Crankshaft And Crankshaft Bearing

1. Clean the crankshaft completely, and check it for cracks using liquid penetrant tester. If defective, replace the crankshaft.
2. Measure warping of the crankshaft. If it exceeds the limit, correct or replace it.
   NOTE: If a suitable V-block is not available, using just the #1 and #5 crankshaft bearings on cylinder block, position the crankshaft on cylinder block. Then, measure the crankshaft bend using a dial gauge.

   Crankshaft bend limit: 

   0.035 mm (0.0014 in) 

   Fig 1: Measuring Crankshaft Bend Using Dial Gauge

   Courtesy of SUBARU OF AMERICA, INC.
3. Inspect the crank journal and crank pin for wear. If they are not within the standard, replace the bearing with a suitable (undersize) one, and replace or grind to correct the crankshaft as necessary. When grinding the crank journal or crank pin, finish them to the specified dimensions according to the undersize bearing to be used.

   Crank pin: 

   Out-of-roundness 

   Standard 

   0.003 mm (0.0001 in) 

   Cylindricality 

   Standard 

   0.004 mm (0.0002 in) 

   Grinding limit (dia.) 

   To 51.750 mm (2.0374 in) 

   Crank journal: 

   Out-of-roundness 

   Standard 

   0.005 mm (0.0002 in) 

   Cylindricality 

   Standard 

   0.006 mm (0.0002 in) 

   Grinding limit (dia.) 

   To 59.758 mm (2.3527 in) 

   Fig 2: Inspecting Crank Journal And Crank Pin

   Courtesy of SUBARU OF AMERICA, INC.

   Unit: mm (in)
   		Crank journal diameter		Crank pin outer diameter
   		#1, #3	#2, #4, #5
   Standard	Journal O.D.	59.984 - 60.008 (2.3616 - 2.3625)	59.984 - 60.008 (2.3616 - 2.3625)	51.976 - 52.000 (2.0463 - 2.0472)
   	Bearing size (Thickness at center)	1.998 - 2.015 (0.0787 - 0.0793)	2.000 - 2.017 (0.0787 - 0.0794)	1.490 - 1.506 (0.0587 - 0.0593)
   0.03 (0.0012) Undersize	Journal O.D.	59.962 - 59.978 (2.3607 - 2.3613)	59.962 - 59.978 (2.3607 - 2.3613)	51.954 - 51.970 (2.0454 - 2.0461)
   	Bearing size (Thickness at center)	2.017 - 2.020 (0.0794 - 0.0795)	2.019 - 2.022 (0.0795 - 0.0796)	1.504 - 1.512 (0.0592 - 0.0595)
   0.05 (0.0020) Undersize	Journal O.D.	59.942 - 59.958 (2.3599 - 2.3605)	59.942 - 59.958 (2.3599 - 2.3605)	51.934 - 51.950 (2.0447 - 2.0453)
   	Bearing size (Thickness at center)	2.027 - 2.030 (0.0798 - 0.0799)	2.029 - 2.032 (0.0799 - 0.0800)	1.514 - 1.522 (0.0596 - 0.0599)
   0.25 (0.0098) Undersize	Journal O.D.	59.742 - 59.758 (2.3520 - 2.3527)	59.742 - 59.758 (2.3520 - 2.3527)	51.734 - 51.750 (2.0368 - 2.0374)
   	Bearing size (Thickness at center)	2.127 - 2.130 (0.0837 - 0.0839)	2.129 - 2.132 (0.0838 - 0.0839)	1.614 - 1.622 (0.0635 - 0.0639)

4. Use a thickness gauge to measure the thrust clearance of crankshaft at #5 crank journal bearing. If clearance exceeds the standard, replace the bearing.

   Crankshaft thrust clearance: 

   Standard 

   0.030 - 0.115 mm (0.0012 - 0.0045 in) 

   Fig 3: Measuring Thrust Clearance Of Crankshaft At #5 Crank Journal Bearing

   Courtesy of SUBARU OF AMERICA, INC.
5. Inspect individual crankshaft bearings for signs of flaking, seizure, melting and wear.
6. Measure the oil clearance on each crankshaft bearing using plastigauge. If the measured value is out of standard, replace the defective bearing with an undersize one, and replace or grind to correct the crankshaft as necessary.

Crankshaft oil clearance: 

Standard 

0.010 - 0.030 mm (0.00039 - 0.0012 in)