Inspecting Main Bearing Surface; Measuring Clearance Between Main Bearing And Crankshaft Journal - Mitsubishi S6S-Y3T61HF Service Manual

4.24 Inspecting main bearing surface

Check the inside surface of each main bearing shell for
abnormal contact, scratches, corrosion and peeling from
foreign material. Also check the outside surface of each
bearing shell which comes into contact with the crankcase
or main bearing cap for abnormal seating.
4.25 Measuring clearance between main bear-
ing and crankshaft journal
(1) Reassemble main bearings.
(2) Tighten the main bearing caps to the specified torque.
(3) Measure the inside diameter of the main bearings.
(4) Measure the outside diameter of the crank journal.
(5) Calculate the clearance between the inside diameter of
the main bearing and outside diameter of the crank
journal.
(6) Replace the main bearing if the clearance exceeds the
limit.
(7) Measure the clearance between the main bearing cap
and the crank journal again. Use the undersize bearing
if the limit is exceeded.
(8) If an undersize bearing is used, grind the crank journal
to the specified undersize.
Item
Clearance between
main bearing and
crankshaft journal
Standard
0.050 to 0.110 mm 0.200 mm
[0.0020 to 0.0043 in.] [0.0079 in.]
INSPECTION AND REPAIR OF BASIC ENGINE
103 ± 5 N·m {10.5 ± 0.5 kgf·m}
[76 ± 3.6 lbf·ft]
Measuring inside diameter of lower hole of main
Limit
Measuring
direction
Measuring crank journal outside diameter
Scratch on the inner
and outer circumference,
corrosion, and detachment
Inspecting main bearing surface
bearing
Measuring
position
Measuring
directions
Measuring
points
6-29