Remove/install primary drive timing chain

AR05.10-P-7612LFB

Remove/install primary drive timing chain

14.03.2018

Engine

157, 278 in model 217

Engine

157, 278 in model 222

05L

Left secondary chain

05R

Right secondary chain

3

Primary chain markings

4M

Punch marks

6

Primary chain drive timing chain

7

Intermediate gear

8AR

Right exhaust camshaft adjuster

8EL

Left intake camshaft adjuster

05L

Left secondary chain

8AR

Right exhaust camshaft adjuster

05R

Right secondary chain

8EL

Left intake camshaft adjuster

01

Cylinder head contact surfaces

1AR

Segmented disc for right exhaust camshaft

05L

Left secondary chain

1EL

Segmented disc for left intake camshaft

05R

Right secondary chain

1ER

Segmented disc for right intake camshaft

1AL

Segmented disc for left exhaust camshaft

 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

 Warning

Risk of injury. Moving parts can pinch, crush or, in extreme cases even sever extremities.

No parts of the body or limbs should be within the operating area of mechanical components when moving components.

AS00.00-Z-0009-01A

 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

Topical note

Notes on avoiding damage through contamination and foreign objects

AH00.00-P-5000-01A

 

Remove/install

1

Remove cylinder head covers

Left cylinder head cover
Engine 157, 278 in model 222

AR01.20-P-5013LFB

Right cylinder head coverEngine 157, 278 in model 222

AR01.20-P-5012LFB

 Installation: Before installing the cylinder head covers, check the engine timing and correct if necessary.

2

Remove timing case cover

AR01.40-P-8000LFB

 Installation: Before installing the timing case cover, check the engine timing and correct if necessary.

3.1

Remove camshafts

For missing color codings on the segmented discs (1AL, 1AR, 1EL, 1ER).

AR05.20-P-6992LFB

3.2

Remove right exhaust camshaft adjuster (8AR) and left intake camshaft adjuster (8EL)

For existing color codings on the segmented discs (1AL, 1AR, 1EL, 1ER).

AR05.20-P-7201LFB

4

Mark segmented discs (1AL, 1AR, 1EL, 1ER) of the camshaft for the cylinder head contact surfaces (01) in color (arrows)

For missing color codings on the segmented discs (1AL, 1AR, 1EL, 1ER).

AR05.20-P-6292-04MM

 Template

*278589002300

5

Remove oil pump

AR18.10-P-6020LFB

6

Remove chain tensioner for primary chain drive timing chain (6)

 Installation: Replace chain tensioner for primary chain drive timing chain (6).

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

*BA05.10-P-1001-01R

7.1

Remove both cylinder heads

When replacing primary chain drive timing chain (6), left secondary chain (05L) and right secondary chain (05R) with slide and tensioning rails.

Right cylinder headEngine 157, 278 in model 222

AR01.30-P-5780LFB

Left cylinder headEngine 157, 278 in model 222

AR01.30-P-5770LFB

7.2

Disconnect left secondary chain (05L) and right secondary chain (05R)

When replacing the left secondary chain (05L) and right secondary chain (05R) without slide and tensioning rails.

Engine 278 in model 217
Engine 278 in model 222

AR05.10-P-7601LFB

 With timing chain stretch, replace the left secondary chain (05L), the right secondary chain (05R) and the primary chain drive timing chain (6).

8

Remove right secondary chain (05R) from intermediate gear (7)

9

Remove screw/bolt for intermediate gear (7) on cylinder crankcase

 Installation: Replace screw/bolt.

 Screw/bolt, journal for intermediate gear to cylinder crankcase

*BA05.10-P-1004-01R

10

Remove the intermediate gear (7) together with the crankshaft gear, timing chain primary chain drive (6) and left secondary chain (05L)

 Installation:
Mount the primary chain drive timing chain (6) in such a way that the primary chain markings, (3) and the punch marks (4M) on the intermediate gear (7) and crankshaft gear match.
Engine damage will occur otherwise.

 Installation: Install the intermediate gear (7) together with the primary chain drive timing chain (6) and left secondary chain (05L).

 A new primary chain drive timing chain (6), the left secondary chain (05L) and right secondary chain (05R) are optionally delivered with color codings or copper links.

 Installation: Replace intermediate gear (7) with journals.

11

Install in the reverse order



Check

12

Check basic position of camshafts, adjust if necessary

AR05.20-P-6010LFB

 Before installing the cylinder head covers and timing case cover, check the engine timing and correct if necessary.

 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

13

Carry out an engine test run, checking the engine for proper operation and leaktightness

 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

 Timing chain, chain tensioner

Number

Designation

Engine 157

Engine 278

BA05.10-P-1004-01R

Screw/bolt, journal for intermediate gear to cylinder crankcase

M10

Nm

55

55