Iveco Stralis AT/AD. Manual — part 16
49018
Figure 61
Figure 62
X
. Detail of main journals connections
Y.
Detail of crank pins connections
Figure 63
MAIN DATA FOR THE CRANK SHAFT PINS AND THE HALF BEARINGS
Check the condition of the journals and the big end pins; there must no be signs of scoring, ovalization or excessive wear.
The data given refer to the normal diameter of the pins.
47537
47538
Upper main journal half bearing
Lower main journal half bearings
BUFF
BUFF
50
ENGINE F2B
S
TRALIS
AT/AD
Base - January 2003
CRANKSHAFT
MEASURING CRANK PINS
During grinding, pay attention to journal and crank pins values
specified in figures 62 and 63.
47535
47536
Figure 64
Figure 65
MEASURING THE MAIN JOURNALS
Before grinding the crank pins using a micrometer (1),
measure the main journals and the crank pins (2) and decide,
on the basis of the undersizing of the bearings, the final
diameter to which the pins are to be ground.
!
It is advisable to enter the values found in a table
(Figure 66).
!
All journals and crank pins must also be ground to
the same undersizing class, in order to avoid any
alteration to shaft balance.
Figure 66
Fill in this table with the measurements of the main journals and the crank pins.
MAIN JOURNALS
36061
Ø MIN.
Ø MAX.
Ø MIN.
Ø MAX.
CRANK PINS
ENGINE F2B
51
S
TRALIS
AT/AD
540812
Measuring main journals and crank pins
For each of the journals of the crankshaft, it is necessary to carry out the following operations:
MAIN JOURNALS:
- Determine the class of diameter of the seat in the
crankcase.
- Determine the class of diameter of the main journal.
- Select the class of the bearing shells to mount.
CRANKPINS:
- Determine the class of diameter of the seat in the
connecting rod.
- Determine the class of diameter of the crankpin.
- Select the class of the bearing shells to mount.
DEFINING THE CLASS OF DIAMETER OF THE SEATS FOR BEARING SHELLS ON THE CRANKCASE
On the front of the crankcase, two sets of numbers are marked in the position shown (Figure 67 at top).
- The first set of digits (four) is the coupling number of the crankcase with its base.
- The following seven digits, taken singly, are the class of diameter of each of the seats referred to (Figure 67 at bottom).
- Each of these digits may be 1, 2 or 3.
47535
89.000 to 89.009
89.010 to 89.019
89.020 to 89.030
Figure 67
CLASS
MAIN BEARING HOUSING
NOMINAL DIAMETER
52
ENGINE F2B
S
TRALIS
AT/AD
Base - January 2003
!
To obtain the required assembly clearances, the main and big end bearing shells need to be selected as described
hereunder.
This operation makes it possible to identify the most suitable bearing shells for each of the journals (the bearing shells, if necessary,
can have different classes from one journal to another).
red
red/black
green
green/black
STD
2.000 to 2.010
2.011 to 2.020
+0.127
2.063 to 2.073
2.074 to 2.083
+0.254
2.127 to 2.137
2.138 to 2.147
+0.508
2.254 to 2.264
2.265 to 2.274
Depending on the thickness, the bearing shells are selected
in classes of tolerance marked by a coloured sign (red-green
— red/black — green/black).
The following tables give the specifications of the main and
big end bearing shells available as spares in the standard sizes
(STD) and in the permissible oversizes (+0.127, +0.254,
+0.508).
* Fitted in production only and not supplied as spares
Figure 68
yellow*
yellow/black*
2.021 to 2.030
red
red/black
green
green/black
STD
3.000 to 3.010
3.011 to 3.020
+0.127
3.063 to 3.073
3.074 to 3.083
+0.254
3.127 to 3.137
+0.508
2.254 to 3.264
yellow*
yellow/black*
3.021 to 3.030
2.084 to 2.093
3.084 to 3.093
ENGINE F2B
53
S
TRALIS
AT/AD
Selecting the main and big end bearing shells
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