MAN D 2876 LF 12, D 2876 LF13 Service Manual

Engine Training

D 2876 LF 12/13

Common Rail

AT-01c

Produced by
Plank / Schier
MAN Steyr
02/ 2004

This documentation is intended solely for training
purposes. It is not subject to ongoing amendment
and updating.

2005 MAN Fahrzeuge Aktiengesellschaft

Reproduction, copying, dissemination, editing, translation,
microfilming and storage and/or processing in electronic
systems, including databases and online services, is forbidden
without the prior written approval of MAN.

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CONTENTS

CONTENTS...................................................................................................3

ENGINE DESCRIPTION D 2876 CR .............................................................5

ENGINE RANGE ...........................................................................................8

GENERAL EXPLANATION OF TYPE DESIGNATION...................................9

EMISSIONS – EXHAUST GAS FIGURES ...................................................10

EXTRA EQUIPMENT ..................................................................................11

EXPLANATION OF ENGINE CODE............................................................12

ENGINE IDENTIFICATION NUMBER .........................................................13

BASICS OF TORQUE .................................................................................14

TECHNICAL DATA...................................................................................... 16

ENGINE BLOCK – CRANK CASE...............................................................20

CYLINDER LINERS.....................................................................................22

PISTON PLAY – CYLINDER LINERS.......................................................... 24

CRANK SHAFT ...........................................................................................26

FLYWHEEL .................................................................................................32

CONNECTING ROD....................................................................................36

PISTONS ....................................................................................................38

ENGINE CONTROL ....................................................................................42

CAM SHAFT................................................................................................44

CHECK OF VALVE TIMING ........................................................................48

CYLINDER HEAD AND VALVE GEAR ........................................................52

CYLINDER HEAD ATTACHMENT............................................................... 54

REMOVAL AND FITTING OF INJECTORS .................................................58

REPAIR OF ROCKER ARM BEARING........................................................60

SETTING OF VALVE PLAY.........................................................................62

EXHAUST VALVE BRAKE (EVB)................................................................64

EVB MAINTENANCE / VALVE PLAY ..........................................................66

EVB MAINTENANCE / NON-REGULATED EXHAUST FLAP ......................68

PRESSURE-REGULATED EVB ..................................................................70

EXHAUST / INTAKE SYSTEM ....................................................................74

EXHAUST TURBO CHARGER WITH WASTE GATE (530 HP ENGINE) ....76

BOOST PRESSURE ...................................................................................78

TURBO CHARGER ..................................................................................... 80

INTERCOOLER........................................................................................... 82

EXHAUST GAS RECIRCULATION (EGR).................................................. 84

V-BELT DRIVE ........................................................................................... 90

ADJUSTABLE FAN BEARING.................................................................... 94

ELECTRICALLY CONTROLLED FAN COUPLING ..................................... 96

ACCIDENT PREVENTION – CLEANLINESS OF COMMON RAIL.............100

WORK ON CR SYSTEM ...........................................................................101

COMMON RAIL ACCUMULATOR INJECTION SYSTEM ..........................104

FUEL SYSTEM..........................................................................................108

LOW-PRESSURE PART ...........................................................................110

HIGH-PRESSURE AREA...........................................................................112

CR HIGH-PRESSURE PUMP....................................................................114

UN-FITTING OF HIGH-PRESSURE PUMP ...............................................116

RAIL ..........................................................................................................118

INJECTOR.................................................................................................120

INJECTOR PRINCIPLE .............................................................................122

INJECTION TIMING ..................................................................................124

COMBUSTION PRESSURE CHARACTERISTIC.......................................126

SPEED SENSORS ....................................................................................128

SEPARFILTER 2000..................................................................................130

GENERAL NOTES ON LUBRICANTS.......................................................132

LUBRICATING OIL SYSTEM.....................................................................134

ENGINE OIL CIRCULATION .....................................................................136

OIL LEVEL SENSOR WITH TEMPERATURE SENSOR............................144

COOLING..................................................................................................146

WATER RETARDER - VOITH ...................................................................152

REMOVAL AND FITTING OF WATER PUMP RETARDER.......................158

FLAME START SYSTEM TGA ..................................................................162

AIR COMPRESSOR ..................................................................................168

ELECTRICAL EQUIPMENT.......................................................................170

STARTER CONTROL................................................................................172

SEALANTS, ADHESIVES, LUBRICANTS..................................................174

CLEARANCES AND WEAR LIMITS ..........................................................176

OBJECTIVE TORQUE FIGURES ..............................................................178

TIGHTENING TORQUES D 28 CR............................................................182

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ENGINE DESCRIPTION D 2876 CR

GENERAL

The inline engines of the D 2876 LF series underwent major modification for the heavy-duty MAN Trucknology Generation (TGA):

 New grading with higher power and torque plus high torque

 Depending on conditions of use and lubricants, oil change

gradients

 Substantial improvement of engine efficiency and fuel

consumption over wide ranges of the operating map through

an increase of engine peak pressure and the new common

rail (CR) technique

 Adaptation of the cylinder head, cylinder head packing,

cylinder liner and crank case bolt fit to the higher gas

pressures

 Reduced engine weight through omission of the secondary

acoustic measures and use of a lighter crank case yoke

 Use of the second-generation Bosch common rail injection

system (1600 bar)

 Engine management by EDC 7 and communication with the

intervals of maximally 100,000 km can be achieved and thus

lower operating costs for the user

 High reliability through adherence to the proven D 2876 LF

12.8 liter engine concept

 Increase of exhaust brake performance in conjunction with

the upgraded, pressure-controlled exhaust valve brake (EVB)

as special equipment

 Further increase of exhaust brake performance through use

of the entirely new, innovative primary braking system water

retarder (PriTarder) in conjunction with the pressure-

controlled EVB as special equipment

vehicle management computer on the CAN bus

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Changes compared to earlier D 28.. Euro 3 engines

Engine

Water pump

Crank case

Crank shaft

Connecting rods

Pistons

Cylinder liners

Cylinder heads

Cylinder head packing

Rocker arm case with rocker arm

Exhaust manifold packing

Oil pump

Oil circulation

MAN PriTarder

Fan bearing

Visco fan Eaton

Common rail injection system

EDC 7

Injectors (7-jet)

High-pressure pump with rail distribution

Sensor technology

New fuel connector system

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D 28.. EURO 3 COMMON RAIL

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ENGINE RANGE

Engines Series Horsepower rating Chassis number

(ISO 1585-88195 EEC) starting with:

D 2876 LF 12 .............. Euro 3 ................................ TGA.........................480 hp / 353 kW .................................... WMAH..

D 2876 LF 13 .............. Euro 3 ................................ TGA.........................530 hp / 390 kW .................................... WMAH..

