Astra HD8Ec User manual

INTRODUCTION 3 ASTRA HD8Ec SECTION I
PREFACE
Definitions adopted in the current Manual
The Company ASTRA VEICOLI INDUSTRIALI, Via Caorsana, 79 - 29100 PIACENZA (Italy) is hereinafter called Manufacturer.
The current WORKSHOP MANUAL is hereinafter called Manual.
The equipment dealt with in the current Manual is hereinafter called vehicle.
The operator directly or indirectly involved in vehicle repair is hereinafter called operator.
Introduction
The current Manual applies essentially to authorised workshop technical staff.
This Manual provides technical information but cannot replace a thorough professional experience.
This Manual contains all data and information required to perform correct checking and setting up operations as well as repair
and overhaul operations.
Read this Manual right through before performing any operation on the vehicle.
Compliance with the provided information and the use of the recommended tools guarantee correct repair and avoid damages
to operators.
You will frequently see that parts of the text are highlighted as shown below:
Failure to heed and/or correctly carry out procedures, technical information and precautions given may cause injury.
Failure to heed and/or correctly carry out procedures, technical information and precautions given may cause damage
to the vehicle.
Procedures, technical information and precautions which must be highlighted.
Failure to heed and/or correctly carry out procedures, technical information and precautions given may cause environ-
mental damages.
This Manual has been divided into Sections, each of which has a number and its relevant contents are indicated in the Index of
Sections.
Each section features a main Unit (e.g.: engine, gears, etc.)
Where possible, the same sequence of procedures has been followed for easy reference.
Diagram and symbols have been widely used to give a clearer and more immediate illustration of the subject being dealt with (see
next page) instead of giving descriptions of some operations or procedures.
α
Example:
Tighten to torque
Tighten to torque + angular value
Ø 1 = Housing for connecting rod small end bush
Ø 2 = Housing for connecting rod bearings

INTRODUCTION 5 ASTRA HD8Ec SECTION I
MEASURES (INTERNATIONAL SYSTEM)
Force in N (Newton)
Conversion:
I N = 0,1019 kg
1 kg = 9,81 N
Power in kW (kilowatt)
Other units in use:
HP (Horsepower)
Conversion:
1 kW = 1,36 CV
1 kW = 1,34 HP
1 CV = 0,736 kW
1 CV = 0,986 HP
1 HP = 0,746 kW
1 HP = 1,014 CV
Torque in Nm (Newton/metre)
Conversion:
1 Nm = 0,1019 kgm
1 kgm= 9,81 Nm
1 kgm= 10 Nm *
Specific consumption in g/kWh (grams per kilo-
watthour)
Other unit in use:
g/CVh (grams per horsepower-hour)
Conversion:
I g/kWh = 0,736 g/CVh
1g/CVh = 1,36g/kWh
Pressure in kPa (kilopascal)
Other units in use:
kg/cm2(kilograms per square centimeter)
Atm (metric atmosphere)
psi (pounds per square inch)
Conversion:
I kg/cm2=1Atm
I kg/cm2= 98,1 kPa
I kg/cm2= 0,981 bar
I kg/cm2=1bar*
I kg/cm2= 14,22 psi
I bar = 100 kPa
I bar = 1,02 kg/cm2
I bar = 14,51 psi
Ipsi = 6,9kPa
I psi = 0,069 bar
I psi = 0,0703 kg/cm2
I kPa = 0,145 psi
I kPa = 0,0102 kg/cm2
IkPa = 0,01bar
Conversion values for British units
0,1 mm = 3,937 mils
I mm = 0,039 inch
I m = 3,281 ft.
I km = 0,621 miles
Icm
3=0,06Icu.in.
I l = I ,759 pts (0,88 imp.qts)
I bar = 14,5038 psi
I g = 0,035 oz. (0,564 dr.)
I kg = 2,205 Ibs.
(in case of differences in temperature 1 °C = 1.8 °F)
(*) Nm and bar are converted according to the ratios 10:1
and 1:1.

