ISUZU TROOPER 1998 Service Repair Manual

4JG2-NA/4JG2-TURBO ENGINE 6A2 Ð 39
CRANKSHAFT AND MAIN BEARING

6A2 Ð 40 4JG2-NA/4JG2-TURBO ENGINE
REMOVAL
1. Engine Assembly
·Refer to ÒEngine AssemblyÓ removal in this
section.
2. Crankshaft Damper Pulley
3. Timing Gear Case Cover
4. Oil Level Gauge and Guide Tube
5. Idler Gear
ÒBÓ and Shaft
6. Idler Gear
7. Injection Pump
8. Camshaft Timing Gear
9. Crankcase
10. Gear Case
11. Flywheel
12. Rear Plate
13. Connecting Rod Caps
14. Crankshaft Main Bearing Caps
15. Crankshaft and Main Bearings
INSTALLATION
15. Crankshaft and Main Bearings
·Install main bearings in the cylinder body and
main bearing cap respectively.
·Apply new engine oil to upper and lower main
bearings.
·Make sure that main bearing are in correct
position.
·Install crankshaft with care.
·Apply engine oil to the thrust washer.
·Install thrust washer on No. 3 journal.
Oil grooves in thrust washer must face the
crankshaft.
14. Crankshaft Main Bearing Caps
·Apply engine oil to the thread and seating surface
of each bearing cap fixing bolt.
·Install bearing caps in the order of numbers,
starting with cylinder body front side.
·Tighten main bearing fixing bolts to the specified
torque.

4JG2-NA/4JG2-TURBO ENGINE 6A2 Ð 41
19 (1.9/14)N·m(Kg·m/lb·ft)
·After tightening the bolts, make sure that the
crankshaft rotates smoothly.
167 (17.0/123)N·m(Kg·m/lb·ft)
13. Connecting Rod Caps
·The cap number must be same as connecting rod
number.
·Apply engine oil to the thread and sealing surface
of each nut.
·Tighten nuts to the specified torque.
·After tightening the nuts, make sure that the
crankshaft rotates smoothly.
12. Rear Plate
·Tighten bolts to the specified torque.
82 (80/61)N·m(Kg·m/lb·ft)
11. Flywheel
·Tighten bolts to the specified torque.
118 (12.0/87)N·m(Kg·m/lb·ft)
10. Gear Case
·Tighten fixing bolts to the specified torque.
19 (1.9/14)N·m(Kg·m/lb·ft)
9. Crankcase
·Remove oil from oil pan mounting surface, and
dry the surface.
·Apply a proper wide bead of sealant (TB1207C or
equivalent) to the crankcase mounting surface.
The bead must be continuous.
·Crankcase must be installed within 5 minutes
after sealant application.
·Tighten fixing bolts and nuts to the specified
torque.
Bolts
1st step 29 (3.0/22) 2nd step 45° – 60°N·m(Kg·m/lb·ft)

6A2 Ð 42 4JG2-NA/4JG2-TURBO ENGINE
8. Camshaft Timing Gear
1) Install the camshaft timing gear to the camshaft.
The timing gear mark ("Y - Y") must be facing out-
ward.
2) Tighten the timing gear to the specified torque.
Nuts
6. Idler Gear
1) Apply engine oil to the idler gear and the idler gear
shaft.
The idler gear shaft oil hole must be facing up.
2) Position the idler gear setting marks "X" and "Y" so
that they are facing the front of the engine.
3) Align the idler gear "X" setting mark with the crank-
shaft timing gear 1 "X - X" setting mark.
4) Align the idler gear "Y" setting mark with the cam-
shaft timing gear 2 "Y - Y" setting mark.
5) Install the thrust collar and bolts to the cylinder body
through the shaft.
The thrust collar oil hole must be facing up, and the
thrust collar chamfered must be outward.
6) Tighten the idler gear bolt to the specified torque.
64 (6.5/47)N·m(Kg·m/lb·ft)
19 (1.9/14)N·m(Kg·m/lb·ft)
5. Idler Gear "B" and Shaft
1) Apply engine oil to the idler gear and the idler gear
shaft.
2) Align the idler gear "B" 3 "Z" setting mark with the
idler gear "A" 4 "Z - Z" setting mark.
3) Tighten the idler gear bolt to the specified torque.
76 (7.7/56)N·m(Kg·m/lb·ft)
24 (2.4/18)N·m(Kg·m/lb·ft)

