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Iveco Stralis AT/AD. Manual - part 20

49030

47593

Figure 102

Figure 103

Figure 104

Install half-bearings (1), selected as specified on page 66, on
both the connecting rod and the cap.

- all pistons belong to the same class, A or B;

- ideogram stamped on the piston crown is placed toward

the engine flywheel, or the cavity, on the piston cover,
corresponds to the position of the oil spray nozzles.

61831

Connecting rod-piston assembly

Marking area on the piston crown of ideogram
specifying the assembly position and the
selection class

Connecting rod marking area (see fig. 96).

Fit the connecting rod-piston assemblies (1) into the piston
liners (2) using band 99360605 (1, Figure 104). Check the
following:

- the openings of the split rings are offset by 120

°;

As spares, class A pistons are provided and can be
fitted also to cylinder barrels belonging to class B.

Piston protrusion check

Once assembly is complete, check piston protrusion from
cylinder barrels: it must be 0.32-0.69 mm.

ENGINE F2B

TRALIS

AT/AD

Base - January 2003

Install the connecting rod caps (1) with half-bearings; tighten
the connecting rod cap fixing screws (2) to 50 Nm (5 kgm)
torque. By tool 99395216 (3), tighten the screws further at
40

° angle.

Remove the caps and check the clearance by comparing the
width of the calibrated wire with the scale calibration on the
envelope containing the wire.

540610

CYLINDER HEAD

Before taking down the cylinder head, check the seal using
the appropriate tool; in case of leakage replace the cylinder
head.

47594

47583

36159

48625

Figure 105

Figure 106

Figure 107

Figure 108

Valve removal

Install and fix tool 99360264 (2) with bracket (4); tighten by
lever (1) until cotters are removed (3); remove the tool (2)
and the upper plate (5), the spring (6) and the lower plate (7).
Repeat the operation on all the valves. Turn the cylinder head
upside down and remove the valves (8).

The planarity (1) is checked using a ruler (2) and a thikness
gauge (3). If deformations exist, surface

the head using

proper surface grinder; the maximum amount of material to
be removed is 0.2 mm.

540622

VALVE

Removing deposits and checking the valves

Remove carbon deposits using the metal brush supplied.
Check that the valves show no signs of seizure or cracking.
Check the diameter of the valve stem using a micrometer
(see fig. 109) and replace if necessary.

To check the clearance proceed as follows:

Connect the connecting rods to the relative main journals,
place a length of calibrated wire on the latter.

Checking the planarity of the head on the
cylinder block

(Demonstration)

After leveling, make sure that valve sinking and
injector protrusion are as described in the relative
paragraph.

ENGINE F2B

TRALIS

AT/AD

540831

Checking assembly clearance of big
end pins

MAIN DATA - VALVES AND VALVE GUIDES

* Values to be obtained after installing the valve guides

47584

47509

Figure 109

Figure 110

Check, by means of a micrometer, that valve stem diameters
are as specified; if necessary, grind the valves seat with a
grinder, removing the minimum quantity of material.

INSTALLATION DIAGRAM FOR VALVE GUIDES AND VALVES

* Values to be obtained after installing the guide valves

540667

VALVE GUIDES

ENGINE F2B

TRALIS

AT/AD

Base - January 2003

41032

45634

Figure 111

Figure 112

Remove valve guides by means of tool 99360288.
Install by means of tool 99360288 equipped with part
99360294, which determines the exact installation position
of valve guides into the cylinder heads; if they are not
available, install the valve guides in the cylinder head so that
they project out by mm 16.3 to 16.7 (fig. 110).
After installing the valve guides, smooth their holes with
sleeker 99390310.

Ream the valve seats (2) on cylinder head using tool
99305019 (1).

After reaming the valve seats, use tool 99370415, to make
sure that the valve position, with respect to the cylinder head
surface, is the following:

- -0.5 to -0.8 mm (recessing) of exhaust valves;

- -1.6 to 1.9 mm (recessing) of discharge valves.

To replace the injector case (2), act as follows:

- thread the case (2) with tool 99390804 (1).

Carry out operations described in figs. 112-115-116-117
by fixing tools to the cylinder head by means of braket A.

Replacing of valve guides

540613

REPLACING INJECTOR HOLDER
CASES

Removal

Replacing - Reaming the valve seats

To replace the valve seats, remove them using the
appropriate tool.

Valve seats must be reamed whenever valves or
valve guides are replaced or ground.

ENGINE F2B

TRALIS

AT/AD

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