Checking main bearing clearances
1. Check the oil clearance between the main bearing and the journal by removing the lower block and liners.
2. Clean the main journals and bearings with a clean cloth.
3. Place a piece of calibrated Plastigage wire across the main journals.
4. Reinstall the bearings and lower block, then tighten the bolts to 29 Nm (3.0 kgf·m) + 56°.
Note: Do not rotate the crankshaft during inspection.
5. Remove the lower block and bearings again and measure the widest part of the flattened wire.
Oil clearance between main bearing and journal:
| Necks No. 1, 2, 4, 5: | Standard (new) | 0.017-0.041 mm |
| Redistribution | 0.050 mm | |
| Neck #3: | Standard (new) | 0.025-0.048 mm |
| Redistribution | 0.055 mm |
6. If the wire is flattened too wide or too narrow, remove the crankshaft and upper bearing shell. Install a new bearing assembly with the same color marking and recheck the clearance. Do not adjust clearance by grinding, shimming, or cleaning bearings or caps.
7. If the wire clearance is still incorrect, move up to the next larger or smaller bearing size (with color coding before or after the one you chose) and repeat the gap check again. If the required clearance cannot be achieved by substituting bearings of the next larger or smaller repair size, respectively, replace the crankshaft and start the procedure over.