Content .. 39 40 41 42 ..

Isuzu engine 4j series. Manual - part 41

6A1 – 32 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE

11. Timing Belt

•

Prepare a fixing bolt (M8x40, P=1.25)

•

Turn crankshaft timing pulley in the normal direction
pulley side mark to timing pulley housing side mark.

•

Make sure that the camshaft pulley and injection
timing pulley fixing bolt holes are set to each other.
Then fit in a fixing bolt and lightly tighten.

•

No.1 cylinder should be at top dead center.
If the fixing bolt holes are not set (No.4 cylinder is at
top dead center) give another turn.

•

Remove tensioner and timing belt.

WARNING

IF CRANKSHAFT AND CAMSHAFT AND TURNED
WITH TIMING BELT BEING NOT MOUNTED, PISTON
AND VALVE WILL INTERFERE WITH EACH OTHER.
THEREFORE, THE SHAFTS MUST NOT BE TURNED.

INSTALLATION

11. Timing Belt

•

When removing the belt, make sure the marks on the
bolt fixed camshaft, injection pulley and crankshaft
timing pulley are set to each other.

CAUTION

Do not turn crankshaft because otherwise piston and
valve will interfere with each other.

CAUTION

For accurate mounting, be sure to mount the belt in
the direction that letters on the belt are readable.

6A1-32-1.tif

6A1-32-2.tif

6A1-32-3.tif

6A1-32-4.tif

4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 33

•

Mount new timing belt on pulleys in the following steps.
Crankshaft timing pulley

→

camshaft

Timing pulley

→

Idle pulley

→

Injection

Pump pulley

→

tensioner

•

Set the belt on crankshaft timing pulley and hold with
one hand.

•

Stretch and pass the belt round each pulley with the
other hand.

•

After passing it round injection pump pulley, install
tensioner while taking care not to slacken the belt.

CAUTION

•

On completion of belt passing, make sure that the
setting mark on crankshaft timing pulley is set.

•

If not set, reset the mark and repeat the belt passing.

•

Remove tension adjust, lever mounting bolt, and
loosen the fulcrum bolt to such extent that the lever is
movable.

•

Hung a spring balance from the end hole of tension
adjust lever, and with the balance pulled down with
9kg., loosen once the tensioner mounting bolt and
there retighten it.

•

Turn the crankshaft by 45° counterclockwise to shift
belt slackness on to the tensioner.

•

Again hang the spring balance from the end hole of
tension adjust lever and pull it down with the specified
force. Under this condition, loosen tensioner mounting
bolt to absorb belt slackness and retighten is to
specified torque.

Belt

N∙(kg/lb)

Tension

98 - 118 (10 - 12/22 - 26)

Bolt

N∙m (kg∙m/lb∙ft)

76 (7.8/56)

•

Fix the tension adjust lever.

6A1-33-1.tif

6A1-33-4.tif

6A1-33-2.tif

6A1-33-3.tif

6A1 – 34 4JB1/4JB1T/4JB1TC/4JG2 - ENGINE

CAUTION

•

In case where the timing belt has been replaced with
the actuation of warning light, put off the light with
change over switch on the reverse side of meter.

•

Refer to Chassis Electrical in Section 8.

•

Tighten the tension adjusting lever nut and bolt.

10. Flange; Camshaft Pulley

•

Install the timing pulley flange

to the camshaft

timing pulley

Flange Bolts Torque

N∙m (kg∙m/lb∙ft)

19 (1.9/14)

9. Timing Pulley Lower Cover

•

Install timing pulley lower cover and tighten bolt to the
specified torque.

Cover Bolts Torque

N∙m (kg∙m/lb∙in)

8 (0.8/69)

8. Timing Pulley Upper Cover

•

Install timing pulley upper cover and tighten bolt to the
specified torque.

Cover Bolts Torque

N∙m (kg∙m/lb∙in)

8 (0.8/69)

7. Crankshaft Damper Pulley

•

Install crankshaft damper pulley and tighten bolt to the
specified torque.

N∙m (kg∙m/lb∙ft)

19 (1.9/14)

6A1-34-1.tif

6A1-34-2.tif

6A1-34-3.tif

6A1-34-4.tif

6A1-34-5.tif

4JB1/4JB1T/4JB1TC/4JG2 – ENGINE 6A1 – 35

6. Power Steering Pump Bracket Assembly (P/S Model)

•

Install the pipe bracket & clip and tighten bolts to the
specified torque.

Pipe Bracket Bolts Torque

N∙m (kg∙m/lb∙ft)

19 (1.9/14)

Pipe Clip Bolts Torque

N∙m (kg∙m/lb∙in)

10 (1.0/87)

•

Install the P/S pump & bracket assembly.

10M bolts

N∙m (kg∙m/lb∙ft)

40 (4.1/30)

8M bolts

N∙m (kg∙m/lb∙ft)

19 (1.9/14)

Lock nut

N∙m (kg∙m/lb∙ft)

27 (2.8/20)

5. AC Generator Drive Belt

•

Install AC Generator drive belt and adjust belt tension.

•

Depress the drive belt mid-portion with a 98N
(10kg/22lb) force.

Drive Belt Deflection

mm (in)

8 (0.31) - 12(0.47)

•

Install fixing bolt and tighten bolts to the specified
torque.

Generator Fixing Bolt

N∙m (kg∙m/lbvft)

40 (4.1/30)

Adjust Plate Fixing Bolt

N∙m (kg∙m/lb∙ft)

19 (1.9/14)

4. A/C Compressor Drive Belt (A/C type)

•

Install A/C compressor drive belt and adjust belt
tension.

•

Depress the drive belt mid-portion with a 98N
(10kg/22lb) force.

Drive Belt Deflection

mm (in)

8 (0.31) - 12 (0.47)

•

Tighten the idler lock nut to the specified torque.

N∙m (kg∙m/lb∙ft)

27 (2.8/20)

6A1-35-1.tif

6A1-35-2.tif

Content .. 39 40 41 42 ..