Remove/install the suspension strut

AR32.25-P-1017RT

Remove/install the suspension strut

29.04.2020

Model

251

Modification notes

29.04.2020

Air suspension pressure line to front air suspension

Model 251 with code 489 (AIRMATIC)

BA32.22-P-1004-03C

Shown on model 251 with engine 113, with AIRmatic (air suspension with level adjustment and adaptive damping system ADS), code 489

1

Clips

4

Partition wall between wheel well liners

2

Air conditioning air intake duct

5

Air spring compressed air line

3

Bolts

Shown on model 251 with engine 113, with AIRmatic (air suspension with level adjustment and adaptive damping system ADS), code 489

3

Bolts

8

Bolts

4

Partition wall between wheel well liners

9

Cover

6

Clip

10

Nuts

7

Air pipe

Shown on model 251 with engine 113, with AIRmatic (air suspension with level adjustment and adaptive damping system ADS), code 489

5

Air spring compressed air line

11

Bracket

10a

Nut

12

Pressure line union nut

Shown on model 251, with AIRmatic (air suspension with level adjustment and adaptive damping system ADS), code 489

13a

ADS plug

20

Nut

13b

ADS connector coupling

21

Threaded connection

14

Catch lug

22

Brake hose retaining clip

15

Upper transverse control arm

23

Cable tie

16

Nut

24

Brake hose

17

Steering knuckle

25

Brake hose bracket

18

Front suspension strut

26

ADS cable

19

Nut

Shown on model 251, with AIRmatic (air suspension with level adjustment and adaptive damping system ADS), code 489

13b

ADS connector coupling

18

Front suspension strut

16

Nut

26

ADS cable

17

Steering knuckle

 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

Notes on AIRmatic

AH32.22-P-1000-02RT

 

Remove/install

1

Open engine hood and raise to vertical position

AR88.40-P-1000RT

2

Jack up vehicle until the wheels are clear of the ground

Model 251
with code 489 (AIRMATIC)

AR00.60-P-1000RT

3

Fully deflate air springs at front using STAR DIAGNOSIS

Model 251
with code 489 (AIRMATIC)

 The vehicle may not be standing on its wheels.

4

Remove bolts (8), slide cover (9) towards the vehicle center (arrow A) and remove upwards

 Bolt, partition wall reinforcement between wheel well liners to fender

*BA62.30-P-1008-01E

5

Remove bolts (3), remove partition wall between wheel well liners (4)

AR62.30-P-2400RT

 Bolt, partition wall between wheel well liners to wheel well liners

*BA62.30-P-1007-01E

6

Unclip clamps (1) from the air inlet duct of the air conditioning (2), remove air inlet duct of the air conditioning (2) upwards

 If the right front suspension strut (18) is to be removed.

 Installation: Make sure that the guide at the bottom of the air conditioning air inlet duct (2) is seated correctly in its mounting.

 Installation: Make sure that the air spring compressed air line (5) is not jammed, pinched or kinked.

7

Unclip air pipe (7) from clip (6) and carefully move backward out of working area, behind brake fluid expansion reservoir

 If the left front suspension strut (18) is to be removed.

 Installation: Make sure that the air pipe (7) is seated correctly in its lower mounting.

8

Remove nuts (10) and nut (10a)

 Installation: The nut (10a) is already mounted, but still needs to be tightened.

 Nut for shock absorber on front end

*BA32.25-P-1001-01H

9.1

Remove bracket (11)

On vehicles with steel suspension on front axle

9.2

Fold bracket (11) far enough back and place on the spring tower so that the compressed air line union nut (12) is accessible

Model 251
with code 489 (AIRMATIC)

10

Unscrew compressed air line union nut (12), remove air spring compressed air line (5)

 Seal off the air spring compressed air line (5) using a blind plug for the duration of the repair work

If pressure line or its connection fittings are damaged:



Repair AIRmatic pressure line connection.

Model 251

Repairing AIRmatic pressure line connection

AR32.22-P-2001-02RT

Leak detection spray

*BR00.45-Z-1002-03A

Leakage detection spray for USA

*BR00.45-Z-1004-03A

 Model 251
except code 489 (AIRMATIC)
Model 251
with code 489 (AIRMATIC)Air suspension pressure line to front air suspension

*BA32.22-P-1004-03C

 Socket wrench bit

*211589000900

 Knife

*000589122800

11

Remove front wheel



AP40.10-P-4050RT

12

Lift vehicle to half height

AR00.60-P-1000RT

13

Remove fender liner front section in front fender

Model 251
with code 489 (AIRMATIC)

AR88.10-P-1310RT

14

Release ADS plug (13a) and detach from ADS connector coupling (13b)

Model 251
with code 489 (AIRMATIC)

15

Release catch lug (14) using a suitable tool (arrow B), detach ADS connector coupling (13b) from its fastening

Model 251
with code 489 (AIRMATIC)

16

Unclip the ADS cable (26) from the bracket in the wheel housing

Model 251
with code 489 (AIRMATIC)

17

Open bracket of brake hose (25), unclip brake hose (24)

On vehicles with 4MATIC.

