Remove/install chain tensioner

AR05.10-P-7800LFB

Remove/install chain tensioner

26.05.2015

Engine

157, 278 in model 217

Engine

157, 278 in model 222

Shown on right chain tensioner

1

Chain tensioner

3

Screw/bolts

 

Remove/install

1.1

Rotate engine at crankshaft center bolt in direction of engine rotation to a 40°crank angle (CKA) after top dead center (TDC) on cylinder 1 (ignition TDC)

To remove the left chain tensioner (1)

AR05.10-P-7620-04MM


For a removed cylinder head cover the engine must not be turned without a mounted hold-down tool.
Damage to the camshafts will occur otherwise and on the cylinder head.

 Socket wrench bit

*001589650900

 Tie-down set

*276589014000

1.2

Rotate engine at crankshaft center bolt in direction of engine rotation to a 40°crank angle after top dead center (overlap TDC) on cylinder 1 (overlap TDC)

To remove the right chain tensioner (1)

AR05.10-P-7620-04MM


For a removed cylinder head cover the engine must not be turned without a mounted hold-down tool.
Damage to the camshafts will occur otherwise and on the cylinder head.

 Socket wrench bit

*001589650900

 Tie-down set

*276589014000

2

Remove oil filter housing

To remove the left chain tensioner (1)

AR18.20-P-3471LFB

3.1

Remove left front cover at cylinder head

To remove the left chain tensioner (1)

AR01.30-P-5711LFB

3.2

Remove right front cover at cylinder head

To remove the right chain tensioner (1)

AR01.30-P-5712LFB

4

Remove screw/bolts (3) of chain tensioner (1) and remove chain tensioner (1)

 Installation: After installation of the chain tensioner (1) the chain tensioner (1) is activated after pulling the securing drift. The chain tensioner (1) moves out and tensions the timing chain. The chain tensioner (1) should be replaced by a new part if this is not the case.

 Screw/bolt, chain tensioner to cylinder crankcase/cylinder head

*BA05.10-P-1001-01R



Check

5

Check chain tensioner (1) for proper operation

 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.

The chain tensioner (1) does not move out on its own:



Replace chain tensioner (1).

6

Reset chain tensioner (1)

When reusing the chain tensioner (1)

AR05.10-P-7800-03MM

Chain tensioner for right engine side basic dimension/extended dimension

*BE05.10-P-1002-02A

Chain tensioner for left engine side basic dimension/extended dimension

*BE05.10-P-1001-02A

7

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

8

Carry out an engine test run and check engine for leaktightness

Basic dimension/extended dimension

Number

Designation

Engine 152, 157, 278

BE05.10-P-1001-02A

Chain tensioner for left engine side basic dimension/extended dimension

mm

74,7

Basic dimension/extended dimension

Number

Designation

Engine 152, 157, 278

BE05.10-P-1002-02A

Chain tensioner for right engine side basic dimension/extended dimension

mm

78,7

 Timing chain, chain tensioner

Number

Designation

Engine 157

Engine 278

BA05.10-P-1001-01R

Screw/bolt, chain tensioner to cylinder crankcase/cylinder head

Nm

9

9