Mercedes-Benz Unimog 416 1976 Instruction Manual
Instruction Manual
UNIMDI 416
IW:ERCEDES-DENZ
0
Instruction Manual
UNIMDIi 416
Edition June 1976
""
Printed in Germany
Technical details of UNIMOG in relation to
data and illustrations of the present manual
subject to change.
4
Reprints and translations, including extracts,
subject to our written permission.
Daimler-Benz Aktiengesellschaft
Stuttg art-UntertUrkhei m
Plant Gaggenau, Department UKD
7560 Gaggenau
P. O. Box 1220
Federal Republic of Germany
Contents
1 General Hints. . . .
Explanation of Contents. . . .. 8
Type Plate and Numbers. . . .. 8
Keys. . . . . . . . . . . . . . 10
Doors, Seats and Tools. . . . . . 10
2 Operating Instructions
. . . . 11
Instruments and Controls. . . . . 11
Instrument Panel. . . . . . . . 11
Shifting Levers. . . . . . . . . 12
Switches. . . . . . . . . . . . 13
Putting Vehicle into Operation. . 14
Preparations Before Starting. . . 14
Starting the Engine. . . . . . . 14
Running-in. . . . . . . . . . . 15
Stationary Operation. . . . . . . 15
Stopping the Engine. . . . . . . 15
Transmission Shifting. . . . . . 15
Special Drive for pto Shift. . . . 16
Four-Wheel Drive, Differential Locks 16
Instruments, Warning Lights. . . 16
Brake System. . . . . . . . . . 16
3 Maintenance Instructions. . . 17
Maintenance. . . . . . . . . . 17
General. . . . . . . . . . . . 17
8
Maintenance Schedule. . . . . . 17
Maintenance Jobs Survey. . . . . 18
Lubrication Points Survey. . . . . 19
Engine. . . . . . . . . . . . . 20
Filling-up Engine Oil. . . . . . . 20
Oil Level and Oil Change - . . . . 20
Cleaning Oil Filter -
. . . . . . . 21
Oil Overpressure. . . . . . . . 21
Retightening Cylinder Head Bolts. 21
Replacing Cylinder Head Gasket. 22
Adjusting Valve Clearances. . - . 22
Checking Compression Over-
pressures. . . . . . . . . . . . 23
Air Filter. . . . . . . . . . . . 23
Fuel. . . . . . . . . . . . . . 24
Filling-up Fuel. . . . . . . . . . 24
Cleaning Fuel Tank. . . . . . . 24
Cleaning Fuel Prefilter. . . . . . 24
Cleaning Fuel Filter. . . . . . . 25
Priming and
Feed Pump. . . . . 26
Bleeding Fuel Filter. . . . . . . 26
Bleeding Fuel System. . . . . . 26
Checking and Cleaning Injectors. . 26
Cooling System. . . . . . . . . 27
Filling-up Coolant. . . . . . . . 27
Coolant Pump. . . . . . . . . . 28
/
. . . . 28
. .. . 28
System - . . . 29
. . . . . . . . . 29
Thermostat. . . . . . .
Draining Coolant
Cleaning Cooling
Coolant Hoses
Clutch, Transmission, Axles. . . . 29
Clutch - . . . . . . . . . . . . 29
Transmission. . . . . . . . . . 30
Axle Drive. . . . . . . . . . . 31
Hub Reduction. . . . . . . . . 31
Steering Knuckle Bearings. . . . 31
Steering. . - . . . . . . . . . 32
Checking Steering. . . . . . . . 32
Oil Level, Oil Change, Oil Filter. . 32
Bleeding Power Steering. . . . . 32
Power Steering Pump V-Belt. . . 32
Wheels, Tyres . . . . . . . . . .
33
Wheels. . . . . . . . . . . . .
33
Check toe-in . . . . . . . . . . 33
Tyres
.,...........
33
reTres...........
33
Checking Tre Overpressure. . . .
33
Grip and Traction. . . . . . . .
34
Care of Wheels and Tyres . . . .
34
Install Spare Tyre . . . . . . . .
