Infiniti QX4 service since 1996 of release
1. Introduction
2. Maintenance instruction
3. Routine maintenance
4. Engine
4.1. Specifications
4.2. Check of kompressionny pressure in cylinders
4.3. Diagnostics of a condition of the engine with use of the vacuum gage
4.4. Removal and engine installation
4.5. Removal and installation of the inlet pipeline
4.6. Replacement of a belt of a drive of GRM
4.7. Removal, check of a condition and installation of a head of cylinders
4.8. Replacement of a forward epiploon of a cranked shaft
4.9. Removal, check of a condition and installation of components of the klapanny mechanism
4.10. Replacement of epiploons of camshafts
4.11. Replacement of a back epiploon of a cranked shaft
4.12. Removal and installation of the pallet of a case
4.13. Removal, service and installation of the oil pump
4.14. Alternative versions of schemes of regenerative repair of the engine
4.15. An order of dismantling of the engine by its preparation for major maintenance
4.16. Dismantling and check of a condition of a head of cylinders and components of the klapanny mechanism
4.17. Recommendations about service of valves
4.18. Assembly of a head of cylinders
4.19. Removal of shatunno-piston assemblies
4.20. Removal of a cranked shaft
4.21. Cleaning of the block of the engine
4.22. Check of a condition of the block of the engine
4.23. Honingovaniye of mirrors of cylinders
4.24. Check of a condition of components of shatunno-piston group
4.25. Check of a condition of a cranked shaft
4.26. Check of a condition and selection of loose leaves of radical and shatunny bearings of a cranked shaft
4.27. Engine assembly order
4.28. Installation of piston rings
4.29. Installation of a cranked shaft and check of working gaps of radical bearings
4.30. Installation of shatunno-piston assemblies and check of size of working gaps in shatunny bearings of a cranked shaft
4.31. Trial start and an engine running in after major maintenance
5. Cooling and heating systems
6. Power supply systems and managements
7. Start and charge systems
8. Transmission line
9. Brake system
10. Suspension bracket and steering
11. Body
12. Electric equipment
 












4-26-proverka-sostoyaniya-i-podbor-vkladyshejj-korennykh-i-shatunnykh.html

4.26. Check of a condition and selection of loose leaves of radical and shatunny bearings of a cranked shaft

Fatigue deformation

Pockets and cavities are specified

Wrong landing

Zapolirovanny sites to shine are specified

Dirt hit

A — Are specified scratches
B — Are specified the extraneous particles introduced in a surface

Lack of greasing

The local wipe of a blanket is specified

Excessive wear

Blanket operation on all area is specified

Neck Konusnost

Radial wear of a local order is specified


Condition check

In spite of the fact that bearings of a cranked shaft in the course of major maintenance of the engine are subject to replacement without fail, old loose leaves should be kept for the purpose of attentive studying of their condition which results can give a lot of useful information about the general condition of the engine. Examples of typical defects of loose leaves of bearings see above.

The exit of bearings out of operation can occur owing to a lack of greasing, hit of particles of dirt, overloads of the engine and corrosion development. Regardless of nature of defects, the reason of damage of loose leaves should be eliminated in the course of performance of major maintenance of the engine in order to avoid recurrence.

For survey take loose leaves of bearings from the beds in the engine block / the bottom heads of rods and radical / shatunny covers and spread out them as installation on a pure working surface. Organization of placement of loose leaves will allow to adhere nature of the revealed defects to a condition of the corresponding necks of a shaft.

Dirt and extraneous particles get to the engine various ways. They can be left in the block in the course of unit assembly, or get via filters or system of ventilation of a case. All particles getting to impellent oil, finally, sooner or later, appear in bearings. Often the metal sawdust which is forming in the course of normal operation of internal components of the engine takes root into a soft material of loose leaves. The probability of presence at bearings of traces of an abrasive is great, in particular, when was not given due consideration to block cleaning after completion of regenerative repair of the engine. Regardless of a way which extraneous particles get to the engine, as a result they with high degree of probability appear introduced in a soft surface of loose leaves of bearings of a cranked shaft and easily come to light at visual survey of the last. Large particles usually are not late in loose leaves, but leave on their surface and a surface of necks of a shaft appreciable traces in the form of scratches, cavities and задиров. The best guarantee from such troubles is the responsible relation to cleaning of components after completion of major maintenance of the engine and care of observance of purity at assembly. Frequent regular change of impellent oil also allows to prolong service life of bearings essentially.

