Crankshaft And Crankshaft Bearing

Clean the crankshaft completely and check for cracks by means of red lead check etc., and replace if defective.
Measure the crankshaft bend, and correct or replace if it exceeds the limit.
NOTE: If a suitable V-block is not available, install the #1 and #5 crankshaft bearing on cylinder block, position the crankshaft on these bearings the crankshaft bend using a dial gauge.
1. Crankshaft bend limit:
2. 0.035 mm (0.0014 in)
Fig 1: Measuring Crankshaft Bend Using Dial Gauge
Courtesy of SUBARU OF AMERICA, INC.
Inspect the crank journal and crank pin for wear. If they are not within the specifications, replace the bearing with a suitable (undersize) one, and then replace or recondition the crankshaft as necessary. When grinding the crank journal or crank pin, finish them to specified dimensions according to the undersize bearing to be used.
1. Crank pin and crank journal:
2. Out-of-roundness
3. 0.005 mm (0.0002 in) or less
4. Taper limit
5. 0.07 mm (0.0028 in)
6. Grinding limit
7. 0.250 mm (0.0098 in)
Fig 2: Measuring Crank Journal Diameter
Courtesy of SUBARU OF AMERICA, INC.

Fig 3: Crank Journal Diameter Specification Chart
Courtesy of SUBARU OF AMERICA, INC.
Measure the thrust clearance of crankshaft at center bearing. If the clearance exceeds the limit, replace the bearing.
Crankshaft side clearance:
1. Standard
2. 0.030 - 0.115 mm (0.0012 - 0.0045 in)
3. Limit
4. 0.25 mm (0.0098 in)
Fig 4: Measuring Thrust Clearance Of Crankshaft At Center Bearing
Courtesy of SUBARU OF AMERICA, INC.
Inspect individual crankshaft bearings for signs of flaking, seizure, melting, and wear.
Measure the oil clearance on each crankshaft bearing by means of plastigage. If the measurement is not within the specification, replace the defective bearing with an undersize one, and replace or recondition the crankshaft as necessary.

Fig 5: Crankshaft Oil Clearance Specification Chart
Courtesy of SUBARU OF AMERICA, INC.