60593
FRONT SIDE
stage 4:
angle, inner
screws
55º
60592
60594
60593
stage 1:
pretightening,
outer screws
30 Nm
FRONT SIDE
FRONT SIDE
stage 2:
pretightenig,
inner screws
120 Nm
stage 5:
angle, outer
screws
60º
60593
FRONT SIDE
stage 3:
angle, inner
screws
60º
FRONT SIDE
Figure 8
ENGINE - F3B 43 ASTRA HD8Ec SECTION 3
TIGHTENING ORDER OF GEARBOX TO ENGINE BLOCK FASTENING SCREWS

1. Fuel valve
2. Pumping element
3. Fuel discharge
4. Filling and flowing back channel
1. Fuel valve
2. Pumping element
3. Fuel discharge
4. Filling and flowing back channel
60669
Figure 227
Filling phase
During the filling phase, the pumping element (2) moves to
its upper position.
The highest cam position is passed and the rocker roller gets
closer to the cam basic circle.
The fuel valve (1) is open and the fuel can flow into the
injector from the lower channel (4) of the cylinder head.
The filling phase continues until the pumping element has
reached its upper end-of-stroke position.
60670
Figure 228
Injection phase
The injection phase starts when, during the pumping element
descending phase, the solenoid valve is energized and the fuel
valve (1) closes. Delivery start time, properly processed by
the electronic control unit, depends on engine operating
conditions. Through the rocker, the cam continues to
activate the pumping element (2) and the injection phase
continues as long as the fuel valve is closed (1).
ENGINE - F3B 133 ASTRA HD8Ec SECTION 3
Injection phases

MANUAL GEARBOX 3 ASTRA HD8Ec SECTION 6
DESCRIPTION
The ZF 16S 1620 and ZF 16S 2320 TD version consist of:
-a central box containing the primary shaft, drive input shaft,
secondary shaft and the cogs of the four forward and one
reverse gear;
-a rear casing containing the Epicyclical Reducer Group
(G.R.E). The function of this is to double the number of
forward gears by means of epicyclical gears with helical
teeth.
This gives a range of gears that starting with four input
ratios permits eight different output ratios (four normal
ratio and four low ratio gears);
-a front casing containing the “splitter”, that gives a further
double selection for each of the eight forward gears and
for the reverse gear.
The “splitter” halves the difference between two
successive gears, effectively splitting each gear into a slow
ratio (L = slow ratio) and a fast ratio (S = fast ratio).
These gearboxes therefore have a total of sixteen forward
gears with finely scaled ratios, all engageable in succession, and
two reverse gears.
Thesynchronisersaresingleconetype.
Lubrication is by means of a gear pump.
The double H type gear shift control is equipped with a
pneumatically powered “servoshift” device to improve gear
selection and engagement.
The servoshift is a device consisting of a mechanical/pneumatic
functional unit and a dual action cylinder.
The advantages of this device are:
-gear selection and engagement more rapid and with less
effort;
-it dampens the vibration of the control linkages, reducing
noise;
-less strain to the synchronisers.
The device functions mechanically in case of pneumatic system
failure.
The gearboxes mounted of vehicles with F3B engines are fitted
with a synchro protection device.
This permits pneumatic power to the servoshift for gear
engagement only after the clutch pedal has completed 70% of
the disengagement stroke.
It consists of an electrovalve controlled by a proximity switch
mounted on the clutch disengage master cylinder.
Figure 1
1. Distributor – 2. Servoshift – 3. Servoclutch – 4. *Servoshift power electrovalve
* only for vehicles with F3B engine
99356

14
8
6
13
3
5
4
7
25
Figure 10
MANUAL GEARBOX
22 ASTRA HD8EcSECTION 6

39593
Figure 37
CAMBER ANGLE CHECK
1. Support - 2. Goniometer - 3. Cross bar - 4. Centering cones - 5. Spacer
FRONT DRIVE AXLE 21 ASTRA HD8Ec SECTION 12.1

NO
Insufficient lubrication Check there are no leaks from gaskets or the axle casing
and top up oil to correct level.
Wheel hub bearings inefficient Remove the hub and replace inefficient parts.
Bad adjustment of wheel hub bearings Adjust bearings
Half-shaft splines to fit planetary gears of epicyclic gears
are worn
Overhaul and replace worn or damaged parts
Lubricating oil level low Check there are no leaks from gaskets or axle casing
and top up to correct level
Half shaft splines to fit the differential crown wheels
damaged
Overhaul the axle and replace worn or damaged parts.
Main axle faults:
1 - Wheel hubs noisy
2-Noise
3-Noiseatrelease
4 - Noise during acceleration
5-Corneringnoise
DIAGNOSTIC
1
YES
NO
NO
NO
YES
YES
YES
YES
YES
WHEEL HUBS NOISY
2NOISE
INTERMEDIATE AXLE IN TANDEM 9 SECTION 12.4ASTRA HD8Ec

