Measuring Main Bearing-To-Journal Clearance - Jeep 1987 Wrangler Workshop Manual

ENGINES
4.2 LITER (258 CID) SIX-CYLINDER ENGINE
With the cotter pin tool in place, rotate the
crankshaft so that the upper bearing insert will
rotate in the direction of its locking tab.
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NOTE: Because there is no hole in the No. 4
main journal, use a tongue depressor (1) or
similar soft-faced tool to remove the bearing
insert (2). After moving the insert
approximately 25mm (1 -in) it can be removed by
applying pressure under the tab.
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Using the same procedure described above,
remove the remaining bearing inserts one at a
time for inspection.
Measuring Main Bearing-to-Journal Clearance
(with Plastigage) (Crankshaft Installed)
Refer to the MOT. 4 . 2 L manual for the
procedure.
Crankshaft Main Bearings Installation
Lubricate the bearing surface of each insert with
engine oil.
Loosen all the main bearing caps. Install the
removed main bearing upper insert(s).
Install the main bearing cap(s) and lower
insert(s).
Tighten all the bolts with 54 N-m (40 ft-lbs)
torque. Then tighten with 95 N-m (70 ft-lbs)
torque. Finally, tighten with 108 N-m (80 ft-lbs)
torque.
Rotate the crankshaft after tightening each main
bearing cap to ensure the crankshaft rotates
freely.
N O T E : When installing a crankshaft kit
(crankshaft plus bearing inserts), measure each
bearing-to-journal clearance with Plastigage to
ensure proper fit.
Install the oil pump. Refer to Oil Pump
Installation for the procedure.