Remove/install engine with front axle carrier

AR01.10-P-2500RFB

Remove/install engine with front axle carrier

06.12.2019

Engine

274.9 in model 253

with code M005 (Vehicles with 4MATIC/all-wheel drive)

Modification notes

07.09.2017

Operation steps revised.

Operation steps 1 to 62.

1

Refrigerant lines

4

Coolant vent line

10

Purge line

2

Refrigerant line

5

Coolant hose

11

Vacuum line

3

Coolant hose

7

Coolant hose

30

Bolts

31

Bracket

22

Fuel hose

23

Steering coupling

25

Diagonal struts

26

High-voltage distributor

28

Attachment point

29

Attachment point

32

High-voltage line

33

High-voltage line

 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

 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

 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

 Danger

Risk of death when working on component parts and systems with U >= 30 V alternating voltage (AC) or U >= 60 V direct voltage (DC)

Do not touch damaged or defective live component parts and lines or non-insulated electrical connections and lines.Engine 274.9 in model 253.354/954
with code M005 (Vehicles with 4MATIC/all-wheel drive)

AS00.00-Z-0035-01A

 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

Topical note

Notes on self-locking nuts and bolts

AH00.00-N-0001-01A

Topical note

Notes on bolted connections with self tapping screws

AH00.00-P-0007-01SF

Topical note

General information on handling vehicles with high-voltage on-board electrical system and/or lithium-ion battery and/or gaseous-fuel drive system

AH00.00-Z-0300-01A

Topical note

Notes on avoiding damage through contamination and foreign objects

AH00.00-P-5000-01A

Topical note

Information on preventing damage to electronic components due to electrostatic discharge

AH54.00-P-0001-01A

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

AH00.00-P-0015-01CW

General information on work on gasoline direct injection system

AH07.00-P-2000-01A

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

AH01.10-P-0001-01A

Notes on repair work on suspension components

AH00.00-P-0100-01A

Notes on automatic transmission

Engine 274.9 in model 253 with transmission 724.2
with code M005 (Vehicles with 4MATIC/all-wheel drive)
Engine 274.9 in model 253 with transmission 725.0
with code M005 (Vehicles with 4MATIC/all-wheel drive)

AH27.19-P-0001-01NKB

Notes on AIRmatic

Engine 274.9 in model 253
with code 489 (AIR BODY CONTROL)
with code M005 (Vehicles with 4MATIC/all-wheel drive)

AH32.22-P-1000-02LW

 

Remove/install

1

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

2

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

 Retainer device

*129589012100

3

Deactivate easy entry and exit feature.

Engine 274.9 in model 253
with code 275 (Memory Package (driver's seat, steering column and mirror))
with code M005 (Vehicles with 4MATIC/all-wheel drive)

4

Perform power disconnect of high-voltage on-board electrical system.

Engine 274.9 in model 253.354/954
with code M005 (Vehicles with 4MATIC/all-wheel drive)

AR54.10-P-1150LVH

5

Clamp off ground line from the battery.

AR54.10-P-0003LW

6

Secure vehicle on vehicle lift.

AR00.60-P-0100CW

7

Relieve pressure in the air suspension with the diagnostic system.



Engine 274.9 in model 253
with code 489 (AIR BODY CONTROL)
with code M005 (Vehicles with 4MATIC/all-wheel drive)

AD00.00-P-2000-04B

8

Remove upper engine cover.

9

Remove lower engine compartment paneling.

AR61.20-P-1105LW

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

10

Remove fuel pressure via the service connection.

AR07.03-P-1460-01MR

 Dust cap at service connection

*BA07.03-P-1003-01F

 Pressure hose

*119589046300

11

Drain engine cooling system coolant.

AR20.00-P-1142LW

12

Drain off low-temperature circuit coolant.

AR09.41-P-6834LW

13

Discharge air conditioning system.

AR83.30-P-1760LW

14

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

15

Place refrigerant line (2) to one side.

16

Remove engine air intake duct upstream of air filter housing.

17

Disconnect engine wiring harness and place to one side.

