Remove/install engine with front axle carrier

AR01.10-P-2500RF

Remove/install engine with front axle carrier

09.08.2019

Engine

651 in model 253

Modification notes

05.09.2017

Operation steps revised.

Operation steps 1 to 60.

1

Refrigerant lines

7

Cold air intake

10

Coolant hose

3

Electrical connector

8

Retaining clips

11

Coolant hose

6

Coolant vent line

9

Coolant hose

12

Vacuum line

30

Bolts

31

Bracket

22

Screw

23

Ground cable

24

Fuel hose

25

Fuel hose

27

Diagonal strut

28

Diagonal strut

29

Steering coupling

 Danger

Risk of explosion caused by fuel igniting, risk of poisoning caused by inhaling and swallowing fuel as well as risk of injury to eyes and skin caused by contactwith fuel.

No fires, sparks, open flames or smoking. Pour fuels into suitable and appropriately marked containers only.
Wear protective clothing when handling fuel.

AS47.00-Z-0001-01A

 Danger

Risk of death caused by vehicle slipping or toppling off of the lifting platform.

Align vehicle between vehicle lift columns and position the four support plates at the vehicle lift support points specified by the vehicle manufacturer.

AS00.00-Z-0010-01A

 Warning

Risk of injury. Skin or eye injuries may result when handling hot or glowing objects.

Wear protective gloves, protective clothing and safety glasses, if necessary.

AS00.00-Z-0002-01A

 Caution

Risk of injury caused by scraping or cutting body parts on sharp vehicle parts

Always wear protective gloves when working on or near sharp and non-deburred vehicle parts.
Deburr repair panels.

AS00.00-Z-0017-01A

Topical note

Notes on bolted connections with self tapping screws

AH00.00-P-0007-01SF

Topical note

Notes on self-locking nuts and bolts

AH00.00-N-0001-01A

Topical note

Information on preventing damage to electronic components due to electrostatic discharge

AH54.00-P-0001-01A

Topical note

Notes on avoiding damage through contamination and foreign objects

AH00.00-P-5000-01A

Note on calculation of tightening torque when using insertion or socket tools with various effective lengths

AH00.00-P-0015-01CW

Use of engine no. when installing reconditioned engines and factory-new replacement engines or crankcases

AH01.10-P-0001-01A

Notes on automatic transmission

Engine 651 in model 253 with transmission 725

AH27.19-P-0001-01NKB

Notes on repair work on suspension components

AH00.00-P-0100-01A

Notes on AIRmatic

Engine 651 in model 253
with code 489 (AIR BODY CONTROL)

AH32.22-P-1000-02LW

 

Remove/install

1

Secure vehicle against rolling away, shift transmission to neutral position, and release parking brake.

2

Deactivate easy entry and exit feature.



Engine 651 in model 253
with code 275 (Memory Package (driver's seat, steering column and mirror))

AD00.00-P-2000-04B

3

Move front wheels to straight-ahead position and fix steering wheel in place with holding device.

 Retainer device

*129589012100

4

Secure vehicle on vehicle lift.

AR00.60-P-0100CW

5

Relieve pressure in the air suspension with the diagnostic system.

Engine 651 in model 253
with code M005 (Vehicles with 4MATIC/all-wheel drive)



AD00.00-P-2000-04B

6

Discharge air conditioning system.

AR83.30-P-1760LW

7

Disconnect refrigerant lines (1) from the separating points and seal openings with suitable stop plugs.



Compressor oils (specification 362.1)

BB00.40-P-0362-01A

 Installation:
Use new sealing rings. Wet all threads and sealing rings with compressor oil.
Refrigerant can otherwise escape.

 Nut, refrigerant line to connecting point

*BA83.30-P-1004-01Q

 Record plug

*129589009100

8

Remove lower engine compartment paneling.

AR61.20-P-1105LW

 Installation: Only install engine compartment paneling after leak test.

9

Drain coolant at radiator.

AR20.00-P-1142LW

10

Drain coolant from low-temperature circuit.