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GENERAL EXPLANATION OF TYPE DESIGNATION

Example TGA 26o530

T Trucknology

G Generation

A -vehicle weight above 18 tons

26 Overall weight in t

530 Horsepower figure without Euro standard specification

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EMISSIONS – EXHAUST GAS FIGURES

In Europe the 13-step test to ECE R49 is used for commercial

vehicles of more than 3.5 t permissible overall weight.

1993 1996 2000

This means measuring the engine's exhaust emissions in 13

ready defined, stationary operating states.

Then the mean emissions are calculated.

In the procedure for Euro 3 engines, in contrast to Euro 2,

measurements will probably also be conducted in the

subdynamic and, depending on the engine version, in the full

dynamic state.

Pollutants Euro 1 Euro 2 Euro 3

CO

Carbon monoxide

HC

Hydrocarbons

NOx

Nitrogen oxide

5 4 2

1.25 1.1 0.6

9 7 5

Particles 0.4 0.15 0.1

Exhaust gas figures in g/kW/h

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EXTRA EQUIPMENT

The following extra equipment is possible depending on how the customer intends to use a vehicle:

 Gear wheel driven power takeoff at engine end with 600 Nm

 Cooling water preheater from Calix (220 V, 1100 W)

(temporarily 720 Nm) torque

 Refrigerant condenser, driven by Poly V-belt, firmly attached

to intermediate case, for vehicles with air-conditioning

 Possibility of adding hydro geared pump to cam shaft power

takeoff

 Possibility of adding steering pumps and hydraulic pumps on

air compressor front and rear

 Ready for attachment of Frigoblock generators

G12/G17/G24 (WR is not possible here)

 MAN PriTarder combination of water retarder and EVB-ec

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EXPLANATION OF ENGINE CODE

ENGINE TYPE LABEL

Typ

Motor-Nr. / Engine-no N I / N II

2120025200B2E1

MAN - Werk Nürnberg

D 2876 LF 12

P1

Box N I / N II

Engine type designation

D 2876 LF 12

D ...........Diesel fuel

28 ..........+100 = bore diameter, e.g. 128 mm

7 ............Stroke: 6 = 155 mm, 7 = 166 mm

6 ............Number of cylinders: 6 = 6-cylinder, 0 = 10-cylinder,

2 = 12-cylinder

L ............Turbo charger with intercooler

F............ Engine incorporation:

F Truck, forward control, vertical engine

OH Bus, rear-engined, vertical

I Deviation of 0.1 mm

II Deviation of 0.25 mm

P Big-end bearing pin

H Crank shaft bearing pin

S Follower of cam shaft (S1 0.25 mm crush)

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UH Bus, rear-engined, horizontal

12 ..........Engine variant, especially important for

procuring spare parts,

technical data and settings

212

0025

200

B2E

1

G

ENGINE IDENTIFICATION NUMBER

Example:

A

A ......... 212 .............. Engine type code

B ......... 0025 ............ Date of assembly

C ......... 200 .............. Assembly sequence (progress figure on date of assembly)

D ......... B ................. Overview flywheel

E ......... 2 .................. Overview injection pump/regulation

F ......... E.................. Overview air compressor

G......... 1 .................. Special equipment like engine-governed power takeoff

B C

D E

F

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BASICS OF TORQUE

A TORQUE

C SPECIFIC FUEL CONSUMPTION

Power and torque increase with speed. After overcoming

the friction loss and greater heat losses at low speeds, the

engine achieves its maximum torque with optimum filling of

the cylinder. If speed increases further, the torque drops

because of the greater flow resistance and short valve

opening times.

B POWER

Power is the product of speed and torque. Seeing as the

drop in torque is slower than the increase in speed, there is

initially an increase if the power output of an engine.

Between the maximum torque and the maximum power

there is an elastic range in which power is kept constant

by increasing torque although the speed is dropping.

The full-load consumption curve in the diagram can be

explained by the fact that you get less than good fuel

consumption in the low range of speed because of the poor

pressure mix of the fuel particles (14.5:1). At high speeds,

combustion is imperfect because of the short time that is

available. And fuel consumption increases.

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TECHNICAL DATA

D 2876 LF 12 Euro 3

Model.............................................................. R6 TI-EDC (4 V)

Idling speed .............................................................. 600 1/min

Cylinder arrangement ...................................6 cylinders inline

Max. power ..................................................... 353 kW / 480 hp

Rated speed ........................................................... 1900 1/min

Max. torque.................................................................2300 Nm

Speed at max. torque.................................1000 to 1300 1/min

Capacity.................................................................. 12,816 cm3

Bore / stroke ...............................................................128 / 166

Ignition sequence ................................................... 1-5-3-6-2-4

Cylinder 1 location ....................................................... fan side

Combustion process, injector ............................................ 7-jet

Compression..........................................................................18

Valve play on cold engine .......................................IV 0.50 mm

Valve play exhaust with EVB ..............EV 0.80 mm / 0.60 mm

Compression pressure.................................................> 28 bar

Admissible pressure difference between cylinders ..max. 4 bar

Coolant ...........................................................50 (I/R 58) liters

Oil charge ....................................................................42 liters

Fuel system.........................................................Bosch EDC 7

Fan coupling actuation........................................hydroelectric

Weight (dry) with WR................................................... 1071 kg

K factor........................................................................... 1.3 m-1

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D 2876 LF 13 Euro 3

Model.............................................................. R6 TI-EDC (4 V)

Idling speed .............................................................. 600 1/min

Cylinder arrangement ...................................6 cylinders inline

Max. power ..................................................... 390 kW / 530 hp

Rated speed ........................................................... 1900 1/min

Max. torque.................................................................2400 Nm

Speed at max. torque.................................1000 to 1400 1/min

Capacity.................................................................. 12,816 cm3

Bore / stroke ...............................................................128 / 166

Ignition sequence ................................................... 1-5-3-6-2-4

Cylinder 1 location ....................................................... fan side

Combustion process, injector ............................................ 7-jet

Compression..........................................................................18

Valve play on cold engine .......................................IV 0.50 mm

Valve play exhaust with EVB ..............EV 0.80 mm / 0.60 mm

Compression pressure.................................................> 28 bar

Admissible pressure difference between cylinders ..max. 4 bar

Coolant ...........................................................50 (I/R 58) liters

Oil charge ....................................................................42 liters

Fuel system.........................................................Bosch EDC 7

Fan coupling actuation........................................hydroelectric

Weight (dry) without WR.............................................. 1049 kg

K factor........................................................................... 1.3 m-1

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ENGINE BLOCK – CRANK CASE

The crank case is cast in one piece together with the cylinder

block from special GJL-250 cast iron. The wet cylinder liners of

highly wear-resistant, special centrifugal cast GJL-250 are

exchangeable. The sealing between the cylinder liner and the

crank case coolant jacket at the top is by a oval elastomer

moulded washer and at the bottom by two elastomer round

sealing rings.

