. Production of fiberglass hoods will be farmed out.

T-Line will remain the chosen name because it helps separate the brand from any possible liability for trucks made by previous owners and companies, Whitman explained.

As before, the name incorporates the ‘T’ from Diamond T, an auto and truck maker founded in 1907 by a C.A. Tilt, in Chicago. Through the years, Diamond T trucks were known for styling and mechanical innovation. 

Ad Loading...

In 1967, Diamond T and Reo, for Ransom E. Olds of automobile fame, were merged into Diamond Reo by their owner, White Motor Co. Operations were consolidated in Lansing, Mich., Reo’s home. An Alabama investor bought the company in 1971, but it went out of business in 1974, the victim of an economic recession.

Loyal Osterlund, a Diamond Reo dealer in Harrisburg, Pa., soon obtained tooling and rights to build and sell the trucks. His company averaged about 150 trucks per year, until 1995. Fylstra, an admitted optimist, would like to see Diamond Specialty Vehicles produce thousands each year.

“I want to build them here in America and provide jobs to American workers,” he said. “I think we’ve got a brilliant future, even if we’re still a bubble gum and bailing wire operation at this point.”

More Equipment

Artist rendering of dealership with trucks and trailers parked outside
Equipmentby News/Media ReleaseJune 2, 2026

Prime Inc. to Open $7.9M Flagship Used-Truck Dealership

A new driver-focused facility to sell Prime Inc's used trucks and trailers will be the first purpose-built location in the company's history.

Read More →
Red Kenworth truck pulling Paper Transport trailer
Fuel Smartsby Deborah LockridgeJune 2, 2026

Lessons Learned About Alternative Fuels: Start Small, Stay Flexible

Practical advice on adopting alternative fuels and ZEVs from HDT's 2026 Top Green Fleets, from renewable diesel and natural gas to electric trucks.

Read More →
Kenworth T680.
Equipmentby News/Media ReleaseMay 27, 2026

Kenworth Names Peter Ahrens General Manager

Leadership changes at Kenworth take effect July 1 as the OEM promotes two longtime Paccar executives to key management roles.

Read More →
Ad Loading...
White Hino Le electric tractor on show floor
Equipmentby News/Media ReleaseMay 26, 2026

Hino Adds Electric Class 6/7 Truck

Hino says the Le Series is an important step in the company's efforts to reduce environmental impact and support its customers’ sustainability goals.

Read More →
Big standing "ACTExpo" sign in convention center lobby
Equipmentby Deborah LockridgeMay 26, 2026

ACT Expo 2026: Highlights in Photos

The 2026 Advanced Clean Transportation Expo featured a broad range of commercial vehicle technologies, from EVs to autonomous trucks to the latest diesel and alternative-fuel engines.

Read More →
Red Hendrickson e-axle at ACT Expo booth
Equipmentby News/Media ReleaseMay 22, 2026

Hendrickson Debuts Electraax E-Axle for Medium-Duty Trucks

Developed with Driventic, Hendrickson's new integrated e-axle is designed to improve efficiency, reduce weight, and extend range in Class 6-7 EV applications.

Read More →
Ad Loading...
Peterbilt Freedom 250 Special Edition Model 589.
Equipmentby News/Media ReleaseMay 21, 2026

Peterbilt Unveils Freedom 250 Special Edition Model 589

Peterbilt’s just-announced limited-run patriotic Model 579 tractor celebrates America’s 250th birthday with custom styling and premium features.

Read More →
Closeup of engine in Mack truck
Equipmentby Deborah LockridgeMay 13, 2026

Mack Unveils EPA 2027-Compliant MP13 Engine With More Power, Better Fuel Economy

Along with unveiling its EPA 2027-compliant MP13 engine, Mack outlined powertrain changes across its Class 6-8 lineup, including new Cummins-based X10 engines.

Read More →
Kodiak Driver-equipped Roehl Transport tractor-trailer.
Equipmentby News/Media ReleaseMay 11, 2026

Kodiak and Roehl Transport Launch Autonomous Route Between Dallas and Houston

Kodiak AI and Roehl Transport have begun autonomous freight operations on a regular Dallas-Houston route, marking another step toward Kodiak’s planned driverless launch by the end of 2026.

Read More →
Ad Loading...
Peterbilt-Kodiak autonomous truck.
Equipmentby Deborah LockridgeMay 8, 2026

Autonomous Trucks at ACT Expo 2026

Autonomous trucks commanded a lot of attention from attendees at ACT Expo this year. Check out this photo gallery.

Read More →