![](https://www.mercedesman.ru/img/another/0130.jpg)
Pic. 95 b. Other parts of the camshaft drive mechanism: 1 - double-row drive chain; 2 - landing pin; 3 - thrust washer of the camshaft; 4 - camshaft; 5 - chain dampers; 6 - support pin of the chain damper on the cylinder block; 7 — a basic finger of a chain damper; 8 - landing pin; 9 - chain guide chute
![](https://www.mercedesman.ru/img/another/0131.jpg)
Pic. 96. Camshaft drive mechanism assembly: 1 - crankshaft sprocket; 2 - chain tension shoe; 3 - chain tensioner; 4 - camshaft drive sprocket; 5 - chain damper; 6 - fuel pump drive sprocket; 7 - chain damper; 8 — the lever of a tension of a chain of a drive of the oil pump; 9 - oil pump drive sprocket
![](https://www.mercedesman.ru/img/another/0132.jpg)
Pic. 101. Details of the camshaft drive chain damper: 1 - puller; 2 - threaded finger for dismantling; 3 - upper support pin; 4 - tension spring lever; 5 - chain tensioner; 6 - malleable bolt, 25 Nm + 90°; 7 - washer of the camshaft drive sprocket; 8 - camshaft drive sprocket; 9 - drive chain damper; 10 - camshaft; 11 - tension spring; 12 - lower support pin; 13 - guide belt pulley
The location of the dampers of the drive chain is shown in fig. 95 b and 96. When they are removed, a hammer is usually required to remove the support pins. An M6 thread is made on the inside of the support pin. With the help of a long M6 bolt, a bushing and a washer, this pin can be dismantled quite simply. On fig. 101 shows the front of the engine with some mounting and dismounting details. When dismantling the upper drive chain damper (in the cylinder head) must be done as follows (it is assumed that all parts that prevent access to dismantled parts have already been removed from the vehicle):
![](https://www.mercedesman.ru/img/another/0133.jpg)
Pic. 102. The location of the marks when the piston of the first cylinder is at TDC
- remove the cylinder head cover. Before the subsequent installation of the cylinder head cover, it is necessary to check the coincidence of the TDC marks on the flange 1 (pic. 102) and on cover 2 of the first camshaft bearing;
- remove the viscous coupling;
- completely remove the drive belt tensioner. Tension arm support pin 4 (see fig. 101) the belt tensioner is also a support for the drive chain damper;
- remove the camshaft drive sprocket, taking into account the instructions contained in the relevant chapter;
- remove chain tensioner (subsection 2.12.1);
![](https://www.mercedesman.ru/img/another/0134.jpg)
Pic. 103. Removing support pins (shown by arrows)
- dismantle both support pins of the chain guide using a knockout hammer and a threaded insert (pic. 103) and remove the chain guide from the top. In the absence of a knockout hammer, which happens quite often, a large washer is put on the support pin, and a sleeve on top. Then a long M6 bolt with a large washer is taken and screwed into the end of the support pin (the washer of the bolt must rest against the top edge of the bushing). When the bolt is subsequently tightened and the sleeve is clamped, the support pin will move out of the seat;
- before installing a new or previously used support pin, sealant must be applied to the flange;
- set the chain guide to the correct position and press the support pins into their seats. To prevent the chain damper from being squeezed out, a screwdriver is pressed against it to exert counterpressure. The guide groove in the support hole of the chain guide should sit on the protrusion of the upper support pin;
- further assembly is carried out in the reverse order to dismantling.
When installing the drive chain on the camshaft drive sprocket, pay attention to the paint marks.
![](https://www.mercedesman.ru/img/another/0135.jpg)
Pic. 104. Installing the chain guide (1) on two supporting fingers (2)
When replacing the lower chain resting bar, the location of which is shown in fig. 104, you must perform the following operations:
- disassemble the front of the car to provide access to all the necessary components and engine parts;
- remove the cover of the camshaft drive mechanism (see subsection 2.5.1);
![](https://www.mercedesman.ru/img/another/0136.jpg)
Pic. 105. Removing the tension lever
- retract the tensioning arm, together with the spring and the chain pressure shoe, until it can pass the chain and rest on the crankshaft, as shown in fig. 105;
- remove the tension lever from the support pin and carefully move it in the direction of weakening the spring, then, unhooking the spring, remove the lever along with it;
- remove the chain resting bar from both support pins;
![](https://www.mercedesman.ru/img/another/0137.jpg)
Pic. 106. The correct position of the tension lever of the oil pump drive chain with a pressure shoe
- insert a new chain guide onto the support pins. Engage the spring on the chain clamp shoe and tensioning arm and slide them together onto the support pins as shown in fig. 106;
- reinstall the camshaft drive mechanism cover following the instructions in subsection 2.5.