Mitsubishi S4Q User Manual page 70

PISTONS, CONNECTING RODS,
CRANKSHAFT AND CRANKCASE
Figure 120 Fillet radius
Measuring diagram
Figure 121 Measuring main bearing
Measuring
Measuring
points
directions
Figure 122 Measuring journal
70 / 174
R
3 mm
[0.12 in.]
NOTE
a Grind all crankpins to the same undersize.
b Finish the fillet radius to 3 mm [0.12 in.]
2. Checking oil clearance of main bearing
1) Install the upper and lower halves of the
bearing and the cap to the crankcase, and
tighten the cap nuts to the specified torque.
Measure the inside diameter of the bearing,
as shown in the illustration.
Tightening torque
2) Measure the diameter of the journal of the
crankshaft, as shown in the illustration, and
subtract the diameter of the journal from the
inside diameter of the bearing (Step (1)). The
difference is the oil clearance of the main
bearing.
Item
Diameter of
journal
(standard)
Oil clearance
3) If the oil clearance exceeds the repair limit,
replace the bearing and recheck the oil
clearance.
4) If the oil clearance still exceeds the repair
limit, use 0.25 mm [0.0098 in.], 0.50 mm
[0.0197 in.] or 0.75 mm [0.0295 in.] undersize
bearings. When using undersize bearings,
ENGLISH
Service Manual Mitsubishi SQ-Series diesel engines
ENGINE MAIN PARTS
83 ± 5 N·m
(8.5 ± 0.5 kgf·m)
[61 ± 4 lbf·ft]
Nominal Assembly
Value Standard
64.965 to 64.985
65
[2.5577 to
[2.56]
2.5585]
0.035 to 0.100
__ [0.0014 to
0.0039]
Unit: mm [in.]
Repair
Limit
__
0.200
[0.0079]
Version 08/2004