Jeep Grand Cherokee

1993-1999 of release

Repair and car operation

Jeep Grand Cherokee
+ Cars of mark Jeep Grand Cherokee
+ Options and routine maintenance
+ Рядный the six-cylinder engine
+ Engine V8
- Procedure of the general and engine major repairs
   The general information
   Engine major repairs - the general information
   Check компрессионного pressure in cylinders
   The diagnostic checks made by means of the vacuum gauge
   Methods of removal of the engine and necessary safety measures
   Removal and engine installation
   Variants of restoration of the engine
   Order of dismantling of the engine
   Dismantling of a head of cylinders
   Cleaning and check of a condition of a head of cylinders
   Service of valves
   Assemblage of a head of cylinders
   Removal of shatunno-piston assemblages
   Removal of a cranked shaft
   Cleaning of the block of the engine
   Check of a condition of the block of the engine
   Хонингование cylinders
   Check of a condition of shatunno-piston assemblages
   Check of a condition of a cranked shaft
   Check of a condition radical and шатунных bearings
   Assembly order of the engine after end of its major repairs
   Installation of a cranked shaft and check of backlashes of radical bearings
   Installation of piston rings
   Installation of shatunno-piston assemblages and check of backlashes in шатунных bearings
   The first start of the engine after major repairs
+ Systems of cooling, heating and air conditioning
+ The power supply system and release of the fulfilled gases
+ System of an electric equipment of the engine
+ Systems of decrease in toxicity of the fulfilled gases and engine management
+ Manual box of a gear change
+ Automatic transmission
+ Distributing box
+ Coupling and трансмиссионная a line
+ Brake system
+ Suspension bracket and steering
+ Body
+ System of an onboard electric equipment
+ Controls and operation receptions


Check of a condition radical and шатунных bearings

In spite of the fact that replacement of loose leaves radical and шатунных bearings on the new is made in the course of engine major repairs without fail, the condition of the old should be subjected the most attentive studying as the analysis of its results can give the valuable information on the general condition of the engine.

Typical defects of bearings of a cranked shaft.

The exit of bearings out of operation can result from insufficient greasing, hit in them of extraneous particles, overloads of the engine and corrosion influence. Irrespective of character of the reason of an exit of bearings out of operation, it should be eliminated prior to the beginning of engine assemblage in avoidance of relapses at operation of the restored unit.

For condition check, take loose leaves from covers radical and шатунных bearings, beds in the block of the engine and the bottom heads of rods and spread out them on an equal pure surface in the same order in what they have been established on the engine. It will allow to connect problems of bearings with a condition of corresponding necks of a shaft.

The dirt and extraneous particles can get to the engine various ways. They can be left at assemblage or get through filters or ventilation system картера (PCV), to get to bearings together with oil. Metal sawdust can be left after carrying out станочной processings or are developed in the course of normal functioning of the engine. Abrasive particles often remain in the engine after carrying out of regenerative procedures, in particular if the proper attention is not given cleaning of the block and internal components. Irrespective of a way of penetration into the engine, extraneous particles and a dirt as a result appear introduced in a soft material of bearings where can be easily identified more often. Large particles do not jam in bearings, and leave scars on surfaces of loose leaves and shaft necks. The best preventive measure on prevention of an exit of bearings out of operation is the conscientious attitude to performance of cleaning of the engine and its components after major repairs with application of recommended methods of its performance. Important value has also carrying out of regular and frequent change of impellent oil and the oil filter.

The greasing lack (or its termination) can be a consequence of several, frequently interconnected, the reasons. It is necessary to carry to them: an overheat (the leader to истончению an oil layer), engine overloads (leading to replacement of an oil layer from backlashes in bearings) and leaving of oil from backlashes of bearings (owing to their too big size, deterioration of the oil pump or excessively high turns of the engine). Passableness infringement маслотоков which results рассовмещения from oil apertures of loose leaves and beds more often, also conducts to oil starvation and an exit of bearings out of operation. When the reason of malfunctions of bearings is the greasing lack, the soft blanket of loose leaves is usually superseded from a steel substrate. Sometimes the temperature raises to such values that the substrate gets a bluish shade.

Essential influence on service life of bearings is rendered also by a driving manner. Full opening заслонки at movement with small speeds leads to loading substantial increase on bearings that conducts to squeezing of an oil film from backlashes. Such overloads lead strong выгибанию loose leaves and to formation on them of thin cracks (fatigue pressure). In due course there is a branch of separate slices of a soft layer of the loose leaf from a steel substrate. Use of the car for movings on short distances conducts to occurrence of corrosion of bearings as a result of insufficient warming up of the engine which is at the bottom of formation of a condensate and aggressive gases. The given products accumulate in impellent oil, forming acids and шлам. When such oil gets to bearings, acid starts to corrode their surfaces, leading to material corrosion.

Incorrect installation of bearings in the course of engine assemblage also can lead to their fast exit out of operation. Pulling of bearings is at the bottom of installation of insufficient size of backlashes and, as consequence, conducts to oil starvation of bearings. Hit between a back of the loose leaf and bed of the bearing of extraneous particles at installation of bearings conducts to formation of eminences подшипниковой surfaces that later becomes the reason of an exit of the bearing out of operation.