Checking the end play
1. Axial play is checked before removing the crankshaft from the engine and can rotate freely in the main bearings.
2. Axial play is checked using a dial gauge. Move the crankshaft all the way to the side and set the indicator scale to zero. Move the crankshaft in the opposite direction and read the indicator reading. Compare the result with the standard. If the play exceeds the norm, then the thrust half rings will need to be replaced.
3. In the absence of an indicator, axial play can be checked with a feeler gauge. Move the crankshaft all the way to the flywheel side, then measure the play by inserting feeler gauges into the gap between the crankshaft web near the 4th crankpin and the thrust half ring next to the 3rd main bearing.
Status check
1. Wash the crankshaft with solvent and dry. Thoroughly clean the oil passages inside the crankshaft.
2. Check the crankpins for signs of uneven wear, cracks, scoring and pitting (fossae).
3. Wear of the connecting rod journal is accompanied by a distinct metallic knock on a running engine (especially audible when pressing the throttle pedal when driving at low speed) and a noticeable drop in oil pressure.
4. Wear of the main bearings is accompanied by a strong vibration of the engine and a dull rumbling sound that increases with increasing engine speed, as well as a noticeable drop in oil pressure.
5. Check the roughness of the crankshaft journals by running your finger over them. Any roughness (which manifests itself simultaneously with obvious signs of wear of the main and connecting rod bearings) indicates the need for regrinding the crankshaft journals or replacing it.
6. Check the runout of the crankshaft in the central part by installing the crankshaft in prism bearings. If the runout exceeds the norm, then the crankshaft must be replaced.
7. If the crankshaft journals have been reground, deburr around the oil holes.
8. Measure the diameter of the main and connecting rod journals and compare the results with the standard. Determine the ovality of the necks by measuring the diameter at several points around the circumference of the neck. Check the taper by measuring the diameter near the opposite cheeks of the necks. Compare the obtained results with the normative ones.
9. Check the condition of the crankshaft seals. If there is a deep groove on these necks that has formed in the place of the working edges of the oil seal, then consult a specialist, as either repair or replacement of the crankshaft will be required.
10. There are two repair sizes for main bearings (with diameter reduction by 0.25 and 0.5 mm) and three repair sizes for connecting rod bearings (0.08, 0.12 and 0.25 mm). If repair liners are available for sale, and the wear of the crankshaft journals exceeds the standard so that further repairs are impossible, then it is advisable to purchase a repaired crankshaft and install repair bearings. About what actions to take next, consult a car service or a specialist.