Optimized wall thicknesses and functional ribbing of the crank

case side walls optimized by the finite element method (FEM)

produce rigidity of form and low noise emission.

The crank case was matched to the higher ignition pressure

(160 instead of 145 bar) by reinforcing the partitions and

geometrically optimizing the cylinder liner fitting, but for the

same crank case weight.

The crank case was matched externally for compact attachment

of the new EDC 7 control unit, rail and cam shaft engine speed

sensor. The casting and machining of the crank case were also

optimized.

The crank case is closed off at the rear by the flywheel/timing

case of GJS-400 ductile cast iron, with the rear crank shaft

sealing ring, and at the bottom by the crank case yoke of

permanent mould cast aluminium (Loctite 518 sealing). Apply a

track with a maximum width of 1 mm.

The crank case venting gases are fed back into the combustion

air by way of a wire-knit oil trap with pressure regulating valve

attached to the rear left of the crank case to avoid emission on

the intake side of the turbo charger.

To improve the oil supply to the valve gear, extra oil holes were

provided in the crank case across from the main oil duct through

the partitions to the cam shaft bearing (and on to the valve

gear).

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CYLINDER LINERS

The wet, exchangeable cylinder liners are produced from a

NOTE:

special centrifugal cast iron.

The oval O-ring (1) for the upper packing must be inserted

without any twist in the second grooves of the liner.

Lightly coat the cylinder liner in the region of the upper O-ring

with engine oil.

Place new O-rings (2) in the crank case (Viton).

Lightly coat the region of the lower O-ring with engine oil, as well

as the transition of the cylindrical part of the bush.

Caution:

Do NOT use a brush!

NOTE:

The packing of the cylinder liners is different.

DO NOT USE ANY KIND OF GREASE / SEALANT.

Method for measuring cylinder liner projection (without the

sealing ring). Place cylinder liners in the crank case without an

O-ring.

Attach a press-on gauge plate and tighten to 40 Nm. Then

measure at at least four points with the dial gauge.

1 Cylinder liner

2 Crank case

C Rim depth in crank case

D Rim height of cylinder liner

D-C Projection of liner from crank case

Cylinder liner projection: min 0.035 mm, max. 0.1 mm

Rim depth C 7.965 to 8.015 mm

Rim height of cylinder liner D 8.05 to 8.07 mm

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PISTON PLAY – CYLINDER LINERS

Measurement of piston play:

NOTE:

Measure the inner diameter of the cylinder liners with an inside

micrometer at three levels from top to bottom, and radially at

intervals of 45°. Read the piston diameter from the bottom of

new pistons. On pistons that have run, measure with an outer

micrometer from the piston bottom edge across the piston axis.

Subtract the piston diameter from the largest measured cylinder

liner diameter.

The figure arrived at is the piston play.

If the piston play is too large, replace the cylinder bush and

piston.

Example of piston play for D 28..LF

Cylinder diameter......................................127.99 to 128.01 mm

Piston diameter. ....................................127.561 to 127.570 mm

Ideal play ..........................................................0.14 to 0.15 mm

Wear limit...................................................................... 0.30 mm

Measure on 3 position, for example 1,2,3

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CRANK SHAFT

The crank shaft has a 7-point bearing and eight forged-on

A Axial bearing of crank shaft............ 0.190 to 0.312 mm

counterweights to balance inertial forces. The main and big-end

bearing pins as well as the lapped bearing collars are induction

hardened and ground.

ON A CRANK SHAFT N1, ALL BIG-END OR MAIN BEARING

PINS ARE IN EVERY CASE ALSO N1.

The axial bearing of the crank shaft is implemented by thrust

washers on the middle bearing block.

Attention: The oil flutes of the thrust washers A must face the

crank webs.

Attention: Never dismantle the vibration damper using a

hammer or fitter's lever. The slightest dent will ruin the damping

function of the vibration damper. This can cause clutch damage

and breakage of the crank shaft.

Wear limit............................................................. max. 1.25 mm

B Main bearing bolts.................................... 300 Nm + 90°

D Crank case yoke to reinforce crank case

Use 04.10394-9272 sealant.

E Designation H and P tolerance N or N1 of big-end or main

bearing pins (N1= 0.1 mm deviation)

Spread of bearing shells F:

 Measure dimension C.

 Measure dimension D.

 Expansion = C minus D

 Spread must be between 0.3 and 1.2 mm.

 Attention: C must be greater than D.

Main bearing pin diameter .................... N 103.98 to 104.00 mm

Main bearing inner diameter ............. N 104.066 to 104.112 mm

Other undersizes.................. 0.25 to 0.50 mm, 0.75 to 1.00 mm

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Crank shaft lining front and rear

On the rear crank shaft lining, like on the front, rotary shaft

Fitting notes:

seals of polytetrafluorethylene (PTFE), trade name Teflon, are

always used.

Because of its own relatively large initial tension, the lip (A)

tends to curve inwards. For this reason the PTFE lining ring is

supplied on a transport wrapper (B). It must be left on this

wrapper until it is used. Another reason for this is that the lip is

very sensitive and the slightest damage can result in leakage.

The sealing lip and the race of the flywheel must not be coated

with oil or other lubricants.

NOTE:

New engines come without a race.

When repairing, only use variants with a race (04.10160-9049

The PTFE lining ring must be fitted absolutely free of oil

and grease. The slightest oil or grease traces on the race or

lining ring can result in leakage.

Before fitting, clean any oil, grease and anti-corrosion agents

off the race and pull-in tool. You can use any conventional

cleaning agent for this purpose.

Never store the PTFE lining ring without the supplied

transport wrapper. After only about 20 min without the

wrapper it will lose its initial tension and is then unusable.

sealant).

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Pull out the rotary shaft seal

Loosen the lining ring by tapping it.

Use the extractor tool

Slide the four hooks under the lip, turn through 90° so that they

grip the ring behind the lip, and pull out the rotary shaft seal by

turning the spindle.

Attach the race

The latest crank shafts come without races. A race is fitted

when renewing the crank shaft sealing ring.

Clean the inside of the race and crank shaft stump, and coat the

crank shaft stump with 04.10160-9049 sealant. Slide the race

and press-fit sleeve onto the adapter. Tighten the spindle in the

adapter with the nut. Screw the adapter tightly to the crank shaft.

The adapter must fit tightly on the crank shaft to ensure the

Fit the rotary shaft seal

Screw the adapter to the crank shaft.

Clean the adapter and the race. The rotary shaft seal must be

assembled dry. Do not coat the lips with oil or other

lubricants.

