1998 ISUZU TROOPER Remove engine

6A±76
ENGINE MECHANICAL
012RS001
7. Install oil pump assembly (5), refer to ªOil pumpº in
this manual.
8. Install oil strainer and O-ring (4).
9. Install oil pipe and O-ring (3) and tighten the bolts.
Torque: 25 N´m (2.5 Kg´m/18 lb ft)
10. Install crankcase with oil pan (2).
1. Completely remove all residual sealant, lubricant
and moisture from the sealing surfaces. The
surfaces must be perfectly dry.
2. Apply a correct width bead of sealant (TBÐ
1207C or its equivalent) to the contact surfaces of
the oil pan. There must be no gaps in the bead.
3. The crankcase assembly must be installed within
5 minutes after sealant application to prevent
premature hardening of the sealant.
4. Tighten the bolts and nuts to the specified torque.
Torque : 10 N´m (1.0 Kg´m/89 lb in)
013RW010
Legend
(1) Portion Between Bolt Holes
(2) Bolt Hole Portion
11. Install cylinder head assembly, refer to ªCylinder
headº in this manual.

6A±77
ENGINE MECHANICAL
Piston and Connecting Rod
Piston, Connecting Rod and Associate Parts
015RW019
Legend
(1) Cylinder Head Assembly
(2) Cylinder Head Gasket
(3) Crankcase with Oil Pan
(4) Oil Pipe and O-Ring
(5) Oil Strainer and O-Ring
(6) Oil Gallery(7) Piston and Connecting Rod Assembly
(8) Piston Ring
(9) Piston Pin
(10) Piston
(11) Connecting Rod
(12) Connecting Rod Cap
Disassembly
1. Remove cylinder head assembly (1). Refer to
ªCylinder Head Removalº in this manual.
2. Remove cylinder head gasket (2).
3. Remove crankcase with oil pan (3). Refer toªOil Pan
and Crankcaseº in this manual.
4. Remove oil pipe and O-ring (4).5. Remove oil strainer and O-ring (5).
6. Remove oil gallery (6).
7. Remove connecting rod cap with connecting rod
lower bearing (12).
8. Remove piston and connecting rod assembly (7).
NOTE: Before removing piston and connecting rod
assembly, measure thrust clearance.

6A±78
ENGINE MECHANICAL
015RS031

Remove any ridge or carbon build up from the top
end of the cylinder.
9. Remove the piston rings (8) with a piston ring
expander. Arrange the removed piston rings in the
cylinder number order.
015RS022
10. Remove the piston pin (9) using 5±8840±0551±0
piston pin service set and piston support with a press.
NOTE: Keep the parts removed from each cylinder
separate. All parts must be reinstalled in their original
positions. Heating the connecting rod will permit easy
removal of the piston pin.
015RX001
Legend
(1) Press Ram
(2) Piston
(3) Connecting Rod
(4) Piston Pin
11. Piston (10)
12. Connecting rod (11)
Inspection and Repair
Pistons (10)
Carefully clean away all the carbon adhering to the piston
head and the piston ring grooves.
NOTE: Never use a wire brush to clean the pistons.
Damage will result. Visually check each piston for
cracking, scoring, and other signs of excessive wear. If
any of the above conditions are found, the piston must be
replaced.
Piston Diameter
1. Measure the piston outside diameter with micrometer
at the piston grading position and a right angle to the
piston pin.
Piston grading position (from piston head)
Piston grading position : 43.0 mm (1.6929 in)

6A±81
ENGINE MECHANICAL
Connecting Rods (11)
1. Check the connecting rod alignment If either the bend
or the twist exceeds the specified limit, the connecting
rod must be replaced.
Bend per 100 mm (3.937 in)
Limit: 0.15 (0.0059)
Twist per 100 mm (3.937 in)
Limit: 0.20 (0.0078)
015RS030
2. Measure the connecting rod thrust clearance. Use a
feeler gauge to measure the thrust clearance at the
large end of the connecting rod If the clearance
exceeds the specified limit, the connecting rod must
be replaced.
Standard : 0.16 mm±0.35 mm
(0.0063 in.±0.0138 in)
Limit : 0.40 mm (0.0157 in)
015RS031
3. Measure the oil clearance between the connecting
rod and the crankshaft.
1. Remove the connecting rod cap nuts and the rod
caps (12).
Arrange the removed rod caps in the cylinder
number order.
2. Clean the rod bearings and the crankshaft pins.
3. Carefully check the rod bearings. If even one
bearing is found to be damaged or badly worn, the
entire bearing assembly must be replaced as a
set. Reinstall the bearings in their original
positions. Apply plastigage to the crank pin.
015RS032

6A±82
ENGINE MECHANICAL
4. Reinstall the rod caps (12) to their original
positions.
Tighten the rod cap nuts.
Torque: 54 N´m (5.5 Kg´m/40 lb ft)
NOTE: Do not allow the crankshaft to rotate.
5. Remove the rod caps.
6. Measure the width of the plastigage and
determine the oil clearance. If the oil clearance
exceeds the limit, replace the rod bearing as a
set.
Standard : 0.019 mm±0.043 mm
(0.0007 in±0.0017 in)
Limit : 0.08 mm (0.003 in)
015RS008
7. Clean the plastigage from the bearings and the
crankshaft pins.
Con±rod Bearing Selection
Select and install the new connecting rod bearings,
paying close attention to the connecting rod big end
diameter size mark (1).
NOTE: Take care not to confuse the alignment mark (2)
and the size mark (1) during the installation procedure.
015RS034
1 Size MarkBig end Bore
DiameterCrankshaft Pin
DiameterConnecting Rod
Bearing Thickness
(Reference)Color of
Size
MarkOil Clearance
(Reference)
A56.994-57.000
(2.2439-2.2441)1.512-1.516
(0.0595-0.0597)Yellow0.025-0.054
(0.0010-0.0021)
B56.988-56.994
(2.2436-2.2439)53.922-53.937
(2.1229-2.1235)1.508-1.512
(0.0594-0.0595)Green0.027-0.056
(0.0011-0.0022)
C56.982-56.988
(2.2434-2.2436)1.504-1.508
(0.0592-0.0594)Pink0.029-0.058
(0.0011-0.0023)
Reassembly
1. Install connecting rod
2. Install piston3. Install piston pin

