Instruction ManualUNIMDI 416

IW:ERCEDES-DENZ 0

Instruction Manual UNIMDIi 416Edition June 1976

""

Printed in GermanyTechnical details of UNIMOG in relation todata and illustrations of the present manualsubject to change.

4

Reprints and translations, including extracts,subject to our written permission.

Daimler-Benz AktiengesellschaftStuttg art-U ntertUrkhei mPlant Gaggenau, Department UKD7560 GaggenauP. O. Box 1220Federal Republic of Germany

Contents

1 General Hints. . . .

Explanation of Contents. . . .. 8Type Plate and Numbers. . . .. 8Keys. . . . . . . . . . . . . . 10Doors, Seats and Tools. . . . . . 10

2 Operating Instructions . . . . 11

Instruments and Controls. . . . . 11Instrument Panel. . . . . . . . 11

Shifting Levers. . . . . . . . . 12Switches. . . . . . . . . . . . 13

Putting Vehicle into Operation. . 14Preparations Before Starting. . . 14Starting the Engine. . . . . . . 14Running-in. . . . . . . . . . . 15Stationary Operation. . . . . . . 15Stopping the Engine. . . . . . . 15Transmission Shifting. . . . . . 15Special Drive for pto Shift. . . . 16Four-Wheel Drive, Differential Locks 16Instruments, Warning Lights. . . 16Brake System. . . . . . . . . . 16

3 Maintenance Instructions. . . 17

Maintenance. . . . . . . . . . 17General. . . . . . . . . . . . 17

8 Maintenance Schedule. . . . . . 17

Maintenance Jobs Survey. . . . . 18Lubrication Points Survey. . . . . 19

Engine. . . . . . . . . . . . . 20Filling-up Engine Oil. . . . . . . 20Oil Level and Oil Change - . . . . 20Cleaning Oil Filter - . . . . . . . 21Oil Overpressure. . . . . . . . 21Retightening Cylinder Head Bolts. 21Replacing Cylinder Head Gasket. 22Adjusting Valve Clearances. . - . 22Checking Compression Over-pressures. . . . . . . . . . . . 23Air Filter. . . . . . . . . . . . 23

Fuel. . . . . . . . . . . . . . 24

Filling-up Fuel. . . . . . . . . . 24Cleaning Fuel Tank. . . . . . . 24Cleaning Fuel Prefilter. . . . . . 24Cleaning Fuel Filter. . . . . . . 25Priming and Feed Pump. . . . . 26Bleeding Fuel Filter. . . . . . . 26Bleeding Fuel System. . . . . . 26Checking and Cleaning Injectors. . 26

Cooling System. . . . . . . . . 27Filling-up Coolant. . . . . . . . 27Coolant Pump. . . . . . . . . . 28

/

. . . . 28

. .. . 28

System - . . . 29. . . . . . . . . 29

Thermostat. . . . . . .

Draining CoolantCleaning CoolingCoolant Hoses

Clutch, Transmission, Axles. . . . 29Clutch - . . . . . . . . . . . . 29Transmission. . . . . . . . . . 30Axle Drive. . . . . . . . . . . 31Hub Reduction. . . . . . . . . 31

Steering Knuckle Bearings. . . . 31

Steering. . - . . . . . . . . . 32Checking Steering. . . . . . . . 32Oil Level, Oil Change, Oil Filter. . 32Bleeding Power Steering. . . . . 32Power Steering Pump V-Belt. . . 32

Wheels, Tyres . . . . . . . . . . 33Wheels. . . . . . . . . . . . . 33Check toe-in . . . . . . . . . . 33

Tyres .,........... 33reTres........... 33

Checking Tre Overpressure. . . . 33

Grip and Traction. . . . . . . . 34

Care of Wheels and Tyres . . . . 34

Install Spare Tyre . . . . . . . . 34 5

BrakeSystem. . . . . . . . . . 35General. . . . . . . . . . . . 35

Filling-up BrakeFluid. . . . . . . 35Bleeding Hydraulic Brake System. 35Checking and Cleaning Brakes. . 36

ReadjustingBrakeShoes. . . . . 36Adjusting Brake Pedal. . . . . . 37Readjusting Parking Brake System 37Leversand Pedals. . . . . . . . 37Brake Hoses, Brake Lines. . . . 37

CompressedAirSystem. . . . . 38General. . . . . . . . . . . . 38Air Compressor. . . . . . . . . 39Pressure Regulator, Inflating Tyres 39Compressed Air Tank. . . . . . 39

