4.7. Camshafts

Removal
Take off a gear belt.
Remove a casing of a head of the block of cylinders.
Remove a camshaft pulley.

Camshaft of final valves
Unscrew a flange and a cover of the bearing of the distributor of ignition.

Fig. 3.2-39. Valvate mechanism: 1 – nuts, 15 N · m; 2 – camshaft bearing cover; 3 – chain; 4 – nut, 15 N · m; 5 – forward cover of the bearing of the camshaft; 6 – hydraulic pushers of valves; 7 – the compensating element; 8 – valve crackers; 9 – top plate of a valvate spring; 10 – valvate springs; 11 – maslootrazhatelny caps; 12 – camshaft of inlet valves; 13 – nuts, 15 N · m; 14 – camshaft of final valves; 15 – hydraulic pushers of valves; 16 – lower plate of a valvate spring; 17 – bolt, 10 N · m; 18 – flange; 19 – head of the block of cylinders; 20 – valves


Fig. 3.2-40. Arrangement and numbering of covers of bearings of camshafts



Unscrew and uncover camshaft bearings from a chain and a cover of 2 and 3 (fig. 3.2-40).
Gradually, evenly cross-wise unscrew covers of 1 and 4 bearings of the camshaft.

Camshaft of inlet valves
Turn out and uncover 6 and 7 bearings of the camshaft.
Gradually, evenly cross-wise unscrew covers of 5 and 8 bearings of the camshaft.
Remove camshafts.

Installation

Fig. 3.2-41. Installation of camshafts of inlet valves



Grease with a thin layer of engine oil camshafts and install them in a head of the block of cylinders so that tags on asterisks of shaft were sent to each other (fig. 3.2-41).
At installation keep in mind that covers of bearings are numbered from a forward part of the camshaft of inlet valves.
Before installation of external covers of camshafts apply a thin film of sealant D 454 300 02 on privalochny surfaces of covers.

Camshaft of inlet valves
Establish covers 5 and 8 (see fig. 3.2-40) bearings of the camshaft and fix them by nuts, tightening them gradually cross-wise.

Camshaft of final valves
Establish covers 1 and 4 (see fig. 3.2-40) bearings of the camshaft and fix them by nuts, tightening them gradually cross-wise.
Establish and fix other covers.
Further installation is carried out to the sequences, the return to removal.

Check of hydraulic pushers of valves
The correct installation of valvate gaps in many respects defines operation of the engine. If valvate gaps too big, noisiness increases and overall performance of the engine as valves open too late decreases and are closed too early. If valvate gaps too small, valves cannot be closed completely on the hot engine that can lead to its serious damage.
On engines hydraulic pushers which automatically under the influence of pressure in the lubrication system compensate a gap between a cam of the camshaft and the corresponding rod of the valve are established. Therefore at operation regular check and adjustment of valvate gaps is not required. However it is necessary to use engine oil of high quality and the recommended viscosity and to replace it with the required frequency. At launch of the cold engine there is a small delay of alignment of pressure of engine oil in all parts of the engine, especially in hydraulic pushers. Valves can knock about 10 seconds then continue to work silently.
If the engine was not launched by several days, valves can knock during longer time as almost all oil flows down from the top part of the engine and the working surfaces of bearings. At this time it is necessary to be careful not to damage the engine: to avoid sharp change of power setting until all pushers are filled with engine oil. At warming up of the engine the frequency of rotation of bystry idling (from 2000 to 2500 min.-1) should not increase within 2 minutes or yet the knock of valves will not stop. If noise of pushers does not stop, stop the engine and perform the following operations, at the same time temperature of the engine has to be not less than 80 °C.
Uncover a head of the block of cylinders.
Turning a bent shaft, establish a cam over the checked pusher directly up.

Fig. 3.2-42. Check of a free wheeling of a pusher



Press a pusher a wooden or plastic wedge (fig. 3.2-42). If the free wheeling of a pusher is more than 0,2 mm, pushers need to be replaced.
Establish a cover of a head of the block of cylinders.
Wait about 30 minutes before launch of the engine. It is necessary in order that work of hydraulic pushers was stabilized, otherwise pistons will hit against valves.

Processing of saddles of valves
Saddles of valves with wear tracks or a podgoraniye need to be processed with obligatory preservation of corners and sizes of a facet.

Fig. 3.2-43. Minimum admissible distance from an end face valves to the top surface of a head of the block of cylinders



If the saddle of the valve needs to be processed, determine the maximum quantity of metal which can be removed. Removal of excessive amount of metal breaks work of hydraulic pushers. Insert the valve into the directing plug and press it to a valve saddle. Measure distance from the end of a rod of the valve to the top surface of a head of the block of cylinders (fig. 3.2-43).
At excessive wear of a saddle of the valve processing is inadmissible therefore the head of the block of cylinders needs to be replaced.
After processing of saddles of valves they need to be ground in.

Replacement of sealing rings of the camshaft
Take off a gear belt.
Remove pulleys of camshafts on the left and right heads of the block of cylinders.

Fig. 3.2-44. Arrangement of bolts of fastening of a casing of a gear belt



Remove casings of a gear belt on the left and right heads of the block of cylinders (fig. 3.2-44).
  
   Prevention

Fig. 3.2-46. An arrangement of sealing rings in a forward part of a head of the block of cylinders



Two sealing rings and sealing ring of the camshaft, on the right side – one sealing ring and a sealing ring of the camshaft are on the left side established (see fig. 3.2-46)

Fig. 3.2-45. Use of special device 2056 for removal of a sealing ring of the camshaft



Using special adaptation 2056, remove a sealing ring of the camshaft (fig. 3.2-45).

Prevention
If one sealing ring is damaged at least, then it is necessary to replace sealing rings on both sides.
Clear an installation site of sealing rings.
Oil engine a working edge and an external surface of a new sealing ring before its installation into place.
Using a mandrel, establish a sealing ring into place.
Establish pulleys of camshafts.
Establish a gear belt.

Check and adjustment of alignment of a poliklinovy belt
Alignment of a poliklinovy belt is checked between the compressor of the conditioner and the pump of the amplifier of steering.

Fig. 3.2-10. Installation of device 3204 for weakening of a tension of a poliklinovy belt



Weaken a tension of a poliklinovy belt for what press the lower branch of a poliklinovy belt and, using adaptation 3204, fix the belt tension mechanism in this situation (see fig. 3.2-10). Take off poliklinovy a belt.

Fig. 3.2-47. Use of device 3201 for check of coincidence of flutes on pulleys of the compressor of the conditioner and pump of the amplifier of steering



Using adaptation 3201, check coincidence of flutes for a belt on pulleys of the compressor of the conditioner and pump of the amplifier of steering (fig. 3.2-47).

Fig. 3.2-48. Use of laying for adjustment of provision of a pulley of the pump of the amplifier of steering



If flutes on pulleys do not coincide, turn off a pulley of the pump of the amplifier of steering. Adjust the provision of a pulley by means of laying 0,5 thick; 1,0 and 1,5 mm which deliver in the spare part (fig. 3.2-48).


Fig. 3.2-49. Flywheel: 1 – a gear wreath (before installation on a flywheel it is necessary to heat to temperature of 200 °C); 2 – a pin for the VMT sensor; 3 – plug of the needle bearing; 4 – bolt