The general requirements to car repairs. Nissan Almera (from 1995 to 1999 of release)
Nissan Almera service from 1995 to 2000 in N15 body
1. General information
2. The general requirements to car repairs
3. Operation and car maintenance
4. Petrol engines
5. Diesel engines
6. Transmission
7. Running gear
8. Steering
9. Brake system
10. Electric equipment
11. Body
12. Appendices
13. Electric equipment schemes
 







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2. The general requirements to car repairs

The main part of malfunctions of mechanical knots and units arises owing to processes of a friction, deformation of elements, aging of a material of details etc. These and other processes впекут for itself wear process and damage of details. Process of wear process can be divided into three periods: to extra earnings, normal and emergency wear. In process extra earnings there is an intensive wear of rubbing details, as a result of microroughness of the interfaced surfaces decrease, the contact area grows, specific loadings decrease, speed of wear is slowed down and there comes the period of normal wear. It is characterized by rather small growth rate of a gap in interface, however on reaching a certain gap speed of wear process sharply increases that testifies to the beginning of the period of emergency wear. Unit operation with emergency wear leads to breakages. It is in use very important to subject knot to repair before emergency wear, thus costs of repair will be much lower, than at unit repair with emergency wear.
Before making decision on repair it is necessary продиагностировать a condition of units. As a rule, diagnosing is conducted on indirect signs, such as the increased noise, vibration, a consumption of oil, break of karterny gases, etc. For better diagnostics the unit is necessary for disassembling, details to wash out, examine and carry out necessary measurements. By results of survey and measurements the decision on continuation of operation or on need of repair is made. Thus it is necessary to be guided by the following reasons: if the actual sizes of details are in limits of fields of the admissions resolved by this management, continuation of operation of the unit without repair possibly; if the sizes left for admissible fields of admissions, repair is required. Expansions of fields of the admissions, given in the real management, it is necessary to understand as possibility of use of a residual resource of knot without restoration of interfaces. In case of unit repair at restoration of interfaces expansion of fields of admissions over nominal is not allowed. The technology of repair can be divided into four main stages of works:
— dismantling and sink;
— control and sorting;
— actually repair: restoration micro and macrogeometry of surfaces of details and physicomechanical properties;
— assembly with preliminary control of the details arriving on assembly.
And washing operations conduct Razborochnye in some stages: an external wash of the unit, preliminary dismantling of the unit on knots, a sink of knots, dismantling of knots on a detail, a sink and cleaning of details. All details before control and sorting should be cleared carefully of dirt and a deposit, to degrease, wash out and dry up.
Oil channels and openings in details should be cleaned, washed out under pressure and to blow the compressed air. Details from aluminum and zinc alloys are not allowed to be washed out in the alkaline solutions applied to a sink of steel and pig-iron details as aluminum and zinc are dissolved in alkalis.
In the course of control of details chips, cracks, dents, and other damages find sinks external survey. At responsible details existence of cracks check by means of the defectoscope. The sizes of details are necessary for supervising in places of the greatest wear. Teeths of gear wheels wear out non-uniformly therefore at their control it is necessary to measure not less than three teeths located approximately at an angle 120 °. In view of need to guarantee work of tooth gearings during all between-repairs run chips on teeths and a vykrashivaniye of fatigue character on a working surface of teeths are not allowed. Assembly units, such as a rod with a cover, the block of cylinders with covers of radical bearings, gear wheels of a transmission and the main transfer, is impossible разукомплектовывать. Other assembly units it is possible разукомплектовывать; but if the decision on continuation of operation of interfaced elements without repair is made, them разукомплектовывать is inexpedient. In all cases of repair of details welding and a naplavka the welded seam should not have the slag inclusions, not boiled thoroughly sites, having cut and other defects. After welding it is necessary to smooth out a seam and to eliminate metal flows that they did not disturb installation of interfaced details.
Carving openings with the worn-out or damaged carving restore a narezaniye of a carving of the increased repair size, tea leaves of openings with the subsequent narezaniye of a carving of the nominal size, installation of spiral carving inserts. Application of carving inserts is more preferable for reasons of quality of restoration and labor costs. The insert represents a spiral reminding a spring, made of a wire of rhombic section. On one end of a spiral will bend a technological lead by means of which an insert wrap in previously prepared opening. Technological process of repair of a carving opening by means of a spiral insert includes the following operations:
— a rassverlivaniye of a defective opening till the repair size;
— a narezaniye in it of the carving corresponding to the size of a spiral insert;
— a vvorachivaniye of a spiral insert and an oblamyvaniye of a technological lead on a notch.
In tab. 1.5 the sizes of openings and a carving under the spiral inserts applied at repair of automobile details are specified.
For repair of carving openings by spiral inserts special sets into which inserts, the drills, special taps, keys for a vvorachivaniye of inserts, small beards for a srubaniye of a technological lead enter are issued.
The details submitted on assembly, should be pure and dry. Carving connections should not have damages. Disposable самоконтрящиеся carving fixing details at assembly should be replaced with the new. In case of impossibility to apply new самоконтрящиеся when using old it is necessary for detail to stop in addition them from an otvorachivaniye.
At assembly surely replace new laying and cuffs. Rubbing surfaces of details at assembly grease with pure oil. At installation of rubber cuffs grease them working surfaces in order to avoid damage at installation. At installation of cuffs with the metal case put in a groove for cuff installation a thin layer of hermetic.
Assembly of knots and units carry out according to the real management.

