Iveco EuroCargo (12 to 26 t). Manual

Thoroughly clean the individual parts making up the
differential. Lubricate the bearings and spin the roller cages
freely; these should rotate evenly without tight spots.
Check the seating surfaces of the bevel crown wheel and the
bedding surface of the half cage so that the crown wheel
adheres to it perfectly; distortion of these faces would cause
vibration

the

crown

wheel

attachment

screws,

compromising the satisfactory operation of the unit.

19397

19391

19383

36323

Figure 31

Figure 32

Figure 33

Figure 34

Heat the support bearing (2) for the opposite side of the
locking differential in a circulating air oven to a temperature of
100

˚C for about 15’ and fit it to the gear cage (3) using a

suitable drift (1).

Position half cage (2) on fixture 99371047.
Position differential gear thrust washer (1) in the half cage (2)
and then fit differential gear.

Fit spider (6) complete with planetary gears (5) and associated
thrust washers (3) to half cage (4).
Position second differential gear (2) with thrust washer (1).

Checking differential components

Thoroughly clean threads of screws, studs and ring
nuts to prevent clearance or torque settings from
being altered.

Check that there is no excessive wear in the splined portion
for fitting the flange to the pinion; if there is, replace the pinion.

Check the planetary gears and associated thrust washers, the
spider and differential gears and thrust washers.
Replace all seals and gaskets, the locking pin for the adjustment
ring nut and all lock washers.

If it should be necessary to replace the crown wheel
or pinion, both must be replaced as the parts are
supplied as matched pairs.

Assembling gear cage

It is always advisable to renew screws (2).

Lock the differential with the parts (1); fit on the half box (3).
Check that the marks made at the time of removal coincide.
Apply a few drops of “LOCTITE 270” on the thread of the
screws (2).
Tighten the screws (2) to the prescribed torque.

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12-26 t

AXLES IN TANDEM MERITOR (REAR)

Where a new pinion/crown wheel assembly has to be fitted,
it is necessary to understand the information stamped on the
pinion and on the crown wheel in order to determine the
correct location of the pinion, in other words:

part number;

tooth combination number;

pinion/crown wheel assembly pairing number;

variation number to determine the thickness of the
stack of shims to be placed between the pinion sup-
port and the differential casing (this variation number
is indicated by CP in the examples);

month and year of manufacture and inspection of the
pinion/crown wheel assembly;

nominal end play of the pinion/crown wheel assembly.

The part number and the tooth combination number are
stamped at the threaded end of all pinions. However,
alternatively, they may be found on the outside diameter
of the crown wheel.

19413

19415

19414

19378

19416

Heat front bearing (1) in a circulating air oven to a
temperature of 100

˚C for about 15’ and fit it to its seat on the

bevel pinion (2) using a suitable drift.

Lubricate seal carrier cover (1) seat with differential oil and
install it in support (2), using a suitable locking ring.

Position drive attachment flange (1) complete with deflector
(2) on the splined part of the bevel pinion. Use a drift to drive
fully home. It is advisable to carry out this operation using a
press.
Temporarily tighten the retaining nut.

If the old pinion/crown wheel assembly is to be refitted,
position shim pack (2) and bevel pinion support (1) on the
differential casing (3), making sure that the groove through
which oil passes is correctly lined up.

In any pinion/crown wheel assembly, the crown wheel will
always have an even category number (for example 36786)
stamped on it, while the corresponding pinion will have an odd
number (for example 36787).

1,2

3,5

1,2

1,2,3,4,5,6

Figure 35

Figure 36

Figure 37

Figure 38

Figure 39

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12-26 t

AXLES IN TANDEM MERITOR (REAR)

Base - February 2003

Example 2

Thickness of original stack

0.76 mm

C.P. engraved on crown wheel - 0.05

+ 0.05

Measurement obtained

0.81 mm

C.P. engraved on the new crown wheel + 0.13

+ 0.13

New thickness of stack to be used

0.94 mm

Example 3

Thickness of original stack

0.76 mm

C.P. engraved on crown wheel + 0.05

- 0.05

Measurement obtained

0.71 mm

C.P. engraved on the new crown wheel - 0.13

- 0.13

New thickness of stack to be used

0.58 mm

Example 4

Thickness of original stack

0.76 mm

C.P. engraved on crown wheel - 0.05

+ 0.05

Measurement obtained

0.81 mm

C.P. engraved on the new crown wheel - 0.13

- 0.13

New thickness of stack to be used

0.68 mm

Read the C.P. engraved on the new crown wheel.
Add or subtract the value according to algebraic
value (+ add, - subtract) from the measurement re-
corded at point 2.
The value obtained indicates the thickness of the new
shim pack to be used.

