Isuzu KB P190. Manual — part 765

Engine Mechanical – V6

Page 6A1–283

Page 6A1–283

Crankshaft Bearing

1

Prepare a piece of cardboard or similar, numbered 1
– 4 for bearing identification.

N O T E

Main bearing journals are numbered from the
front of the engine.

2

Remove the crankshaft upper bearing halves from the
cylinder block. Note the position of the thrust
bearing (1) at the number 3 journal (2).

3

Place the crankshaft upper bearing halves on the
cardboard in the correct positions.

Figure 6A1 – 504

4

Remove the crankshaft lower bearing halves (2) from
the crankshaft bearing caps (1).

5

Place the crankshaft lower bearing halves in the
correct positions on the cardboard.

Figure 6A1 – 505

Clean and Inspect

Crankshaft and Main Bearing Cleaning

Safety glasses must be worn when using
compressed air.

Clean the following components in solvent and then dry with compressed air:
•

crankshaft bearings,

•

connecting rod bearings,

•

crankshaft journals,

•

crankpin journals,

•

crankshaft oil passages, and

•

crankshaft threaded holes.

Engine Mechanical – V6

Page 6A1–284

Page 6A1–284

Crankshaft and Main Bearing Visual Inspection

1

Perform the following visual inspections:
•

Inspect the crankshaft balancer bolt hole (1) for
thread damage.

•

Inspect the crankshaft balancer mounting
area (2) for damage.

•

Inspect the crankshaft sprocket pin hole (3) for
damage.

•

Inspect the oil pump drive flats (4) for damage.

•

Inspect the crankshaft main journals (5) for
damage.

•

Inspect the crankshaft connecting rod
journals (6) for damage.

•

Inspect the crankshaft oil passages (7) for
obstructions.

•

Inspect the crankshaft main bearing thrust wall
surfaces (8) for damage.

•

Inspect the crankshaft counterweights (9) for
damage.

•

Inspect the crankshaft reluctor ring teeth (10) for
damage.

•

Inspect the crankshaft rear main oil seal surface
(11) for damage.

•

Inspect the crankshaft engine flexplate
mounting surface (12) for damage.

•

Inspect the crankshaft pilot hole (13) for
damage.

•

Inspect the crankshaft engine flywheel bolt
holes (14) for thread damage.

2

Repair or replace the crankshaft as required.

Figure 6A1 – 506

Engine Mechanical – V6

Page 6A1–285

Page 6A1–285

Crankshaft Main Bearing Inspection

CAUTION

All connecting rod and main journal bearings
that have been used in a running engine must
be replaced. Never re-use the crankshaft or
connecting rod bearings.

N O T E

The following bearing wear conditions should be
used to diagnose engine operating conditions or
root cause of a condition.

1

Inspect for fatigue indicated by craters or pockets (2).
Flattened sections on the bearing halves (1) also
indicate fatigue.

Figure 6A1 – 507

2

Inspect for excessive scoring or discoloration (2) on
both front and back of the bearing halves (1).

3

Inspect the main bearings for dirt embedded into the
bearing material.

Figure 6A1 – 508

Engine Mechanical – V6

Page 6A1–286

Page 6A1–286

4

Inspect for incorrect seating indicated by bright,
polished sections (1).

Figure 6A1 – 509

Crankshaft Measurement

1

Using a suitable fixture (1), support the crankshaft (2).

Figure 6A1 – 510

2

Using a dial indicator (1) and magnetic base (2),
rotate the crankshaft (3) carefully by hand. Measure
the crankshaft main journals for runout and compare
with the engine specifications, refer to

5 Specifications

.

Figure 6A1 – 511