Place the rotary shaft seal with the transport wrapper on the

adapter and slide the seal onto the adapter.

Remove the transport wrapper.

Slide the winding sleeve onto the adapter.

Screw the spindle into the adapter.

Pull in the rotary shaft seal as far as the stop of the winding

sleeve on the end cover.

correct press-fit depth of the race. Pull in the race as far as the

stop of the press-fit sleeve.

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FLYWHEEL

The flywheel is centered on the crank shaft by a set pin and

Caution:

attached by ten torque screws.

Tightening method for flywheel screws

Anti-fatigue screws M16 x 1.5 (12.9)

 Pretighten to 100 Nm.

 Turn 900.

 Tighten finally by turning 90°.

 NOT reusable

Make sure the race (2) is properly seated.

Use 04.10160-9049 sealant.

Place the faced side first and use a mandrel to push it right on.

Coat the seat of the race with green Omnifit.

Clutch shaft guide bearing (1)

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Machining of flywheel

In the event of heavy scoring, the permissible material wear of

Maximal lateral runout of starter rim: 0.5 mm

the press-on surface is max. 1,6 mm.

Minimum dimension A: 60.5 mm

Standard dimension A: 62 ±0.1 mm

Outer diameter of flywheel: 488 to 487.8 mm

The starter rim is heated to between 200 and 230°C for

assembly.

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CONNECTING ROD

The connecting rods are drop-forged from heat-treatable

C38mod steel, without weight compensating battens, and split

obliquely by cracking the bearing cap. The oblique split

NOTE:
 The top bearing shell is marked TOP or has a red spot on the

side (tempered backing shell).

simplifies assembly and repair, because the connecting rods can

be taken out through the top of the cylinders.

The big-end bearings are designed for extremely high stress and

long service life. The upper bearing shell consists of highly

wear-resistant sputter metal. There is a long oil hole from the

large to the small connecting rod eye for proper supply of oil to

the latter.

Measurement of big-end bearing

Measure the inner bore of the big-end bearing shells in an

assembled state on the axes 1, 2 and 3 and at levels a and b.

Bearing shells whose bore is within tolerance limits can be re-

used, if they are outside you must renew the bearing.

 Scrap them if the bore is larger or oval.

Big-end bearing pin dia. (standard). .........89.980 to 90.000 mm

Big-end bearing inner dia. (standard) .......90.060 to 90.102 mm

Big-end bearing spread (Miba) .........................95.5 to 96.4 mm

Big-end bearing radial play ...........................0.060 to 0.122 mm

Spread C...........................................................95.5 to 96.4 mm

Tightening torque of connecting rod screws:

100 Nm

+10

+ 90°

+10

Connecting rod screws: M14 x 1.5 x 65/10.9 Torx

Re-use of the screws is not permissible.

Caution:

Do NOT place the connecting rod or the cover on the seam.
Any damage (change) to the structural fracture will destroy
it.

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PISTONS

The three-ring pistons are of a special cast aluminium with a

moulded ring insert for the uppermost piston ring. The combustion

chamber is slightly retracted, graduated and omega-shaped.

There are valve recesses on the inlet and outlet side. To reduce

the effects of heat, the pistons have a cast integral cooling duct

and are cooled by an oil jet from injection nozzles.

The pistons were adapted to the higher ignition pressures by

graduated bracing of the connecting rod, suitable selection of

materials and appropriate scaling of the combustion chamber.

The oil injection nozzles in the crank case are matched in their

flow cross-section to the new cooling duct of the pistons. The oil

pressure valve in the injection nozzles is omitted to ensure proper

piston cooling also at low engine speeds.

A new, smooth piston pin of larger diameter is used to take load

off the piston pin boss.

Rings

Double-faced trapezoidal ring and second compression ring as

compression rings, ventilated oil scraper ring with spiral expander

and bevelled outer edges.

Piston projection under/over top edge of crank case:

-0.03 to +0.331 mm

Gap of piston rings, wear limit

I Trapezoidal ring, wear limit 1.5 mm

II Second compression ring, wear limit 1.5 mm

III Oil scraper ring, wear limit 1.5 mm

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Pistons (technical data from Kolben Schmidt)

1 Piston diameter, measured across boss:

KS measured 20 mm

above piston bottom edge (2)......... 127.561 to 127.570 mm

4 Compression height:

Standard dimension: D 2876 LF........................... 79.25 mm

Undersize: 0.2 mm / 0.4 mm / 0.6 mm

A Piston projection under/over crank case top edge:

- 0.03 to +0.30 mm

Piston ring flutes

(5) Compression ring 1 .........................................4 to 4.05 mm

(6) Compression ring 2 ....................................3.04 to 3.06 mm

Piston ring height

Double-faced trapezoidal compression ring

Height .......................................................3.99 to 4.025 mm

Gap.............................................................0.35 to 0.55 mm

Second compression ring ...................................2.97 to 3.0 mm

Gap.................................................................0.7 to 0.9 mm

Oil scraper ring

KS.............................................................3.975 to 3.99 mm

Gap.............................................................0.25 to 0.55 mm

Piston weight difference per engine set...................... max. 50 g

Fit with arrow pointing to the frontend

(7) Oil scraper ring.......................................... 4.04 to 4.06 mm

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ENGINE CONTROL

Setting of timing

The marking of the crank shaft gear must match with the marking

of the shrink-fit cam shaft gear (not the same as TDC of

cylinder 1).

A Gear wheels on flywheel side

1 Crank shaft

2 Oil pump drive

3 Oil pump delivery wheels

4 Cam shaft

5 Intermediate gear for high pressure pump

6 High pressure pump drive

7 Auxiliary drive

B Gear wheels on fan side

8 Cam shaft wheel

9 Compressor drive gear

10 Fan drive gear

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CAM SHAFT

The cam shaft is forged from Cf53 steel with induction hardened

The cam shaft is driven from the crank shaft by case-hardened,

and ground cams and bearing points. It is seated in the crank

case with a 7-point bearing in white metal bushes. The axial

bearing of the cam shaft takes the form of a collar end bearing in

the crank case on bearing 7. In the timing case there is a butting

ring screwed in as an axial stop.

Engines with cam shaft power takeoff are fitted with a specially

forged shaft of carburizing 16MnCr5 steel with a highly wear-

resistant, sputter collar end bearing 7 in the crank case.

helically toothed spur wheels on the rear side of the engine.

Bolted at the back of the cam shaft is also the drive wheel for

high-pressure pump CP3.4 (M10 x 35 10.9 Nm 65). This gear

wheel bears markings for the cam shaft engine speed sensor.

Valve lifter lubricant paste 09.15011-0011.

A spur wheel is fitted to the front end of the cam shaft to drive

the air compressor and the fan shaft.