Refer to the following examples which cover all possible
calculation combinations.

Every crown wheel has a variation number which indicates the
nominal assembly distance. Use this variation number to
calculate the thickness of the shims to be placed between the
pinion support and the differential casing.
This variation number (for example C.P. + 0.1, or C.P. - 0.1
mm) is stamped on the outer part of the crown wheel.

To calculate the thickness of the shims to be placed between
the pinion support and the differential casing, proceed as
follows :

measure the thickness of the shim pack used with the
pinion/crown wheel assembly to be replaced. Use a
micrometer or gauge and take note of the measure-
ment recorded;

read the C.P. engraved on the crown wheel to be re-
placed. If this number represents a plus value (+),
subtract it from the measurement recorded above at
point 1.
If this number represents a minus value (-), add it to
the measurement recorded at point 1 above.

Take note of this measurement.

The tooth combination number (for example 5-37) indicates
that the pinion has 5 teeth and the crown wheel 37, equal to
a drive ratio of 7.4 / 1.
- Pinion/crown wheel assemblies are matched pairs.
- Both parts are, therefore, engraved with the same number.
On pinions, this number is generally engraved on the end of the
head while on crown wheels it is generally engraved on the
outside diameter

36328

Figure 40

Fit the eight screws (2) complete with washers and tighten
them, using torque wrench (1), to the specified torque.

Never use a pinion and a crown wheel which do not
have the same number.

The measurement obtained at point 2 will be used to
calculate the shim pack to be placed between the
pinion support and the differential casing, depending
on the new pinion/crown wheel assembly.

Specimen calculations

Example 1

Thickness of original stack

0.76 mm

C.P. engraved on crown wheel + 0.05

- 0.05

Measurement obtained

71 mm

C.P. engraved on the new crown wheel + 0.13

+ 0.13

New thickness of pack to be used

0.84 mm

The shims to be placed between the differential casing
and the bevel pinion support are supplied as spare
parts in thicknesses of 0.05 - 0.125 - 0.200 - 0.500 mm.

Every pinion and every crown wheel is marked with the
month and year in which they were ground and inspected
jointly to form a matched pair.

On the pinions, this information is given at the head end.
On the crown wheels, this information is shown on the
outside diameter.

All assemblies are engraved with a number which shows the
nominal end play between the pinion and crown wheel
obtained when machining was finished. This end play is
shown on the outside diameter of the crown wheel.

Assembling differential casing

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12-26 t

AXLES IN TANDEM MERITOR (REAR)

Swivel the stand through 90

˚.

Prevent the flange from rotating using tool 99370317 (3).
Position polygon wrench 99355088 (1) and use adaptor (2)
and torque wrench (4) to tighten the pinion retaining nut to
the specified torque.
Recheck the rolling torque of the bevel pinion, the values are
shown in the table on page 55.

36329

20670

19419

36330

36331

Figure 41

Figure 42

Figure 43

Figure 44

Figure 45

Position the caps, taking care to line up the reference marks.
Insert the screws complete with washers and tighten them
using a torque wrench to the specified torque.
Then check that the outer races of the bearings slide into their
housings when pushed gently without sticking.
Unscrew the retaining screws with washers again and remove
the caps.

Use hook (1) to lift gear cage (2), assembled previously, and
position it on differential casing (3).

Position caps (2), screw in screws (1) with washers and tighten
to the specified torque.

Lubricate taper roller bearings (1) and fit outer races.
Screw in adjustment ring nuts (2).

Note that the rolling torque increases by 1.5 Nm
when the seal is lubricated.

URO

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12-26 t

AXLES IN TANDEM MERITOR (REAR)

Base - February 2003

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Iveco EuroCargo (12 to 26 t). Manual - part 112