Though mainly used for shunting and freight hauling, T44 class members have occasionally been used to haul passenger trains. In the 1970s they were used on the unelectrified Borlänge-Mora line, and in 1990s on the Inland Line. Compared to the predecessor T43 class, the T44 is more powerful and has a modernized drivers cab, with better noise insulation, though there are many similarities between the models. In appearance the T44 is somewhat more square than the predecessors. Up to three T44s can run multiply.
In 1993, SJ T44 276 was sold to the NSB for use as a shunter on the Ofoten Line, and given the designation NSB Di 7, and numbered 634. This engine was transferred, along with SJ T44 283, to Malmtrafik in 1996. When the Swedish State Railways (Swedish: Statens Järnvägar, SJ) was split in 2001, Green Cargo took over all the T44 locomotives, though four were sold to the Swedish railway company TGOJ (now a subsidiary of Green Cargo). In 2007, Green Cargo has ordered a full renovation of 100 units from Bombardier Transportation which included new four-stroke engines from MTU (type 12V 4000 R43). The renovation is expected to extend the life-time with 15–20 years.
The first rebuilt units were delivered in 2009 and are called Td