There were two diesel engine prime movers and each drove one bogie through a hydraulic transmission. Past experience led MTE to place the transmission units directly on the bogies: cardan shafts led from the engine to the transmission, which unusually was mounted transversely, and the transmissions were geared to the typically French monomotor bogie. The transmissions used were Voith L821gr, These had two torque converters and a fluid coupling. The first torque converter was scoop-controlled and was only fully filled for starting. For efficiency, high-speed running used a coupling. A 500 hp hydraulic retarder was also considered, although not initially installed, and this would be used for long descents.[2]
- Cooling
Each engine had a separate cooling group mounted in the side panels with a pair of cooling fans in the roof. These had three separate circuits: high-temperature engine cooling water, medium-temperature cooling water and engine oil. An oil-water heat exchanger cooled the transmission oil.[2]
