Mitsubishi S4E - Rocker Arm and Rocker Shaft Inspection

Before installing the v.1v., lap the valve and soat,
using 'he lapping compound. Check for contact
pattern oft.r lapping, usi ng a paste of red lead to
visualize the pattern. The pattern s.houJd be uni·
fonn and continuo us.
(6) Valve ",a' ,.movallllld installation
To remove th~ v~Jye seal, thin it in place by
cuttmg with n rotary cutter, and break it loost
wi th a chisel, t aking eare not to nick the counter·
bore in which the seal is se iz ed by expansion
fitting.
To i ns ert the replacement se at , c hill it first to
aboul -80 · C (- 112°F). This l ow temperature can
be reached by immersing the sea! in a pool of
eith" or alcohol and by placing dry ice in the
pool. Force the chilled seat into the counterbore,
which has been trimmed clean and smooth , and
calk around the seat wi th the calking tool (31391.
130 I 0 for intake valve or 3 1391 -13020 for exh,ust
valve).
•
34.6 mm (eKheLlu'
r-f I 42 .6 mm lints ks I
J..
3
c
'·Tool bo dy
2·Valva S4Iilt
3~'r'l in do r hsa
4Na
l
.... g
uide-
5..calking ring
i nstalling \lalve seat by u sing calk i og tool
Valve spring inspection
Inspect each spring for cracks, and check il for ,qUOte-
ness, free length and as -i nstalled length against these
speclfic.lion s:
MAINTENANCE AND ADJUSTMENT
Unit: mm fin .)
Item Standard
Repair"
limit
Val;'. sp'ing 48.85 47.6
f,e. length
(1.923) (1.874)
V.lve sprin! 0.4/25, max.
squareneS$
(0.016/0,98), max .
As-installed
43 44
length
(1.693)
(1.732)
Checking valve spring for square ness
Rocker ann and lo.cker shaft inspection
(I) The valve-actuating tip of the rocker arm IS subject
to weal, If the tip face is excessively worn. replace
the rocker arm.
(2) Tak. diameter readings on lbe bushings and the
rocker 3rm shaft, and compute the radial clearance
from these r .cadjngs . If the limit is exceeded.
reduc e the clearance by r eplacing. the bushings O[
locker ann sh. ft.
Unit: mm {In..)
Item
Standard
Repair
limit
B .. hing bore
20 +0.021
-0
diameter
(0.787 j.00083)
Rock.r shaft
20 -0.016
-0.034
diameter
-0.00063
(0.787 -0.00134)
Shaft c1emnce
0.016 - 0.055
0.Q7
in bushing
(0.0006 - 0. 0022)
(0.0028)
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