Crankshaft Inspection

End Play Inspection

PROCEDURE

1. End play is checked before removing the crankshaft from the engine, and the crankshaft must rotate freely in the main bearings.

2. Check end play using a dial indicator. Push the crankshaft fully to one side and set the indicator dial to zero. Push the crankshaft to the opposite side and read the indicator. Compare the result with the specification. If the play exceeds the specification, replace the thrust half-washers.

3. If a dial indicator is not available, the end play can be checked with a feeler gauge. Push the crankshaft fully toward the flywheel, then measure the clearance by inserting feeler gauges between the crankshaft web near the 4th connecting rod journal and the thrust half-washer next to the 3rd main bearing.

Condition Inspection

PROCEDURE

1. Wash the crankshaft with solvent and dry it. Thoroughly clean the oil passages inside the crankshaft.

2. Check the connecting rod journals for uneven wear, cracks, scoring and pitting.

3. Worn connecting rod journals cause a distinct metallic knocking noise with the engine running (most noticeable when the accelerator pedal is pressed at low vehicle speed) and a noticeable drop in oil pressure.

4. Worn main bearings cause strong engine vibration and a deep rumbling noise that increases with engine speed, as well as a noticeable drop in oil pressure.

5. Check the crankshaft journals for roughness by running a finger over them. Any roughness (which appears together with clear signs of wear of the main and connecting rod bearings) indicates that the crankshaft journals must be ground undersize or the crankshaft must be replaced.

6. Check the crankshaft runout at the center section with the crankshaft installed on V-blocks. If the runout exceeds the specification, replace the crankshaft.

7. If the crankshaft journals have been ground undersize, remove the burrs around the oil holes.

8. Measure the diameter of the main and connecting rod journals and compare the results with the specifications. Determine journal out-of-round by measuring the diameter at several points around the circumference of each journal. Check taper by measuring the diameter near opposite crank webs of each journal. Compare the results with the specifications.

9. Check the condition of the crankshaft seal journals. If a deep groove has formed where the seal lips run, consult a specialist, as the crankshaft will need either repair or replacement.

10. Two repair sizes are available for the main bearings (undersize by 0.25 mm and 0.5 mm) and three repair sizes for the connecting rod bearings (0.08 mm, 0.12 mm and 0.25 mm). If repair bearings are available and the journal wear exceeds the specification to the point that further repair is not possible, it is advisable to purchase a reconditioned crankshaft and install repair bearings. For further action, consult an automotive service center or a specialist.