CYLINDER HEAD — Disassembly and Inspection (Distortion) (Supplement-V)

EM-5021prose procedure

Two flatness numbers appear: the body text gives 0.05 mm (limit) and resurfacing limit 0.4 mm; the figure caption gives a warpage threshold of 0.1 mm (different criterion — likely the maximum allowable warpage before disassembly inspection vs. final flatness after resurfacing). Both are recorded.

Continued from EM-5020

Disassembly

Cylinder head — Disassembly

1
Remove EGR valve, intake and exhaust manifold, vacuum pump and thermostat housing.
2
Remove camshaft sprocket and hub using SST KV109B0070 or a suitable tool.
NEM275
3
Remove camshaft brackets in order from outside to inside.
Loosen camshaft bracket nuts in two or three stages.
4
Remove camshaft and oil seal.
5
Remove valve lifters.
6
Remove valve component parts using special service tool or a suitable tool.
Keep each valve and its components together and mark them so they can be reassembled in their original positions.
NEM262
7
Remove valve oil seals using special service tool or a suitable tool.
NEM263

Inspection

CYLINDER HEAD DISTORTION

Cylinder head distortion inspection

1
Visually check for cracks and deformation.
2
Check cylinder head for distortion.
Head surface flatness: Less than 0.05 mm (0.002 in).
If beyond the specified limit, replace or resurface cylinder head.
Resurfacing limit: 0.4 mm (0.016 in).
After resurfacing cylinder head, check that camshaft rotates freely by hand. If resistance is felt, the cylinder head must be replaced.
Nominal height of cylinder head: 136.3 - 136.5 mm (5.366 - 5.374 in).
SEM595A

Specification	Value
Head surface flatnessIf exceeded — resurface or replace	Less than 0.05 (0.002)mm (in)
Resurfacing limitMax material removed by resurfacing	0.4 (0.016)mm (in)
Nominal height of cylinder headAfter resurfacing — check camshaft turns freely	136.3 - 136.5 (5.366 - 5.374)mm (in)
Warpage of surface (figure note)Straightedge across head — see SEM595A	Less than 0.1 (0.004)mm (in)

Head surface flatnessIf exceeded — resurface or replace

Less than 0.05 (0.002)mm (in)

Resurfacing limitMax material removed by resurfacing

0.4 (0.016)mm (in)

Nominal height of cylinder headAfter resurfacing — check camshaft turns freely

136.3 - 136.5 (5.366 - 5.374)mm (in)

Warpage of surface (figure note)Straightedge across head — see SEM595A

Less than 0.1 (0.004)mm (in)

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