Apply a thin coat of engine oil to the piston pin. Try to
insert the piston pin into the piston pin hole with
normal finger pressure.
NOTE: W h e n changing piston / connecting rod
combinations, do not change the piston / piston pin
combination and do not reuse the old piston pin.

6A±85
ENGINE MECHANICAL
Cylinder Block
Cylinder Block and Associated Parts
012RW010
Legend
(1) Cylinder Head Assembly
(2) Cylinder Head Gasket
(3) Crankcase with Oil Pan
(4) Oil Pipe and O-Ring
(5) Oil Strainer and O-Ring
(6) Oil Pump Assembly
(7) Cylinder Block Side Bolts(8) Oil Gallery
(9) Piston and Connecting Rod Assembly
(10) Flywheel
(11) Rear Oil Seal Retainer Assembly
(12) Main Bearing Cap
(13) Crankshaft
(14) Cylinder Block
Disassembly
1. Remove cylinder head assembly.
2. Remove cylinder head gasket.
3. Remove crankcase with oil pan.
4. Remove oil pipe and O-ring.5. Remove oil strainer and O-ring.
6. Remove oil pump assembly.
7. Remove crankcase side bolts.
8. Remove oil gallery.
9. Remove piston and connecting rod assembly.
10. Remove flywheel.

6A±86
ENGINE MECHANICAL
11. Remove rear oil seal retainer assembly.
12. Remove main bearing cap.
13. Remove crankshaft.
14. Remove cylinder block.
Inspection and Repair
1. Remove the cylinder head gasket and any other
material adhering to the upper surface of the cylinder
block. Be very careful not to allow any material to
accidentally drop into the cylinder block. Be very
careful not to scratch the cylinder block.
2. Carefully remove the oil pump, rear oil seal retainer,
and crankcase assembly installation surface seal.
3. Wipe the cylinder block clean.
4. Visually inspect the cylinder block. If necessary, use a
flaw detector to perform a dye penetrate and
hydraulic (or air pressure) test. If cracking or other
damage is discovered, the cylinder block must either
be repaired or replaced.
Flatness
1. Using a straight±edge and feeler gauge, check that
the upper surface of the cylinder block is not warped.
CAUTION: Be very careful not to allow any material
to accidentally drop into the upper surface of the
cylinder block. Be very careful not to scratch the
upper surface of the cylinder block.
2. The cylinder block must be reground or replaced if the
warpage exceeds the limit.
Warpage
Limit : 0.15 mm (0.0059 in)
Maximum repairable limit: 0.15 mm (0.0059 in)
012RS004
Cylinder Bore
Use a cylinder gauge to measure the cylinder bore
diameter in both the axial and thrust directions. Each
measurement should be made at six points.CAUTION: Be very careful not to allow any material
to accidentally drop into the upper surface of the
cylinder block. Be very careful not to scratch the
upper surface of the cylinder block.
Cylinder Bore Inside Diameter
Limit : 93.530 (3.6823)
If the measurement exceed the specified limit, the
cylinder block must be replaced.
Diameter
Grade A : 93.400 mm±93.410 mm
(3.6772 in±3.6776 in)
Grade B : 93.411 mm±93.420 mm
(3.6776 in±3.6779 in)
Grade C : 93.421 mm±93.430 mm
(3.6780 in±3.6783 in)
012RS005
NOTE: For information on piston diameter, please refer
to the section ºInspection of the Piston and Connecting
Rod Assemblyº in this manual.

The ºGradeº mark (1) is stamped at the position
illustrated.

6A±87
ENGINE MECHANICAL
012RS006
Reassembly
1. Install cylinder block.
2. Install crankshaft.

Install the main bearings to the cylinder block and
the main bearing caps.

Be sure that they are positioned correctly.

Apply new engine oil to the upper and lower main
bearing faces.
NOTE: Do not apply engine oil to the bearing back faces.
015RS012
Legend
(1) Number 1 and 4 main bearing upper and lower.
(2) Number 2 and 3 main bearing upper.
(3) Number 2 and 3 main bearing lower.

Carefully mount the crankshaft.

Apply engine oil to the thrust washer.
Assemble the thrust washer to the No. 3 bearing
journal. The oil grooves must face the crankshaft.
015RS013
3. Install rear oil seal retainer.

Remove oil on cylinder block and retainer fitting
surface.

Apply sealant (TB1207B or equivalent) to retainer
fitting surface as shown in illustration.

The oil seal retainer must be installed within 5
minutes after sealant application before the sealant
hardens.
015RW002
Legend
(1) Around Bolt Holes
(2) Around Dowel Pin

Apply engine oil to oil seal lip and align a dowel pin
hole in the cylinder block with that in the retainer.

Tighten retainer fixing bolts to the specified torque.
Torque: 25 N´m (2.5 Kg´m/18.4 lb ft)