Crankshaft Bearing Inspect
^ 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 for 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 without any signs of scoring, without any wear, or without any damage.
6. Inspect the crankshaft journals for grooves or for scoring (2).
7. Inspect the crankshaft journals for scratches or for wear (3).
8. Inspect the crankshaft journals for pitting or for imbedded bearing material (4).
9. Measure the crankshaft journals for an out of round condition.
10. Measure the crankshaft journals for taper.
11. Measure the crankshaft runout.
Using wooden V blocks, support the crankshaft on the front journal and on the rear journal.
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 for pockets. Flattened sections on the bearing halves also indicate fatigue.
2. Inspect the crankshaft bearings for excessive scoring or for discoloration.
3. Inspect the crankshaft bearings for dirt or for debris that is imbedded into the bearing material.
4. Inspect the crankshaft bearings for incorrect seating that is indicated by bright sections, polished sections of the bearing.
If the lower half of the bearing is worn or damaged, then the upper half and the lower half should be replaced.
Usually, if the lower half is suitable for use, the upper half should also be suitable for use.