Compressed Air Brake Assistance 39Compressed Air Operated Differen-tial Locks. . . . . . . . . . 40/41

Chassis,Body. . . . . . . . . 48BoltedConnections. . . . . . . 48ShockAbsorber, Trailer Coupling. 48Tilting Driver's Cab. . . . . . 48/49Folding Top. . . . . . . . . . 50Windscreen. . . . . . . . . . . 50Canvas. . . . . . . . . . . . . 51Tow-Bar. . . . . . . . . . . . 51Benches. . . . . . . . . . . . 52

Cleaning. . . . . . . . . . . . 53CleaningCanvas. . . . . . . . 53CleaningUNIMOG. . . . . . . . 53Laying-upUNIMOG. . . . . . . 53Putting into Operation after Laying-upPeriod. . . . . . . . . . . . 54

Winch. . . . . . . . . . . . . 54

WinchMounting. . . . . . . . . 54Pto Shaft. . . . . . . . . . . . 54

BrakeFluid. . . . . . . . . . . 56TransmissionOil. . . . . . . . . 56Grease. . . . . . . . . . . . . 56Anti-corrosiveOil. . . . . . . . 56

5 TroubleShooting. . . . . . . 57

General . . . . . . . . 57

Towing. . . . . . . . . . . . . 57

EngineGroup. . . . . . . . . . 57Engine Fails to Start. . . . . . . 57Engine Difficult to Start. . . . . 58Engine Beginsto Knock Heavily. . 58Engine Emits Black Smoke. . . . 58Poor Engine Performance. . . . 59ExcessiveCoolantTemperature. . 59Oil Overpressure Drops Suddenly 60

Clutch. . . . . . . . . . . . . 60ClutchDisengagesInsufficiently. . 60ClutchSlips. . . . . . . . . . 60

SteeringSystem. . . . . . . . . 61Intermittent Stiffness of PowerSteering. . . . . . . . . . . . 61Power Steering Stiff. . . . . . . 61Directional Stability of UNIMOG inStraightahead Position Unsatis-factory. . . . . . . . . . . . . 61

Electrical System . . . . . . . . 42

General .........,.. 42 4 Operative Materials. . . . . . 55Three-PhaseAlternator. . . . . . 42

Regulator 42 Filling Capacities . . . . . . . . 55. . . . . . . . . . .Starter. . . . . . . . . . . . . 42 ConsumptionValues. . . . . . . 55

Wiring Diagram . . . . . . . 43/44/45 Coolant............. 56Checking 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. . . . . . . . . . 62WheelBrakes. . . . . . . . . . 62Hydraulic Brake System. . . . . 62CompressedAir Brake AssistanceSystem. . . . . . . . . . . . . 63

Compressed Air System. . . . . 63

Warning Light Lights up WhileDriving. . . . . . . . . . . . . 63Insufficient or too Slow Over-pressure Build-up. . . . . . . . 63

Dual Overpressure Gauge IndicatesIncorrectly. . . . . . . . . . . 64Air Compressor. . . . . . . . . 64Pressure Regulator. . . . . . . 64

ElectricalSystem. . . . . . . . 64Charging Current Warning LightDoesnot Light up . . . . . . . . 64Charging Current Warning LightLights up while Driving. . . . . . 64StarterMotor Doesnot Operate. . 65Current Consumer Inoperative. . 65lnefficient Headlights. . . . . . 66Direction Indicator System. . . . 66

6 Technical Data . . . . 67

Typesand Models. . . . . . . . 67

Engine. . . . . . . . . 67

Clutch,Transmission,Axles. . . . 68Clutch. . . . . . . . . . . . . 68Transmission. . . . . . . . . . 69Front Axle. . . . . . . . . . . 69RearAxle. . . . . . . . . . . . 69

Steering. . . . . . . . . . . . 69Powersteering. . . . . . . . . 69

Tyre . . . . . . . . . . . . . . 70TyreTreads. . . . . . . . . . . 70Tyre Overpressures. . . . . . . 70Toe-in. . . . . . . . . . . . . 69

BrakeSystem. . . . . . .Hydraulic Brake System. .Parking Brake System. . . .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 of Contents

In addition to general explanations, thissection 1 General Hints also containsimportant details with regard to per-tinent numbers, keys and equipment ofthe UNIMOG.

A careful study of section 2 OperatingInstructions in particular prior to initialoperation, is one of the prerequisites fortroublefree operation of the UNIMOG.

In addition, relevant instructions in sec-tion 3 Maintenance Instructions areintended to guarantee that the UNIMOGremains efficient and constantly avail-able for use.