Engine 274.9 in model 253.354/954 with transmission 724.2
with code M005 (Vehicles with 4MATIC/all-wheel drive)

AR15.18-P-1000-05MRB

Engine 274.9 in model 253 with transmission 716.7
with code M005 (Vehicles with 4MATIC/all-wheel drive)
Engine 274.9 in model 253 with transmission 725.0
with code M005 (Vehicles with 4MATIC/all-wheel drive)

AR15.18-P-1000-05MRC

 Nut, positive line to busbar on firewall

*BA54.18-P-1001-02C

 Nut, ground line to pin/underfloor

*BA00.19-P-1043-01E

 M61

*BA00.10-P-1002-04A

18

Remove coolant vent line (4) from cylinder head cover and coolant pipe.

 Hose clamp pliers

*003589033700

19

Remove coolant hose (3) from oil cooler.

AR20.20-P-7441-01RQ

20

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

21

Remove coolant hose (5) from engine.

 Hose clamp pliers

*003589033700

22

Remove coolant hose (7) from firewall.

AR20.20-P-7441-01RQ

23

Remove vacuum line (11) from firewall.

24

Release and disconnect purge line (10) and seal with suitable stop plugs.

 Record plug

*129589009100

25

Remove low-temperature circuit coolant line from charge air cooler.

AR20.20-P-7441-01RQ

26

Remove low-temperature circuit coolant line from the oil filter housing.

 M61

*BA00.10-P-1002-04A

27

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

AR20.20-P-7441-01RQ

28

Remove front bumper.

AR88.20-P-2000LW

29

Remove screws (30) and remove brackets (31).

 Bolt, strut to soundproofing

*BA62.30-P-1004-01H

30

Release and disconnect electrical connectors from electric power steering actuator motor.

AR46.20-P-0600LW

31

Unclip wiring harness of electric power steering from front axle carrier.

32

Remove center exhaust system.

AR49.10-P-7283RF

33

Remove fuel hose (22) from the engine and seal connections with suitable stop plugs.

 Installation: Replace hose clamps.

 Pliers for click clamps

*171589003700

 Record plug

*129589009100

34

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

AR41.10-P-0050LWX

35

Remove covers over the diagonal struts (25).

AR61.30-P-1001LW

36

Remove diagonal struts (25).

 Bolt, front diagonal strut to longitudinal member

*BA61.10-P-1007-01L

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

*BA61.10-P-1006-01L

 Engine mount wrench set

*001589011600

37

Remove rear screws of the longitudinal struts from the front axle carrier.

 Bolt, front diagonal strut to longitudinal member

*BA61.10-P-1007-01L

38

Remove steering coupling (23) from the steering shaft.


Do not turn steering wheel when steering coupling (23) is removed.
Otherwise the clock spring contact will be destroyed.

39.1

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

Engine 274.9 in model 253
with code M005 (Vehicles with 4MATIC/all-wheel drive)4-piston fixed-caliper brake

AR42.10-P-0070LWA

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

39.2

Detach brake calipers with brake caliper supports and fasten to vehicle free of tension with brake hose connected.

Engine 274.9 in model 253
with code M005 (Vehicles with 4MATIC/all-wheel drive)1-piston floating caliper brake

AR42.10-P-0070LW

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

40

Remove rpm sensors from steering knuckles.

AR42.30-P-0712LW

41

Unclip electric lines from spring links and steering knuckles.

42

Remove steering knuckles from the top transverse control arms and secure steering knuckles.

AR33.25-P-0400LW


Secure steering knuckle.
Joints will otherwise be damaged.

43

Remove suspension struts from spring links.

Engine 274.9 in model 253
with code 489 (AIR BODY CONTROL)
with code M005 (Vehicles with 4MATIC/all-wheel drive)

AR32.25-P-1017LWL

Engine 274.9 in model 253
with code M005 (Vehicles with 4MATIC/all-wheel drive)
except code 489 (AIR BODY CONTROL)

AR32.25-P-1017LW

44

Secure radiator package against falling down.