1 Reference markers to identify first cylinder

2 High-pressure pump drive wheel

3 Cam shaft drive wheel

4 Retaining screw 65 Nm

5 Oil hole

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Admissible play of cam shaft

Measure the axial play of the cam shaft.

Cam shaft axial play .......................................0.20 to 0.90 mm

Wear limit ................................................................... 1.50 mm

Test without the air compressor attached.

NOTE:

For cam shaft power takeoff, the cam shaft is held reinforced

between bearings 6 and 7 and in a highly wear-resistant,

special collar end bearing on bearing 7.

Tightening torque:

Screws for butting ring 40 Nm

Secure with Loctite 648.

Press the cam shaft tightly against the crank case.

Add the seal thickness z = 0.5 mm to dimension y.

Cam shaft axial play = y + z - x

Dimension x = margin of sealing face of crank case

to butting face of cam shaft drive wheel

Dimension y = margin of sealing face of timing case

to butting ring

Dimension z = thickness of seal pressed

1 Crank case

2 Gauge rail

3 Cam shaft gear wheel

4 Sealing face of crank case

5 Sealing face of timing case

6 Butting ring

7 Timing case

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CHECK OF VALVE TIMING

Check the timing for the specified valve cycle.

Twisting of the shrink-fit cam shaft drive wheel can result in

serious engine damage.

Consequently, after engine malfunctions that can cause such

twisting, e.g. failure of the air compressor, make sure seating is

correct by checking the valve timing.

Requirement: push roads must not be bent.

D 2876 LF 12 0.50 IV / 0.60 EV / 0.40 EVB Valve play

Valve travel 9.0 to 9.5 mm

D 2876 LF 13 0.50 IV / 0.60 EV / 0.40 EVB Valve play

Valve travel 9.0 to 9.5 mm

Proceed as follows:

 Attach the engine turning gear to the timing case.

 Remove the cylinder head.

 Correctly set the inlet and exhaust valves.

 Set the flywheel to TDC so that the valves overlap.

 Place the dial gauge with approx. 11 mm advance on the

disk of the inlet valve on the 4th cylinder and set to "O".

 Turn the engine in the running direction (left) until the dial

gauge pointer no longer moves.

 If the timing is correct, the figures shown on the dial

gauge must be within the following tolerances.

Read the valve travel from the dial gauge.

.

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Timing

Timing D 2876 LF 12/13

Inlet opens 23° before TDC

Inlet closes 12° after BDC

Exhaust opens 60° before BDC

Exhaust closes 30° after TDC

Timing diagram

Degrees referred to crank shaft angle

1 = Direction of engine turning

2 = Inlet opens

3 = Inlet closes

4 = Inlet opening time

5 = Center inlet cam

6 = Exhaust opens

7 = Exhaust closes

8 = Exhaust opening time

9 = Center exhaust cam

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1

5

2

1

5

2 7 0

BDC

4

TDC

7

2

°

3

2

3

0

°

9

°

0

6

1

2

°

6

3

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CYLINDER HEAD AND VALVE GEAR

The engines have cylinder heads of special GJL-250 cast iron,

NOTE:

with cast integral, swirl inlet and exhaust ports, shrunk-in inlet

and exhaust valve seat rings, and press-fit, exchangeable valve

tracks.

The cylinder heads were adapted to the higher ignition pressure

by reinforcing the baseplate and using smaller valve diameters.

To increase the prestressing force, the cylinder heads are now

each attached to the crank case by six larger, high-strength Torx

collar screws with an M16 x 2 thread.

New steel cylinder head seal inserts were developed for D 2876

LF 12/13 engines, with a newly designed seal plus drain moved

forward to the combustion chamber, elastomer seals on the fluid

ports and an elastomer seal on the outer contour.

.

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CYLINDER HEAD ATTACHMENT

The cylinder head is attached to the crank case with the fluid

sealed rocker arm case by six Torx screws. The cylinder head

screws (dia. 16 mm) have spacers and a thread in the top

region. This thread serves for better tracking and centering

between cylinder head and rocker arm case.

NOTE:

Use Loctite 5900 or 5910 sealant between the rocker arm

bearing case and the cylinder head.

Use 09.16012-0017 paste.

Length of cylinder head screws:

Bold with fixed shim (2,3,5) 227,5 mm

Bold with fixed shim (1,4,6) 285,3 mm

Bold with unfixed shim (2,3,5) 225,8 mm

Screws with Torx head

1) Fit the cylinder heads, align them and tighten the screws to

10 Nm (paint the screw heads with Optimol White and oil

the threads).

2) Pretighten to 80 Nm.

3) Pretighten to 150 Nm.

4) Pretighten to 90°

5) Finally tighten to 90°

+10

.

+10

.

NOTE:

Retightening of the cylinder head screws is no longer necessary.

Bold with unfixed shim (1,4,6) 287,3 mm

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4V Cylinder Head Inlet and Exhaust Valve Side

The inlet and exhaust valves are friction clamped by the three

C Valve cover

grooves in the stem and the cotters. There are stem seals on all

valves to minimize oil consumption. Valves are actuated by the

bridge of the rocker arm. Make sure the bridge is correctly fitted.

The milled face of the bridge is towards the push rod.

The inlet valve only differs slightly from the exhaust valve.

Distinguishing feature: spherical recess (B) of small diameter

in the valve disk from the inlet valve.

Inlet valve diameter 44 mm

Exhaust valve diameter 41 mm

The inlet valve retrusion is 0.60 0.2 mm.

The exhaust valve retrusion is 0.69 0.2 mm.

The EVB mechanism is incorporated in the exhaust valve

bridge (3). The oil supply of the rocker arms and the EVB is

through the rocker arm bearing case. The EVB arrester is

integrated into the rocker arm bearing case.

D Bridge

E Setting screw

F Check nut

G Inlet valve setting (0.50 mm)

1 Valve steam seal

2 Retaining screw

3 Exhaust valve bridge

4 Setting screw EVB (0.6 mm)

5 Check nut EVB (tighten to 40 Nm)

6 Setting screw with elephant foot (0.80 mm)

7 Check nut (tighten to 40 Nm)

Inlet valve seat 120°

Exhaust valve seat 90°

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REMOVAL AND FITTING OF INJECTORS

Removal of injector

1. Undo the injection lead and cover up the pipe.

2. Undo and remove the screw for the pad.

3. Take out the pressure pipe stub using a special-purpose tool.

4. Remove the cheese-head screw of the pressure flange.

5. Pull out the injector using a special-purpose tool and keep it

in a safe place (not above the pressure flange).

3) Tighten the injector cheese-head screw (5) to 25 Nm +
90°.

4) Tighten the pad for the pressure pipe stub,
screw (8) 20 Nm + 90°.

5) Connect the high-pressure lines from and to the rail.