34
5
BrakeSystem. . . . . . . . . . 35
General. . . . . . . . . . . . 35
Filling-upBrakeFluid. . . . . . . 35
BleedingHydraulic BrakeSystem. 35
Checkingand CleaningBrakes. . 36
ReadjustingBrakeShoes. . . . . 36
Adjusting Brake Pedal. . . . . . 37
Readjusting Parking Brake System 37
Leversand Pedals. . . . . . . . 37
Brake Hoses,Brake Lines. . . . 37
CompressedAirSystem. . . . . 38
General. . . . . . . . . . . . 38
Air Compressor. . . . . . . . . 39
Pressure Regulator, Inflating Tyres 39
Compressed Air Tank. . . . . . 39
Compressed Air Brake Assistance 39
Compressed Air Operated Differen-
tial Locks. . . . . . . . . . 40/41
Chassis,Body. . . . . . . . . 48
BoltedConnections. . . . . . . 48
ShockAbsorber,Trailer Coupling. 48
Tilting Driver'sCab. . . . . . 48/49
Folding Top. . . . . . . . . . 50
Windscreen. . . . . . . . . . . 50
Canvas. . . . . . . . . . . . . 51
Tow-Bar. . . . . . . . . . . . 51
Benches. . . . . . . . . . . . 52
Cleaning. . . . . . . . . . . . 53
CleaningCanvas. . . . . . . . 53
CleaningUNIMOG. . . . . . . . 53
Laying-upUNIMOG. . . . . . . 53
Putting into Operation after Laying-
upPeriod. . . . . . . . . . . . 54
Winch. . . . . . . . . . . . . 54
WinchMounting. . . . . . . . . 54
PtoShaft. . . . . . . . . . . . 54
BrakeFluid. . . . . . . . . . . 56
TransmissionOil. . . . . . . . . 56
Grease. . . . . . . . . . . . . 56
Anti-corrosiveOil. . . . . . . . 56
5 TroubleShooting. . . . . . . 57
General . . . . . . . . 57
Towing. . . . . . . . . . . . . 57
EngineGroup. . . . . . . . . . 57
EngineFailsto Start. . . . . . . 57
Engine Difficult to Start. . . . . 58
EngineBeginsto KnockHeavily. . 58
Engine Emits Black Smoke. . . . 58
Poor Engine Performance. . . . 59
ExcessiveCoolantTemperature. . 59
Oil Overpressure Drops Suddenly 60
Clutch. . . . . . . . . . . . . 60
ClutchDisengagesInsufficiently. . 60
ClutchSlips. . . . . . . . . . 60
SteeringSystem. . . . . . . . . 61
Intermittent Stiffness of Power
Steering. . . . . . . . . . . . 61
Power Steering Stiff. . . . . . . 61
Directional Stability of UNIMOGin
Straightahead Position Unsatis-
factory. . . . . . . . . . . . . 61
Electrical System
. . . . . . . .
42
General .........,..
42
4
Operative Materials. . . . . .
55
Three-PhaseAlternator. . . . . .
42
Regulator
42
Filling Capacities
. . . . . . . . 55
. . . . . . . . . . .
Starter. . . . . . . . . . . . .
42
ConsumptionValues. . . . . . .
55
Wiring Diagram
. . . . . . . 43/44/45
Coolant.............
56
Checking Battery
. . . . . . . . 46
Coolant for Operation
56
. . . . . .
COnnectingBattery
. . . . . . .
46
HeadlightAlignment. . . . . . .
46
EngineOil
. . . . . . . . . . . 56
Replacing Headlight Bulb
. . . .
47
Running-in Oil
.. . . . . ..
56
{)
AlternatorV-Belt. . . . . . . . .
47
Heavy-dutyOil
. . . . . . . . .
56
Brake System. . . . . . . . . . 62
WheelBrakes. . . . . . . . . . 62
HydraulicBrake System. . . . . 62
CompressedAir Brake Assistance
System. . . . . . . . . . . . . 63
CompressedAir System. . . . . 63
Warning Light Lights up While
Driving. . . . . . . . . . . . . 63
Insufficient or too Slow Over-
pressure Build-up. . . . . . . . 63
Dual Overpressure Gauge Indicates
Incorrectly. . . . . . . . . . . 64
Air Compressor. . . . . . . . . 64
PressureRegulator. . . . . . . 64
ElectricalSystem. . . . . . . . 64
ChargingCurrent Warning Light
Doesnot Light up . . . . . . . . 64
Charging Current Warning Light
LightsupwhileDriving. . . . . . 64
StarterMotor Doesnot Operate. . 65
Current ConsumerInoperative. . 65
lnefficient Headlights. . . . . . 66
Direction Indicator System. . . . 66
6 Technical Data
. . . . 67
TypesandModels. . . . . . . . 67
Engine. . . . . .
