Despite new model introductions and excellent reputation Diamond Reo was forced into bankruptcy on December 6, 1974.

One year later Loyal Osterlund and partner Ray Houseal bought the rights to Diamond Reo trucks and made room to continue production in their Harrisburg, Pennsylvania, facility, originally a dealership and maintenance facility.

The single model C-116 Giant was continued in production with the Cummins NTC-290 diesel engine as standard power.

The company continued to build about 150 Class 8 trucks annually through 1995 all as Diamond Vehicle Solutions LLC.

[1] The T-Line's series included one long-nose and two medium-nose models with the company manufacturing frames and other parts, and outfits basic cabs it obtained from Navistar; it offered Caterpillar and Cummins diesels, Eaton and Allison transmissions, and Dana and Meritor axles.