Mitsubishi S4Q, User Manual

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26 / 174 Service Manual Mitsubishi SQ-Series diesel engines
Version 08/2004
ENGLISH
CYLINDER HEADS AND VALVE
MECHANISM
ENGINE MAIN PARTS
2. Measuring valve spring perpendicularity and free
length
Measure the free length and perpendicularity of
each valve spring. If the free length or
perpendicularity exceeds the service limit, replace
the spring.
Unit: mm [in.]
Inner valve spring (high-speed option)
Unit: mm [in.]
7.2.3 Valve pushrods
Using V-blocks and a dial indicator, check for runout, as
shown in the illustration. If runout exceeds the
assembly standard, replace the pushrod.
Unit: mm [in.]
Figure 19 Measuring valve spring perpendicularity
and free length
Free
length
Perpendicularity
Item
Assembly
Standard
Service Limit
Free length 48.85 [1.92] 47.60 [1.87]
Perpendicularity 1.5° or less __
Set force N (kgf)
[lbf]
177 to 196
(18 to 20)
[40 to 44]
147
(15)
[33]
Item
Assembly
Standard
Service Limit
Free length 50.0 [1.9685] 49.0 [1.9291]
Perpendicularity 1.5° or less __
Set force N (kgf)
[lbf]
56.9
(5.8)
[12.8]
48.1
(4.9)
[10.8]
Figure 20 Measuring valve pushrod runout
Item Assembly Standard
Pushrod runout 0.3 [0.012] or less
NOTE
Assembly standards refer to dial gage readings.