. . . 67
Clutch,Transmission,Axles. . . . 68
Clutch. . . . . . . . . . . . . 68
Transmission. . . . . . . . . . 69
Front Axle. . . . . . . . . . . 69
RearAxle. . . . . . . . . . . . 69
Steering. . . . . . . . . . . . 69
Powersteering. . . . . . . . . 69
Tyre . . . . . . . . . . . . . . 70
TyreTreads. . . . . . . . . . . 70
Tyre Overpressures. . . . . . . 70
Toe-in. . . . . . . . . . . . . 69
BrakeSystem. . . . . . .
Hydraulic Brake System. .
Parking BrakeSystem. . . .
BrakeAssistanceSystem
. . . 71
. . 71
. . 71
. 71
Electrical System. . . . . . . . 71
PtoShaft. . . . . . . . . . . . 72
Weight. . . . . . . . . . . . . 72
Dimensions. . . . . . . . . . . 73
Max.Speed. . . . . . . . . . . 73
Tightening Torque
. . . . . . . 74
V-Belts. . . . . . . . . . . . . 75
7
1 General Hints
Explanation ofContents
In addition to general explanations, this
section 1 General Hints also contains
important details with regard to per-
tinent numbers, keys and equipment of
the UNIMOG.
A careful study of section 2 Operating
Instructions in particular prior to initial
operation, is one of the prerequisites for
troublefree operation of the UNIMOG.
In addition, relevant instructions in sec-
tion 3 Maintenance Instructions are
intended to guarantee that the UNIMOG
remains efficient and constantly avail-
able for use.
Use only the types of fuels, lubricants,
coolants, etc. described in section
4 Operative Materials in the quantities
specified.
In the following section 5 Trouble Shoot-
ing we are providing remedies and refer-
ences as to their possible cause, as
well as recommendations for their
repair.
8
For fast information, all the significant
dimensional data concerning the eng;ne,
the chassis and the body are listed in
section 6 Technical Data.
Type Plate and Numbers
In all inquiries concerning the UNIMOG,
and when ordering spare parts and
special equipment, be sure to name the
type and model designation, chassis
and engjne number, as well as any other
unit number.
The type plate is located above the
right-hand foot compartment underneath
the outside hood.
The chassis number is on the type plate
and on the frame at the right front in
front of the spring bracket.
The engine number plate is located on
the right rear next to the oil filter and
on the cylinder head cover.
The designations "right-hand" and "Ieft-
hand" apply as seen in driving direction.
The statements 1st, 2nd cylinder, etc.
are always as seen from the direction
of the radiator.
1 Chassis number
2 Type plate
3 Transmission number
4 Cab number
5 Engine number
6 Axle Number
Fig.1 Arrangement of type plate and numbers
URO-OOO6
9
Fig. 2 Door locks
1 Driving position (latched)
2 Garage position
3 Open
10
Fig. 3 Vehicle tool box under
co-driver's seat
Fig. 4 Seat adjustment
1 Longitudinal adjustment
2 Tilt of seat cushion
3 Tilt of backrest
Keys
The switch box key serves for switching
the switch box in the instrument panel.
The square drive bonnet key is in the
left-hand door box. It is used for opening
the bonnet.
Doors, Seats and Tools
The door locks of the folding top cab
must be latched from inside while driv-
ing. In latched condition the inside door
latch is positioned at an upward angle.
The door can be locked only when in
this position.
For seat adjustment refer to Fig. 4.
/
For tools refer to Fig. 3.
2 Operating Instructions
Fig.5
Arrangement of instruments
and controls
8 Hand throttle
9 Accelerator pedal
10 Brake pedal
11 Clutch pedal
12 Parking brake lever
13 Socket for emergency light
1 Starter switch
2 Windshield wiper switch
3 Switch box
4 Blinker - Horn - Dimmer switch lever
5 Spedometer
6 Cut-out switch for blinker
7 Instrument cluster
-
/9
2
8
/
7
5
6
Fig.6
Instrument cluster
1 Brake overpressure warning light (red)
2 Blinker control light UNIMOG (green)
3 Oil overpressure indicator
4 High beam control light (blue)
5 Fuel gauge
6 Charging current control light (red)
7 Dual brake overpressure gauge
White needle ~ tank overpressure
Red needle ~ brake overpressure
8 Coolant temperature gauge
9 Blinker control light for 2nd trailer (green)
11
Fig.7 Shifting levers
1 Main shifl lever
2 Forward-reverse levar
3 High-low range lever
4 Four wheel drive/differential lock lever
5 Plo-shifl lever
12
Transmission with 2 x 4 gear shifting
I:
5
Shifting position 2 x 4
0
VA
1
'H3
I .v
2 4
I 00
R!
