Connecting Rod

WARNING: This page is about a different car, the 2012 Subaru Forester. However, it is still accessible from the selected car via links, so may be relevant.

Check that the large or small end thrust surface is not damaged.
Install the connecting rod to the crankshaft, and check the thrust clearance using a thickness gauge. If it is not within the standard, replace the connecting rod.
NOTE:
- Do not forget to install the connecting rod bearing and the connecting rod cap bearing, when installing the connecting rod to the crankshaft.
- Measurement should be performed at a temperature of 20°C (68°F).
- Measure the thrust clearance of each connecting rod at several points, and replace the connecting rod if there is uneven wear.
Connecting rod thrust clearance:

Standard

0.070 - 0.330 mm (0.0028 - 0.0130 in)

Fig 1: Checking Connecting Rod Thrust Clearance
Courtesy of SUBARU OF AMERICA, INC.
Check for bend or twist using a connecting rod aligner. If it exceeds the limit, replace the connecting rod.
Limit of bend or twist per 100 mm (3.94 in) in length:

0.10 mm (0.0039 in)

Fig 2: Checking Connecting Rod For Bend Or Twist Using Connecting Rod Aligner
Courtesy of SUBARU OF AMERICA, INC.
Inspect the connecting rod bearing for scar, peeling, seizure, melting or wear, etc.

Check the oil clearance on each connecting rod bearing using plastigage. If it is not within the standard, replace the connecting rod bearing.

NOTE:

Measurement should be performed at a temperature of 20°C (68°F).
Measure the outer diameter of crank pin using micrometer, and select the suitable size connecting rod bearing when replacing the connecting rod bearing.

BEARING SPECIFICATION CHART

Unit: mm (in)
Bearing	Bearing size (Thickness at center)	Outer diameter of crank pin
Standard	1.492 - 1.508 (0.0587 - 0.0594)	47.976 - 48.000 (1.8888 - 1.8898)
0.03 (0.0012) Undersize	1.511 - 1.515 (0.0595 - 0.0596)	47.946 - 47.970 (1.8876 - 1.8886)
0.05 (0.0020) Undersize	1.521 - 1.525 (0.0599 - 0.0600)	47.926 - 47.950 (1.8868 - 1.8878)
0.25 (0.0098) Undersize	1.621 - 1.625 (0.0638 - 0.0640)	47.726 - 47.750 (1.8790 - 1.8799)

Connecting rod oil clearance:

Standard

0.017 - 0.047 mm (0.0007 - 0.0019 in)

Check the bushing at connecting rod small end for damage.
Check the clearance between piston pin and bushing at connecting rod small end. Check the clearance between the piston pin and bushing at connecting rod small end by measuring respectively the outer diameter of piston pin and the inner diameter of bushing at connecting rod small end.
1. Measure the outer diameter of piston pin with a micrometer.
  NOTE:
  - Measurement should be performed at a temperature of 20°C (68°F).
  - Record the measured value.
    
    Fig 3: Measuring Outer Diameter Of Piston Pin With Micrometer
    Courtesy of SUBARU OF AMERICA, INC.
2. Using a caliper gauge, measure the inner diameter of bushing at connecting rod small end.
  NOTE:
  - Measurement should be performed at a temperature of 20°C (68°F).
  - Record the measured value.
    
    Fig 4: Measuring Inner Diameter Of Bushing Using Caliper Gauge
    Courtesy of SUBARU OF AMERICA, INC.
3. Calculate the clearance between piston pin and bushing at connecting rod small end.
  Clearance between piston pin and bushing at connecting rod small end:
  
  Standard
  
  0.004 - 0.026 mm (0.0002 - 0.0010 in)
If the clearance between piston pin and bushing at connecting rod small end exceeds the standard, replace the piston pin and bushing at connecting rod small end as a set. For replacement procedure of bushing at connecting rod small end, refer to the following.
1. Using the ST and a press, pull out the connecting rod bushing from the small end of the connecting rod.
  NOTE: The direction of ST for pulling out and for press fitting is different. Therefore, attention must be paid to the direction of usage for ST.
  ST 18350AA000 CONNECTING ROD BUSHING REMOVER AND INSTALLER
  
  Fig 5: Pressing Bushing With ST
  Courtesy of SUBARU OF AMERICA, INC.
2. Press the connecting rod bushing with ST and the press, after applying engine oil on the periphery of connecting rod bushing.
  NOTE:
  - Clinch area of the connecting rod bushing is as shown in the figure.
    
    Fig 6: Identifying Clinch Area Of Connecting Rod Bushing
    Courtesy of SUBARU OF AMERICA, INC.
  - The direction of ST for pulling out and for press fitting is different. Therefore, attention must be paid to the direction of usage for ST.
    ST 18350AA000 CONNECTING ROD BUSHING REMOVER AND INSTALLER
    
    Fig 7: Pressing Bushing With ST
    Courtesy of SUBARU OF AMERICA, INC.
3. Make two 3 mm (0.12 in) holes in the pressed connecting rod bushing by aligning with the pre-manufactured holes provided on the small end of the connecting rod.
4. Using a reamer, ream the inside surface of the connecting rod bushing. Insert the reamer in the connecting rod bushing, and turn slowly clockwise while pushing lightly. Bring the reamer back while rotating it clockwise.
  NOTE:
  - Use a reamer with a diameter of Ø22.
  - Apply engine oil to the reamer.
  - If the inner surface of valve guide is damaged, the edge of reamer should be slightly ground with oil stone.
  - If the inner surface of connecting rod bushing becomes lustrous and the reamer does not chip, use a new reamer or remedy the reamer.
5. After completion of reaming, clean the connecting rod bushing to remove chips.