Engine Mechanical – V6 Page 6A1–226
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 – 416
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ISUZU KB P190 2007
Engine Mechanical – V6 Page 6A1–229
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 – 422
6 Inspect the crankshaft main journals (1) for undersize, using an outside micrometer (2).
Figure 6A1 – 423
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 – 424
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ISUZU KB P190 2007
Engine Mechanical – V6 Page 6A1–233
Crankshaft Final Installation Procedure
1 If removed, install the crankshaft sprocket drive
pin (1). Lightly tap the pin in place with a small soft
face, bronze/plastic, hammer until it bottoms in the
hole.
Figure 6A1 – 432
CAUTION
Ensure the crankshaft position sensor has
been removed from the cylinder block prior
to loading the crankshaft, as damage to the
sensor may occur.
2
Apply a liberal amount of clean engine oil to the upper
and lower bearing surfaces.
3 Gently lower the crankshaft (1) into position in the cylinder block (2).
Figure 6A1 – 433
4 Install the crankshaft main bearing caps.
5 Loosely install the original inner main cap bolts (1).
CAUTION
The outer crankshaft bearing cap bolts (2)
are yield tightened during assembly and
must be replaced prior to reassembly. Outer
crankshaft bearing cap bolts that are not
replaced will not torque to the correct clamp
load and can lead to serious engine damage.
6 Loosely install the new outer main bearing cap bolts (2).
7 Gently tap the crankshaft main bearing caps with a soft-faced hammer to help seat the caps.
Figure 6A1 – 434
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ISUZU KB P190 2007
Engine Mechanical – V6 Page 6A1–239
Inspect
Visual Inspection
NOTE
The following procedure assumes the engine has
been disassembled and cleaned, as described
above.
1 Inspect the crankshaft bearing journals for damage or spun bearings. The crankshaft bearing journals are not repairable and if damage is found, the cylinder block assembly must be replaced.
2 Inspect the primary camshaft chain tensioner mounting surface on the engine block for burrs or any defects that would affect the sealing of the new primary camshaft chain tensioner gasket.
3 Inspect all sealing and mating surfaces for damage, repair or replace the cylinder block assembly if required.
4 Inspect all threaded and through holes for damage or excessive debris.
5 Inspect all bolts for damage, if damaged replace with new bolts only.
6 Inspect the cylinder walls for cracks or damage. The cylinder sleeves are not serviced separately, if the cylinders are damaged the cylinder block assembly must be replaced.
7 Inspect the engine block for cracks. Do not repair any cracks. If cracks are found, the cylinder block assembly must be replaced. Repair any damaged threaded holes, refer to 4.9 Thread Repair Specifications.
Measuring Cylinder Bore Diameter
1 Measure the cylinder bore diameter 37 mm from the deck face (1) using a commercially available bore
gauge or Tool No. J-8087 (2).
2 Record the results and compare with the dimensions listed in the specifications, refer to 5 Specifications.
NOTE
If the cylinder diameter exceeds the
specifications, the cylinder block may be
oversized to 0.25 mm. Only one size of
oversized pistons and rings are available for
service. If the cylinder bore diameter exceeds
specification by more than 0.25 mm, the
cylinder block must be replaced.
Figure 6A1 – 448
Measuring Cylinder Bore Taper
1 Measure the cylinder bore along the thrust surfaces, perpendicular to the crankshaft centreline, at 10 mm below the deck surface and record the measurement.
2 Measure the cylinder bore along the thrust surfaces, perpendicular to the crankshaft centreline, at 100 mm below the deck surface and record the measurement.
3 Calculate the difference between the two measurements. The result will be the cylinder taper.
4 Compare the results with the dimensions listed in the specifications, refer to 5 Specifications.
NOTE
If the cylinder diameter exceeds the
specifications, the cylinder block may be
oversized to 0.25 mm. Only one size of oversized
pistons and rings are available for service. If the
cylinder bore diameter exceeds specification by
more than 0.25 mm, the cylinder block must be
replaced.
Measuring Cylinder Bore Out-of-Round
1 Measure both the thrust and non-thrust cylinder diameter at 10 mm below the deck. Record your measurements.
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ISUZU KB P190 2007
Engine Mechanical – V6 Page 6A1–240
2 Calculate the difference between the two measurements. The result will indicate out-of-round at the upper end of
the cylinder.
3 Measure both the thrust and non-thrust cylinder diameter at 100 mm below the deck surface. Record your measurements.
4 Calculate the difference between the two measurements. The result will indicate out-of-round at the lower end of the cylinder.
5 Compare your results with the dimensions listed in the specifications, refer to 5 Specifications.
NOTE
If the cylinder diameter exceeds the
specifications, the cylinder block may be
oversized to 0.25 mm. Only one size of oversized
pistons and rings are available for service. If the
cylinder bore diameter exceeds specification by
more than 0.25 mm, the cylinder block must be
replaced.
Deck Flatness Inspection
1 Ensure the engine block decks are clean and free of gasket material.
2 Inspect the surface for any imperfections or scratches that could inhibit correct cylinder head gasket sealing.
3 Place a straight-edge diagonally across the cylinder block deck face surface.
4 Measure the clearance between the straight-edge and the cylinder block deck face using a feeler gauge
at 4 points along the straight-edge.
5 If the warpage is less than 0.05 mm, the cylinder block deck surface does not require resurfacing.
6 If the warpage is between 0.05 ±0.20 mm or any imperfections or scratches that could inhibit correct
cylinder head gasket sealing are present, the cylinder
block deck surface requires resurfacing.
7 If resurfacing is required the maximum amount that can be removed is 0.25 mm.
8 If the cylinder block deck surface requires more than 0.25 mm material removal the block must be
replaced.
Figure 6A1 – 449
Reassemble
1 Install the cylinder block-to-cylinder head alignment
dowels (1).
Figure 6A1 – 450
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ISUZU KB P190 2007