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Nissan Frontier. Manual - part 755

CYLINDER HEAD

EM-209

< REMOVAL AND INSTALLATION >

[VQ40DE]

Exploded View

INFOID:0000000009478143

Disassembly and Assembly

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DISASSEMBLY

1. Remove spark plug.
2. Remove valve lifter.

• Identify installation positions, and store them without mixing them up.

3. Remove valve collet.

• Compress valve spring and remove valve collet with magnet

hand using Tool.

CAUTION:

When working, take care not to damage valve lifter holes.

4. Remove valve spring retainer, valve spring and valve spring seat.
5. Push valve stem to combustion chamber side, and remove valve.

• Identify installation positions, and store them without mixing them up.

Valve lifter

Valve collet

Valve spring retainer

Valve spring

Valve oil seal

Valve spring seat

Valve guide

Spark plug

Spark plug tube

10. Cylinder head (right bank)

11. Valve seat

12. Valve (EXH)

13. Valve (INT)

14. Cylinder head (left bank)

PBIC2637E

Tool numbers

: KV10109220 (

—

)

: KV10116200 (J-26336-B)
: KV10115900 (J-26336-20)

WBIA0578E

EM-210

< REMOVAL AND INSTALLATION >

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CYLINDER HEAD

6. Remove valve oil seals using Tool.

7. If valve seat must be replaced. Refer to

EM-211, "Inspection After Disassembly"

8. If valve guide must be replaced. Refer to

EM-211, "Inspection After Disassembly"

9. Remove spark plug tube, as necessary.

• Using a suitable tool, pull spark plug tube out of cylinder head.

CAUTION:

• Take care not to damage cylinder head.

• Once removed, spark plug tube will be deformed and cannot be reused. Do not remove it unless

absolutely necessary.

ASSEMBLY

1. When valve guide is removed, install it. Refer to

EM-211, "Inspection After Disassembly"

2. When valve seat is removed, install it. Refer to

EM-211, "Inspection After Disassembly"

3. Install valve oil seals using Tool.

4. Install valve spring seat.
5. Install valves.

• Install it in the original position.

NOTE:

Larger diameter valves are for intake side.

6. Install valve spring (uneven pitch type).

• Install narrow pitch end (paint mark) to cylinder head side

(valve spring seat side).

7. Install valve spring retainer.

Tool number

: KV10107902 (J-38959)

WBIA0489E

Tool number

—

(J-39386)

Height (H) (Without valve spring seat installed)

Intake and exhaust

: 14.3 - 14.9 mm (0.563 - 0.587 in)

WBIA0490E

SEM085D

CYLINDER HEAD

EM-211

< REMOVAL AND INSTALLATION >

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8. Install valve collet.

• Compress valve spring using Tool, attachment and adapter

using Tool. Install valve collet with magnet hand.

CAUTION:

When working, take care not to damage valve lifter holes

or valve stems.

• Tap valve stem edge lightly with plastic hammer after installa-

tion to check its installed condition.

9. Install valve lifter.

• Install it in the original position.

10. Install spark plug tube.

• Press-fit spark plug tube as follows:

a. Remove old liquid gasket adhering to cylinder head mounting hole.
b. Apply sealant to area within approximately 12 mm (0.47 in) from edge of spark plug tube press-fit side.

Use Genuine High Strength Locking Sealant or equivalent. Refer to

GI-21, "Recommended Chemi-

cal Products and Sealants"

c. Press-fit spark plug tube so that its height (H) is as specified

using suitable drift.

CAUTION:

• When press-fitting, take care not to deform spark plug

tube.

• After press-fitting, wipe off liquid gasket protruding onto

cylinder-head upper face.

11. Install spark plug. Refer to

EM-132, "Removal and Installation"

Inspection After Disassembly

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VALVE DIMENSIONS

• Check dimensions of each valve. Refer to

EM-247, "Standard and Limit"

• If dimensions are out of the standard, replace valve and check the valve seat contact.

VALVE GUIDE CLEARANCE

Valve Stem Diameter

Measure the diameter of valve stem with micrometer.

Valve Guide Inner Diameter

Measure the inner diameter of valve guide with inside micrometer.

Tool numbers

: KV10109220 (

—

)

: KV10116200 (J-26336-B)
: KV10115900 (J-26336-20)

WBIA0578E

Standard press-fit height (H)

: Refer to

EM-108, "Standard and Lim-

it"

PBIC2638E

Standard

Intake

: 5.965 - 5.980 mm (0.2348 - 0.2354 in)

Exhaust

: 5.955 - 5.970 mm (0.2344 - 0.2350 in)

SEM938C

EM-212

< REMOVAL AND INSTALLATION >

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CYLINDER HEAD

Valve Guide Clearance

(Valve guide clearance) = (Valve guide inner diameter) – (Valve stem diameter).

• If the calculated value exceeds the limit, replace valve and/or valve guide.

VALVE GUIDE REPLACEMENT

When valve guide is removed, replace with oversized [0.2 mm (0.008 in)] valve guide.
1. To remove valve guide, heat cylinder head to 110

° to 130°C

(230

° to 266°F) by soaking in heated oil.

2. Drive out valve guide with a press [under a 20 kN (2 ton, 2.2 US

ton, 2.0 Imp ton) pressure] or hammer and suitable tool.

WARNING:

Cylinder head contains heat. When working, wear protec-

tive equipment to avoid getting burned.

3. Ream cylinder head valve guide hole using suitable tool.

Standard

Intake and Exhaust

: 6.000 - 6.018 mm (0.2362 - 0.2369 in)

Valve guide clearance:
Standard

Intake

: 0.020 - 0.053 mm (0.0008 - 0.0021 in)

Exhaust : 0.030 - 0.063 mm (0.0012 - 0.0025 in)

Limit

Intake

: 0.08 mm (0.003 in)

Exhaust : 0.09 mm (0.004 in)

SEM008A

SEM931C

Valve guide hole diameter (for service parts):

Intake and exhaust

: 10.175 - 10.196 mm (0.4006 - 0.4014 in)

SEM932C

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