On diesel engines D49 1A9DG isp.3, crankshafts 2-9DG-8spch-1 made of steel or high-strength cast iron are used. Steel crankshafts are equipped with counterweights attached to the shaft cheeks with three special bolts each. Counterweights of crankshafts made of cast iron are cast together with the shaft. The working surface of the crankshaft journals is nitrided, the fillets are strengthened by knurling. The shafts have drillings for supplying oil from the main bearings to the connecting rod bearings. Viscous friction dampers or combined torsional vibration dampers are installed at the end of the shaft opposite the power take-off flange.
