Part 2
DISASSEMBLY
15. INSPECT CAMSHAFT JOURNALS
Using a micrometer, measure the journal diameter.
Journal diameter:
If the journal diameter is not as specified, check the oil clearance.
16. INSPECT CAMSHAFT TIMING TUBE JOURNALS
HINT: There are 2 size of the camshaft timing tube journal diameter, green and red painted mark accordingly. The mark is painted I on the face of the camshaft timing tube.
Using a micrometer, measure the journal diameter.
Journal diameter:
If the journal diameter is not as specified, check the oil clearance.
17. INSPECT CAMSHAFT GEAR SPRING
Using vernier calipers, measure the free distance between the spring ends.
Free distance: 18.2 - 18.8 mm (0.712 - 0.740 inch)
If the free distance is not as specified, replace the gear spring.
18. INSPECT CAMSHAFT BEARINGS
Check that bearings for flaking and scoring.
If the bearings are damaged, replace the bearing caps and cylinder head as a set.
19. INSPECT CAMSHAFT TIMING TUBE AND CAMSHAFT JOURNAL OIL CLEARANCE
HINT: There are 2 size of the camshaft timing tube journal oil clearance, Marked "A" and "B" accordingly. The mark is stamped on the top of the cylinder heads.
a. Install the camshaft timing tube.
b. Clean the bearing caps and camshaft journals.
c. Place the camshafts on the cylinder head.
d. Lay a strip of Plastigage across each of the camshaft journals.
e. Install the bearing caps.
Torque: 16 Nm (160 kgf-cm, 12 ft. lbs.)
NOTICE: Do not turn the camshaft.
f. Remove the bearing caps.
g. Measure the Plastigage at its widest point.
Standard Oil clearance:
Maximum oil clearance:
If the oil clearance is greater than maximum, replace the camshaft. If necessary, replace the bearing caps and cylinder head as a set.
h. Completely remove the plastigage.
i. Remove the camshafts.
j. Remove the camshaft timing tube.
20. IF NECESSARY REPLACE CAMSHAFT TIMING TUBE
Select a camshaft timing tube according to mark on the cylinder head.
21. INSPECT CAMSHAFT THRUST CLEARANCE
a. Install the camshaft timing tube.
b. Install the camshaft.
c. Using a dial indicator, measure the thrust clearance while moving the camshaft back and forth.
Standard thrust clearance:
Maximum thrust clearance:
If the thrust clearance is greater than maximum, replace the camshaft. If necessary, replace the bearing caps and cylinder head as a set.
d. Remove the camshafts.
e. Remove the camshaft timing tube.
22. INSPECT CAMSHAFT GEAR BACKLASH
a. Install the camshaft timing tube.
b. Install the camshafts without installing the exhaust cam sub gear and front bearing cap.
c. Using a dial indicator, measure the backlash.
Backlash:
If the backlash is greater then maximum, replace the camshafts.
d. Remove the camshafts.
23. INSPECT VALVE LIFTERS AND LIFTER BORES
a. Using a caliper gauge, measure the lifter bore diameter of the cylinder head.
Lifter bore diameter: 31.000 - 31.016 mm (1.2205 - 1.2211 inch)
b. Using a micrometer, measure the lifter diameter at the valve lifter center line, 12.3 - 12.7 mm (0.484 - 0.500 inch) from the valve lifter head.
Lifter diameter: 30.966 - 30.976 mm (1.2191 - 1.2195 inch)
c. Subtract the lifter diameter measurement from the lifter bore diameter measurement.
Standard oil clearance:
If the oil clearance is greater than maximum, replace the lifter. If necessary, replace the cylinder head.
24. INSPECT INTAKE MANIFOLD
a. Upper intake manifold:
Using a precision straight edge and feeler gauge, measure the surface contacting the lower intake manifold for warpage.
Maximum warpage: 0.15 mm (0.0059 inch)
If warpage is greater than maximum, replace the upper intake manifold.
b. Lower intake manifold: Using a precision straight edge and feeler gauge, measure the surface contacting the cylinder head and upper intake manifold for warpage.
Maximum warpage: 0.15 mm (0.0059 inch)
If warpage is greater than maximum, replace the lower intake manifold.
25. INSPECT EXHAUST MANIFOLD
Using a precision straight edge and feeler gauge, measure the surface contacting the cylinder head for warpage.
Maximum warpage: 0.50 mm (0.0197 inch)
If warpage is greater than maximum, replace the manifold.
26. INSPECT CYLINDER HEAD BOLTS
Using vernier calipers, measure the thread outside diameter of the bolt.
Outside diameter:
If the diameter is less than minimum, replace the bolt.
REPLACEMENT
1. REPLACE VALVE GUIDE BUSHINGS
a. Gradually heat the cylinder head to 80 - 100°C (176 - 212°F).
b. Using SST and a hammer, tap out the guide bushing.
SST 09201-01055, 09950-70010 (09951-07100)
c. Using a caliper gauge, measure the bushing bore diameter of the cylinder head.
d. Select a new guide bushing (STD or O/S 0.05).
If the bushing bore diameter of the cylinder head is greater than 10.306 mm (0.4057 inch), machine the bushing bore to the following dimension: 10.335 - 10.356 mm (0.4069 - 0.4077 inch)
If the bushing bore diameter of the cylinder head is greater than 10.356 mm (0.4077 inch), replace the cylinder head.
HINT: Different the bushings are used for the intake and exhaust.
e. Gradually heat the cylinder head to 80 - 100°C (176 - 212°F).
f. Using SST and a hammer, tap in a new guide bushing to the specified protrusion height.
Protrusion height:
SST 09201-01055, 09950-70010 (09951-07100)
g. Using a sharp 5.5 mm reamer, ream the guide bushing to obtain the standard specified clearance between the guide bushing and valve stem.
2. REPLACE SPARK PLUG TUBE GASKETS
a. Bend the 4 ventilation case claw installed on the cylinder head cover to an angle of 90° or more.
b. Using a screwdriver, pry out the gasket.
NOTICE: Be careful not to damage the cylinder head cover, Tape the screwdriver tip.
c. Using SST and a hammer, tap in a new gasket until its surface is flush with the upper edge of the cylinder head cover.
SST 09950-60010 (09551-00240, 09951-00440, 09952-06010), 09950-70010 (09951-07100)
NOTICE: Be careful of the installation direction.
d. Apply a light coat of MP grease to the gasket lip.
e. Return the ventilation case claw to its original position.