Disassembly and Assembly

REMOVAL
1. Keep removed parts, intake/exhaust, in order according to the cylinder number.





2. When removing the cylinder head bolts, use cylinder head bolt wrench tool No. MB991654, or equivalent, to loosen the cylinder head bolts. Loosen bolts evenly, little by little.





3. When removing the retainer locks, store and tag removed valves, springs and other parts to indicate their cylinder number and location, for reassembly.





4. Remove the valve stem seal with a suitable tool.

NOTE: Do not reuse valve stem seal.

INSTALLATION
Reverse the removal procedure to install, noting the following:
- When installing the valve stem seal:
1. Install the valve spring seat.





2. Valve stem seal installer tool No. MD998774, or equivalent, must be used to install the valve stem seal. Improper installation could result in oil leaking past the valve guide.

NOTE: Do not reuse the valve stem seal.





3. When installing the valve spring, direct the valve spring end with identification color end toward the spring retainer.





NOTE: The valve spring, if excessively compressed, causes the bottom end of the retainer to be in contact with, and damage the stem seal.





4. Identify and install the cylinder head gasket. The identification mark is 4G64N.





5. When installing the cylinder head bolts, check that the shank length of each bolt meets the limit. If the limit is exceeded, replace the bolt. The maximum limit is 99.4 mm (3.91 inch).
6. Apply engine oil to the threaded portions of bolts and to the washers.





7. According to the tightening sequence shown, tighten the bolts to torque 78 Nm (58 ft. lbs.) using cylinder head bolt wrench tool No. MB991654, or equivalent.
8. Loosen bolts completely.
9. Retighten the loosened bolts to 20 Nm (14.5 ft. lbs.) in the specified tightening sequence.
10. Make a paint mark across each bolt head and cylinder head.
11. Give a 90° turn to the bolts in the specified tightening sequence.
12. Give another 90° turn to the bolts and make sure that the paint mark on the head of each bolt and that on the cylinder head are on the same straight line.

NOTE:
- If the bolt is turned less than 90°, proper fastening performance may not be expected. When tightening the bolt, therefore, be careful to give a sufficient turn to it.
- If the bolt is overtightened, loosen the bolt completely and then retighten it.