39381
The rear axle is a double reduction type: the first reduction is
by means of the pinion - ring bevel gear unit and the second
is obtained through an epicyclic unit in the wheel hubs.
The differential housing, with the ring bevel gear , is supported
by two taper roller bearings that can be adjusted through two
threaded ring nuts.
The pinion is supported by two taper roller bearings and a
third straight roller bearing.
The bevel pinion unit is adjusted through adjusting rings that
are fitted between the the two taper roller bearings.
The axle is equipped with a pneumatically controlled device
to lock the differential.
The half shafts coming from the differential transmit the mo-
tion to the epicyclic gears.
PICTORIAL CROSS SECTION OF THE DIFFERENTIAL
1. Coupling flange - 2.Oil seal - 3. Outer seal ring - 4. Front bearing - 5. Adjusting ring - 6. Screw - 7. Bevel pinion support -
8. Intermediate bearing - 9. Adjusting ring - 10. Rear bearing - 11. Adjusting ring nut - 12. Differential housing bearing -
13. Short pin - 14. Spider - 15. Planetary gear - 16. Crown wheel - 17. Cover - 18. Gear housing - 19. Cover - 20. Screw -
21. Screw - 22. Long pin - 23. Safety plate - 24. Engaging sleeve - 25. Sliding sleeve - 26. Shoulder washer - 27. Split ring -
28. Engaging fork - 29. Transmitter - 30. Spring - 31. Plug - 32. Differential housing - 33. Taper pinion - 34. Oil baffle -
35. Lock nut
Figure 1
REAR AXLE IN TANDEM 3 SECTION 12.5ASTRA HD8Ec
DESCRIPTION

40430
WHEEL HUB COMPONENTS
1. Brake drum –2. Adjusting screw and nut –3. Cover –4. Gasket –5. planetary gear pin and rollers –6. Planetary gear carrier
–7. Adjusting nut –8. Crown wheel carrier –9. Planetary wheel –10. Crown wheel –11. Crown wheel gear –12. Half-shaft –
13. Bleeder –14. Bracket –15. Shoulder pin –16. Axle casing –17. Bearing shaft –18. Braking unit –19. Phonic wheel –20.
Oil cup –21. Supporting ring –22. Seal ring –23. Seal ring –24. Bearing –25. Wheel hub –26. Bearing –27. Bolt
Figure 9
REAR AXLE IN TANDEM 13 SECTION 12.5ASTRA HD8Ec

REAR SUSPENSIONS
6SECTION 14.2 ASTRA HD8Ec
Hydraulic shock absorbers
Figure 4
The hydraulic shock absorbers are of the telescopic double act-
ing type.
These shock absorbers are also defined ”direct acting” since
their braking action is directly performed on the suspension el-
ements without levers.
They are fitted with thermostatically controlled valves, thus en-
suring that there are no noticeable differences in their perform-
ance, even following sharp changes in temperature.
Shock absorbers are divided into three different parts:
1. the cylinder part located above the piston (always filled
with oil);
2. the cylinder part located under the piston (always filled
with oil);
3. the oil reserve, i.e. the compartment between the cylin-
ders (5 and 6) (never completely filled with oil).
During the bouncing stage, i.e. when the shock absorber ex-
tends, the oil pushed by the piston (4) passes through the com-
partment, from the upper part of the piston to the lower part
of the cylinder.
During the compression stage, i.e. when the shock absorber
lengthens and piston goes downwards, the oil located under
the piston passes directly to the upper part of the cylinder.
For oil passing from one part of the piston to the other, a forcing
pressure intervenes acting on the piston and opposing piston
movement thus causing suspension braking.
Noise
This defect, which is often laid to shock absorbers, can have dif-
ferent origins. It is therefore recommended to inspect suspen-
sions carefully, including shock absorber connections to chassis
or leaf spring.
Check whether no shock absorber part is in ”metallic” touch
with the leaf spring or the chassis.
Shock absorber dust protection distortion, due to wheel rota-
tion, or short oil due to accidental leaks, can cause noise; in this
case the shock absorber must be replaced.
Changes in braking effect
A change in the braking effect can take place accidentally.
The decrease of the braking effect can be due to breakage of
internal parts, short oil or jams.
Replace the shock absorber in any case.