sv
3 2
Shifting I
Shifting position
lever
1
I
Main shifting lever
I
1-4
I
1s1 10 41h gear
2
Forward-reverse shifting lever
V
Forward gears
0
Neulral position
R
Reverse gears
3
High-low range shifting lever
GV+R
Low range forward and reverse
SV
High range forward
4 Four-wheel drive-ditto lock
0
Rear axle drive
shifting lever
VA Four-wheel drive
VA+AS Four-wheel drive and difl. lock
5
Plo shifling lever
E
Engaged
A
Disengaged
Switch, Explanation
Switch _
I
Positions
~
I
I
Consumer
Off
Socket, interior light
Parking position
Parking, Clearance light
Instrument cluster light
Socket
P
1
Drive position
Charging current control light
Starter switch
Horn, socket, interior light
Blinker-tail-stop light
Windshield wiper
Instrument indicator
2
to 1, additional
Parking, Clearance light
Instrument cluster light
I
I
to 1 and 2, additional
Headlight low beam
I
Headlight high beam
High beam control light
3
* To switchinq from "0" to "P"
and from "3" to "2" push ignition key down.
Switches
UZ54-0025
Fig. 8 Switch box
Fig. 9 Blinker-Horn-dimmer switch
1 High beam
2 Low beam
3 Blinker light right
4 Blinker light left
5 Horn
13
Putting UNIMOG into
Operation
Preparations
before Starting
Check coolant level in compensation
tank. Actuate push button of safety valve
prior to opening closing cap to relieve
any excess pressure.
The coolant of the cold engine should
be up to 30 mm below the upper edge
of the filler hole of the compensation
tank. Add coolant, if required.
Be sure to add 10 cc of inti-corrosive
agent for each liter of coolant.
4
Fig.10 Coolant compensation tank
1 Closing cover with safety valve
2 Overflow line
Run engine for 5 minutes at increased
idling speed. If required, add coolant
with the engine running, until cooling
liquid level is reached.
Check oil level in oil pan with wiped-
off oil dipstick with the UNIMOG on
level ground. The oil level should be on
the maximum level mark. When checking
the oil level of the engine be sure to
consider that the oil cooler and various
oil passages can be completely drain-
ed when the engine has been inopera-
tive for some time. To determine the
exact oil level in the oil pan it is neces-
sary that the check is conducted imme-
diately after shutting off the warm engine
or after a short running period of the
previously cold engine.
Do not fill up beyond the maximum level
mark!
Check contents of fuel tank.
Check tyre pressure.
Check lights.
Test brakes after moving off.
Important
Move vehicle only after red light on
instrument cluster is gone off.
Starting the Engine
Move main shift lever and hand throttle
into center position (idling speed).
Insert switch box key into switch box
and turn to position 1:
Red charging current control lamp lights
up and fuel gauge responds.
Declutch and step on accelerator pedal.
Push starter switch and hold for some
seconds. Engine will fire. Release star~
switch immediately after engine fires
since this can otherwise cause damage
to the starter.
If the engine does not fire immediately,
repeat starting attempt only when the
engine and the starter have come to
a stop. During repeated starting attempts
short recovery periods for cooling the
starter and conserving the battery
should be imposed.
Watch oil pressure gauge after engine
fires.
If no oil pressure is indicated with the
engine running, stop engine immedia-
tely and look for the cause.
Adjust idling position with hand throttle
until the engine runs "smoothly" at
slightly increased idling speed.
Running-in
It is of decisive importance for the life
and the operational safety that the
engine and drive train of a new UNI-
MOG, an exchange engine or recon-
ditioned engine are not fully exploited
during the first 1500 km.
Complete the specified service jobs
according to schedule once during the
running-in time up to 500 km. The regu-
lar service jobs according to schedules
will then begin. Page 17.
Stationary Operation
For stationary operation of the pto shaft
and low-speed operation the desired
engine speed can be fixed by means of
the hand throttle control. Tighten round
locking disc in clockwise direction.
While operating the pto drive stationary
make sure that the low range/high
range lever is in "high range" to
guarantee the oil supply to all rotating
parts inside the transmission.
Stopping the Engine
Pull hand throttle control toward the
rear and turn completely to the right.
Engine will stop. Immediately turn hand
throttle control back to idle position. At
a coolant temperature of 90 to 95° C do
.
