Remove/install chain tensioner

AR05.10-P-7800MT

Remove/install chain tensioner

19.10.2016

Engine

270 in model 117, 156, 176, 242, 246.2

1

Chain tensioner

 Danger !

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 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



Notes on avoiding damage through contamination and foreign objects

AH00.00-P-5000-01A

 

Remove/install

1

Remove rear lower engine compartment paneling

AR61.20-P-1105NKB

2

Remove cap of chain tensioner (1)

 Removal:
Penetrate the cap of chain tensioner (1) using a screwdriver and pry out.
Otherwise the timing case cover will be damaged and leaks occur.

 Installation: Replace cap of chain tensioner (1).

3

Remove chain tensioner (1)

 Screw/bolt, chain tensioner to bracket

*BA05.10-P-1001-01F



Check

4

Check chain tensioner (1)

 The chain tensioner (1) may only now be reset and reused if it did not have any noticeable problems during previous operation and all components of the chain drive do not show any signs of damage or no components of the chain drive were replaced.

 The chain tensioner (1) is pretensioned by an internal spring and moves out autonomously when being removed.

If the chain tensioner (1) does not move out on its own.



Replace chain tensioner (1).

5

Check the bracket of chain tensioner (1) for damage

For damage



Remove the timing case cover and remove the holder of the chain tensioner (1).

AR01.40-P-8000MT

 Screw/bolt, chain tensioner holder to crankcase

*BA05.10-P-1003-01F

6

Install in the reverse order

 Danger !

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

7

Carry out an engine test run and check engine for leaktightness

 Timing chain, chain tensioner

Number

Designation

Engine 270

BA05.10-P-1001-01F

Screw/bolt, chain tensioner to bracket

Nm

40

 Timing chain, chain tensioner

Number

Designation

Engine 270

BA05.10-P-1003-01F

Screw/bolt, chain tensioner holder to crankcase

Nm

20