If the valve overall length is less than minimum, replace the valve.
(e) Check the surface of the valve stem tip for wear.
If the valve stem tip is worn, regrind it with grinder or replace the valve if necessary.
NOTICE: Do not grind off more than minimum overall length (See page EM-45).
12. INSPECT AND CLEAN VALVE SEATS
(a) Using a 45° cutter, resurface the valve seats. Remove only enough metal to clean the seats.
(b) Check the valve seating position.
Apply a thin coat of Prussian blue (or white lead) to the valve face. Install the valve. Lightly press the valve against the seat. Do not rotate the valve.
(c) Check the valve face and seat for the following:
• If blue appears 360° around the face, the valve is concentric. If not, replace the valve.
• If blue appears 360° around the valve seat, the guide and seat are concentric. If not, resurface the seat.
• Check that the seat contact is on the middle of the valve face with the following width:
If not, correct the valve seat as follows:
• If seating is too high on the valve face use 30° and 45° cutters to correct the seat.
• If seating is too low on the valve face, use 60° and 45° cutters to correct the seat.
(d) Hand-lap the valve and valve seat with an abrasive compound.
13. INSPECT VALVE SPRINGS
(a) Using a steel square, measure the squareness of the valve springs.
Maximum squareness: 1.5 mm (0.059 in.)
If squareness is greater than maximum, replace the valve spring.
(b) Using calipers, measure the free length of the valve spring.
If the free length is not within specification, replace the valve spring.
(c) Using a spring tester, measure the tension of the valve spring at the specified installed length.
If the installed tension is not as specified, replace the valve spring.
(a) Place the camshaft on V-blocks and, using a dial gauge, measure the circle runout at the center journal. Maximum circle runout: 0.03 mm (0.0012 in.)
If the circle runout is greater than maximum, replace the camshaft.
(b) Using a micrometer, measure the cam lobe height.
Standard cam lobe height:
7M-GTE 38.35 mm <1.5098 in.) Exhaust 38.35 mm (1.5098 in.)
Minimum cam lobe height:
7M-GTE 38.00 mm (1.4961 in.) Exhaust 38.00 mm (1.4961 in.)
If the cam lobe height is less than minimum, replace the camshaft.
(c) Using a micrometer, measure the journal diameter.
Standard diameter: No.1 journal
26.949 - 26.965 mm (1.0610 - 1.0616 in.) No.2 — No.7 journals
26.888 - 26.975 mm (1.0586 - 1.0620 in.) If the journal diameter is less than specified, replace the camshaft.
15. INSPECT CAMSHAFT OIL CLEARANCE
(a) Clean the bearing caps and camshaft journal.
(b) Place the camshaft in the cylinder head.
(c) Lay a strip of Plastigage across each journal.
(d) Place the bearing caps with the top of the number on the cap pointing toward the front and in numerical order from the front side.
(e) Install and torque the cap bolts gradually in the sequence shown in the figure.
HINT: Do not turn the camshaft while the Plastigage is in place.
(f) Remove the caps and measure the Plastigage at its widest point.
Standard oil clearance: No.1 journal
0.035 - 0.072 mm (0.0014 - 0.0028 in.) No.2 — No.7 journals
Maximum oil clearance: 0.13 mm (0.0051 in.)
If clearance is greater than maximum, replace the cylinder head and/or camshaft.
(g) Clean out the pieces of Plastigage from the bearing caps and journals.
16. INSPECT CAMSHAFT THRUST CLEARANCE
(a) Clean and install the camshaft and bearing caps.
(b) Using a dial gauge, measure the thrust clearance while moving the camshaft back and forth.
Standard thrust clearance: 0.08 — 0.19 mm
Maximum thrust clearance: 0.30 mm (0.0118 in.)
If clearance is greater than maximum, replace the camshaft and/or cylinder head.
17. INSPECT VALVE LIFTER OIL CLEARANCE
(a) Using a micrometer, measure the diameter of the valve lifter.
Valve lifter diameter: 27.975 - 27.985 mm
(b) Using a dial indicator, measure the inside diameter of the cylinder head bore.
Lifter bore diameter: 28.000 - 28.021 mm
(c) Subtract the valve lifter measurement from the cylinder head bore.
Standard oil clearance: 0.015 — 0.046 mm
(0.0006 - 0.0018 in.) Maximum oil clearance: 0.10 mm (0.0039 in.)
If clearance is greater than maximum, replace the cylinder head and/or valve lifter.
18. INSPECT INTAKE, EXHAUST MANIFOLDS AND AIR IN-TAKE CHAMBER
Using a precision straight edge and thickness gauge, check the surfaces contacting the cylinder head or intake manifold for warpage.
Maximum warpage: Intake manifold Exhaust manifold 7M-GE 7M-GTE
0.10 mm (0.0039in.) 0.75 mm (0.0295in.) 0.50 mm (0.0197in.) 0.10 mm (0.0039in.)
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