- Tighten the retaining screws of the rail (hand tight).

- Tighten the nuts of new high-pressure lines
to 10 Nm + 60° (not reuseable)

- Tighten the retaining screws of the rail.

NOTE:

The pressure pipe stub must not be used again after removal,

6) Tightening torque for electrical connection M4 1.5 Nm.

1 O-ring (grease)

and always use new O-rings and a Cu gasket (1.5 mm).

2 Copper gasket

Fitting of injector

3 Retaining pressure flange

Do not remove the protective cap until immediately before fitting

4 Spherical washer

the injector in the engine.

5 Pressure flange screw

1) Pretighten the injector with the pressure flange (ensure

correct position) with the cheese-head screw (5) M8 x 55

10.9 in the cylinder head to 1 to 2 Nm.

2) The thinner end (10) of the pressure pipe stub must face

the injector. Pretighten the cheese-head screw (8) to

6 Pad

7 Spherical washer

8 Retaining screw

9 Pressure pipe stub

10 Pressure flange

10 Nm.

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REPAIR OF ROCKER ARM BEARING

To disassemble, first knock out the rocker arm axle (3) on the

Fitting of rocker arm axles

exhaust valve side with the extractor (4) (thread), and then press

out the rocker arm axle (1) of the inlet valve.

When pressing in the rocker arm axles (09.16012-0117 paste),

make sure that the openings (5) for the cylinder head screws are

correctly positioned.

Press the rocker arm axle of the inlet and exhaust valve side

flush into the rocker arm case using the appropriate special-

purpose tool.

Do NOT forget the O-ring (2) (06.56936-1200).

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5

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SETTING OF VALVE PLAY

There are two overhead inlet and exhaust valves per cylinder.

Schematic of valve arrangement

Valve actuation is by carbide metal lifters, push rods and forged

rocker arms.

Force is transmitted from the rocker arm to the valves by way of

a setting screw with elephant foot and a forged bridge only

across the valve stem ends.

The rocker arms are held by wear-resistant axles pressed into a

rocker arm bearing case and bolted to the cylinder head. The

EVB mechanism is incorporated in the exhaust valve bridge. The

oil supply of the rocker arm bearing and the EVB is through the

rocker arm bearing case.

The valve lifter is arranged slightly offset from the cam of the

forged cam shaft in lengthwise direction to produce forced

rotation and thus reduce wear.

.

I Valves overlapping

II Cylinders to be set

Check of valve play

Set valve play when the engine is cold.

Valve play inlet valve = 0.50 mm

Valve play exhaust valve without EVB = 0.60 mm

Valve play exhaust valve with EVB = 0.60 mm / 0.40 mm

Schematic of cylinder sequence

I Fan side

II Flywheel side

A Exhaust valve

E Inlet valve

Ignition sequence D 2866/76

1 - 5 - 3 - 6 - 2 - 4

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EXHAUST VALVE BRAKE (EVB)

All D 2876 LF engines for TGA are fitted with the EVB. The

braking action compared to a conventional exhaust brake is

improved by approx. 60%.

In the exhaust valve bridge there is a hydraulic piston to which

engine oil pressure is applied, and a relief hole by which oil

pressure can reduce again. Above the valve bridge there is an

arrester (adjustment screw), whose pressure plate closes the

relief hole when the exhaust valve is closed. When the camshaft

open the valve , the relief hole is open and oil pressure before

the piston can reduce.

When the exhaust brake flap is closed, pressure waves build up

in the exhaust manifold and cause short re-opening of the

exhaust valve, i.e. the exhaust valve is briefly pushed open

again every time it closes. The piston is under oil pressure, so it

is pushed after the briefly opening valve, but cannot return

because the arrester closes the relief hole, and the non-return

valve closes the oil entry. So the exhaust valve remains open by

a gap during the compression stroke and the subsequent

expansion stroke. This means that the compression energy of

the piston is lost, which otherwise would have driven the crank

shaft, and the braking action of the engine increases.

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EVB MAINTENANCE / VALVE PLAY

Check the valve play at the customary intervals and set if

Turn back the setting screw (1) far enough to insert a 0.80 mm

necessary (engine cold, coolant temperature max. 50°C). In the

case of the inlet valve, there is no difference between engines

with EVB and those without EVB.

Proceed as follows for the exhaust valve:

Setting of exhaust valve play

Set the piston of the particular cylinder to ignition TDC.

Turn back the setting screw (2) in the arrester as far as possible

(without using force).

NOTE:

Press on the valve bridge with a screwdriver and drain the piston

of engine oil.

valve gauge between the rocker arm and valve bridge.

Turn the setting screw (1) until the valve gauge is held firmly

(the piston is pressed back).

Loosen the setting screw (1) , but only enough to pull out the

valve gauge with slight resistance. Tighten the check nut (1) to

40 Nm.

Insert a 0.60 mm valve gauge between the valve bridge and

screw (2), hold the piston down and turn the setting screw (2)

until the valve gauge is held firmly.

Loosen the setting screw (2) but only enough to pull out the

valve gauge with slight resistance. Tighten the check nut (2) to

40 Nm.

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2

1

2

1

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EVB MAINTENANCE / NON-REGULATED EXHAUST FLAP

The exhaust flap has an internal torsion bar spring to regulate

If the initial tension is too low (gap too small), the exhaust

the exhaust back-pressure.

It is important that the flap should always be closed with the

prescribed initial tension (correct gap).

If the initial tension is too high (gap too large), the exhaust

valves are subjected to excessive thermal load and can burn

out.

braking loss is approx. 60 kW at 1400 1/min.

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2

5

Setting of gap of exhaust brake flap

Check and set the gap with the operating cylinder detached

T2876029

Gap with the operating cylinder
detached and the exhaust brake flap
closed by hand.

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If the gap is too large, reduce the initial
tension of the torsion bar spring, i.e.

open the flap by hand and carefully
press the torsion bar spring against the
"open" stop.

If the gap is too small, increase the
initial tension of the torsion bar spring,
i.e.

place an object between the "closed"
stop and the flap lever, close the flap by
hand and carefully press the torsion bar
spring against the stop.

PRESSURE-REGULATED EVB

The pressure-regulated EVB was designed to cut the large

The governor unit integrated in the FFR computes the pulse

spread in braking action and for possible integration into brake

management. The aim was indirect regulation of the engine

braking power through regulation of the exhaust back pressure.

Regulation of the exhaust pressure means that the braking

power can be set continuously, and power fluctuations, also

those caused by tolerances, can be prevented.