45

Remove bottom brackets of the radiator package from damping.

AR20.20-P-3865RF

46

Remove bottom refrigerant line from the condenser and seal connections 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

47

Remove mounting bolt of the bottom refrigerant line from the condenser.

 Installation: Replace mounting bolt.

 M61

*BA00.10-P-1002-04A

48

Remove high-voltage distributor (26) from the power electronics.

Engine 274.9 in model 253.354/954
with code M005 (Vehicles with 4MATIC/all-wheel drive)

AR08.20-P-0011LVH

49

Unclip attachment point (28).

Engine 274.9 in model 253.354/954
with code M005 (Vehicles with 4MATIC/all-wheel drive)

50

Remove high voltage line (32) from the frame floor assembly.

Engine 274.9 in model 253.354/954
with code M005 (Vehicles with 4MATIC/all-wheel drive)

51

Remove wiring of the rear high voltage line from the frame floor assembly and place to one side.

Engine 274.9 in model 253.354/954
with code M005 (Vehicles with 4MATIC/all-wheel drive)

 Remove rear high voltage line with engine and front axle carrier.

52

Unclip attachment point (29).

Engine 274.9 in model 253.354/954
with code M005 (Vehicles with 4MATIC/all-wheel drive)

53

Remove high voltage line (33) from the PTC heater.

Engine 274.9 in model 253.354/954
with code M005 (Vehicles with 4MATIC/all-wheel drive)

AR83.70-P-8001LWH

54

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



000 588 03 62 00 Lifting platform

WS01.00-P-0091A


Engine 274.9 in model 253.354/954
with code M005 (Vehicles with 4MATIC/all-wheel drive)
Carefully support the front axle carrier.
Otherwise damage will occur to the high-voltage distributor (26) and the high-voltage lines (32, 33).

55

Remove rear engine crossmember from the frame floor assembly.

AR22.10-P-4360LWB

 The rear engine crossmember remains on transmission.

56

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

 Bolt, front axle carrier to longitudinal member

*BA33.10-P-1001-01Q

57

Lower front axle carrier with the engine transmission unit.



000 588 03 62 00 Lifting platform

WS01.00-P-0091A


Ensure that engine does not touch the 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.

58

Install in the reverse order.

Concluding tasks

59

Check engine oil level and correct if necessary.



AP18.00-P-1811MP

60

Check oil level of the transmission and correct if necessary.

Engine 274.9 in model 253 with transmission 725.047
with code M005 (Vehicles with 4MATIC/all-wheel drive)

AR27.00-P-0270EWH

Engine 274.9 in model 253 with transmission 716.7
with code M005 (Vehicles with 4MATIC/all-wheel drive)

AR26.00-P-0200LW

Engine 274.9 in model 253 with transmission 724.2
with code M005 (Vehicles with 4MATIC/all-wheel drive)

AR27.00-P-0270EH

Engine 274.9 in model 253 with transmission 725.0 (except 725.047)
with code M005 (Vehicles with 4MATIC/all-wheel drive)

AR27.00-P-0270EWN

61

Perform wheel alignment measurement.

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

62

Perform an engine test run and check engine and transmission for proper operation and leak tightness while doing so.

 Metric screws/bolts and nuts as per MBN 10 105, 10 143

Number

Designation

8.8

10.9

BA00.10-P-1002-04A

M61

Nm

9

13

 Ground points

Number

Designation

Model 253 (except 253.99)

BA00.19-P-1043-01E

Nut, ground line to pin/underfloor

M8

Nm

20

 Injection nozzles, injection valves, lines

Number

Designation

Engine 274

BA07.03-P-1003-01F

Dust cap at service connection

Plastic

Nm

2

Metal

Nm

15

 Front axle carrier

Number

Designation

Model 253

BA33.10-P-1001-01Q

Bolt, front axle carrier to longitudinal member

Nm

180

 Wiring harness

Number

Designation

Model 253

BA54.18-P-1001-02C

Nut, positive line to busbar on firewall

M6

Nm

8

M8

Nm

16

 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