5.11.1. Replacement of camshafts

Camshafts replace in the following cases:
– pressure fell in the engine lubrication system. The increased wear of necks of camshafts and beds of bearings of camshafts in a head of the block of cylinders happens the reason of this malfunction often. At wear of beds and their covers the head of the block is replaced assembled as beds are executed directly in its case;
– knock of valves at normal gaps in the mechanism of the drive of valves. Is caused by the increased wear of cams of the camshaft because of use of low-quality engine oil or damage of an oil filter.
It will be required to you: the same tools, as for removal of a belt of the drive of the gas-distributing mechanism (see. "Replacement of a belt of the drive of the gas-distributing mechanism"), epiploons of camshafts (see. "Replacement of epiploons of camshafts"), and also TORX E11 key, dynamometer key.
1. Uncover a head of the block of cylinders (see. "Replacement of laying of a cover of a head of the block of cylinders").
2. Take off a belt of the drive of the gas-distributing mechanism (see. "Replacement of a belt of the drive of the gas-distributing mechanism").
3. Having fixed camshafts from a provorachivaniye, turn out bolts of fastening of pulleys of camshafts …
4. … also remove pulleys from shaft.
5. Turn out bolts of fastening of covers of bearings of camshafts as it should be, the return shown in fig. 5.10 …
6. … uncover, epiploons from necks of camshafts …
7. … also remove camshafts.

Prevention
Their serial numbers are applied on covers of bearings of camshafts. Remember or write down an arrangement of covers to establish them on former places: covers process together with a head of the block of cylinders and it is forbidden to depersonalize them.

Note
Replace epiploons of camshafts at each removal new.

8. Examine camshafts. The surfaces of basic necks and cams have to be well polished also without damages. On the working surfaces of necks teases, zaboina, scratches, an aluminum navolakivaniye from nests of bearings in a block head are not allowed. If on working surfaces of cams there are traces of jammings, an overheat, deep risks or wear in the form of a facet, replace shaft.

Prevention
Grinding of cams of camshafts for elimination of step wear is forbidden as at change of the sizes of a profile of cams gas distribution phases will be broken.

9. In the workshops equipped with special tools and devices it is possible to check a radial beating of necks of the camshaft. If a beating more than 0,02 mm or necks are not coaxial, replace a shaft as its editing is not allowed.
10. Oil beds of camshafts pure engine and lay in them camshafts in such situation that any of cams did not lean the highest part of the sock on an adjusting washer of a pusher of the valve.
11. Grease covers of forward bearings of camshafts with sealant.

Fig. 5.10. Order of an inhaling of bolts of covers of bearings of camshafts

12. Establish covers of bearings of camshafts and tighten bolts of their fastening in the order shown in fig. 5.10 in three stages:
The 1st stage — evenly tighten bolts half way everyone until covers of bearings do not adjoin to surfaces of a head of the block of cylinders;
The 2nd stage — tighten bolts of fastening of covers of bearings of the camshaft the moment of 7 N · m;
The 3rd stage — tighten bolts of fastening of covers of bearings of the camshaft on 45 °.
13. Press epiploons of camshafts in nests of covers of forward bearings of camshafts (see. "Replacement of epiploons of camshafts").
14. Establish other details as it should be, the return to removal.