To achieve the required exhaust back pressure, the pressure-

regulated EVB specifically alters the pressure applied to the

operating cylinder of the exhaust brake flap. In this flap there is

no torsion bar spring. The applied pressure is set by a

proportional action valve driven by the vehicle management

computer (FFR) with a pulse-width-modulated (PWM) voltage

signal. To regulate the exhaust back pressure, the latter is

metered by a pressure sensor and the information is sent to the

FFR.

width of the output voltage signal from the input variables

exhaust back pressure, engine speed, required braking action,

onboard voltage, compressed air supply, etc.

The proportional action valve, pressure sensor and rigid brake

flap components are integrated into a module from the supplier.

To reduce the temperature load on the components in the

combustion chamber during longish braking phases, a strategy

founded on engine speed and time functions is used to slightly

reduce the maximum brake torque.

When the brake is applied, first the maximum permissible
shortterm exhaust back pressure is utilized.

After approx. 30 s, down regulation commences to the exhaust
back pressure for permanent braking.

After approx. 1 min, this regulation process is ended and the
exhaust back pressure admissible for permanent braking is
reached.

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Advantages compared to former, non-pressure-regulated
EVB:

 Exhaust brake torque can be set continuously.

 With the regulated exhaust brake it is possible to regulate

over the entire engine speed range to the maximum possible

or maximum permissible exhaust brake torque. This means

substantially higher braking power, especially in the lower

range of engine speed.

 The pressure-regulated EVB is used to reduce the

temperature load on critical components. This is done by

down regulation to defined, engine-speed-dependent

permanent braking power after a limited braking interval with

full exhaust back pressure.

 The pressure-regulated EVB substantially reduces the

marked hysteresis of the torsion bar spring flap (different

braking power when braking with increasing or reducing

 The diagnostic possibilities very much simplify checking the

functionality of the exhaust brake.

Functional schematic of electronically controlled exhaust

flap

1 Compressed air

2 Pulse-width-modulated actuator signal (+)

3 Pulse-width-modulated actuator signal (-)

4 Operating cylinder

5 Brake flap

6 Exhaust back pressure sensor

7 Proportional action valve

8 Speed signal

9 Engine speed

10 Exhaust back pressure

A Vehicle management computer

engine speed).

 The torsion bar spring in the brake flap is omitted, so the

brake flap is less susceptible to external influence.

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B Input signals 8/9

C Output signals 2/3

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EXHAUST / INTAKE SYSTEM

Exhaust system

Engines with 4V cylinder heads have three-part exhaust

manifolds. The manifold parts are sealed and joined by metal

rings.

NOTE:

When assembling the exhaust manifold seal:

1. Attach rim to manifold.

2. Manifold seal marked TOP.

3. Tightening torque of screws 60 Nm

+5 Nm

+ 90°

+10°

.

Intake system

In TGA vehicles with the short lefthand drive cab, there is an

intake muffler instead of the boost pressure connecting pipe.

The muffler eliminates the disturbing bubbling sounds.

A) Output muffler (direction of intercooler)

B) Input muffler (direction of turbo charger)

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EXHAUST TURBO CHARGER WITH WASTE GATE (530 HP ENGINE)

Venting control

Waste gate

The buildup of boost pressure and thus the dynamic in the

lowest range of speed are improved without exceeding the

speed limit of the turbo charger.

In this way it is possible to create an ample torque curve towards

low speeds without disadvantages in the upper speed and load

range in terms of gas emissions and peak pressure.

Waste gate means full torque from low speed and constant

boost pressure over the entire range of speed.

The purpose of the waste gate is to regulate and limit the boost

pressure generated by the turbo charger within a tolerance

band.

If a defined boost pressure is exceeded, the valve opens and

conducts part of the exhaust gas mass flow past the turbine.

This produces less power because of the reduced mass flow.

The compressor power reduces to the same degree, the boost

pressure falls to the defined value.

This regulating function is repeated for each change of engine

power.

The waste gate is adjusted by the producer and must not be

altered.

There is no extra maintenance for the turbo charger apart from

regular engine inspection.

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BOOST PRESSURE

Minimum boost pressure on full load

When determining the boost pressure, remember that the

The maximum permissible boost pressure is also stated for

measurement must be made after the intercooler and on

engines fitted with a turbo charger with waste gate.

constant full load.

Minimum boost pressure

Engine type Boost pressure after intercooler at 1900 1/min 1800 1/min 1600 1/min 1400 1 min 1200 1 min

 D 2876 LF 12 1750mbar 1900 mbar 1800 mbar 1600 mbar 1280 mbar

 D 2876 LF 13 1720mbar 1850 mbar 1850 mbar 1760 mbar 1360 mbar

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TURBO CHARGER

Make the following checks before replacing the turbo charger

IF OIL CONSUMPTION IS TOO HIGH:

 Check the air filter for soiling.

 Check the intake line to see if its cross-section is reduced

(e.g. through damage, soiling).

 Both cause higher oil consumption because of the increased

underpressure.

IF ENGINE POWER IS UNSATISFACTORY:

The requirement for satisfactory engine power is proper setting

 the air filter for soiling,

 the intake system for reduced cross-section of the lines and

leaks,

 the exhaust system for damage.

If no possible cause is detected by these checks, check the

turbo charger for

 coking up in the turbine, which makes the rotor sluggish (can

be remedied by axial movement),

of

 valve play,

 heavy soiling in the compressor,

 damage through foreign matter,

 the exhaust brake must open fully.

Also check

 boost pressure,

 compression pressure,

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 rubbing of the turbine rotor on the case.

If there is heavy soiling, clean the compressor and check the

bearing clearance.

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INTERCOOLER

The intercooler cools the increased temperature of the

The intercooler works with air cooling.

boost air.

The result of this is low boost air temperature.

Whereas greater boost air density results in higher power or

lower fuel consumption, lower boost air temperature reduces the

thermal stress on the engine, the exhaust temperature and thus

NOx emission.

The socalled air/air cooler has become popular in the

commercial vehicle sector.

The intercooler is always located between the charger and the

engine.

Check of boost pressure

The requirement is a warmed up engine. The boost pressure

stated for certain speeds is created at full load after approx. 3

minutes at constant speed.

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EXHAUST GAS RECIRCULATION (EGR)

D 2876 LF 12/13 Euro 3 engines are also fitted with externally

Further downstream there is a peak pressure valve for each

regulated exhaust gas recirculation for operating economies,

high energy utilization and low fuel consumption.

In EGR, part of the burnt gases is recirculated to the cylinder

filling (approx. 10%). This produces lower combustion

temperatures and thus fewer NOx emissions. Fuel consumption

can be reduced by appropriate matching of the commencement

of injection. In EGR, the exhaust gas is taken from both channels

of the exhaust manifold.