1
-,
I \
I,.A<,
\,
~\
"
\'
\'
,,'
2
"'-,
( I
"J.,.J
II
I,
II
II
II
II
"-""../
UZ 30-0001
Fig. 11 Hand throttle control
1 Full throttle position
2 Idle position
3 Stop position
4 Locking plate
not stop the engine immediately but
keep it running at increased idling
speed for 1 or 2 minutes, so that the
coolant remains in circulation and is
not thrown out by the reheating effect
of the engine.
Transmission Shifting
2 x 4 Shifting
3
The manual synchromesh transmission
has 4 forward low range gears, 4 forward
high range gears and 4 reverse gears.
The 4 forward low range gears have
been provided for increased traction.
They are shifted with the low range/hi!;lh
range lever (3) after disengaging the
clutch. Page 12.
For road operation, the 4 forward high
range gears are sufficient, i. e. start the
vehicle, depending on trailer weight,
with the 1st high range gear engaged.
For reverse operation, declutch and
move the short forward/reverse lever to
the" reverse" position, the UNIMOG
being stationary.
For repeated forward and reverse ope-
ration, keep main shift lever in its posi-
tion and shift to forward and reverse
only with the short forward/reverse lever.
See page 12.
15
Special Drive for pto Shaft
A special drive for pto shaft of 1/min,
540 can be installed.
The rotation of pto shaft will stop dur-
ing declutching.
Four-Wheel Drive, Differential
Locks
If under difficult ground conditions or
with a high total train weight the ground
adhesion of the rear wheels is inade-
quate, engage the four-wheel drive or
the four-wheel drive with differential
locks. This will provide high tractive
power for the UNIMOG in sprre. ot.-its
low dead weight. Putting an additional
load on the platform may improve
ground adhesion still further.
The four-wheel drive and the differential
locks can be engaged while driving
without declutching, but only when the
wheels are not spinning, that is, as long
as the wheels are rotating in contact
with the ground.
If a wheel slips when the four-wheel
drive or the differential locks are
engaged, declutching is required so that
all the wheels are turning at uniform
speed or that the UNIMOG comes to a
stop.
16
The differential locks and the four-wheel
drive can also be disengaged while
driving without declutching. Briefly
release accelerator pedal when disen-
gaging the four-wheel drive.
Try not to engage the differential locks
when driving around a road bend to
eliminate additional stresses.
With the differential locks engaged the
turning circle increases as a result of
the automatically resulting wheel slip.
Instruments, Warning Lights
Check instruments" warning and control
lights occasionally while driving. The
most favorable operating temperature
of the coolant is at approximately 80° C
and is indicated on the coolant tempera-
ture gauge. At this temperature the
engine wear and the fuel consumption
are the lowest. If possible, the operating
temperature should not exceed 95° C.
Brake System
Test brakes immediately after moving
off. Establish braking action on a dry
road affording good grip.
The hand brake system serves as an
auxiliary and a parking brake system
acting on the rear wheels only.
3 Maintenance Instructions
Maintenance
General
The maintenance jobs specified for the
UNIMOG are specified in the Service
Booklet.
When driven on roads the maintenance
intervals are subdivided according to
km.
If, for organizational reasons, the main-
tenance jobs have to be accomplished
by your own personnel we urgenlly
recommend adherence to the required
maintenance procedures.
Thoroughly clean grease nipples, oil
filler and drain plugs prior to lubrication
jobs.
Maintenance Schedule
at
jkm
Job schedule
Job accomplishment
Maintenance
interval
500
* Only once during running-in period of vehicle
Normal
operating
conditions
1000
2000
3000
4000
5000
6000
7000
8000
etc.
* Lubrication jobs:
Change engine oil
Replace bypass oil filter element
Change transmission oil
Change oil in differential (2)
Change oil in wheel hub drive (4)
Check oil level in steering
Check brake fiuid level
Lubricate thrust ball (2)
Lubricate steering knuckle bearings (4)
Lubricate clutch release. shaft
Lubricate pto shaft universais (2)
Lubricatetrailer coupling (2)
Lubricate intermediate hand brake lever
-
* Inspection and cleaning jobs:
Clean dry air filter element
Retighten cylinder head nuts
Check valve clearance, adjust
Retighten air intake-manifold and oil pan
mounting screws
Check V-belt
Check clutch play
Retighten stabilizer bar/drive units mounting-
and connecting
screws
Check pHman arm for tight seat, steering for
correct functioning
Check wheel nuts
Check brake system
17
}
1stT.M.
2nd T.M.