Use only the types of fuels, lubricants,coolants, etc. described in section4 Operative Materials in the quantitiesspecified.

In the following section 5 Trouble Shoot-ing we are providing remedies and refer-ences as to their possible cause, aswell as recommendations for theirrepair.

8

For fast information, all the significantdimensional data concerning the eng;ne,the chassis and the body are listed insection 6 Technical Data.

Type Plate and Numbers

In all inquiries concerning the UNIMOG,and when ordering spare parts andspecial equipment, be sure to name thetype and model designation, chassisand engjne number, as well as any otherunit number.

The type plate is located above theright-hand foot compartment underneaththe outside hood.

The chassis number is on the type plateand on the frame at the right front infront of the spring bracket.

The engine number plate is located onthe right rear next to the oil filter andon 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 directionof the radiator.

1 Chassis number2 Type plate3 Transmission number4 Cab number5 Engine number6 Axle Number

Fig.1 Arrangement of type plate and numbers

URO-OOO6

9

Fig. 2 Door locks

1 Driving position (latched)2 Garage position3 Open

10Fig. 3 Vehicle tool box under

co-driver's seat

Fig. 4 Seat adjustment

1 Longitudinal adjustment2 Tilt of seat cushion3 Tilt of backrest

Keys

The switch box key serves for switchingthe switch box in the instrument panel.The square drive bonnet key is in theleft-hand door box. It is used for openingthe bonnet.

Doors, Seats and Tools

The door locks of the folding top cabmust be latched from inside while driv-ing. In latched condition the inside doorlatch is positioned at an upward angle.The door can be locked only when inthis 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 throttle9 Accelerator pedal

10 Brake pedal11 Clutch pedal12 Parking brake lever13 Socket for emergency light

1 Starter switch2 Windshield wiper switch3 Switch box4 Blinker - Horn - Dimmer switch lever5 Spedometer6 Cut-out switch for blinker7 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 indicator4 High beam control light (blue)5 Fuel gauge6 Charging current control light (red)7 Dual brake overpressure gauge

White needle ~ tank overpressureRed needle ~ brake overpressure

8 Coolant temperature gauge9 Blinker control light for 2nd trailer (green)

11

Fig.7 Shifting levers1 Main shifl lever2 Forward-reverse levar3 High-low range lever4 Four wheel drive/differential lock lever5 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 positionlever

1 I Main shifting lever I 1-4 I 1s1 10 41h gear

2 Forward-reverse shifting lever V Forward gears0 Neulral positionR Reverse gears

3 High-low range shifting lever GV+R Low range forward and reverseSV High range forward

4 Four-wheel drive-ditto lock 0 Rear axle driveshifting lever VA Four-wheel drive

VA+AS Four-wheel drive and difl. lock

5 Plo shifling lever E EngagedA Disengaged

Switch, Explanation

Switch _

I

Positions

~I

I

Consumer

Off

Socket, interior light

Parking positionParking, Clearance lightInstrument cluster lightSocket

P

1 Drive positionCharging current control lightStarter switchHorn, socket, interior lightBlinker-tail-stop lightWindshield wiperInstrument indicator

2 to 1, additionalParking, Clearance lightInstrument cluster light

I

I

to 1 and 2, additionalHeadlight low beam

I

Headlight high beamHigh 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 beam2 Low beam3 Blinker light right4 Blinker light left5 Horn 13

Putting UNIMOG intoOperation

Preparations before Starting

Check coolant level in compensationtank. Actuate push button of safety valveprior to opening closing cap to relieveany excess pressure.

The coolant of the cold engine shouldbe up to 30 mm below the upper edgeof the filler hole of the compensationtank. Add coolant, if required.

Be sure to add 10 cc of inti-corrosiveagent for each liter of coolant.

4

Fig.10 Coolant compensation tank1 Closing cover with safety valve2 Overflow line

Run engine for 5 minutes at increasedidling speed. If required, add coolantwith the engine running, until coolingliquid level is reached.

Check oil level in oil pan with wiped-off oil dipstick with the UNIMOG onlevel ground. The oil level should be onthe maximum level mark. When checkingthe oil level of the engine be sure toconsider that the oil cooler and variousoil passages can be completely drain-ed when the engine has been inopera-tive for some time. To determine theexact oil level in the oil pan it is neces-sary that the check is conducted imme-diately after shutting off the warm engineor after a short running period of the

previously cold engine.

Do not fill up beyond the maximum levelmark!

Check contents of fuel tank.

Check tyre pressure.

Check lights.

Test brakes after moving off.