18

Unscrew nut (19), remove link rod from front suspension strut (18)

 Nut, torsion bar linkage to front suspension strut

*BA32.20-P-1003-02L

19.1

Cut off cable ties (23), remove retaining clip of brake hose (22) from steering knuckle (17)

On vehicles with 4MATIC.

 Installation: Pay attention to installation position.

 Installation: Install a new cable tie (23).

 Pliers

*164589013700

19.2

Undo bracket of brake hose from front suspension strut (18); to do this, separate cable ties

On vehicles without 4MATIC.

20

Unscrew nut (20), detach tie rod using thrust piece and puller from steering knuckle (17)

On vehicles with 4MATIC.

 Self-locking nut, tie rod to steering knuckle

*BA46.40-P-1002-01L

 Thrust piece

*140589006300

 Puller

*140589093300

21

Unscrew nut (16), detach steering knuckle (17) using thrust piece and puller from top transverse control arm (15)

On vehicles with 4MATIC.

 Self-locking nut, upper ball joint out of upper transverse control arm to steering knuckle

*BA33.20-P-1001-01L

 Thrust piece

*140589006300

 Puller

*601589043300

22

Prop up lower transverse control arm

On vehicles with 4MATIC.

23

Pull axle shaft by tilting the steering knuckle (17) at its lower mounting out of the front axle gear, then place gearing of axle shaft onto a soft underlay

Model 251
with code 489 (AIRMATIC)

 The axle shaft should be horizontal, as it can then be pulled out of the front axle gear or pushed into it without any great effort.

24

Push front axle shaft out of front axle shaft flange, remove front axle shaft

On vehicles with steel suspension and 4MATIC.

AR33.30-P-0620RT

25

Unscrew nut of bolted connection (21), remove bolt

 Installation:
Perform final tightening when the vehicle is on the measuring platform or in the K0 position.
The rubber mounts must not be subjected to stress.

 Self-locking nut, shock absorber to wishbone

*BA32.25-P-1002-01H

26.1

Lower and remove support, tilt steering knuckle (17) as far down as possible and turn to rear, remove front suspension strut (18)

On vehicles with 4MATIC.

 Installation: Lower the vehicle far enough so that the spring tower is accessible from above. Insert the three studs at the upper end of the front suspension strut (18) through the holes in the spring tower, screw on nut (10a) as far as possible by hand. Raise the vehicle halfway again.

26.2

Pull the spring control arm downwards and remove the front suspension strut (18)

On vehicles without 4MATIC.

 An assistant is required.



Check

27.1

Check front suspension strut (18) and air spring for signs of damage and wear, if necessary replace front suspension strut (18)

Model 251
with code 489 (AIRMATIC)

27.2

Check front suspension strut (18) and all components for damage and wear, replace front suspension strut (18) or components if necessary

On vehicles with steel suspension.

28

Install in the reverse order



Check

29

Check AIRmatic for leaks

Model 251
with code 489 (AIRMATIC)

AR32.22-P-8100RT

30

Remove transport fastening or split ring below air spring bellows

Model 251
with code 489 (AIRMATIC)

31

Check headlamp adjustment, correct if necessary



AP82.10-P-8260RT

 Only for vehicles with steel suspension and only of the front suspension strut (18) or components of the front suspension strut (18) were replaced or if the vehicle level has been adjusted.

 Front axle torsion bar

Number

Designation

Model 251

BA32.20-P-1003-02L

Nut, torsion bar linkage to front suspension strut

Stage 1

Nm

100

Stage 2: Loosen

°

180

Stage 3

Nm

120

Stage 4

°

45

 Air suspension

Number

Designation

Model 251
with code 489 (AIRMATIC)

Model 251
except code 489 (AIRMATIC)

BA32.22-P-1004-03C

Air suspension pressure line to front air suspension

Nm

2

–

 Front axle shock absorber

Number

Designation

Model 251

BA32.25-P-1001-01H

Nut for shock absorber on front end

Stage 1

Nm

30

Stage 2

°

–180

Stage 3

Nm

27

 Front axle shock absorber

Number

Designation

Model 251

BA32.25-P-1002-01H

Self-locking nut, shock absorber to wishbone

Nm

265

 Wheel control, hub

Number

Designation

Model 251

BA33.20-P-1001-01L

Self-locking nut, upper ball joint out of upper transverse control arm to steering knuckle

Stage 1

Nm

20

Stage 2

°

90

 Tie rod

Number

Designation

Model 251

BA46.40-P-1002-01L

Self-locking nut, tie rod to steering knuckle

Stage 1

Nm

45

Stage 2

°

90

 Crossmember and front reinforcement

Number

Designation

Model 251

BA62.30-P-1007-01E

Bolt, partition wall between wheel well liners to wheel well liners

Nm

23

 Crossmember and front reinforcement

Number

Designation

Model 251

BA62.30-P-1008-01E

Bolt, partition wall reinforcement between wheel well liners to fender

Nm

10

Repair materials

Number

Designation

Order number

BR00.45-Z-1002-03A

Leak detection spray

Christof Fischer GmbH
www.kaeltefischer.de

BR00.45-Z-1004-03A

Leakage detection spray for USA

LIQUI MOLY
www.liqui-moly.com