Checking the end play
1. The crankshaft axial play is checked before removal from the engine, when the crankshaft can rotate freely in the main bearings.
2. End play is checked with 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 (see photo). 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, end 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 and the thrust half ring next to the 3rd main bearing
Status check
4. Wash the crankshaft with solvent and dry. Thoroughly clean the oil passages inside the crankshaft.
5. Check the crankpins for uneven wear, cracks, nicks and pitting (fossae).
6. Wear of the crankpin 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.
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.
7. 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
8. 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.
9. If the crankshaft journals have been reground, deburr around the oil holes.
10. Measure the diameter of the main and connecting rod journals (see photo). 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.
11. Check up a condition of condensed necks of the crankshaft. If a deep groove has formed on these necks at the site of the working edges of the oil seal, then consult a specialist, as either repair or replacement of the crankshaft will be required.
12. Spare parts are supplied with main and connecting rod bearings of two repair sizes (with diameter reduction by 0.25 and 0.5 mm). If the crankshaft has not been repaired, the necks should be reground and the liners replaced with repair ones.
Visitor comments