Referto Maintenance
}
Lubrication Points
1stT.M.
Survey
2nd T.M.
etc.
Maintenance Job Survey
Inspection and cleaning jobs
Pos.
Nr.
daily
1st TM 2nd TM
Engine
Check engine oil
Clean air filter element
Check valve clearance, adjust
Clean fuel pre-filter
Retighten suction-Iexhaust- and
oilpan mounting screws
Cooling water
Check V-belt, retighten
Clean fuel fiIter felt element, paper
filter element must be changed,
bleed
Chassis
Check clutch adjustment
Check differential locks for
functioning
Retighten stabilizer, drive train
fastening and connecting bolts
Check shock absorbers for leaks
Check brake- and clutch fluid
Check pitman arm for tight seat
steering for free travel, correct
Check toe-in
Interchange wheels
Retighten wheel nuts
Check brakes, adjust
Check compressed air system for
functioning and leaks, drain conden-
sation from compressed air tank
and differential lock
Electrical system
Check all current consumers, fuses
and line connections
Check battery
Check head light alignement, correct
Check all electrical instruments
Body
Check bolts of cab and body attach-
ment for tight seat, retighten
1
14
15
12
8
2
5
18
- = work to be performed
..
Lubrication jobs
Pos.
No.
Oil
Lub. Grease daily
Points Qly.
1st TM 2nd TM
x = Check
xx = Lubricate
v ~ Change oil
Engine 011:SAE 20 or SAE 30
Change oil in engine,
change oil filter
1+3
1
10.0
x v
v
Change oil in air filter
14
1
1.0 x
v v
Lubricate starter pinion
11
1
5 gr
xx
Transmission 011:SAE 90
Transmission
9 1 6.0 x
v
Front axle differential 6 1 2.5 x v
Rear axle differential
6 1 2.5
K v
Wheel hub drive front 7 2 0.3 x
v
Wheel hub drive rear
7
2 0.3 x
v
Grease: Calcium No.3
Thrust ball front and
rear axle 4
2
10 gr
xx xx
- Grease clutch shaft 8 1
5 gr
xx
xx
I G"", """"""";00 '"
2
10 gr
xx xx
Grease front winch 1
10 gr
xx xx
Grease pto shaft universal 13 2
10 gr
xx xx
Grease joints and nipples
on manual and pedal
lever assy. door hinges
5 gr
xx
xx
Grease hand brake
-
intermediate lever
10 1
10 gr
xx
xx
Greease steering knuckles
7
4
10 gr
xx xx
Hydraulic 011
Steering *
5 1
2.0
x
x x
Brake fluid
Check brake- and clutch
fluid level
2 1 1.0
x x x
* Change oil and replace paper oil filter element after the first 52000 km
or once a year.
a Fill-in engine oil
b Fill-in transmission oil
c Check oil level
d Drain oil
e Lubricate with grease
f Replace oil filter element
CDFill-in and check brake fluid
14
11
8
13
4
10
7-
16
12
19
Fig.13 Engine lubrication
1 Oil filter
2 Oil dipstick
3 Oil filler neck
4 Crankcase breather
5 Oil filter filler plug
6 Mounting bolt
7 Oil filter drain plug
UR-0035
20
Fig.14 Oil drain plug
..
Engine
Filling-up Engine Oil
The oil filler neck is located at the rear
in the cylinder head cover, accessible
from the cab after removal of the inside
engine hood. Filling-up may also be ac-
complished at the breather neck on the
timing gear case.
Engines of the new UNIMOG, exchange
engines and fully reconditioned engines
are filled with running-in oil for the first
500 km.
After this, only HD (heavy-duty) engine
oil grades of the specified viscosity class
are permitted. Refer to page 56.
Change HD engine oil brand if at all
possible only during an oil change.
Oil Level and Oil Change
Check oil level regularly depending on
the UNIMOG operating conditions and
make adjustments, if required.
Check oil level in oil pan with the UNI-
MOG on level ground and with the oil
dipstick wiped off.
The oil level should be between the
minimum and maximum mark.
When checking the oil level of the
engine, it must be considered that the
011cooler and various oil passages will
drain after not being run for some time.
In order to exactly determine the. oil
level in the oil pan, it is necessary that
the check be made either immediately
after turning off the warm engine, or
after briefly running the previously cold
engine.
If oil must be added already prior to the
first oil change and if no running-in oil is
available, an HD engine oil of the same
viscosity class may be used as an ex-
ception.
Do not add 011beyond the max. level
mark!
