Crankshaft
Cast from ductile iron and has five support (indigenous) necks, hardened by high-frequency currents to a depth of 2-3 mm. At the rear end of the crankshaft there is a socket for installing the gearbox input shaft bearing.
The connecting rod and main journals of the crankshaft are connected by channels through which oil is supplied to lubricate the connecting rod bearings. Technological outlets of the channels are closed with cap plugs, which are pressed in and for reliability are stamped in three points.
The axial movement of the crankshaft is limited by two thrust half rings installed in the cylinder block on both sides of the rear main bearing (see fig. 51, a). A steel-aluminum half ring is placed on the front side of the bearing, and a metal-ceramic half ring on the back side (yellow color). Before 1980 both half rings (front and back) steel-aluminum were installed. Ceramic-metal and steel-aluminum semi-rings have the same dimensions and are made with a thickness of 2.31-2.36 mm and 2.437-2.487 mm (repair). When assembling the engine, the half rings are selected in thickness so that the axial free play of the crankshaft is within 0.06-0.26 mm.
The crankshaft is balanced separately from the flywheel. Therefore, these parts are interchangeable individually. The crankshafts of the 2101 and 21011 engines are the same and also interchangeable.
To prolong the service life of the crankshaft, it is possible to regrind the crankshaft journals when their surfaces are worn or damaged. By grinding, the diameters of the necks are reduced by 0.25; 0.5; 0.75; 1.00 mm. In this case, the diameters of the main journals after grinding should be respectively equal to 50.545-0,020; 50,295-0,020; 50,045-0,020; 49,795-0,020 mm, and the diameters of the connecting rod journals are 47.584-0,020; 47,334-0,020; 47,084-0,020; 46,834-0,020 mm.
Inserts of main and connecting rod bearings
All of them are thin-walled, bimetallic, steel-aluminum. The shells of the 1st, 2nd, 4th and 5th main bearings have a groove on the inner surface (since 1987 the lower shells of these bearings have been installed without a groove). Center insert (3rd) The main bearing differs from other liners in the absence of a groove on the inner surface and a larger width. All connecting rod bearing shells are non-grooved, identical and interchangeable.
The shells of each bearing consist of two identical halves. They are kept from turning by projections that fit into the corresponding grooves of the connecting rod or main bearing.
The nominal thickness of the main bearing shells is 1.831-0,007 mm, and connecting rod bearings 1,730-0,007 mm. Liners of repair dimensions are supplied under the crankshaft journals, reduced in diameter by 0.25; 0.50; 0.75; 1.00 mm. The thickness of the repair shells of the connecting rod bearings, respectively, is 1.855-0,007; 1,980-0,007; 2,105-0,007; 2,230-0,007 mm, and indigenous - 1.956-0,007; 2,081-0,007; 2,206-0,007; 2,331-0,007 mm.
Flywheel
It is attached to the crankshaft flange with six self-locking bolts, under which one common washer is placed. These bolts must not be replaced by any other. The arrangement of the bolts is such that the flywheel can only be attached to the shaft in two positions. It must be installed so that the mark is a cone-shaped hole B (see fig. eleven) - was against the connecting rod neck of the 4th cylinder. The label is used to determine the TDC in the first and fourth cylinder. The flywheel with the crankshaft is centered by the front bearing of the gearbox input shaft.
The flywheel is cast iron and has a steel ring gear for starting the engine with a starter. The crown is pressed onto the flywheel while hot. Crown teeth are hardened with high frequency currents to increase wear resistance and strength.