Crankshaft Bearing Inspect

Crankshaft Cleaning and Inspection

^ Tool Required
- J 7872 Magnetic Base Dial Indicator Set

Important: Use care when handling the crankshaft. Avoid damage to the bearing surfaces.





1. Clean the crankshaft with solvent.
2. Thoroughly clean all oil passages and inspect for restrictions or burrs.

Caution: Wear safety glasses in order to avoid eye damage.

3. Dry the crankshaft with compressed air.
4. Perform a visual inspection of the crankshaft for damage.





5. Inspect the crankshaft journals for wear (1). Journals should be smooth with no signs of scoring, wear, or damage.
6. Inspect the crankshaft journals for grooves or scoring (2).
7. Inspect the crankshaft journals for scratches or wear (3).
8. Inspect the crankshaft journals for pitting or imbedded bearing material (4).





9. Measure the crankshaft journals for out-of-round.
10. Measure the crankshaft journals for taper.





11. Measure the crankshaft runout.
Using a suitable fixture, support the crankshaft (1) on the front and rear journals.
12. Use the J 7872 in order to measure the crankshaft runout at the front and rear intermediate journals.
13. Use the J 7872 in order to measure the runout of the crankshaft rear flange.
14. Replace or repair the crankshaft if the measurements are not within specifications.

Crankshaft Main Bearing Inspection





1. Inspect crankshaft bearings for craters or pockets. Flattened sections on the bearing halves also indicate fatigue.





2. Inspect the crankshaft bearings for excessive scoring or discoloration.
3. Inspect the crankshaft bearings for dirt or debris imbedded into the bearing material.





4. Inspect the crankshaft bearings for improper seating indicated by bright, polished sections of the bearing.
If the lower half of the bearing is worn or damaged, both upper and lower halves should be replaced.
Generally, if the lower half is suitable for use, the upper half should also be suitable for use.