Complete oil change according to the
maintenance schedule.
Complete oil change only following ex-
tended operation of the engine, as long
as the engine oil is still warm and thin.
Change the bypass oil filter element
during every oil change. HD engine oil
will become dark sooner than unblended
engine oil, because the combustion
residue entering the oil will not settle in
the crankcase and on crank assembly
components, but will be kept suspended
in the oil. Do not change the HD engine
oil too early because of its dark color.
...
~
Cleaning Oil Filter
Clean the combination oil filter with
main flow and bypass oil filter element
according to maintenance schedule.
Attach approximately 0.6 m of hose to
the drain connection of oil filter. Place
a collecting vessel underneath, loosen
drain plug, unscrew filler plug and drain
engine oil.
Loosen mounting bolt of oil filter bowl.
Remove filter bowl with filter elements.
Close center hole of main flow oil filter
element on both sides, rinse with gaso-
line and then clean with a soft and not
too large a brush, so that the filter fabric
is not damaged.
Change bypass oil filter element. When
assembling, place the main flow oil
filter element, the bypass oil filter ele-
mentand the resilient sealing washer on
the oil filter housing.
Replacesealing rings.
To get oil pressure at once during start-
ing procedure, fill-up oil filter bowl half
way.
Watch out for correct position of drain
plug screw on oil filter bowl.
t
Oil Overpressure
Under normal operating conditions and
when using engine oil of viscosity class
SAE 30 at nominal speed the oil over-
pressure is at least 2.5 bar (kp/cm2). At
idling speed it may drop to 0.6 bar
(kp/cm2) without in any way endangering
the operational safety of the engine.
.>UR.OO28
Fig.15 Oil filter of engine,
disassembled
1 Oil filter bracket
2 Oil filler plug
3 Seal ring
4 Oil filler housing
5 Drain plug
6 Seal ring
7 Mounting bolt
8 Bypass oil filter element
9 Main flow oil filter element
10 Spring plate
Retightening Cylinder Head Nuts
This maintenance job is done only once.
Clean area around cylinder head cover
thoroughly. Remove cylinder head cover
and rocker arm shafts. Should it occa-
sionally happen that the cylinder head
cover removal is impeded by the lower
edge of the instrument panel, loosen the
front portion of the cab mounting and
liftthe cab approximately 20 mm.
First loosen each individual nut slightly
prior to retightening.
Injection pump side
@@@@0000@@@@
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@@ 00 @@
Fig.16 Tightening pattern of cylinder
head nuts
Uniformly retighten cylinder head nuts
with the engine cold according to
tightening pattern with torque wrench
to specified torque of 110 NM (11 kpm).
Adjust valve clearance Refer to page 67.
21
Fig.17 Retightening cylinder head nuts
1 Torquewrench
Replacing Cylinder Head Gasket
If a cylinder head gasket leaks combu-
stion gases, replace immediately with a
new original gasket.
Indications for a damaged gasket may
be among others:
Missing of one or several cylinders, tra-
ces of water on oil dipstick, traces of oil
in coolant or coolant in compression
chamber. Boiling coolant.
22
To check the cylinder head gasket for
leaks, run engine warm and watch in the
coolant filler neck whether gas bubbles
are rising in the coolant.
Fig.18 Valve adjustment
1 Feeler gauge between rocker arm and valve
stem
2 Adiustment bolt
3 Counter nut
1st cylinder at TDC
,1., ,2. ,3. ,4. ,5. 6.
@)§@)§@)8
UZ 05-0002
6th cylinder at TDC
Fig.19 Valve arrangement
0 Exhaust valves
0 Intake valves
Drain coolant if cylinder head gasket is
damaged, Remove cylinder head cover
and gasket. Unscrew rocker arm bearing
brackets. Loosen cylinder head nuts with
the engine cold in reverse to tightening
sequence. Unscrew stud bolts and
remove cylinder head, Clean contact
surfaces of cylinder head gasket. Posi-
tion new cylinder head gasket and cy-
linder head, Screw in stud bolts with
screwdriver; apply graphite oil to threads
of nuts and bolts. Uniformly tighten cy-
linder head nuts with engine cold ac-
cording to tightening pattern (Fig. 16)
with torque wrench in three steps from
60 Nm (6 kpm) via 90 Nm (9 kpm) to the
specified torque of 110 (11 kpm). Adjust
valve clearance. Complete all other jobs
in reverse sequence.