4JG2-NA/4JG2-TURBO ENGINE 6A2 Ð 43
7. Injection Pump
1) Install the O-ring 1 to the injection pump flange 2.
2) Install the injection pump to the timing gear case.
Align the idler gear "B" 3 "V - V" mark with the
injection pump timing gear 4 "V" mark.
3) Temporarily tighten the six injection pump nuts 5.
The injection pump nuts will be finally tightened after
the injection pump rear bracket bolts.
7) Tighten the injection pump bracket bolts 8 to the
specified torque.
4. Timing Gear Oil Pipe
1) Install the oil pipe to the timing gear case and idler
gear "A".
2) Tighten the oil pipe eye bolt 1 and bolt 2 to the
specified torque.
4) Install the injection pump rear bracket 6 and the rear
bracket bolts 7 to the cylinder body.
5) Install the rear bracket bolts 8 to the injection pump
bracket 9.
Do not tighten the bolts.
The rear bracket bolts 7 and 8 will be finally tight-
ened to the specified torque after the injection pump
nuts.
13 (1.3/9)N·m(Kg·m/lb·ft)
6) Tighten the infection pump bracket bolts 7 to the
specified torque.
20 (2.0/15)N·m(Kg·m/lb·ft)
40 (4.1/30)N·m(Kg·m/lb·ft)

6A2 Ð 44 4JG2-NA/4JG2-TURBO ENGINE
3. Timing Gear Case Cover
1) Align the gear case with the timing gear case knock
pin and then install the timing gear case cover.
2) Tighten the gear case cover bolts to the specified
torque.
2. Crankshaft Damper Pulley
Tighten the crankshaft damper pulley bolt to the specified
torque.
NOTE:
Hold the flywheel ring gear stationary to prevent the
crankshaft from turning when tightening the damper
pulley.
1. Engine Assembly
8 (0.8/69)N·m(Kg·m/lb·in)
206 (21.0/152)N·m(Kg·m/lb·ft)

4JG2-NA/4JG2-TURBO ENGINE 6A2 Ð 45
FRONT OIL SEAL
REMOVAL
1. Crankshaft Damper Pulley
2. Timing Gear Case Cover Assembly
3. Front Oil Seal
·Remove crankshaft front oil seal using suitable size
box wrench for push the oil seal from inside of
timing gear case cover.
INSTALLATION
3. Front Oil Seal
·Use the installer to install the front oil seal 1 to the
gear case cover 2.
Oil Seal Installer: 5-8840-2061-0
Note the oil seal installation depth 3 shown in the
illustration.
Depth 3 = 1 mm (0.039 in).
2. Timing Gear Case Cover Assembly
1) Align the timing gear case cover with the timing
gear case dowel pin then install the timing gear case
cover.
2) Tighten the timing gear case cover bolts to the
specified torque.
8 (0.8/69)N·m(Kg·m/lb·in)
1. Crankshaft Damper Pulley

6A2 Ð 46 4JG2-NA/4JG2-TURBO ENGINE
REAR OIL SEAL
REMOVAL
1. Transmission Assembly
·Refer to ÒTransmissionÓ removal in section 7.
2. Flywheel
3. Rear Oil Seal
·With the oil seal pushed in deep, install the special
tool as shown in the illustration and remove the oil
seal.
Oil Seal Remover : 5-8840-2362-0
INSTALLATION
3. Rear Oil Seal
8. Crankshaft Rear Oil Seal
1) Tighten the adapter to the crankshaft rear and
section with 2 bolts.
2) Insert the oil seal into the peripheral section of the
adapter,
3) Insert the sleeve into the adapter section, and 1)
tighten it with a bolt (M12 x 1.75L = 70) until the
adapter section hits the sleeve.
4) Remove the adapter and the sleeve.
5) With the seal pressed in, check the dimension of
the oil seal section.
Standard Dimension = 12.5 ± 0.3 mm
Oil Seal Installer: 5-8840-2359-0

4JG2-NA/4JG2-TURBO ENGINE 6A2 Ð 47
2. Flywheel
·Tighten bolts to the specified torque.
118 (12.0/87)N·m(Kg·m/lb·ft)
1. Transmission Assembly
·Refer to ÒTransmissionÓ installation in section 7.

6A2 Ð 48 4JG2-NA/4JG2-TURBO ENGINE
ENGINE ASSEMBLY
REMOVAL
Preparation
·Space stands and removal front tires.
·Removal battery. (two batteries for cold area)
·Drain coolant.
·Disconnect window washer hose and remove engine
hood.
1. Radiator Hose
·Disconnect upper and lower hoses from engine
side.
2. Fan Shroud
·Disengage clips and remove upper and lower fan
shrouds.