Engine Mechanical (H4SO): Overhaul Subaru Forester SH

DISASSEMBLY

Note. Intake valve rocker assembly cannot be disassembled.

1. Remove the exhaust valve rocker arm from the rocker shaft. NOTE: Keep all the removed parts in order for re-installing in their original positions.
2. Remove the nut and adjusting screw from exhaust valve rocker.

ASSEMBLY

Note. Intake valve rocker assembly cannot be disassembled.

1. Install the adjusting screw and nut to the exhaust valve rocker.
2. Insert the exhaust valve rocker arm to rocker shaft. NOTE: Valve rocker arms, and rocker shaft have identification marks. Make sure the parts with same markings are properly assembled.

INTAKE VALVE ROCKER ASSEMBLY

1. If the roller or valve contact surface of valve rocker arm is worn or dented excessively, replace the valve rocker assembly.
2. Check that the valve rocker arm roller rotates smoothly. If not, replace the valve rocker assembly.

Scheme 207

Scheme 208

1. Measure the inner diameter of valve rocker arm and outer diameter of valve rocker shaft, and confirm the difference (oil clearance) between the two values. Clearance between arm and shaft: Standard 0.020 - 0.054 mm (0.0008 - 0.0021 in)
2. If the oil clearance exceeds the limit, replace the valve rocker arm or shaft, whichever shows the greater amount of wear. Rocker arm inside diameter: 22.020 - 22.041 mm (0.8669 - 0.8678 in) Rocker shaft diameter: 21.987 - 22.000 mm (0.8656 - 0.8661 in)
3. If the roller or valve contact surface of valve rocker arm is worn or dented excessively, replace the valve rocker arm.
4. Check that the valve rocker arm roller rotates smoothly. If not, replace the valve rocker arm.

1. Place the cylinder head on the ST.
2. Compress the valve spring and remove the valve spring retainer key using ST. Remove each valve and valve spring. ST 499718000 VALVE SPRING REMOVER

Note. Keep all the removed parts in order for re-installing in their original positions. Mark each valve to prevent confusion. Pay careful attention not to damage the lips of intake valve oil seals and exhaust valve oil seals. For removal and installation procedures of the valve guide, intake valve oil seal and exhaust valve oil seal, refer to "Inspection". Refer to VALVE GUIDE , INSPECTION, Cylinder Head . Refer to INTAKE AND EXHAUST VALVE OIL SEAL , INSPECTION, Cylinder Head .

Scheme 209

Scheme 210

Scheme 211

1. Install the valve spring and valve. Coat the stem of each valve with engine oil and insert the valve into the valve guide. NOTE: When inserting the valve into valve guide, use special care not to damage the oil seal lip. Set the cylinder head on ST. ST 498267800 CYLINDER HEAD TABLE Install the valve spring and retainer. NOTE: Be sure to install the valve spring with its close-coiled end facing the seat on cylinder head. Set the ST on valve spring. ST 499718000 VALVE SPRING REMOVER Compress the valve spring and fit the valve spring retainer key. After installing, tap the valve spring retainers lightly with a plastic hammer for better seating.

Scheme 212

1. Check for cracks or damage. Use liquid penetrant tester on the important sections to check for fissures. Check that there are no marks of gas leaking or water leaking on gasket installing surface.
2. Place the cylinder head on the ST. ST 498267800 CYLINDER HEAD TABLE
3. Measure the warping of the cylinder head surface that mates with cylinder block using a straight edge (A) and thickness gauge (B). If the warping exceeds the limit, correct the surface by grinding it with a surface grinder. Warping limit: 0.035 mm (0.0014 in) Grinding limit: 0.1 mm (0.004 in) Standard height of cylinder head: 97.5 mm (3.839 in) NOTE: Uneven torque for the cylinder head bolts can cause warping. When reassembling, pay special attention to the torque so as to tighten evenly.