The hot exhaust gases are fed to the EGR module through

corrugated tubing compensators. In the EGR module the gases,

initially still in two channels, flow through a high-grade steel,

bundled tube heat exchanger. In the EGR cooler the exhaust

gas is cooled by water from approx. 700°C down to less than

channel that only allows the pressure peaks of the exhaust gas

to pass and cuts off in the reverse direction. This is necessary

because of the positive flushing gradient at higher engine loads.

The exhaust gas channels are combined after the peak pressure

valves. A shutoff flap is provided here to close the EGR in

certain engine operating states (e.g. exhaust brake). This flap is

actuated by a compressed air cylinder, in which the solenoid

valve and limit sensing are integrated. After the shutoff flap, the

cooled exhaust gas, now in one channel, is fed across a

corrugated tubing compensator to the intake air in the air

distributor pipe.

A Air filter

B Intercooler

C Intake manifold, engine

D EGR cooler

200°C.

E Peak pressure valves

F Electropneumatically controlled shutoff flap

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EGR actuating flap remains closed.

The EGR is cut out when: This prevents:

Boost air temperature < 10°C Sulphurous acids in cold intake air through condensation

Boost air temperature > 70°C Overheating of boost air by recirculated exhaust gas

Water temperature > 95°C Overheating of engine

Dynamic engine mode Poor engine performance

Exhaust brake active Reduced exhaust brake power

Setting of EGR compressed air cylinder

Set the ball head of the compressed air cylinder so that it is

hooked in when the shutoff flap is closed with approx. 4 mm

initial tension.

Exhaust gas recirculation consists of the following parts:

A Input cylinder 4 to 6

E EGR flap

 Compressed air cylinder to actuate shutoff flap

 Solenoid valve to drive cylinder

 Reed contact for feedback from piston rod to EDC control unit

- Pin 1 (3100) – pin 2 (60367) < 1 

- Pin 3 (60031) – pin 4 (60153) 34 to 47 

B Input cylinder 1 to 3

C Exhaust gas lines (high-quality steel)

D Peak pressure valves

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Pressure in exhaust manifold

In the exhaust manifold there are pressure peaks when exhausting.

Only these pressure peaks can be added to new combustion.

The pressure peaks are higher than the maximum boost pressure.

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V-BELT DRIVE

The V-belt is no longer driven by a pulley from the crank shaft. A

V-BELT TENSIONING DEVICE

second gear wheel is driven by the driven wheel of the cam

shaft. This wheel sits on a shaft that is mounted in the

intermediate case. On the opposite side there is a multi-groove

drive wheel for the poly V-belt to drive the alternator. The fan

with electric coupling is mounted on this drive wheel.

The two bearings are lubricated by oil slung up from the driven

wheel of the cam shaft.

V-BELT

No conventional V-belt is used but a poly V-belt. This is very

flexible and a belt pulley is also possible on the back. Higher

pretensioning is necessary than for narrow V-belts.

The automatic V-belt tensioning device consists of a spring

damper element. This needs a basic setting with a gauge

80.99607-6014 to 95.5 mm.

NOTE:

To prevent damage to the damper unit, it is important to slowly

slacken it. Under no circumstances let the damper whip back,

because this will damage the overflow valves in the damper.

Only perform a sight check of the damper for oil leaks while it is

slackened. Make sure you fit the damper the right way round, i.e.

with UP or the arrow pointing upwards.

Removal

Hold the arrester with a size 19 box-end spanner. Then undo the

two retaining screws. Keep holding the arrester while doing this

and slowly slacken it.

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Assembly

Put the poly V-belt in place. Tighten the arrester (A) until you

can push on the gauge 80.99607-6014 (B). Tighten the two

retaining screws to the appropriate torque.

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ADJUSTABLE FAN BEARING

The adjustable fan bearing (Euro 3) differs from the non-

Fitting with basic setting

adjustable one through the separate retaining ring. A basic

setting is necessary for the adjustable fan bearing (tooth surface

play).

 Using a measuring tape, make two marks 7 mm apart on the

top of the fan bearing rim.

 Slide in the oiled fan bearing, with new O-rings, by a slight

turning movement.

 Tighten the flange so that the fan bearing can still be turned

by hand.

 Turn the fan bearing counterclockwise manually (not with a

tool) and mark on the facing case.

 Turn the fan bearing clockwise by the 7 mm and tighten the

flange to the prescribed torque.

1) Turn manually counterclockwise to the stop.

2) Turn back clockwise by 7 mm.

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ELECTRICALLY CONTROLLED FAN COUPLING

Fan with visco fan coupling

Technical data

The gear-driven, 9-vane jacket fan with diameter of 670 mm is

provided with an electrically driven visco fan coupling. To

prevent accentuation of the noise of the air compressor by the

fan, the latter is isolated from structure-borne sound.

A voltage signal from the vehicle management computer drives a

solenoid valve in the fan. The solenoid valve of the fan coupling

is controlled by the FFR.

The fan speed is governed by:

 Coolant temperature

 Outside temperature

 Boost air temperature (Euro 3)

 Settings from secondary retarder

Control ................................................................. 24 V from FFR

Drive speed n1 (fan shaft) .....................................engine speed

............................................................................+26% (I = 1.26)

Fan speed switched ....................................... approx. 88% of n1

Fan idling speed

at engine limit speed.......................................500 to 1000 1/min

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H

A

I

B

J

C

K

L

D

E

F

M

N

G

T2876001

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Check of fan coupling

Static check

This check only tells you about the functioning of the magnet.

Dynamic check

 Set the limit speed.

 When the magnet engages and disengages, you hear a low

clicking from the armature (or with MAN-cats II).

 FFR

 Visco fan controller

 Undo the connector (line 61304 to magnet coupling).

 The maximum fan speed must be reached after 2 min (engine

speed x fan transmission I = 1.26 minus slip approx. 12%).

The fan coupling has cut in.

 Replace the connector.

 Within 1 min the fan speed should have dropped to between

500 and 1000 rpm (idling speed). The fan coupling has cut

out.

Fan coupling without power  fan coupling switched

Fan coupling with power  fan coupling cut out

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ACCIDENT PREVENTION – CLEANLINESS OF COMMON RAIL

Caution

Caution

Risk of injury!
Jets of fuel can cut through the skin.
Atomization of the fuel produces a fire risk.

When the engine is running, never undo the screwed joints of
the high-pressure fuel side on the common rail system (injection
line from high-pressure pump to rail, on rail and on cylinder head
to injector).
Avoid standing close to the running engine.

Caution

Risk of injury!
When the engine is running, the lines are constantly under a
fuel pressure of up to 1600 bar.

Before undoing a screwed joint, wait at least 1 min for the
pressure to decrease.
It is possible to check the pressure decrease in the rail with
MAN-cats.

Risk of injury!
Wearers of a heart pacemaker must not go closer than
20 cm to the running engine.

Do not touch live parts on the electrical connection of the
injectors while the engine is running.

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