ImportantMove vehicle only after red light oninstrument 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 boxand turn to position 1:

Red charging current control lamp lightsup 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 firessince this can otherwise cause damageto the starter.

If the engine does not fire immediately,repeat starting attempt only when theengine and the starter have come toa stop. During repeated starting attemptsshort recovery periods for cooling thestarter and conserving the batteryshould be imposed.

Watch oil pressure gauge after enginefires.

If no oil pressure is indicated with theengine running, stop engine immedia-tely and look for the cause.

Adjust idling position with hand throttleuntil the engine runs "smoothly" atslightly increased idling speed.

Running-in

It is of decisive importance for the life

and the operational safety that theengine and drive train of a new UNI-

MOG, an exchange engine or recon-ditioned engine are not fully exploitedduring the first 1500 km.

Complete the specified service jobsaccording to schedule once during therunning-in time up to 500 km. The regu-lar service jobs according to scheduleswill then begin. Page 17.

Stationary Operation

For stationary operation of the pto shaftand low-speed operation the desiredengine speed can be fixed by means ofthe hand throttle control. Tighten roundlocking disc in clockwise direction.

While operating the pto drive stationarymake sure that the low range/highrange lever is in "high range" toguarantee the oil supply to all rotatingparts inside the transmission.

Stopping the Engine

Pull hand throttle control toward therear and turn completely to the right.Engine will stop. Immediately turn handthrottle control back to idle position. Ata coolant temperature of 90 to 95° C do

.

1

-,I \

I,.A<,\, ~\"\'\'

,,'

2

"'-,( I

"J.,.JII

I,II

IIII

II"-""../

UZ 30-0001

Fig. 11 Hand throttle control

1 Full throttle position2 Idle position3 Stop position4 Locking plate

not stop the engine immediately but

keep it running at increased idlingspeed for 1 or 2 minutes, so that thecoolant remains in circulation and is

not thrown out by the reheating effectof the engine.

Transmission Shifting2 x 4 Shifting

3 The manual synchromesh transmission

has 4 forward low range gears, 4 forwardhigh range gears and 4 reverse gears.

The 4 forward low range gears havebeen provided for increased traction.

They are shifted with the low range/hi!;lhrange lever (3) after disengaging theclutch. Page 12.

For road operation, the 4 forward highrange gears are sufficient, i. e. start thevehicle, depending on trailer weight,with the 1st high range gear engaged.

For reverse operation, declutch andmove the short forward/reverse lever tothe" reverse" position, the UNIMOGbeing stationary.

For repeated forward and reverse ope-ration, keep main shift lever in its posi-tion and shift to forward and reverseonly 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, DifferentialLocks

If under difficult ground conditions orwith a high total train weight the groundadhesion of the rear wheels is inade-quate, engage the four-wheel drive orthe four-wheel drive with differentiallocks. This will provide high tractivepower for the UNIMOG in sprre. ot.-itslow dead weight. Putting an additionalload on the platform may improveground adhesion still further.

The four-wheel drive and the differential

locks can be engaged while drivingwithout declutching, but only when thewheels are not spinning, that is, as longas the wheels are rotating in contactwith the ground.

If a wheel slips when the four-wheeldrive or the differential locks areengaged, declutching is required so thatall the wheels are turning at uniformspeed or that the UNIMOG comes to astop.

16

The differential locks and the four-wheel

drive can also be disengaged whiledriving without declutching. Brieflyrelease accelerator pedal when disen-gaging the four-wheel drive.

Try not to engage the differential lockswhen driving around a road bend toeliminate additional stresses.

With the differential locks engaged theturning circle increases as a result ofthe automatically resulting wheel slip.

Instruments, Warning Lights

Check instruments" warning and controllights occasionally while driving. Themost favorable operating temperatureof the coolant is at approximately 80° Cand is indicated on the coolant tempera-ture gauge. At this temperature theengine wear and the fuel consumptionare the lowest. If possible, the operatingtemperature should not exceed 95° C.

Brake System

Test brakes immediately after movingoff. Establish braking action on a dryroad affording good grip.

The hand brake system serves as anauxiliary and a parking brake systemacting on the rear wheels only.

3 Maintenance Instructions

Maintenance

General

The maintenance jobs specified for theUNIMOG are specified in the ServiceBooklet.

When driven on roads the maintenance

intervals are subdivided according tokm.

If, for organizational reasons, the main-tenance jobs have to be accomplishedby your own personnel we urgenllyrecommend adherence to the requiredmaintenance procedures.

Thoroughly clean grease nipples, oilfiller and drain plugs prior to lubricationjobs.

