Mitsubishi Heavy Industries S4S, Service Manual

Page: 94 / 220

INSPECTION AND REPAIR OF BASIC ENGINE
6-22
4.10 Replacing connecting rod bushing
Use a connecting rod bushing installer to replace the
connecting rod bushing.
(1)
With the bushing joints oriented as shown in the
illustration, align the oil hole of bushing with the oil
hole of connecting rod, and press-fit the connecting rod
bushing into the connecting rod.
(2)
After press-fitting, insert the piston pin, and make sure
the smooth movement of the connecting rod and piston
without looseness.
Replacing connecting rod bushing
4.11 Inspecting connecting rod bend and twist
(1)
Measure the dimensions of C and L in the illustration to
check bend and twist of the connecting rod. Straighten
the connecting rod with a press to meet the standard.
If the standard is exceeded after correction, replace the
connecting rod with a new one.
(2)
In general, a connecting rod aligner is used to check
bend and twist.
Note: Before checking bend, tighten the connecting rod cap
to the specified torque.
(3)
To inspect the connecting rod with the piston installed,
turn the piston upside down and place it on a surface
plate. Insert a round bar having the same diameter as
the crankpin into the big-end bore, and measure the
height of the bar using a dial gauge.
Inspecting connecting rod bend and twist
Using a connecting rod aligner to measure rod bend
and twist
Measuring with a dial gauge
Connecting rod bushing installer
P/N:32A91-00500
Match marks side
Oil hole
Bushing joint
Item Standard Limit
Connecting rod
bend and twist
0.05/100 mm
[0.0020/3.94 in.]
or less
0.15/100 mm
[0.0059/3.94 in.]
C
C
L
L
54 ± 5 N·m {5.5 ± 0.5 kgf·m}
[40 ± 3.6 lbf·ft]
Piston pin
Connecting rod bend
Connecting rod twist
Unit: mm [in.]
3.94
[ ]
0.05
100
C
L
0.0020
3.94
[ ]
0.05
100
C
L
0.0020
C
A
B
D
Unit: mm [in.]
D
C
100
0.05
3.94
0.0020
[ ]