Special Tools
|     •  | J-8087 Cylinder Bore Gage
  | 
 
For equivalent regional tools, refer to 
Special Tools.
Note: Use care when handling the crankshaft. Avoid damage to the crankshaft position sensor reluctor wheel teeth. Nicks, burrs or other damage to the teeth may effect on-board diagnostics (OBD) 2 system performance.
- Clean the crankshaft of the following elements:
 
- Inspect the crankshaft oil passages for obstructions.
 
- Inspect the crankshaft keyway for the following conditions:
 
| •  | A worn crankshaft key (1) | 
 
| •  | A worn crankshaft keyway (2) | 
 
- Inspect the crankshaft threads (3) for damage.
 
Note: If cracks, severe gouges or burned spots are found, replace the crankshaft. Remove slight roughness using a fine polishing cloth soaked in clean engine oil. Remove any burrs using a fine oil stone.
- Inspect the crankshaft bearing journals and the crankshaft thrust surfaces for the following conditions:
 
| •  | Wear without any grooves or scratches (1) | 
 
| •  | Scratches or excessive wear (3) | 
 
| •  | Pitting or embedded bearing material (4)--Inspect the corresponding crankshaft bearing inserts for embedded material and determine the source of the material. | 
 
| •  | Overheating or discoloration | 
 
- The crankshaft bearings are the precision insert type.
 
- Inspect the outer surfaces of the crankshaft bearings for the following conditions:
 
| •  | Wear--surface wear indicates either movement of the insert, or high spots in the surrounding material - spot wear. | 
 
| •  | Overheating or discoloration | 
 
| •  | Looseness or rotation indicated by flattened tangs and wear grooves | 
 
Note: Note the location of the crankshaft main bearing high spots. If the spots are not in line, the crankshaft is bent. Replace the crankshaft.
- Inspect the crankshaft main bearings for craters or pockets. Flattened sections on the crankshaft bearing halves also indicate fatigue.
 
- Inspect the thrust surfaces of the main thrust bearing for the following conditions:
 
| •  | Grooving--Grooves are caused by irregularities of the crankshaft thrust surface. | 
 
- Inspect the crankshaft bearings for excessive scoring or discoloration.
 
- Inspect the crankshaft main bearings for dirt or imbedded debris.
 
- Inspect the crankshaft main bearings for improper seating indicated by bright, polished sections.
 
- Inspect the crankshaft bearings for uneven side-to-side wear. This may indicate a bent crankshaft or a tapered bearing journal.
 
Note: If crankshaft bearing failure is due to conditions other than normal wear, investigate the cause of the condition. Inspect the crankshaft or connecting rod bearing bores.
- Inspect the connecting rod bearing bores or crankshaft main bearing bores using the following procedure:
 
| 14.1.  | Tighten the bearing cap to specification. | 
 
| 14.2.  | Use the 
J-8087 gage
 in order to measure the bearing bore for taper and out-of-round. Record the readings for bearing selection. | 
 
| 14.3.  | No taper or out-of-round should exist. | 
 
Bearing Selection
Measure the bearing clearance to determine the correct replacement bearing insert size. There are two methods to measure bearing clearance. Method A gives more reliable results and is preferred.
|     •  | Method A yields measurement from which the bearing clearance can be computed. | 
 
|     •  | Method B yields the bearing clearance directly. Method B does not give any indication of bearing run-out. | 
 
Method A
Note: Do not mix inserts of different nominal size in the same bearing bore.
- Measure the crankshaft bearing journal diameter with a micrometer in several places, 90 degrees apart. Average the measurements.
 
- Measure the crankshaft bearing journal taper and runout. 
 
- Install the crankshaft bearing inserts. Tighten the bearing cap bolts to specification using 
J-45059 meter
.
 
- Measure the connecting rod inside diameter in the same direction as the length of the rod with an inside micrometer.
 
- Measure the crankshaft main bearing inside diameter with an inside micrometer.
 
- Select a set of bearing inserts that will produce the desired clearance.
 
- If the specified clearances cannot be met, the crankshaft journals must be reconditioned and undersized bearing inserts installed.
 
Method B
Note: Do not mix inserts of different nominal size in the same bearing bore.
- Clean the used bearing inserts.
 
- Install the used bearing inserts.
 
- Place a piece of gaging plastic across the entire bearing width.
 
- Install the bearing caps.
 
Caution: In order to prevent the possibility of cylinder block or crankshaft bearing cap damage, the crankshaft bearing caps are tapped into the cylinder block cavity using a brass, lead, or a leather
mallet before the attaching bolts are installed. Do not use attaching bolts to pull the crankshaft bearing caps into the seats. Failure to use this process may damage a cylinder block or a bearing cap.
- Install the bearing cap bolts to specification using 
J-45059 meter
.
 
Note: Do not rotate the crankshaft.
- Remove the bearing cap, leaving the gaging plastic in place. It does not matter whether the gaging plastic adheres to the journal or to the bearing cap.
 
- Measure the gaging plastic at its widest point with the scale printed on the gaging plastic package.
 
- Remove the gaging plastic.
 
- Select a set of bearing inserts that will produce the desired clearance.