Dismantling
Attention! The crankshaft can only be removed after the engine has been removed from the vehicle. Remove the flywheel first (or master disk), idler pulley, belt (chain), sump, oil receiver, oil pump, front cover and connecting rods with pistons.
1. Pre-check the axial play of the crankshaft.
2. Move the crankshaft towards the rear of the engine, applying maximum effort, and in this position, set the indicator scale to zero.
3. Then push the crankshaft towards the front of the engine and read the indicator. The amount of axial play is equal to the distance that the shaft has moved. If the axial play exceeds the standard value, then check the wear of the thrust surfaces of the crankshaft cheeks. If their wear is insignificant, then the play should be corrected by replacing the main bearings with new ones.
4. In the absence of an indicator head, the play can be measured using a set of feeler gauges.
5. Carefully move the crankshaft towards the front of the engine and measure the end play by inserting a feeler gauge between the crankshaft web and the end face of the thrust main bearing.
6. Check the caps for orientation arrows and cylinder number markings. Usually the covers are numbered starting from the front of the engine, the arrows present should point towards the front of the engine. If there is no marking, then mark the marks.
7. Loosen the cover bolts 1/4 turn at a time until the bolts can be turned away by hand. When assembling, the bolts should be wrapped in their original places. Keep in mind that on the engine part, the bolts are used as pins, which also need to be screwed back into place.
8. Carefully slide the covers and remove them together with the liners.
9. Carefully remove the crankshaft. Leave the liners in the grooves of the cylinder block and covers. Replace the covers and tighten the bolts by hand.
Examination
1. Wash the crankshaft with solvent and dry, clean the oil channels, clean the necks and remove burrs with a needle file.
2. Check the condition of the shaft journals, the presence of cracks, potholes, burrs. Check the roughness of the necks by rubbing a copper coin on them. If traces remain, then the necks should be reground. It is recommended to perform an internal flaw detection of the crankshaft.
3. Measure the diameter of the necks in several places and determine the taper and ovality.
4. In case of noticeable damage, the crankshaft should be reground and the liners replaced with repair ones.
5. If a deep groove has formed on the necks for the oil seals from the working edge of the oil seal, there are scratches or other damage, then it is recommended to replace the crankshaft, or consult a car service where the neck can be bored and the bushing can be pressed in.