Pic. 44. Cover of the camshaft drive mechanism with the indication of individual parts (the details of the lid are shown below): 1 - support pin of the generator drive belt tensioner; 2 - guide tube of the oil dipstick; 3 - pin-indicator of the TDC position; 4 - hole with a flange for a vacuum pump; 5 - TDC sensor mounting pin on four-cylinder engines; 6 - front cuff of the crankshaft; 7 — a bolt of fastening of a cover of the mechanism of a drive of a camshaft to the block of cylinders; 8 - pin-indicator of the TDC position; 9 - mounting sleeve for mounting the TDC sensor; 10 - front cuff of the crankshaft; 11 — a bolt of fastening of a cover of the mechanism of a drive of a camshaft to the block of cylinders; 12 - elastic spring washer; 13 - the place of installation of the front cuff of the crankshaft; 14 - cover of the camshaft drive mechanism; 15 — the landing plug of the pump of the hydraulic booster of a steering
The front crankshaft seal in the camshaft drive mechanism cover can be replaced on a vehicle-mounted engine if oil leaks are detected. You must first make sure that the oil is leaking through the front crankshaft seal, and not at the sealing point of the camshaft drive mechanism cover. If leaks are caused by depressurization of the cover, then it should be sealed again (see subsection 2.4 and the right side of Fig. 44).
Replacing the front crankshaft seal must be carried out as follows:
- remove the belt pulley, vibration damper and hub, following the instructions described in subsection 2.9;
Pic. 94. Removing the front crankshaft seal
- Using a screwdriver, pull out the cuff from the cover of the camshaft drive mechanism. In this case, a piece of thick rag should be placed under the screwdriver so as not to accidentally damage the cover or the crankshaft (pic. 94);
- thoroughly clean all parts, if necessary, remove burrs from the edges of the hole in the cover of the camshaft drive mechanism;
- if necessary, pull the cuff out of the cover using a screwdriver. You have to be very careful not to damage the lid in the process;
- carefully clean the sealing surfaces on the cylinder block and the cover of the camshaft drive mechanism;
- install a new crankshaft seal in the cover if the old one has been removed and needs to be replaced. The sealing lip of the new ring is offset by 3mm so it will not work on the crankshaft flange at the same point as the old ring. The space between the sealing lip and the dust lip should be filled with approx. 1 g of grease;
- apply sealant to the sealing surface of the cover and attach it to the cylinder block so that the dowel pins fit into the holes provided for them. Gently tap the top of the lid to make it fit snugly. At Mercedes-Benz workshops, a special clamping tool is used for this purpose;
- first tighten the two lower bolts, and then all the others with a torque of 10 Nm;
- then perform the work in the reverse order of removal.