Timing Drive — General Information, Component Maintenance (Mercedes-Benz S-Class W140)

Contents: General information ↡ Servicing Timing Drive Components ↡

Note: The camshafts can be turned without the risk of valve-piston collision when the crankshaft is set to a position 30° before TDC of the piston of the first cylinder.

Note: The timing chain can be replaced without disassembling the engine. Using the tools listed below, the new chain can be connected to the old one, threaded around the sprockets and calked.

Attention! If assembled incorrectly, the valves may collide with the piston crowns!

General information

Timing drive components installation details (the gas distribution chain consists of 126 links)
1 - Timing marks for bringing the engine to the TDC position of the end of the compression stroke of the first cylinder; 2 - Rods with a diameter of 4 mm for fixing camshafts; 3 - When installing the chain, ensure that the camshaft adjuster tabs [3] are in the "retard" position.; 4 - Spring loaded tensioner nut; 5 - Pin; 6 - Spring; 7 - Plunger; 8 - Tensioner housing

To perform the procedures for removing and installing timing drive components, you will need the following special tools:

Camshaft Key (Type 1) - No.104589010100;
Camshaft Key (Type 2) - No.119589000100;
Crankshaft Hub/Pulley Puller - #103589003300;
Crankshaft Sprocket Puller - No.615589013300;
Flywheel/Drive Disc Locking Tool - #601589024000;
Bolts M6ґ90 for fixing the flywheel/drive disc locking tool;
Timing Chain Link Installation Tool - No.602589003900;
Set of stamp holders for installing timing chain links - No.112589096300;
Timing chain link puller (item 1) - No.602589023300;
Timing chain link puller (item 2) - No.602589056300;
Viscous coupling puller holder (series 129/140) - № 120589020100.

Please note the following points:

Unless otherwise stated, rotate the engine in the normal direction only;
Observe the specified tightening forces for fasteners;
If equipped, do not forget to mark the installation position of the CKP sensor before removal;
Do not turn the crankshaft by the camshaft sprockets or other timing drive sprockets;
Do not turn the crankshaft or camshafts with the timing chain removed.

Servicing Timing Drive Components

1. Disconnect the negative cable from the battery.

2. To make it easier to turn the engine, remove all spark plugs.

3. Insert the locking rods (2) with a diameter of 4 mm into the camshafts.

4. When installing the chain, ensure that the camshaft adjuster tabs (3) are in the "retard" position.

Publication taken from an online resource mercedesman.ru

Caution! If assembled incorrectly, the valves may collide with the piston crowns! 5. Before repairing the engine, loosen the tensioner nut by one turn.

6. Remove the tensioner assembly.

7. Fully loosen the tensioner spring nut (4).

8. Remove the pin (5) and spring (6).

9. Push the plunger (7) into the tensioner housing (8) in the direction indicated by the arrow.

10. Install the tensioner housing (8) and tighten it to 80 Nm.

11. Insert the plunger (7), install the spring (6) and pin (5).

12. Screw on the tensioner nut (4) and tighten it to 40 Nm.

13. Tighten the new intake camshaft adjuster bolt to 7 Nm (type A bolt with separate washer) or 5 Nm + 90° (type B bolt with built-in washer).