Maintenance Schedule

at jkmJob schedule Job accomplishment

Maintenance interval

500 * Only once during running-in period of vehicle

Normaloperatingconditions

10002000300040005000600070008000etc.

* Lubrication jobs:

Change engine oilReplace bypass oil filter elementChange transmission oilChange oil in differential (2)Change oil in wheel hub drive (4)Check oil level in steeringCheck brake fiuid levelLubricate thrust ball (2)Lubricate steering knuckle bearings (4)Lubricate clutch release. shaftLubricate pto shaft universais (2)Lubricate trailer coupling (2)Lubricate intermediate hand brake lever

-

* Inspection and cleaning jobs:

Clean dry air filter elementRetighten cylinder head nutsCheck valve clearance, adjustRetighten air intake-manifold and oil panmounting screwsCheck V-beltCheck clutch playRetighten stabilizer bar/drive units mounting-and connecting screwsCheck pHman arm for tight seat, steering forcorrect functioningCheck wheel nutsCheck brake system

17

}1stT.M.

2nd T.M. Referto Maintenance

}

Lubrication Points1stT.M. Survey

2nd T.M.etc.

Maintenance Job Survey

Inspection and cleaning jobsPos.Nr. daily 1st TM 2nd TM

EngineCheck engine oilClean air filter elementCheck valve clearance, adjustClean fuel pre-filterRetighten suction-Iexhaust- and

oilpan mounting screwsCooling waterCheck V-belt, retightenClean fuel fiIter felt element, paper

filter element must be changed,bleed

Chassis

Check clutch adjustmentCheck differential locks for

functioningRetighten stabilizer, drive train

fastening and connecting boltsCheck shock absorbers for leaksCheck brake- and clutch fluidCheck pitman arm for tight seat

steering for free travel, correctCheck toe-inInterchange wheelsRetighten wheel nutsCheck brakes, adjustCheck compressed air system for

functioning and leaks, drain conden-sation from compressed air tankand differential lock

Electrical systemCheck all current consumers, fuses

and line connectionsCheck batteryCheck head light alignement, correctCheck all electrical instruments

BodyCheck bolts of cab and body attach-

ment for tight seat, retighten

114

15

12

8

2

5

18 - = work to be performed

..

Lubrication jobsPos.No.

OilLub. Grease dailyPoints Qly.

1st TM 2nd TM

x = Checkxx = Lubricatev ~ Change oil

Engine 011:SAE 20 or SAE 30Change oil in engine,

change oil filter 1+3 1 10.0 x v vChange oil in air filter 14 1 1.0 x v vLubricate starter pinion 11 1 5 gr xx

Transmission 011:SAE 90Transmission 9 1 6.0 x vFront axle differential 6 1 2.5 x vRear axle differential 6 1 2.5 K vWheel hub drive front 7 2 0.3 x vWheel hub drive rear 7 2 0.3 x v

Grease: Calcium No.3Thrust 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 xxGrease front winch 1 10 gr xx xxGrease pto shaft universal 13 2 10 gr xx xxGrease joints and nipples

on manual and pedallever 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 011Steering * 5 1 2.0 x x x

Brake fluidCheck brake- and clutch

fluid level 2 1 1.0 x x x

* Change oil and replace paper oil filter element after the first 52000 kmor 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 lubrication1 Oil filter2 Oil dipstick3 Oil filler neck4 Crankcase breather5 Oil filter filler plug6 Mounting bolt7 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 rearin the cylinder head cover, accessiblefrom the cab after removal of the insideengine hood. Filling-up may also be ac-complished at the breather neck on thetiming gear case.

Engines of the new UNIMOG, exchangeengines and fully reconditioned enginesare filled with running-in oil for the first500 km.

After this, only HD (heavy-duty) engineoil grades of the specified viscosity classare permitted. Refer to page 56.

Change HD engine oil brand if at allpossible only during an oil change.

Oil Level and Oil Change

Check oil level regularly depending onthe UNIMOG operating conditions andmake adjustments, if required.

Check oil level in oil pan with the UNI-MOG on level ground and with the oildipstick wiped off.

The oil level should be between theminimum and maximum mark.

When checking the oil level of theengine, it must be considered that the011cooler and various oil passages willdrain after not being run for some time.In order to exactly determine the. oillevel in the oil pan, it is necessary thatthe check be made either immediatelyafter turning off the warm engine, orafter briefly running the previously coldengine.

If oil must be added already prior to thefirst oil change and if no running-in oil isavailable, an HD engine oil of the sameviscosity class may be used as an ex-ception.

