Remove/install chain tensioner

AR05.10-P-7800MSC

Remove/install chain tensioner

18.12.2018

Engine

256.9 in model 167

6

Bracket

7

Bolts

8

Heat shield

9

Bolts

1

Cover

2

Bolts

4

Chain tensioner

5

Sealing ring

 Caution

Risk of injury to skin and eyes due to handling of engine oil. Risk of poisoning caused by swallowing engine oil

Wear protective gloves, protective clothing and safety glasses.
Do not fill engine oil into beverage containers.

AS18.00-Z-0001-01A

 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 avoiding damage through contamination and foreign objects

AH00.00-P-5000-01A

 

Remove/install

1

Remove exhaust gas aftertreatment unit.

AR49.20-P-1500MSC

2

Remove screws (9) and remove heat shield (8).

 M61

*BA00.10-P-1002-04A

 Bolt, heat shield to timing case

*BA22.10-P-1005-02A

 Bolt, heat shield to crankcase

*BA22.10-P-1004-02A

3

Remove bracket of 48 V wiring harness from bracket (6) and place to one side.

 M61

*BA00.10-P-1002-04A

4

Remove screws (7) and remove bracket (6).

 Nut/bolt, holder for catalytic converter to crankcase

*BA49.10-P-1007-02P

5

Remove screws (2) and remove cap (1).

 Installation: Replace cap (1).

 Screw/bolt, chain tensioner housing cover to crankcase

*BA05.10-P-1006-01MRT

6

Remove chain tensioner (4) and collect escaping engine oil using a rag.

 Installation:
Only reuse chain tensioner (4) if it has had no noticeable problems in previous operation and no chain drive components have been replaced.
Engine damage will occur otherwise.

 Chain tensioner (4) is pretensioned via an internal spring and extends fully during removal.

 Installation: Replace sealing ring (5).

 Chain tensioner at crankcase

*BA05.10-P-1003-01MRT



Check

7

Check whether the chain tensioner (4) is fully extended.

If chain tensioner (4) has not fully extended,



replace chain tensioner (4).

8

Install in the reverse order.

9

Check and correct engine oil level.



AP18.00-P-1812SKI

 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

 Camshaft positioner, timing chain drive

Number

Designation

Engine 256.9

BA05.10-P-1003-01MRT

Chain tensioner at crankcase

Nm

80

 Camshaft positioner, timing chain drive

Number

Designation

Engine 256.9

BA05.10-P-1006-01MRT

Screw/bolt, chain tensioner housing cover to crankcase

Nm

8

 Engine support (engine side)

Number

Designation

Engine 256

BA22.10-P-1004-02A

Bolt, heat shield to crankcase

Nm

8

 Engine support (engine side)

Number

Designation

Engine 256

BA22.10-P-1005-02A

Bolt, heat shield to timing case

Nm

8

 Exhaust system

Number

Designation

Model 167 with engine 256

BA49.10-P-1007-02P

Nut/bolt, holder for catalytic converter to crankcase

Nm

20