Isuzu KB P190. Manual — part 766

Engine Mechanical – V6

Page 6A1–287

Page 6A1–287

3

Measure the crankshaft thrust wall width (1) for wear
using an inside micrometer and compare with the
engine specifications, refer to

5 Specifications

.

4

Measure the crankshaft thrust wall surface (2) for
runout using a dial indicator, mounted to a magnetic
stand and compare with the engine specifications,
refer to

5 Specifications

.

5

If the crankshaft journals are damaged or worn
beyond specifications, the crankshaft may be ground
0.25 mm. There is only one size of oversized main
bearings available for service.

Figure 6A1 – 512

6

Inspect the crankshaft main journals (1) for undersize,
using an outside micrometer (2).

Figure 6A1 – 513

7

Inspect the crankpins (1) for undersize using an
outside micrometer (2).

8

Compare your measurements with those listed in the
engine specifications, refer to

5 Specifications

. If the

crankpin journals are worn beyond the specifications,
the crankshaft may be ground 0.25 mm. Only one
size of oversized connecting rod bearings available
for service.

Figure 6A1 – 514

Engine Mechanical – V6

Page 6A1–288

Page 6A1–288

9

Measure the main bearing and crankpin journals for
out-of-round using the following procedure:

a

Using an outside micrometer, measure the
journal at the extreme front and rear locations
on the journal. Call these points A and B.

b

Measure the journal in two new locations
exactly 90 degrees from the first points. Call
these points C and D.

c

Subtract A from C and B from D. The
differences will indicate journal out-of-round.

d

The out-of-round should not exceed 0.004 mm
maximum.

e

If the journals are worn beyond the
specifications, the crankshaft may be ground
0.25 mm. There is only one size of oversized
crankshaft and connecting rod bearings
available for service.

10

Measure the main bearing and crankpin journals
for taper using the following procedure:

a

Using an outside micrometer, measure the
journal at the extreme front (A) and rear (B) of
the journal parallel to the crankshaft centreline.

b

Subtract the smallest from the largest
measurement. The result will be the journal
taper.

c

If the main bearing journal taper exceeds
0.004 mm, replace the crankshaft.

d

If the journals are worn beyond the
specifications, the crankshaft may be ground
0.25 mm. There is only one size of oversized
crankshaft and connecting rod bearings
available for service.

Figure 6A1 – 515

Reinstall

Crankshaft Bearing Installation Procedure

CAUTION

If the crankshaft bearings have been used in
a running engine, replace them with new
crankshaft bearings for reassembly.

1

Clean the crankcase crank bore with a lint-free cloth.

2

Clean all the oil from the backside of new bearing
halves.

3

Install the new upper crankshaft bearings into
position. The thrust bearing (1) belongs in the number
3 journal(2). Ensure the upper bearing insert contains
the oil transfer hole and groove. Roll the bearing into
position so the lock tang engages the crank slot. The
bearing must fit flush with the upper crankcase.

Figure 6A1 – 516

Engine Mechanical – V6

Page 6A1–289

Page 6A1–289

4

Install the new lower crankshaft bearings (2) into
position in the main bearing caps (1). The lower
crankshaft bearings are identified by no grooves or
holes. The bearings must fit flush with the crankshaft
bearing caps.

Figure 6A1 – 517

Crankshaft Main Bearing Clearance Measurement

1

Place a length of fresh, room temperature plastic
gauging material all the way across all the crankshaft
bearing journals.

2

Install the crankshaft main bearing caps.

3

Loosely install the original inner main cap bolts (1).

4

Loosely install the original outer main cap bolts (2).

Figure 6A1 – 518

5

Loosely install the original short/inner side main cap
bolts.

6

Loosely install the original long/outer side main cap
bolts (3).

7

Gently tap the crankshaft main bearing caps with a
soft-faced hammer to help seat the caps.

8

Tighten the main caps bolts to the correct torque
specification, and in the following sequence.

Crankshaft main bearing cap inboard
attaching bolt torque specification:
Stage

1 . . . . . . .20.0 Nm

Stage

2 . . . . . . . . .80°

Crankshaft main bearing cap outboard
attaching bolt torque specification:
Stage

1 . . . . . . .15.0 Nm

Stage

2 . . . . . . . ...110°

Crankshaft main bearing cap side
attaching bolt torque specification:
Stage

1 . . . . . . .30.0 Nm

Stage

2 . . . . . . . . .60°

Figure 6A1 – 519

Engine Mechanical – V6

Page 6A1–290

Page 6A1–290

N O T E

Do not rotate the crankshaft.

9

Allow the assembly to sit for 2 minutes.

10

Remove the crankshaft bearing cap side bolts.

11

Remove the crankshaft bearing cap outer bolts (2).

12

Remove the crankshaft bearing cap inner bolts (1).

13

Install the crankshaft main bearing cap remover Tool
No. J-41818 as previously described and remove the
crankshaft bearing cap.

14

Repeat steps 10 to 13 for the remaining crankshaft
bearing caps.

Figure 6A1 – 520

15

Determine the crankshaft bearing clearance by
comparing the width of the flattened plastic gauging
material (1) at its widest point with the graduation on
the gauging material scale (2).

16

Compare the measurements listed in the
specifications, refer to

5 Specifications

. If the new

bearings do not provide the correct crankshaft to
bearing clearance, inspect the following:

17

Measure the crankshaft journals for the correct
specified size and ensure new bearings are being
installed. If the crankshaft journals are incorrectly
sized, replace or regrind the crankshaft. Crankshaft
machining is permitted and undersized bearings are
available.

18

Measure the engine block crankshaft bearing bore
diameter to ensure correct size. The engine block
crankshaft bearing bore is not machineable and the
block must be replaced if out of specification.

19

Clean the plastic gauging material from the crankshaft
bearing journals with a soft, lint-free cloth.

Figure 6A1 – 521