Table of 1.5 Sizes of an opening and a carving under repair spiral inserts
Nominal carving
Diameter of a drill, mm
Carving under a spiral insert
М5 x 0,8
5,2
М6 x 0,8
Mb x 1,0
7
М8х 1,0
М8х 1,25
8,7
М10х 1,25
MYuH 1,5
10,5
М12х 1,5
М11 x 1,0
12
М13х 1,0
М12х 1,75
12,2
М14х 1,75
М12х 1,5
12,5
М14х 1,5
М14х 1,25
14,7
М16х 1,25
М14х 1,5
14,7
М16х 1,5
М16х 1,5
16,5
М18х 1,5
М18 x 1,5
18,1
М20 x 1,5

By means of the measuring tool check before assembly the sizes of interfaced details. At assembly of the details having in interface mobile landing, their free relative moving without jammings should be provided. Plugs, rings of ball and roller bearings establish by means of opravka. At a press fitting of bearings the effort should not be transferred through balls or rollers. The tool for a press fitting should rest against a pressed ring. The effort of a press fitting should be directed parallel to a bearing axis in order to avoid a distortion of rings. If on assembly conditions installation of responsible details is carried out by hammer blow, it is necessary to apply opravka and hammers from soft metal, plastic, rubber, and also the adaptation to a press fitting of details.
By Shponki should be densely planted in shponochny grooves of shaft by means of a hammer or an opravka from soft metal. Люфт the shponok in grooves of shaft is not allowed.
Hairpins should be wrapped in carving openings densely, without люфта. Details should be put on hairpins freely. Podgibaniye of hairpins at installation of details on them is not allowed, knot or detail fastening by several nuts or bolts should be carried out evenly on perimeter — at first previously, and then is final. All identical nuts or bolts of one connection should be tightened by one moment.
In all cases provided by the management, it is necessary to apply the dinamometrichesky keys, allowing to regulate the inhaling moment. The moments of an inhaling of carving connections if they specially are not stipulated in specifications, are defined depending on diameter of a carving according to tab. 1.6.
When fastening details bolts should act from nuts not less than on two-three rounds of a carving, except especially stipulated cases.

Table 1.6 the Recommended moments of an inhaling of carving connections
Diameter of a carving, mm
Moment of an inhaling, kgf-m
6
0,6-0,9
8
1,4-1,7
10
3,0-3,5
12
5,5-6,0
14
8,0-9,0
16
12-14
18
16-19
20
23-27

Shplinta should not act from cuts of nuts. The ends шплинтов should be dissolved and unbent — one on a bolt, and another on a nut.
Tubes топливопроводов and a drive of brakes before assembly to blow the compressed air.

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