Checking the crankshaft axial play using a dial indicator
Checking the crankshaft axial play using a feeler gauge blade
Measuring the crankshaft journal with a micrometer
Checking the axial play of the crankshaft
1. The crankshaft axial play is checked when it is installed in the engine cylinder block.
2. The axial clearance is checked using a dial indicator, the bracket of which is mounted on the engine cylinder block, and the measuring tip rests on the end of the crankshaft.
3. By moving the crankshaft from stop to stop along the axis, measure the axial clearance. The measurement result indicates the need to use new thrust half rings.
4. If a dial indicator is not available, the crankshaft axial play can be measured with a feeler gauge blade by moving the crankshaft to one side until it stops and measuring the gap between the thrust half ring and the crankshaft.
Examination
1. Clean the crankshaft using a suitable solvent and dry it with compressed air.
2. Check the crankshaft main and connecting rod journals for wear, corrosion and cracks.
3. Wear of the connecting rod journal is characterized by metallic knocks during engine operation, especially under load at low speeds and a decrease in oil pressure.
4. Wear of the crankshaft main journals is characterized by strong engine vibration and metallic knocking, which increases with increasing engine speed, as well as a decrease in oil pressure.
5. Check the crankshaft journals for roughness. Any noticeable roughness indicates that the crankshaft needs to be reground or replaced.
6. If the crankshaft has been reground, check for burrs around the oil holes. If there are any, remove them with a fine file or scraper and thoroughly clean the holes and passages of chips.
7. Using a micrometer, measure the diameter of the main and connecting rod journals of the crankshaft and compare the results with the technical requirements. Measure the journals at several points both along the diameter and along the length of the journal, which will allow you to identify ovality and taper, if they are present.
8. Inspect the oil seal contact surfaces at each end of the crankshaft for wear or other damage. If the journal wear from the seal is severe, the crankshaft may need to be replaced.
9. On some engines, if the crankshaft journals have been reground to the repair size, it is necessary to install larger size liners.