Adjusting Valve Clearances
Check valve clearance according to
maintenance schedule each time upon
removal of cylinder head or when
retightening the cylinder head nuts.
Measure valve clearance at pressure
point between rocker arm and valve
stem of intake and exhaust valves with
engine cooled down to below 25° C.
Rotate crankshaft until the piston of the
1st cylinder is at TDC. Adjust the intake
valves 2, 3, 7 and the exhaust valves 1,
5, 9 in the
sequence mentioned.
Thereafter position the piston of the
6th cylinder at the TDC and adjust the
intake valves 6, 10, 11 and the exhaust
valves 4, 8, 12 in the sequence men-
tioned. Fig. 19.
Adjust valve clearance by turning
adjustment bolts after lossening their
counter nuts with afeeler gauge. Fig. 18.
After adjustment tighten the counter
nutsagain. Check valve clearance again.
When the valve clearance is properly
adjusted the feeler gauge should pass
tightly.
Renew cylinder head cover gasket.
Checking Compression Overpressures
Whenthe engine output drops, measure
compression pressure in each cylinder
by means of compression pressure
gauge. Measure at starter speed of
approximately 150 to 200/min and
warmed up engine. Crank engine with
starter for at least eight rotations.
If the minimum value is not attained,
check valve clearance. If required,
remove cylinder head and check valve
for leaks, condition of cylinder head
gasket, cylinder wear and piston ring
contact pattern in cylinder.
Refinish valve seats, if required. Engine
must be reconditioned in the event of
cylinder or piston ring damage.
,;
Air Filter
A carefully cleaned air filter is absolutely
necessary to protect the pistons and cy-
linder contact surfaces and in order to
avoid damage.
Oil bath air filter
Change oil according to UNIMOG con-
ditions of operation.
Loosen quick-release lock for removing
filter bowl on front folding part of fender.
Force filter element and filter bowl from
filter housing with screwdriver. Lift filter
element out of filter bowl.
The oil level must be at the appropriate
mark.
Complete oil change according to main-
tenance schedule, performing all the
specified jobs. Remove oil, clean filter
element and filter bowl with benzene
and fill up with fresh engine oil.
Dust deposits on the clean air en9 and
in the intake manifold are a sure sign
that the oil bath air filter must be
cleaned more often than stated in the
maintenance schedule.
Cyclone prefilter
Under extremely dusty operating con-
ditions, we recommend using a cyclone
prefilter in addition to the oil bath air
filter in order to triple the service life of
the oil bath air filter.
The cyclone normally requires no main-
tenance. Remove the cyclone and
thoroughly clean according to type of
dust accumulation.
3
~~
Fig.20 Oil bath air filter, disassembled
1 Filter bowl
2 Gasket
3 FiIter element
4 Filter housing w. oil level mark (arrow)
23
Fig. 21 Fuel system of engine
24
Fig. 22 Injection pump
1 Fuel feed pump
2 Sugtion- and pressure valve
3 Fuel primer pump
4 Bleeding screw
5 Pressure valve
To Fig. 21
1 Injection pump
2 Fuel priming pump
I
' 3 Fuel feed pump
4 Fuel return line
5 Fuel suction line
6 Fuel filter
i 7 Fuel injection line
Fuel System
Filling-up Fuel
When filling fuel into the fuel tank make
sure to avoid impurities, that the cap
gasket is not damaged and seals tightly.
Clean cap regularly.
Dirty fuel will result in early wear of the
high-grade and very expensive injection
pump elements.
When filling up from barrels or call's the
following points should be observed:
Always suck fuel from closely under
the fuel level of the barrel, that is, do
not simply set suction pump into barrel.
Maintain minimum distance between
bottom of barrel and end of intake pipe,
so that deposits such as dirt, sludge
and water will not be sucked in.
Cleaning Fuel Tank
Clean the fuel strainer in the fuel tank
regularly.
If installed, remove filler strainer after
unscrewing the cap and wash with
brush in diesel fuel.
Drain fuel tank completely to clean the
fuel tank and intake strainer. Have
collecting vessel ready for use, unsc"rew
drain plug and drain remainder of fuel.
Pull intake strainer from intake pipe and
clean. Fig. 23 and 24.
Cleaning Fuel Prefilter
Clean prefilter according to main-
tenance schedule. Loosen wing nut, push
clip aside and remove bowl. Unscrew
strainer body. Carefully wash bowl and
strainer in clean gasoline or diesel fuel.
During reinstallation replace worn or
hardened gaskets since otherwise air
will enter the fuel system. Fig. 25.
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