Initially, the tractor was equipped with a four-cylinder, four-stroke liquid-cooled diesel engine SMD-14 with a swirl combustion chamber rude with a capacity of 75 hp. In the DT-75M modification, the A-41 engine with a capacity of 90 hp is used, and in the DT-75N modification, the SMD-18N engine is used, which differs from the SMD-14 in the presence of a turbocharger and an increased capacity of 95 hp. The engine is started from the driver's seat using a starting engine with an electric starter powered by a storage battery. Currently [when?] the DT-75DE tractor is equipped with a diesel engine A-41SI. To warm up the engine before starting at an ambient temperature below -5 °C, the tractor is equipped with a pre-heater PZhB-200. The tractor units and mechanisms are mounted on a welded frame, which consists of two longitudinal welded side members of a closed rectangular cross-section, connected to each other by transverse ties. The clutch is dry, double-disk, constantly closed. The gearbox and rear axle are mounted in a single housing. The rear axle has two single-stage planetary turning mechanisms with band brakes, providing reliable braking of the tractor both in forward and reverse gear. The planetary mechanism reduces the effort on the tractor turning control levers. The chassis consists of drive and guide wheels, support rollers with rubber bands, four suspension balance carriages and two track chains. DT-75 with a rounded cabin. Initially, the tractor was equipped with a rounded all-metal two-seater cabin with symmetrical doors opening against the direction of travel. The seat is adjustable for the weight and height of the driver. The fuel tank was located on the rear wall of the cabin. The characteristic shape of the fuel tank resembled an army duffel bag. Accordingly, the tractor received several nicknames at once: sidor, tourist, bagman, and so on. A characteristic feature of the rounded cabin was less snagging on tree branches and a smaller overall width. Again, if it was impossible to get out on one side, you could always get out on the other. For example, if one track was in a deep puddle, and the other was on dry ground. The DT-75M tractor had a wider cabin - the fuel tank was added to its width. The cabin had a deeper stamping of the cabin ceiling (increased height above the driver's head) and control levers bent towards the tractor driver. There was only one door to the cabin, on the right. The DT-75B (swamp-going) tractor with a cabin similar to the DT-75M had an increased support surface of the track chains due to the increased width of the track links and the ability to lower the guide wheels. Due to this, the ground pressure was 0.031 MPa with raised guide wheels, 0.023 MPa with lowered guide wheels versus 0.047 MPa for the DT-75M. The DT-75B tractor was equipped with an SMD-14NG engine with a capacity of 80 hp at 1800 rpm. The DT-75K (steep-slope) tractor was equipped with a cabin of an original design, allowing for the placement of duplicate controls. The tractor was intended for work on slopes with a steepness of up to 20 degrees. It had two mounting mechanisms: front and rear, a reverse gear, thanks to which it could operate in a shuttle manner, that is, without turning around at the end of the run. It was equipped with an SMD-14NG engine. Since 1978, the tractor has been equipped with a new sprung cabin and plumage. To improve visibility, the new-model cabin is shifted to the right of the tractor axis, and the increased-capacity fuel tank is located on the left side of the cabin. However, many machine operators were dissatisfied with the new panoramic cabin. Although the new-model cabin is more comfortable compared to the old one, the tractor with the new cabin cannot cultivate the soil under the crowns of trees (the height of the cabin interferes). As a result, the plant began to receive letters from consumers asking to return the automobile-type cabin. To create normal temperature conditions, the cabin is equipped with a ventilation unit that supplies air purified from dust, humidified and cooled. It automatically turns on when the windows and doors of the cabin are closed. To ensure the optimum air temperature at the driver's workplace in winter, the tractor cab is equipped with a heater of the air heater type. The design of the cab allows working on the tractor in any weather conditions. In everyday life, the DT-75 tractor with a fuel tank located on the side of the cab is often called a "postman". The following modifications belong to this type of tractors: DT-75V with the SMD-14NG engine and its swamp-going modification DT-75BV; DT-75M and DT-75MV with the A-41 engine; DT-75N with the SMD-18N engine and its swamp-going modification DT-75NB; DT-75D (A-41I or D-440-22 engine) and its peat modification DT-75DT (track width 670 mm.); DT-75RM (RM-80 engine (80 hp) or RM-120 (100 hp).