Main Bearing Cap - Install - Mitsubishi S12A2 Service Manual

Chapter 7 ASSEMBLY OF BASIC ENGINE

1.7 Main Bearing Cap - Install

Be sure to observe the specified tightening sequence
when tightening the main bearing cap bolts and side
bolts.
(1) Make sure that the main bearings and thrust plates
installed to main bearing caps are evenly coated with
clean engine oil.
(2) Install the main bearing cap so that its number stamp
lines up in numerical order from the front to rear of the
engine, and also the embossed part number side faces
toward the engine front (so that all rug grooves are
aligned on the same side).
(3) Apply oil to the main bearing cap bolts and washers and
hand tighten them.
(4) Tap the main bearing caps with a soft-head hammer
evenly to install them in position.
(5) Apply oil to the side bolts and O-ring and hand tighten
them.
(6) Snug tighten the main bearing cap bolts and side bolts
except the rearmost ones, to the half of specified torque
in the specified tightening sequence as shown in the
illustration.
(7) Tighten the main bearing cap bolts and side bolts
except the rearmost ones to the specified torque in the
specified sequence shown in the illustration.
(8) Hand tighten the rearmost cap bolts and side bolts to
make the rearmost main bearing be lightly seated.
Measure the crankshaft end play in this condition.
7-6
Main Bearing Cap - Install
First time:
Tighten to the specified
Main bolt
torque in the numerical
order in two steps.
[Wet]
Side bolt 3,
1 2
Bottom
3
Top
Left
Right
Tightening Sequence of Main Bearing Cap Bolts
Side bolt Side bolt Side bolt
147 ± 7.4 N·m
147 147 ± ± 7.4 N 7.4 N·m
{15 ± 0.75 kgf·m}
{15 ± ± 0.75 kgf {15 0.75 kgf·m} m}
[108 [108 ± ± 5.4 lbf [108 ± 5.4 lbf·ft] 5.4 lbf·ft] ft]
[Wet] [Wet] [Wet]
Main bearing cap bolt - Install
Main bearing cap
1, 2: 294 ± 15 N·m
{30 ± 1.5 kgf·m}
[217 ± 11.1 lbf·ft]
4: 74 ± 3.7 N·m
{7.5 ± 0.38 kgf·m}
[54.6 ± 2.73 lbf·ft]
Second time:
Main bolt 1, 2: 588 ± 29 N·m
{60 ± 3.0 kgf·m}
4
[434 ± 21.7 lbf·ft]
Side bolt 3, 4: 147 ± 7.4 N·m
{15 ± 0.75 kgf·m}
[108.4 ± 5.46 lbf·ft]
View from engine rear side
Main bolt
588 ± 29.4 N·m
{60 ± 3.0 kgf·m}
[434 ± 21.7 lbf·ft]
[Wet]