PNEUMATIC SYSTEM - BRAKES 9 SECTION 16ASTRA HD8Ec
BRAKING SYSTEM DIAGRAM
8x4 vehicles without tow hook
1 Air compressor
2 Air drier
3Tank(30l)
3a Tank (20 l)
4 Condensation drain valve
5 Relay valve
6 Anticompound relay valve
7 Duplex distributor 7.6 bar
8 RVM cock
9Notused
10 Not used
11 Not used
12 Brake cylinder (24’’x 275) 8x4
13 Not used
14 Combined brake cylinder (16’’X190/7300N)
15 Pressure switch (6.6 bar)
16 Test union
17 Pressure control
18 Pressure gauge (6.5 bar)
A = Hand brake
B=Rear
C=Front
D=Services

ELECTRICAL SYSTEM
12 ASTRA HD8EcSECTION 17
4 - DIGIT CABLE COLOUR CODES
0300 6-diode self-rectifying alternator
0000 General earth
0001 Radio set insulated earth
0002 Hazard lights earth
0003 Earth of ceiling lamp switch on device (door post switch)
0004 UNIC project: parking lights insulated earth (dangerous cargo vehicles)
0005 Earth of trailer brake/exhaust brake interlock relay
0006 Earth of rheostat connected optical indicators
0007 Earth of stop rerequest optical indicator switch off relay
0008 Earth of starter motor relay
0009 Earth of windshield wiper unit fixed stop
0010 Earth of ceiling lamp switch on device (switch/lamp)
0011 Earth of rear door open optical indicator
0012 Earth of main current relay
0013 Earth of exhaust brake enablement relay
0014 Earth of ventilation motors operation relay
0015 Earth of auxiliary heater water recirculating pump motor
0016 Earth of relay for windshield heater/defroster operation (water auxiliary heater)
0017 Earth of front door open optical indicator
0018 Hydraulic braking system signal
0019 Earth of MS6 control unit terminal 8
0020 Earth of heater mirror relay excitation device (relay control unit)
0021 Insulated earth of MS6 control unit terminal 25
0022 Auxiliary heater insulated earth
0023 Earth of flasher light optical indicators
0024 Earth of optical indicators connected to lamp test pushbutton
0025 Earth of emergency optical indicator (central safety unit)
0027 Terminal 85 of Retarder/ABS operation relay
0028 KICKDOWN signal
0030 Earth supply for engine rpm diagnosis sensor no. 1 (n=1/1) and engine rpm electronic sensor
0031 Earth supply for engine rpm diagnosis sensor no. 2 (n=1/1)
0032 Earth supply for engine rpm diagnosis sensor (n=1/2 injection pump)
0033 Hydraulic brake solenoid valve control
0034 Hydraulic brake reducing solenoid valve control
0035 Thermometric switch controlling relais for gas oil heating
0036 Earth of centre door open relay
0037 Earth of belt warning lamp excitation relay
0038 Earth of key rotation inhibiting solenoid valve
0040 Cross differential lock switch off control
0041 Cross differential lock switch on control
0043 Insulated earth on exhaust brake control circuit
0044 Earth of belt control warning lamp
0045 Insulated earth for exhaust brake “R2” resistor

120 ASTRA HD8EcSECTION 17

CAB AND CHASSIS 11 SECTION 18ASTRA HD8Ec
Finding chassis twist
Figure 27
17357
Slight torsion may only be detected with the cab and mech-
anical units removed. To make the check, proceed as follows:
-place the chassis on two stands;
-fasten one side of the chassis to the stand with two
clamps;
-set the other side of the chassis on the knee of an ”L” iron
(1, Figure 27) in central position under the rear cross
member;
-place a ruler in cross position and a spirit level (2,
Figure 27) on the ruler and check the readings.
The same value should result at each check point, otherwise
thechassisisdeformed.
PRECAUTIONS
Figure 28
17358
When welding, drilling, grinding or cutting near the pipes of
the braking system, especially near plastic parts or electrical
wiring, take adequate precautions to protect them, and if
necessary, remove them. All parts of the chassis that are re-
conditioned are to be protected from oxidation and cor-
rosion.
Protection and painting operations are to be carried out accu-
rately on all the parts involved, following any instructions,
methods, and preventive precautions indicated by the paint
manufacturers.
Figure 29
17359
The chassis reconditioning is obtained by wedge heating the
part concerned with a torch.
During this operation the metal must become cherry red
coinciding with a temperature ranging between 600 and
680°C.
The points already heated must not be re-heated.
Let the heated points cool slowly without using water, com-
pressed air or other cooling agents.
Figure 30
17360
Straighten chassis lateral bending by wedge heating the upper
and lower edge of the chassis length concerned.
The wedge point must in the desired bending direction.
If the base (a, Figure 30) of the two wedges is on the upper
edge plate of the side member, the plate must also be heated,
but last.