27. Crankshaft and Bearing Clean and Inspect

Crankshaft and Bearings Cleaning and Inspection





1. Use solvent to clean the crankshaft.
2. Use compressed air to dry the crankshaft.
3. Use a micrometer to measure the crankshaft rod journals in 2 locations on the front edge for the following conditions:
^ Measure for out-of-round.
^ Measure for taper.
^ Measure for wear.
^ The rod journal diameter (STD).
The rod journal diameter is 48.971 - 48.987 mm (1.927 - 1.928 inch).
4. Use a micrometer to measure the crankshaft rod journals in the middle for the following conditions:
^ Measure for out-of-round.
^ Measure for taper.
^ Measure for wear.
^ Rod journal diameter (STD).
The rod journal diameter is 48.971 - 48.987 mm (1.927 - 1.928 inch).
5. Use a micrometer to measure the crankshaft rod journals in 2 locations on the rear edge for the following conditions:
^ Measure for out-of-round.
^ Measure for taper.
^ Measure for wear.
^ Rod journal diameter (STD).
The rod journal diameter is 48.971 - 48.987 mm (1.927 - 1.928 inch).
6. Use a micrometer to measure the crankshaft main journals in 2 locations on the front edge for the following conditions:
^ Measure for out-of-round.
^ Measure for taper.
^ Measure for undersize.
^ Main journal maximum out-of-round.
The main journal maximum out-of-round is 0.03 mm (0.0012 inch).
7. Use a micrometer to measure the crankshaft main journals in the middle for the following conditions:
^ Measure for out-of-round.
^ Measure for taper.
^ Measure for undersize.
^ Main journal maximum out-of-round.
The main journal maximum out-of-round is 0.03 mm (0.0012 inch).
8. Use a micrometer to measure the crankshaft main journals in 2 locations on the rear edge for the following conditions:
^ Measure for out-of-round.
^ Measure for taper.
^ Measure for undersize.
^ Main journal maximum out-of-round.
The main journal maximum out-of-round is 0.03 mm (0.0012 inch).





9. Use a micrometer to measure the crankshaft run-out at the front intermediate journals and use a micrometer to measure the crankshaft run-out at the rear intermediate journals. Perform the measurement with the crankshaft in the engine block or perform the measurement by supporting the crankshaft front and rear journals on V-blocks.
10. Replace or recondition the crankshaft if the measurements are not within specifications.
11. Inspect the crankshaft fit.
12. Inspect the upper half of the crankshaft bearing.
13. Replace the upper half and the lower half if the upper half is worn and/or damaged.
14. Inspect the lower half of the crankshaft bearing.
15. Replace the upper half and the lower half if the lower half is worn and/or damaged.





Important: Measure the clearance of each crankshaft bearing to determine the proper sizes. Factory installed crankshaft bearings may not be the same size for each journal and/or the block bearing may be of a different size than the cap bearings. Also, check the appropriate color coding of the bearings. Return the bearings to their EXACT location if the bearings are to be reused. The cap bearings for the numbers 2 and 3 do not have oil journals.

Important: DO NOT rotate the crankshaft while gaging plastic is between the journal and the crankshaft bearing.

16. Perform the following steps to measure the crankshaft bearing:
^ Place a piece of gaging plastic full width of the crankshaft bearing onto the journal.
^ Measure all 5 bearing clearances at the same time.





Notice: Refer to Fastener Notice in Service Precautions.

17. Install the crankshaft bearing caps exactly as removed.
^ Tighten the crankshaft bearing cap to 50 Nm (37 ft. lbs.) plus 60 degrees plus 15 degrees.
18. Install the crankshaft torsional bearing bridge exactly as removed with the arrow pointing toward the front of the engine.
^ Tighten the crankshaft bearing bridge bolts to 20 Nm (15 ft. lbs.).





19. Remove the crankshaft torsional bearing bridge.





20. Remove the crankshaft torsional bearing caps.





21. Use the scale provided with gaging plastic to measure the gaging plastic at its widest point.
22. Replace with a standard bearing if gaging plastic shows an irregularity in the crankshaft's main bearing clearance exceeding the bearing clearance specification or if an excessive clearance is evident and the crankshaft's main journal is within specification.
23. Always replace both the upper and the lower crankshaft bearings as a set.
24. Regrind the crankshaft for use with an undersize bearing if the clearance can not be brought to specifications.
25. Crankshaft bearings are available for service in the standard size and 2 under sizes.





26. Perform the following steps to measure the crankshaft's end play:
A. Install the crankshaft bearing caps.
B. Install the crankshaft torsional bearing bridge.
C. Mount a dial indicator onto the back of the engine block.
D. Move the crankshaft forward and move the crankshaft rearward.
E. Note the total movement.
F. The crankshafts end play clearance specification is 0.01 - 0.76 mm (0.0004 - 0.0300 inch).
G. Replace the thrust bearing if the clearance is not within specification.