Inspection - Main Bearings - Engine Block
WARNING: This page is about a different variant/trim than selected.
| 1 - Upper Bearing |
| 2 - Lower Bearing |
| 3 - Thrust Bearings |
- Wipe the upper and lower bearing inserts clean.
- Inspect the inserts for abnormal wear patterns, scoring, grooving, fatigue, pitting and for metal or other foreign material imbedded in the lining.
- Inspect the back of the inserts for fractures, scrapes, or irregular wear patterns.
- Inspect the insert locking tabs for damage.
- Inspect the crankshaft thrust bearings for scoring, scratches, wear or blueing.
- Replace any bearing that shows abnormal wear. Refer to
ENGINE/ENGINE BLOCK/STANDARD PROCEDURE .
1 - Straight Edge 2 - Feeler Gauge - Check the deck surface flatness with a straight edge and a feeler gauge.
- The deck surface must be flat within specification. Refer to ENGINE - SPECIFICATIONS .
- Inspect the main bearing bores for signs of scoring, nicks and burrs.
- If the cylinder block main bearing bores show damage the engine block must be replaced.
1 - Cylinder Bore Gauge - Use a cylinder bore gauge to correctly measure the inside diameter of the cylinder bore. A cylinder bore gauge capable of reading in 0.003 mm (0.0001 in.) INCREMENTS is required. If a bore gauge is not available, do not use an inside micrometer.
- Measure the inside diameter of the cylinder bore at three levels below the top of the bore. Start at the top of the bore, perpendicular (across or at 90 degrees) to the axis of the crankshaft.
- Repeat the measurement near the middle of the bore, then repeat the measurement near the bottom of the bore.
- Determine taper by subtracting the smaller diameter from the larger diameter.
1 - Cylinder Bore Gauge - Rotate the cylinder bore gauge (1) 90° and repeat the three measurements. Verify that the maximum taper is within torque specification. Refer to ENGINE/SPECIFICATIONS .
- Determine out-of-roundness by comparing the difference between the measured diameters at each of the three levels. Verify that the maximum out of round is within torque specification. Refer to
ENGINE/SPECIFICATIONS .NOTE:
A slight amount of taper always exists in the cylinder bore after the engine has been in use for a period of time.
- If cylinder bore taper and out-of-roundness are within specification, the cylinder bore can be honed. Refer to CYLINDER BORE DEGLAZING . If the cylinder bore taper or out-of-round condition exceeds the maximum limits, the cylinder block must be replaced.