Do not add 011beyond the max. levelmark!

Complete oil change according to themaintenance schedule.

Complete oil change only following ex-tended operation of the engine, as longas the engine oil is still warm and thin.Change the bypass oil filter elementduring every oil change. HD engine oilwill become dark sooner than unblendedengine oil, because the combustionresidue entering the oil will not settle inthe crankcase and on crank assemblycomponents, but will be kept suspendedin the oil. Do not change the HD engineoil too early because of its dark color.

...

~

Cleaning Oil Filter

Clean the combination oil filter withmain flow and bypass oil filter elementaccording to maintenance schedule.

Attach approximately 0.6 m of hose tothe drain connection of oil filter. Placea collecting vessel underneath, loosendrain plug, unscrew filler plug and drainengine oil.

Loosen mounting bolt of oil filter bowl.Remove filter bowl with filter elements.Close center hole of main flow oil filterelement on both sides, rinse with gaso-line and then clean with a soft and nottoo large a brush, so that the filter fabricis not damaged.

Change bypass oil filter element. Whenassembling, place the main flow oilfilter element, the bypass oil filter ele-ment and the resilient sealing washer onthe oil filter housing.

Replace sealing rings.

To get oil pressure at once during start-ing procedure, fill-up oil filter bowl halfway.

Watch out for correct position of drainplug screw on oil filter bowl.

t

Oil Overpressure

Under normal operating conditions andwhen using engine oil of viscosity classSAE 30 at nominal speed the oil over-pressure is at least 2.5 bar (kp/cm2). Atidling speed it may drop to 0.6 bar(kp/cm2) without in any way endangeringthe operational safety of the engine.

.>UR.OO28

Fig.15 Oil filter of engine,disassembled

1 Oil filter bracket2 Oil filler plug3 Seal ring4 Oil filler housing5 Drain plug6 Seal ri ng7 Mounting bolt8 Bypass oil filter element9 Main flow oil filter element

10 Spring plate

Retightening Cylinder Head Nuts

This maintenance job is done only once.Clean area around cylinder head coverthoroughly. Remove cylinder head coverand rocker arm shafts. Should it occa-sionally happen that the cylinder headcover removal is impeded by the loweredge of the instrument panel, loosen thefront portion of the cab mounting andlift the cab approximately 20 mm.

First loosen each individual nut slightlyprior to retightening.

Injection pump side

@@@@0000@@@@

@@000@@@@ 00 @@

Fig.16 Tightening pattern of cylinderhead nuts

Uniformly retighten cylinder head nutswith the engine cold according totightening pattern with torque wrenchto specified torque of 110 NM (11 kpm).Adjust valve clearance Refer to page 67.

21

Fig.17 Retightening cylinder head nuts1 Torquewrench

Replacing Cylinder Head Gasket

If a cylinder head gasket leaks combu-stion gases, replace immediately with anew original gasket.

Indications for a damaged gasket maybe among others:

Missing of one or several cylinders, tra-ces of water on oil dipstick, traces of oilin coolant or coolant in compressionchamber. Boiling coolant.

22

To check the cylinder head gasket forleaks, run engine warm and watch in thecoolant filler neck whether gas bubblesare rising in the coolant.

Fig.18 Valve adjustment

1 Feeler gauge between rocker arm and valvestem

2 Adiustment bolt3 Counter nut

1st cylinder at TDC

,1., ,2. ,3. ,4. ,5. 6.

@)§@)§@)8UZ 05-0002

6th cylinder at TDC

Fig.19 Valve arrangement0 Exhaust valves0 Intake valves

Drain coolant if cylinder head gasket isdamaged, Remove cylinder head coverand gasket. Unscrew rocker arm bearingbrackets. Loosen cylinder head nuts withthe engine cold in reverse to tighteningsequence. Unscrew stud bolts andremove cylinder head, Clean contactsurfaces of cylinder head gasket. Posi-tion new cylinder head gasket and cy-linder head, Screw in stud bolts withscrewdriver; apply graphite oil to threadsof 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 from60 Nm (6 kpm) via 90 Nm (9 kpm) to thespecified torque of 110 (11 kpm). Adjustvalve clearance. Complete all other jobsin reverse sequence.

Adjusting Valve Clearances

Check valve clearance according tomaintenance schedule each time uponremoval of cylinder head or whenretightening the cylinder head nuts.Measure valve clearance at pressurepoint between rocker arm and valvestem of intake and exhaust valves withengine cooled down to below 25° C.

