Lexus NX: Replacement

REPLACEMENT

PROCEDURE

1. REPLACE INTAKE VALVE GUIDE BUSH

(a) Heat the cylinder head sub-assembly to approximately 80 to 100°C (176 to 212°F).

(b) Place the cylinder head sub-assembly on wooden blocks.

(c) Using SST and a hammer, tap out the intake valve guide bush. SST: 09201-01055 SST: 09950-70010 09951-07100

(d) Using a caliper gauge, measure the bush bore diameter of the cylinder head sub-assembly.

Standard bush bore diameter:

10.285 to 10.306 mm (0.405 to 0.406 in.)

If the bush bore diameter of the cylinder head sub-assembly is between 10.285 and 10.306 mm (0.405 and 0.406 in.), proceed to the next step.

If the bush bore diameter of the cylinder head sub-assembly is 10.356 mm (0.408 in.) or more, replace the cylinder head sub-assembly.

(e) Select a new intake valve guide bush (STD or O/S 0.05) and measure its diameter.

(f) Machine the bush bore of the cylinder head sub-assembly to the diameter of the selected intake valve guide bush.

Standard Bush Diameter:

Standard bush length:

41.3 to 41.7 mm (1.626 to 1.642 in.)

(g) Heat the cylinder head sub-assembly to approximately 80 to 100°C (176 to 212°F).

(h) Using SST and a hammer, tap in the selected intake valve guide bush to the standard protrusion height. SST: 09201-10000 09201-01050 SST: 09950-70010 09951-07100 Standard protrusion height: 14.8 to 15.2 mm (0.583 to 0.598 in.)

*a Protrusion Height

(i) Using a sharp 5.5 mm reamer, ream the intake valve guide bush to obtain the standard oil clearance between the intake valve guide bush and valve stem. Standard oil clearance: 0.025 to 0.060 mm (0.000984 to 0.00236 in.)

2. REPLACE EXHAUST VALVE GUIDE BUSH

(a) Heat the cylinder head sub-assembly to approximately 80 to 100°C (176 to 212°F).

(b) Place the cylinder head sub-assembly on wooden blocks.

(c) Using SST and a hammer, tap out the exhaust valve guide bush. SST: 09201-01055 SST: 09950-70010 09951-07100

(d) Using a caliper gauge, measure the bush bore diameter of the cylinder head sub-assembly.

Standard bush bore diameter:

10.285 to 10.306 mm (0.405 to 0.406 in.)

If the bush bore diameter of the cylinder head sub-assembly is between 10.285 and 10.306 mm (0.405 and 0.406 in.), proceed to the next step.

If the bush bore diameter of the cylinder head sub-assembly is 10.356 mm (0.408 in.) or more, replace the cylinder head sub-assembly.

(e) Select a new exhaust valve guide bush (STD or O/S 0.05) and measure its diameter.

(f) Machine the bush bore of the cylinder head sub-assembly to the diameter of the selected exhaust valve guide bush.

Standard Bush Diameter:

Standard bush length:

46.8 to 47.2 mm (1.843 to 1.858 in.)

(g) Heat the cylinder head sub-assembly to approximately 80 to 100°C (176 to 212°F).

(h) Using SST and a hammer, tap in the selected exhaust valve guide bush to the standard protrusion height. SST: 09201-10000 09201-01050 SST: 09950-70010 09951-07100 Standard protrusion height: 14.2 to 14.6 mm (0.559 to 0.575 in.)

*a Protrusion Height

(i) Using a sharp 5.5 mm reamer, ream the exhaust valve guide bush to obtain the standard oil clearance between the exhaust valve guide bush and valve stem. Standard oil clearance: 0.030 to 0.065 mm (0.00118 to 0.00256 in.)

3. REPLACE SPARK PLUG TUBE

HINT:

When using a new cylinder head sub-assembly, the spark plug tubes must be replaced.

(a) Apply adhesive onto the shaded area of a new spark plug tube. Adhesive: Toyota Genuine Adhesive 1324, Three Bond 1324 or equivalent. Standard application width: 1.0 to 3.0 mm (0.0394 to 0.1181 in.) Distance: 1.0 to 7.0 mm (0.0394 to 0.2756 in.) NOTICE: Install the spark plug tube within 3 minutes after applying adhesive. Be careful not to deform the spark plug tube. Be careful not to expose the seal to coolant for at least 1 hour after installing it.

*a Adhesive *b Application Width *c Distance

(b) Using a wooden block and hammer, tap in the spark plug tube to the specified protrusion height. Standard protrusion height: 112 mm (4.41 in.) NOTICE: To avoid tapping in the spark plug tube too far, measure the protrusion height while tapping it.

*a Protrusion Height

4. REPLACE RING PIN

NOTICE:

It is not necessary to remove the ring pin unless it is being replaced.

(a) Remove the ring pins.

(b) Using a plastic-faced hammer, tap in new ring pins to the cylinder head sub-assembly. Standard protrusion height: 6.5 to 7.5 mm (0.256 to 0.295 in.)

*a Protrusion Height

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