6-36.1 REMOVAL. Remove the cylinder head according to the following steps. Unless otherwise noted, call- outs refer to figure 7-34.
a. If necessary, remove fuel injection nozzles. Refer to paragraph 6-25.1. b. If necessary, remove the exhaust manifold (12,figure 7-18).
c. If necessary, remove rocker lever assemblies. Refer toparagraph 6-35.1.
d. Remove the remaining cylinder hex head cap screws (15 and 16) working from the center to each end of the head evenly.
WARNING
To prevent injury or death, ensure extreme care and proper lifting devices are used during handling. The equipment is heavy.
e. Remove cylinder head (9) and gasket (4) from the cylinder block (figure 7-37).
6-36.2 DISASSEMBLY. Disassemble the cylinder head according to the following steps. Unless otherwise noted, callouts refer to figure 7-34.
a. Identify and tag or mark the valves as to their location.
WARNING
To prevent serious eye injury, wear safety eye protection when removing springs under pressure.
b. Using a valve spring compressor, compress valve springs (11) and remove collets (13). c. Slowly release the valve spring and remove retainer (12) and spring (11).
d. Remove valves (7 or 8), whichever applies. Keep the valves in a labeled rack. e. Repeat step b and step c for the remaining collets, retainers, springs, and valves. f. Remove valve stem seals (14).
6-36.3 CLEANING AND INSPECTION. Clean and inspect the cylinder head according to the following steps. a. Clean carbon from the injection nozzle seat with a nylon or brass brush.
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b. Remove gasket residue from all gasket surfaces.
WARNING
Never turn a stream of compressed air on anyone. Severe injury or death could result.
c. Wash the cylinder head in hot soapy water solution. Rinse with clean water and dry with compressed air. d. Polish the head gasket sealing surfaces with a sanding block and 400-grit sand paper. Clean the head of all
grit after sanding.
e. Inspect the valve guides for scuffing or scoring.
f. Inspect the valve guide bore (minimum 0.3157 inch; maximum 0.3185 inch). g. Inspect the head surface for nicks, erosion, etc.
h. Inspect for head distortion using a straight-edge and a feeler gauge. Variations of 0.0039 inch within a 2 inch diameter area or 0.003 inch overall, end-to-end or side-to-side are acceptable. If these limits are exceeded, the head must be replaced.
i. Clean and inspect the valves according to the following steps.
1. Clean the valve heads with a soft wire wheel. Remark valve locations, as necessary.
2. Polish the valve stem with a crocus cloth. Remark the valves according to cylinder head location.
3. Inspect for abnormal wear on the valve heads and stems. Measure the valve stem diameter (minimum 0.3126 inch; maximum 0.3142 inch). Mark the new valve(s), if required, for the replacement location. 4. Check for and replace bent valve(s). Mark new valve(s) if required, for replacement location.
5. Regrind valve faces, as necessary; intake valves at 30 degrees and exhaust valves at 45 degrees. 6. Measure valve face rim thickness; minimum thickness is 0.031 inch.
7. Inspect the valve stem tip for flatness. Resurface the tip, if necessary. j. Insert the valve springs as follows:
1. Measure the valve spring free length. The limit is 2.190 inches and maximum spring inclination is 0.039 inch.
2. Measure the valve spring tension. A minimum load of 65 to 72.2 lbs is required to compress the spring to a height of 1.94 inches. Replace any springs that do not pass this test.
6-36.4 VALVE SEAT GRINDING. Grind the valve seats according to the following steps.
NOTE
Previously re-ground seats can be replaced with new seats.
a. Install the valves (one at a time) without springs, in the designated location. b. Measure the depth of each valve (minimum 0.039 inch; maximum 0.060 inch).
c. Grind valve seats to remove scores, scratches, and burns. Seat angles are 30 degrees for intake and 45 degrees for exhaust.
d. Install the valves in their respective bores and re-measure valve depth. Record the depth of each valve. Sub- tract the recorded depth before grinding from the recorded depth after grinding to obtain the grinding depth. Grinding depth limit is 0.010 inch. Mark an X on the cylinder head to indicate reground valve seats. Replace valves if the valve depth is not within specifications.
e. Apply a light coat of lapping compound to each valve. Lap each valve to its respective valve seat.
f. Clean the valve and seat after lapping. Measure the valve seat width (minimum 0.060 inch; maximum 0.080 inch).
g. If required, grind the valve seat with a 60-degree stone then a 15-degree stone to center the seat of the valve face. Maintain the valve seat width limits (minimum 0.060 inch; maximum 0.080 inch).
6-36.5 REASSEMBLY. Reassemble the cylinder head according to the following steps. Unless otherwise noted, callouts refer to figure 7-34.
NOTE
Ensure all cylinder head components are cleaned prior to reassembly.
a. Reinstall valve stem seals (14).
b. Before reinstalling the valve, lubricate the valve stems with 90-weight engine oil.
WARNING
To prevent serious eye injury, wear safety eye protection when removing springs under pressure.
c. Using a spring compressor, reinstall and compress valve spring (11) and retainer (12) and reinstall collets (13). Release the spring tension after reassembly; tap the valve stems to ensure the collets are seated.
6-36.6 REINSTALLATION. Reinstall the cylinder head according to the following steps. Unless otherwise noted, callouts refer to figure 7-34.
a. If removed, reinstall the two cylinder head dowels. Drive the dowels to the bottom of the dowel bore. b. Ensure the cylinder head is clean and free of surface imperfections on the gasket surface.
c. Ensure head gasket (4) is correctly aligned with the holes in the block and position the head over the dow- els.
d. Carefully place cylinder head (9) on the block and seat it on the dowels. e. Position the push rods into the valve tappets.
f. Lubricate the push rod sockets with clean engine oil. g. Lubricate the valve stems with clean engine oil.
h. Completely loosen the rocker lever adjusting setscrews (9,figure 7-33). S9233-C9-MMA-010
i. Reinstall rocker lever supports (1, figure 7-33). Ensure the supports are aligned with the locating dowels in the head.
j. Using clean engine oil, lubricate the hex head cap screw threads and under the cap screw heads. k. Reinstall hex head cap screws (2, figure 7-33) finger-tight.
l. Using clean engine oil, lubricate the hex head cap screw threads and under the cap screw heads. m. Reinstall hex head cap screws (3, figure 7-33) finger-tight.
n. Using clean engine oil, lubricate the remaining hex head cap screws threads and under the heads. o. Reinstall hex head cap screws (15 and 16) finger-tight.
p. Torque the cylinder head hex head cap screws (figure 6-47) as follows: 29 lb-ft; 62 lb-ft; 92 lb-ft. q. Torque pedestal hex head cap screws (2 and 3,figure 7-33) at 18 lb-ft.
r. Adjust the valve clearance. Refer toparagraph 6-5.
s. Reinstall the valve covers in reverse order of removal,paragraph 6-34. t. Reinstall the exhaust manifold and any other accessories removed. 6-37. OIL PAN.
Remove/reinstall the oil pan according to the following steps. Unless otherwise noted, callouts refer tofigure 7-35.
NOTE
Ensure all oil has been drained from the engine sump.
a. Rotate the engine on the overhaul stand so oil pan (9) is on top.
b. Remove hex head cap screws (3), the oil pan, and gasket (16). Discard the gasket. c. Reinstall the oil pan in the reverse order of removal. Use a new gasket.