Service Infiniti QX4 since 1996 of release
1. Introduction
2. The maintenance instruction
3. Routine maintenance
4. The engine
4.1. Specifications
4.2. Check компрессионного pressure in cylinders
4.3. Diagnostics of a condition of the engine with vacuum gauge application
4.4. Removal and engine installation
4.5. Removal and installation of the inlet pipeline
4.6. Replacement of a belt of drive ГРМ
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 клапанного the mechanism
4.10. Replacement of epiploons of camshafts
4.11. Replacement of a back epiploon of a cranked shaft
4.12. Removal and pallet installation картера
4.13. Removal, service and installation of the oil pump
4.14. Alternative variants of schemes of regenerative repair of the engine
4.15. An order of dismantling of the engine by its preparation for major repairs
4.16. Dismantling and check of a condition of a head of cylinders and components клапанного the mechanism
4.17. Recommendations about service of valves
4.18. Assemblage of a head of cylinders
4.19. Removal of shatunno-piston assemblages
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. Хонингование 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 radical and шатунных bearings of a cranked shaft
4.27. An engine assembly order
4.28. Installation of piston rings
4.29. Installation of a cranked shaft and check of working backlashes of radical bearings
4.30. Installation of shatunno-piston assemblages and check of size of working backlashes in шатунных bearings of a cranked shaft
4.31. Trial start and обкатка the engine after major repairs
5. Cooling and heating systems
6. Power supply systems and managements
7. Start and charge systems
8. A transmissionnaja line
9. Brake system
10. A suspension bracket and a steering
11. A body
12. An electric equipment
 












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

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

Fatigue deformation

Pockets and cavities are specified

Wrong landing

Sites are specified заполированные to shine

Dirt hit

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

Greasing lack

The local wipe of a blanket is specified

Excessive deterioration

Blanket operation on all area is specified

Конусность necks

Radial deterioration of a local order is specified


Condition check

In spite of the fact that bearings of a cranked shaft in the course of engine major repairs 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 helpful information on 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 a dirt, overloads of the engine and corrosion development. Without dependence from character of defects, the reason of damage of loose leaves should be eliminated in the course of performance of major repairs of the engine in order to avoid relapse.

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

The dirt and extraneous particles get to the engine various ways. They can be left in the block in the course of unit assemblage, or get through filters or ventilation system картера. All particles getting to impellent oil, finally, sooner or later, appear in bearings. Often the metal sawdust formed 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 the proper attention has not been given cleaning of the block after end of regenerative repair of the engine. Without dependence from 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 end of major repairs of the engine and carefulness of observance of cleanliness at assemblage. 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 engine overheat conducts to разжижению engine oil and to its replacement from working backlashes of bearings. The lack of greasing of bearings can speak in excessive size of working backlashes, and also usual leaks (internal or external). Often meeting reason of replacement of oil from backlashes of bearings is constant excess of turns of the engine. Passableness infringement маслотоков (usually connected with wrong combination of apertures at installation of components) also conducts to reduction of giving of greasing to bearings. Typical result of oil starvation is the full or local wipe/vyshcherblivanie of 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 the raised transfer leads to considerable overloads of the bearings, accompanied replacement of an oil film from their working backlashes. Such overloads lead to increase of plasticity of loose leaves and occurrence 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 a condensate and allocation of chemically aggressive gases. The given 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.

Wrong installation of loose leaves in the course of engine assemblage also can be at the bottom of their fast destruction. Too hard landing does not provide the demanded size of a working backlash 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 corresponding bearings can have insignificant disorder for the purpose of which indemnification loose leaves of radical bearings of several standard dimensional groups (on a thickness are issued), — group number 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 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 bed. So, for example, if the neck has dimensional group 1, and 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 colour code is used.

  Marks of bed of the bearing
0 1 or I 2 or II

Marks 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 проточке, it should be completed by loose leaves corresponding repair (with belittling) the sizes. Usually selection of loose leaves is carried out by the experts making проточку of necks of a shaft. Without dependence from a technique of definition of the demanded size of loose leaves working backlashes of bearings should be then are checked up with application of measuring set Plastigage (Installation of a cranked shaft and check of working backlashes of radical bearings see).

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


Shatunnye bearings

The selection шатунных loose leaves is made on the basis of definition of size of working backlashes in corresponding bearings (Spetsifikatsiii Installation of shatunno-piston assemblages and check of size of working backlashes in шатунных bearings of a cranked shaft see).


All bearings

Remember that in the definitive parametre defining correctness of selection of loose leaves, the result of measurement of working backlashes in bearings is. With any questions safely address to representatives of firm HUNDRED companies Infiniti.


On page back
4.25. Check of a condition of a cranked shaft
On the following page
4.27. An engine assembly order