Rotate crankshaft until the piston of the1st cylinder is at TDC. Adjust the intakevalves 2, 3, 7 and the exhaust valves 1,5, 9 in the sequence mentioned.

Thereafter position the piston of the6th cylinder at the TDC and adjust theintake valves 6, 10, 11 and the exhaustvalves 4, 8, 12 in the sequence men-tioned. Fig. 19.

Adjust valve clearance by turningadjustment bolts after lossening theircounter nuts with a feeler gauge. Fig. 18.After adjustment tighten the counternuts again. Check valve clearance again.When the valve clearance is properlyadjusted the feeler gauge should passtightly.

Renew cylinder head cover gasket.

Checking Compression Overpressures

When the engine output drops, measurecompression pressure in each cylinderby means of compression pressuregauge. Measure at starter speed ofapproximately 150 to 200/min andwarmed up engine. Crank engine withstarter for at least eight rotations.

If the minimum value is not attained,check valve clearance. If required,remove cylinder head and check valvefor leaks, condition of cylinder headgasket, cylinder wear and piston ringcontact pattern in cylinder.

Refinish valve seats, if required. Enginemust be reconditioned in the event ofcylinder or piston ring damage.

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Air Filter

A carefully cleaned air filter is absolutelynecessary to protect the pistons and cy-linder contact surfaces and in order toavoid damage.

Oil bath air filter

Change oil according to UNIMOG con-ditions of operation.

Loosen quick-release lock for removingfilter bowl on front folding part of fender.Force filter element and filter bowl fromfilter housing with screwdriver. Lift filterelement out of filter bowl.

The oil level must be at the appropriatemark.

Complete oil change according to main-tenance schedule, performing all thespecified jobs. Remove oil, clean filterelement and filter bowl with benzeneand fill up with fresh engine oil.

Dust deposits on the clean air en9 andin the intake manifold are a sure signthat the oil bath air filter must becleaned more often than stated in themaintenance schedule.

Cyclone prefilter

Under extremely dusty operating con-ditions, we recommend using a cycloneprefilter in addition to the oil bath airfilter in order to triple the service life ofthe oil bath air filter.

The cyclone normally requires no main-tenance. Remove the cyclone andthoroughly clean according to type ofdust accumulation.

3

~~Fig.20 Oil bath air filter, disassembled1 Filter bowl2 Gasket3 FiIter element4 Filter housing w. oil level mark (arrow) 23

Fig. 21 Fuel system of engine

24

Fig. 22 Injection pump

1 Fuel feed pump2 Sugtion- and pressure valve3 Fuel primer pump4 Bleeding screw5 Pressure valve

To Fig. 21

1 Injection pump2 Fuel priming pump

I' 3 Fuel feed pump4 Fuel return line5 Fuel suction line6 Fuel filter

i 7 Fuel injection line

Fuel System

Filling-up Fuel

When filling fuel into the fuel tank makesure to avoid impurities, that the capgasket is not damaged and seals tightly.Clean cap regularly.

Dirty fuel will result in early wear of thehigh-grade and very expensive injectionpump elements.

When filling up from barrels or call's thefollowing points should be observed:

Always suck fuel from closely underthe fuel level of the barrel, that is, donot simply set suction pump into barrel.Maintain minimum distance betweenbottom of barrel and end of intake pipe,so that deposits such as dirt, sludgeand water will not be sucked in.

Cleaning Fuel Tank

Clean the fuel strainer in the fuel tankregularly.

If installed, remove filler strainer afterunscrewing the cap and wash withbrush in diesel fuel.

Drain fuel tank completely to clean thefuel tank and intake strainer. Havecollecting vessel ready for use, unsc"rewdrain plug and drain remainder of fuel.Pull intake strainer from intake pipe andclean. Fig. 23 and 24.

Cleaning Fuel Prefilter

Clean prefilter according to main-tenance schedule. Loosen wing nut, pushclip aside and remove bowl. Unscrewstrainer body. Carefully wash bowl andstrainer in clean gasoline or diesel fuel.

During reinstallation replace worn orhardened gaskets since otherwise airwill enter the fuel system. Fig. 25.

Cleaning Fuel Filter

Clean fuel filter according to main-tenance schedule:

Loosen fastening bolts of both filterbowls. Fig. 26. Remove filter bowls andtake off felt tube elements. Clean outfilter bowls. In no case disassemblefelt tube elements for cleaning. Carefullyclose off both openings of a felt tubeelement so that no dirt can enter. Shakeout felt tube elements in clean dieselfuel.