AR09.41-P-6834LW

11

Disconnect ground line from battery.

AR54.10-P-0003LW

12

Release and disconnect electrical connectors from the CDI control unit of the diesel injection system control unit (N3/9).

AR07.08-P-7008OLD

13

Remove air filter housing with CDI control unit of the diesel injection system control unit (N3/9).

AR09.10-P-1150OLD

14

Release and disconnect electrical connection (3).

15

Remove engine wiring harness and place to one side.

AR01.00-P-2410-03RF

 Engine wiring harness ground connection to cylinder head cover

*BA00.19-P-1038-01E

16

Remove coolant vent line from the expansion reservoir, cooler, and engine.

AR20.20-P-7441-01RQ

17

Remove coolant vent line (6) from the low-temperature circuit coolant expansion reservoir.

AR20.20-P-7441-01RQ

18

Remove cold air intake (7).

19

Remove retaining clips (8) from the cooler.

20

Remove coolant hose (9) from the engine.

21

Remove coolant hose (10) from the cooler.

22

Remove coolant hose (11) from the firewall.

AR20.20-P-7441-01RQ

23

Remove vacuum line (12).

24

Release and disconnect electrical connectors from the electric power steering actuator motor and unclip wiring harness of the electric power steering from the front axle carrier.

25

Remove front bumper.

AR88.20-P-2000LW

26

Remove screws (30) and remove brackets (31) from the left and right damping.

 Bolt, strut to soundproofing

*BA62.30-P-1004-01H

27

Remove top coolant hose from the oil cooler.

28

Remove coolant hoses from the cooler and from the low-temperature circuit cooler.

AR20.20-P-7441-01RQ

29

Unclip oil cooler from the fan unit and secure against falling down with connected lines at the engine.

30

Remove heating circuit pump from the bracket of the front axle carrier and fasten to the vehicle with connected lines.

31

Remove SCR catalytic converter.

Engine 651 in model 253
with code U77 (Diesel Emission control BLUETEC (SCR))

AR14.40-P-2006LWB

32

To relieve overpressure in the fuel tank, briefly open the fuel filler cap.

33

Mark fuel hoses (24, 25) relative to the fuel pipes.

34

Disconnect fuel hoses (24, 25) from the fuel pipes and seal openings with suitable stop plugs.

 Installation: Replace clamps.

 Installation: Observe markings.

 Pliers for click clamps

*171589003700

 Record plug

*129589009100

35

Remove propeller shaft from the output flange and secure on the vehicle against falling down.

AR41.10-P-0050LWX

36

Release rear section of the front fender liner in the area of the diagonal struts (27, 28).

37

Remove screws of the diagonal struts (27, 28) from the torsion bar mount shells.

 Bolt, front diagonal strut to front axle carrier/torsion bar bearing shell/radiator mounting console

*BA61.10-P-1006-01L

38

Loosen screws of the diagonal struts (27, 28) from the longitudinal members.

 Bolt, front diagonal strut to longitudinal member

*BA61.10-P-1007-01L

 Engine mount wrench set

*001589011600

39

Disconnect steering coupling (29) from the steering shaft.

AR46.10-P-8000LW


Do not twist the steering wheel after the steering coupling (29) has been removed.
Otherwise the clock spring contact will be destroyed.

40

Remove brake calipers with brakepads and attach to the vehicle with the brake hose attached and free of tension.

Model 253 with engine 6511-piston floating caliper brake

AR42.10-P-0070LW

Model 253 with engine 6514-piston fixed-caliper brake

AR42.10-P-0070LWA


Do not kink, crush or subject lines to tension.
This leads to line damage.

41

Release and disconnect electrical connectors of the engine mounts in the front wheel well.

42

Remove screw (22) and remove ground line (23).

43

Remove rpm sensors from steering knuckles.

AR42.30-P-0712LW

44

Unclip electric lines from the spring links and steering knuckles.

45

Remove steering knuckles from the top transverse control arms.

AR33.25-P-0400LW


Secure steering knuckle.
Otherwise the joints will be damaged.

