Isuzu engine 4j series. Manual - part 37

6A1 – 16  4JB1/4JB1T/4JB1TC/4JG2 - ENGINE

1. PCV Hose

•

Connect the PCV hose to the intake pipe.

•

Connect battery ground cable.

4JB1/4JB1T/4JB1TC/4JG2 – ENGINE  6A1 – 17

ROCKER ARM SHAFT ASSEMBLY

REMOVAL

Preparation:

•

Disconnect battery ground cable.

1. PCV Hose

2. Cylinder Head Cover

3. Rocker Arm Shaft Assembly

•

Loosen bolts and nuts of rocker shaft bracket by turns
and remove rocker shaft assembly.

INSTALLATION

3. Rocker Arm Shaft Assembly

•

Install rocker arm shaft with larger oil hole (

φ

4) to the

front of engine.

•

Align fixing bolt with nut of rocker arm shaft and
tighten fixing bolts to the specified torque.

N∙m (kg∙m/lb∙ft)

                                                                                                                   

54 (5.5/40)

                                                                                                                   

6A1-17-1.tif

6A1-17-2.tif

6A1-17-3.tif

Removal steps

1. PCV hose
2.  Cylinder head cover
3.  Rocker arm shaft Assembly

Installation steps

To install, follow the removal steps in
the reverse order.

6A1 – 18  4JB1/4JB1T/4JB1TC/4JG2 - ENGINE

Valve Clearance Adjustment

!

Bring the piston in either the No.1 cylinder or the No.4
cylinder to TDC on the compression stroke by turning
the crankshaft until the crankshaft damper pulley TDC
line is aligned with the timing pointer.

"

Check the rocker arm shaft bracket nuts for
looseness.
Tighten any loose rocker arm shaft bracket nuts
before adjusting the valve clearance.

Rocker Arm Shaft Bracket Nut Torque

N∙m (kg∙m/lb∙ft)

                                                                                                                   

54 (5.5/40)

                                                                                                                   

#

Check for play in the No.1 intake and exhaust valve
push rods.
If the No.1 cylinder intake and exhaust valve push rods
have play, the No.1 piston is at TDC on the
compression stroke.
If the No.1 cylinder intake and exhaust valve push rods
are depressed, the No.4 piston is at TDC on the
compression stroke.

Adjust the No.1 or the No.4 cylinder valve clearances
while their respective cylinders are at TDC on the
compression stroke.

Valve Clearance (At Cold)

mm (in)

                                                                                                                   

0.4 (0.016)

                                                                                                                   

$

Loosen each valve clearance adjusting screw as
shown in the illustration.

%

Insert a feeler gauge of the appropriate thickness
between the rocker arm and the valve stem end.

&

Turn the valve clearance adjusting screw until a slight
drag can be felt on the feeler gauge.

'

Tighten the lock nut securely.

(

Rotate the crankshaft 360°.

)

Realign the crankshaft damper pulley TDC notched
line with the timing pointer.

*

Adjust the clearances for the remaining valves as
shown in the illustration.

6A1-18-1.tif

6A1-18-2.tif

6A1-18-3.tif

6A1-18-4.tif

6A1-18-5.tif

4JB1/4JB1T/4JB1TC/4JG2 – ENGINE  6A1 – 19

2. Cylinder Head Cover

•

Install cylinder head cover and tighten bolts to the
specified torque.

N∙m (kg∙m/lb∙in)

                                                                                                                   

13 (1.3/113)

                                                                                                                   

1. PCV Hose

•

Connect battery ground cable.