Immerse heavily dirtied felt tube ele-ment in diesel fuel until drawn full ofoil and blowout with compressed airor with an air pump through one of theholes from inside, Repeat procedureuntil the blown out fuel remains clean.During reinsertion pay particular atten-tion to upper and lower felt gasket.

Paper filter elements cannot be washedbut should be changed during each 1stTM.

Trouble-free engine operation requires

a carefully cleaned fuel filter.

Fig. 23 Fuel tank1 Intake line2 Return line3 Fuel gauge sending unit4 Vent5 Filter strainer

Fig.24 Intake strainer

1 Intake pipe2 Intake strainer3 Drain plug

Fig. 25 Fuel prefilter 25

Fig.26 Fuel filter1 Fastening bolts of filter bowls2 Bleed screws

26 Fig.27 Cleaning of fuel filter element

Primingand Feed Pump

To operate priming pump first turn itshandle counter-clockwise. After usingprimer pump screw handle down againby turning clockwise.

The fuel feed pump is a double actingpiston pump. Normally, no service isrequired. If required, remove feed pump,disassemble, clean, assemble andreinstall. Fig. 21.

Bleeding Fuel Filter

Unscrew both bleeding screws of fuelfilter one after the other for 1-2 com-plete turns and actuate fuel primerpump. Pump until fuel free of bubblesflows out of bore in bleeder screw.

Bleeding Fuel System

Complete bleeding of the injection pumpor the entire fuel system is one of thebasic conditions for perfect running ofthe engine.

If air bubbles collect in any part of thefuel system they are compressed withoutfuel being ejected out of the injectornozzle. To prevent such trouble in thefuel system never run the fuel tankcompletely empty.

Bleed entire fuel system prior to initialoperation, as well as after each majorrepair:

When the fuel system has not beenrun empty completely bleeding of thefuel filter may be sufficient. If thereafterthe engine does not fire immediatelybleed the injection pump.

Bleed fuel filter.

Loosen bleeder screw on injection pumpby a few turns and add fuel-with theprimer pump until fuel emerges absolu-tely free of bubbles. Primer pump requi-res fast actuation.

Checking and Cleaning Injectors

Trouble on injector nozzles may occurwhen the fuel system has dirt accumula-tions whereby the engine will emit blacksmoke, will knock badly or run errati-cally.

A stuck nozzle needle may be madeoperable when the engine is runningby actuating the accelerator pedal se-veral times. To find the damaged nozzle,loosen the pressure lines to the nozzleholders of the injector nozzles one afterthe other, that is, loosen only one pres-sure line at a time and watch operation,speed and exhaust of engine. If thespeed changes not at all or only slightlyand the abnormal noise or the black

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smoking of the exhaust stop, thedamaged injection nozzle has beenlocated.

Replace a damaged injection nozzle orclean on an absolutely clean workbench:

Remove cylinder head cover. Imme-diately cover the thus unprotectedintake ports so that no foreign mattercan fall into them. Loosen glands in cy-linder head which retain the injectionlines. Unscrew pressure and leak fuellines.

Unscrew union nut. Remove nozzle andwatch out for washers under the spring.)f damaged, only replace nozzle bodyand nozzle needle together.

Clean nozzle body and nozzle needleexternally. Clean ejection bore and theupper annular surface with a pointedpiece of hardwood or a soft brush.

Carefully clamp cylindrical pin ofnozzle needle between lead jaws andpull nozzle needle out of nozzle body.If required, first soften both parts indiesel fuel.

Clean nozzle body inside with woodenstick, gasoline or diesel fuel. Cleannozzle needle with clean rag; holdnozzle needle by pin only to preventany corrosion of the lapped surface.

r

Remove carbon deposits on nozzle bodyand nozzle needle only with hardwoodstick.

Prior to reassembly immerse nozzleneedle and nozzle body in clean dieselfuel. Drop test: Nozzle needle pulled outby half its length should drop back to itsseat under its own weight.

Assemble nozzle needle, nozzle bodyand nozzle holder. Check ejection pres-sure. Refer to page 67.

Insert new copper gasket.

Screw in nozzle holder with specifiedtightening torque since otherwise thenozzles might be subject to distortion.Refer to page 74.

Connect pressure line and leak fuelline tightly.

Cooling System

Filling-up Coolant

Regularly check coolant level in expan-sion tank. Actuate push button of safetyvalve prior to opening cap to relieve anyexcess pressure. Fig. 10.

Fig.28 Engine cooling system

1 Coolant pump2 Thermostat3 Sending unit (Temperature)

Fig.29 Radiator drain cock1 Drain cock 27