Oil starvation can be a consequence of several various, but often interconnected phenomena. So, the overheat of the engine conducts to a razzhizheniye of engine oil and its replacement from working gaps of bearings. The lack of greasing of bearings can speak in excessive size of working gaps, and also usual leaks (internal or external). Often meeting reason of replacement of oil from gaps of bearings is continuous excess of turns of the engine. Passableness violation маслотоков (usually connected with the wrong combination of openings at installation of components) also conducts to reduction of supply of greasing to bearings. Typical result of oil starvation is the full or local wipe / выщербливание a blanket of loose leaves from a metal substrate. Thus the working temperature can rise to such level that the substrate as a result of an overheat gets a bluish shade.

Essential influence on service life of bearings is rendered also peculiar to the owner of the car by a driving manner. Movement with small speed on an overgear leads to considerable overloads of the bearings, being accompanied replacement of an oil film from their working gaps. Such overloads lead to increase of plasticity of loose leaves and emergence of cracks in a blanket (fatigue deformation). Thus the superficial material starts to crumble and separate from a steel substrate. Car operation in a city cycle (on short distances) conducts frequent trips to development of corrosion of bearings because the insufficient warming up of the engine involves loss of condensate and allocation of chemically aggressive gases. These products accumulate in impellent oil, forming slags and acids. At hit of such oil in bearings aggressive substances promote development of corrosion of loose leaves.

The wrong installation of loose leaves in the course of engine assembly also can be at the bottom of their fast destruction. Too hard landing does not provide the demanded size of a working gap of bearings that leads to their oil starvation. Result of hit under loose leaves (in the course of their installation) extraneous particles is formation of eminences the blanket with which is quickly wiped.


Selection of loose leaves


Radical bearings

A.

B.

Standard diameters of radical necks of a cranked shaft and beds of the corresponding bearings can have insignificant disorder for the purpose of which compensation loose leaves of radical bearings of several standard dimensional groups (on thickness are issued) — number of group is beaten out on cheeks of cranks and on the bottom of the block of cylinders.

A — Numbers of standard dimensional groups of radical necks of a cranked shaft are beaten out on cheeks of the corresponding cranks
B — Numbers of standard dimensional groups of beds of radical bearings are beaten out on the bottom of the block of cylinders

Calculation of number of dimensional group of the loose leaf is carried out by addition to number of group of a neck of number of group of a bed. So, for example, if the neck has dimensional group "1", and a bed of the corresponding bearing — «2», it is necessary to choose the loose leaf of dimensional group "3". For definition of dimensional group of loose leaves the color code is used.

  Marking of a bed of the bearing
«0» «1» or «I» «2» or «II»

Marking of a neck of a cranked shaft

«0»

0 (Black)

1 (Brown)

2 (Green)

«1» or «I»

1 (Brown)

2 (Green)

3 (Yellow)

«2» or «II»

2 (Green)

3 (Yellow)

4 (Dark blue)

If the cranked shaft was exposed to a pro-point, it should be completed with loose leaves corresponding repair (with belittling) the sizes. Usually selection of loose leaves is carried out by the experts making a pro-point of necks of a shaft. Regardless of a technique of determination of the demanded size of loose leaves working gaps of bearings should be then are checked with application of a measuring set of Plastigage (see. Installation of a cranked shaft and check of working gaps of radical bearings).

If it is not possible to correct properly size of working gaps by selection of loose leaves, it is necessary to replace a shaft.


Shatunnye bearings

The selection of shatunny loose leaves is made on the basis of determination of size of working gaps in the corresponding bearings (see Spetsifikatsiy Ustanovka of shatunno-piston assemblies and check of size of working gaps in shatunny bearings of a cranked shaft).


All bearings

Remember that in the final parameter defining correctness of selection of loose leaves, the result of measurement of working gaps in bearings is. With any questions safely address to representatives of the firm HUNDRED companies Infinitis.


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4.25. Check of a condition of a cranked shaft
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4.27. Engine assembly order