Cylinder Head Inspection

Using a precision straightedge and feeler gauge, measure the warpage of the surface where the cylinder head sub-assembly contacts the cylinder block sub-assembly, and the surfaces where the cylinder head sub-assembly contacts each manifold.

Maximum Warpage:

Item	Specified Condition
Cylinder Block Sub-assembly Side	0.05 mm (0.00197 in.)
Intake Manifold Side	0.10 mm (0.00394 in.)
Exhaust Manifold Side	0.10 mm (0.00394 in.)

Using a dye penetrant, check the intake ports, exhaust ports and cylinder surface for cracks.
If there are cracks, replace the cylinder head sub-assembly.

Using a vernier caliper, measure the free length of the valve compression spring.

Standard free length:

52.4 mm (2.06 in.)

Using a steel square, measure the deviation of the valve compression spring.

Maximum deviation:

1.8 mm (0.0709 in.)

Maximum angle (reference):

2°

Using a gasket scraper, chip off any carbon from the intake valve head.

NOTICE:

Be careful not to damage the intake valve face.

Using a wire brush, thoroughly clean the intake valve.

Using a vernier caliper, measure the overall length of the intake valve.

Standard overall length:

99.98 mm (3.94 in.)

Minimum overall length:

99.48 mm (3.92 in.)

Using a micrometer, measure the diameter of the intake valve stem.

Standard valve stem diameter:

5.970 to 5.985 mm (0.2350 to 0.2356 in.)

Using a vernier caliper, measure the intake valve head margin thickness.

Standard margin thickness:

1.0 to 1.4 mm (0.0394 to 0.0551 in.)

Minimum margin thickness:

0.5 mm (0.0197 in.)

Using a gasket scraper, chip off any carbon from the exhaust valve head.

NOTICE:

Be careful not to damage the exhaust valve face.

Using a wire brush, thoroughly clean the exhaust valve.

Using a vernier caliper, measure the overall length of the exhaust valve.

Standard overall length:

99.39 mm (3.91 in.)

Minimum overall length:

98.89 mm (3.89 in.)

Using a micrometer, measure the diameter of the exhaust valve stem.

Standard valve stem diameter:

5.960 to 5.975 mm (0.2346 to 0.2352 in.)

Using a vernier caliper, measure the exhaust valve head margin thickness.

Standard margin thickness:

1.0 to 1.4 mm (0.0394 to 0.0551 in.)

Minimum margin thickness:

0.5 mm (0.0197 in.)

Using a caliper gauge, measure the inside diameter of the valve guide bush.

Standard valve guide bush inside diameter:

6.010 to 6.030 mm (0.2366 to 0.2374 in.)

Subtract the valve stem diameter measurement from the valve guide bush inside diameter measurement.

Standard Oil Clearance:

Item	Specified Condition
Intake Side	0.025 to 0.060 mm (0.000984 to 0.00236 in.)
Exhaust Side	0.035 to 0.070 mm (0.00138 to 0.00276 in.)

Maximum Oil Clearance:

Item	Specified Condition
Intake Side	0.11 mm (0.00433 in.)
Exhaust Side	0.12 mm (0.00472 in.)

Apply a light coat of Prussian blue to the intake valve face.

Lightly press the intake valve face against the intake valve seat.

HINT:

Do not rotate the intake valve while pressing the intake valve.

Check the intake valve face and intake valve seat.

1. Check that Prussian blue appears around the entire intake valve face and that the intake valve face is concentric. If not, replace the intake valve.
   

2. Check that Prussian blue appears around the entire intake valve seat and that the guide and intake valve face are concentric. If not, resurface the intake valve seat.
   

3. Check that the intake valve seat contacts the middle of the intake valve face with the width between 1.2 to 1.6 mm (0.0472 to 0.0630 in.).
   

Apply a light coat of Prussian blue to the exhaust valve face.

Lightly press the exhaust valve face against the exhaust valve seat.

HINT:

Do not rotate the exhaust valve while pressing the exhaust valve.

Check the exhaust valve face and exhaust valve seat.

1. Check that Prussian blue appears around the entire exhaust valve face and that the exhaust valve face is concentric. If not, replace the exhaust valve.
   

2. Check that Prussian blue appears around the entire exhaust valve seat and that the guide and exhaust valve face are concentric. If not, resurface the exhaust valve seat.
   

3. Check that the exhaust valve seat contacts the middle of the exhaust valve face with the width between 1.6 to 2.0 mm (0.0630 to 0.0787 in.).
   

Install the No. 2 camshaft and camshaft to the cylinder head sub-assembly (LandCruiser RM000005UDU000X_01_0008.html).

Using a dial indicator, measure the camshaft thrust clearance and No. 2 camshaft thrust clearance while moving the camshaft back and forth.

Standard thrust clearance:

0.060 to 0.200 mm (0.00236 to 0.00787 in.)

Maximum thrust clearance:

0.25 mm (0.00984 in.)

Remove the No. 2 camshaft and camshaft from the cylinder head sub-assembly (LandCruiser RM000005UDT000X_01_0053.html).

Clean the No. 1 camshaft bearing cap, No. 2 camshaft bearing caps, camshaft journals and No. 2 camshaft journals.

Place the camshaft and No. 2 camshaft on the cylinder head sub-assembly.

Lay a strip of Plastigage across each of the camshaft journals.

Install the No. 1 camshaft bearing cap and No. 2 camshaft bearing caps to the cylinder head sub-assembly (LandCruiser RM000005UDU000X_01_0010.html).

NOTICE:

Do not turn the camshaft and No. 2 camshaft.

Remove the No. 1 camshaft bearing cap and No. 2 camshaft bearing caps from the cylinder head sub-assembly (LandCruiser RM000005UDT000X_01_0053.html).

Measure the Plastigage at its widest point.

Standard Oil Clearance:

Item	Specified Condition
No. 1 journal	0.040 to 0.077 mm (0.00157 to 0.00303 in.)
Other journals	0.025 to 0.062 mm (0.000984 to 0.00244 in.)

Maximum Oil Clearance:

Item	Specified Condition
No. 1 journal	0.117 mm (0.00461 in.)
Other journals	0.102 mm (0.00402 in.)

Completely remove the Plastigage from the camshaft journals.