46

Detach suspension struts from spring links.

Model 253 with engine 651
except code 489 (AIR BODY CONTROL)

AR32.25-P-1017LW

Model 253 with engine 651
with code 489 (AIR BODY CONTROL)

AR32.25-P-1017LWL

47

Fasten radiator package to the reinforcement using suitable means and secure against falling down.

48

Remove screw and remove bottom bracket of the radiator package from the damping.

49

Remove bottom refrigerant line from the condenser and seal openings with suitable stop plugs.



Compressor oils (specification 362.1)

BB00.40-P-0362-01A

 Installation:
Use new sealing rings. Wet all threads and sealing rings with compressor oil.
Refrigerant can otherwise escape.

 Nut, line to condenser

*BA83.30-P-1002-01Q

 Record plug

*129589009100

50

Support front axle carrier and use suitable means to secure entire engine transmission unit against slipping and falling down.



000 588 03 62 00 Lifting platform

WS01.00-P-0091A

51

Remove rear engine carrier from the frame floor assembly.

AR22.10-P-4360LWB

 The rear engine support remains on the transmission.

52

Remove screws of the front axle carrier from the longitudinal members.

 Bolt, front axle carrier to longitudinal member

*BA33.10-P-1001-01Q

53

Lower engine transmission unit with front axle carrier and radiator package.



000 588 03 62 00 Lifting platform

WS01.00-P-0091A


Ensure that engine and its detachable parts are not in contact with body panels or major assemblies.
Do not kink, crush or subject lines to tension.
This leads to component and/or line damage.

 Aid of helper required.

54

Install in the reverse order.

Concluding tasks

55

Check engine oil level and correct if necessary.



AP18.00-P-1811MP

56

Correct transmission oil level.

Engine 651 in model 253 with transmission 725

AR27.00-P-0270EWN

57

Check engine cooling system for leak tightness.

AR20.00-P-1010LW

58

Check low-temperature circuit for leak tightness.

AR09.41-P-1010LW

59

Perform chassis alignment.

AR40.20-P-0200LW

 Warning

Risk of burn injuries, suffocation and poisoning when working on the exhaust system and the components connected to it. Risk of suffocation and risk of poisoning caused by inhalation of gaseous and solid components of the exhaust. Risk of poisoning caused by skin contact with solid components of the exhaust.

Wear protective clothing and safety glasses. Use the extraction system. Move people out of the hazard area.

AS49.00-Z-0001-01A

 Warning

Risk of accident from vehicle starting off by itself when engine running. Risk of injury (bruises and burns) resulting from working on the engine while it is being started or when it is running.

Secure vehicle to prevent it from starting off by itself. Wear closed and snug-fitting work clothes. Do not touch hot or rotating parts.

AS00.00-Z-0005-01A

60

Perform engine test run; in doing so, check the engine and major assemblies for proper operation and leak tightness.

 Ground points

Number

Designation

Model 253 (except 253.99)

BA00.19-P-1038-01E

Engine wiring harness ground connection to cylinder head cover

Nm

9

 Front axle carrier

Number

Designation

Model 253

BA33.10-P-1001-01Q

Bolt, front axle carrier to longitudinal member

Nm

180

 Frame floor assembly

Number

Designation

Model 253

BA61.10-P-1006-01L

Bolt, front diagonal strut to front axle carrier/torsion bar bearing shell/radiator mounting console

Nm

50

 Frame floor assembly

Number

Designation

Model 253

BA61.10-P-1007-01L

Bolt, front diagonal strut to longitudinal member

Nm

50

 Cross member and front reinforcement

Number

Designation

Model 253

BA62.30-P-1004-01H

Bolt, strut to soundproofing

M8

Nm

20

 Air conditioning

Number

Designation

Model 253

BA83.30-P-1002-01Q

Nut, line to condenser

Nm

12

 Air conditioning

Number

Designation

Model 253

BA83.30-P-1004-01Q

Nut, refrigerant line to connecting point

Nm

12