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
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Check of a condition of the block of the engine
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Before starting check of a condition of the block of its engine it is necessary to clear carefully (the Section Cleaning of the block of the engine see).
Make external survey of the block on presence in it of cracks and corrosion traces. Check up болтовые apertures on presence of failures of a carving. It is quite good to make also block check on presence of the latent cracks in the conditions of a repair truck where for this purpose there is a special equipment. In case of revealing of defects it is necessary to make block repair (if it probably) or its replacement.
Check up mirrors of cylinders on presence of scratches and задиров.
Measure diameter of everyone of their cylinders in its top part (directly under border of area of step deterioration), in the middle of height and is closer to the bottom cut. Measurements make in a plane passing through an axis of a cranked shaft.
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Measurement of diameter of the cylinder is made to coaxially cranked shaft in three cross-section sections - under border of area of step deterioration (), in an average part () and over the bottom cut ().
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Then measure diameter of cylinders in the same planes, but across an axis of a cranked shaft. Compare results of measurements to requirements of Specifications.
In the absence of access to exact measuring tools the backlash between the piston and cylinder walls can be defined (the truth less authentically) by means of special measuring probeа лезвийного type. Щуп should be equipped by the complete set of edges of a various thickness in length about 30.5 sm and to get it it is possible practically in any shop of autospare parts.
For backlash definition choose probe a necessary thickness and enter it between the piston and a cylinder wall. The piston should be located in the cylinder also as it settles down during normal work. The edge probeа is densely entered into a backlash between the piston and a cylinder wall on one of persistent surfaces (under 90 to an aperture under a piston finger).
After introduction of an edge the piston should slide in the cylinder with moderate resistance.
If the piston fails, or slides too freely its replacement is required. If piston jamming occurs only in the bottom part of the cylinder at free sliding above, it is available конусность the cylinder. Change of density of landing probeа in the cylinder at piston rotation (together with probeом) in the cylinder speaks about presence of ovality of the last.
Repeat procedure for all remained pistons and cylinders.
At presence on mirrors of cylinders of deep scratches or strong задиров or in a case revealing exceeding admissible values конусности or ovality the block should be given to a workshop for проточки and хонингования cylinders. After carrying out проточки cylinders the complete set of the block is made by pistons and piston rings of the new, repair sizes.
If mirrors of cylinders are found in a satisfactory condition and their deterioration lies in admissible limits, and also at conformity of sizes of backlashes between pistons and walls of their cylinders to requirements of Specifications, проточка cylinders it is not required. Everything that should be made - хонингование mirrors (Razdel Honingovanie of cylinders).
Engines can be equipped by components of one of three types of the standard size (nominal, with excess and with belittling). For example cylinders can have the size with excess, necks radical and шатунных bearings - with belittling, and camshaft bearings - with excess. On such engines of a surface of the block, a cranked shaft or a cavity of pushers the digital or alphabetic code specifying the size фабрично of established pistons is beaten out. On engines V8 on a counterbalance of the eighth crank of the size equipped with necks with belittling of a cranked shaft alphabetic indexes "M" or R are put down. The code М-2-3 says that the second and third radical necks have the size with belittling in 0,025 mm while the letter R in a code speaks about belittling of the size шатунных necks.
Engines c nests of pushers of the exceeded size usually are marked by the label which having the form of diamond and has been beaten out on a platform in the top part of a forward wall of the block whereas the index Х, beaten out on a platform at an end face of a head of cylinders means installation of valves with cores of the size with excess (0,127 mm).
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The cranked shaft of engine V8 can be marked by the alphanumeric code which has been beaten out on a counterbalance of the eighth crank and saying that the shaft is equipped radical (a label "M") or шатунными (a label R) by necks of the size with belittling.
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The labels speaking about the equipment by components of the repair sizes of engine V8
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CONDITION
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DESIGNATION
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CODE SITE
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NECKS OF THE CRANKED SHAFT (THE SIZE WITH BELITTLING) 0,0254 MM (0,001 INCHES)
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R or M; М-2-3 etc. (specifies for the size with belittling of radical necks №№ 2 and 3); and-or R-1-4 etc. (specifies for the size with belittling шатунных necks №№ 1 and 4)
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Vyfrezerovannaja platform on a counterbalance of the eighth crank
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HYDRAULIC PUSHERS (THE SIZE WITH EXCESS) 0,2032 MM (0,008 INCHES)
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Label in the form of diamond (rhombus)
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The label is beaten out on a platform in the top part of a forward wall of the engine and on a platform on an external surface of a nest of everyone О/S a pusher
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RODS OF VALVES (THE SIZE WITH EXCESS) 0,127 MM (0,005 INCHES)
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Х
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Platform, выфрезерованная near to two конусными apertures (3/8 inches (9,5 mm)) on each of end faces of a head of cylinders
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Codes of the repair sizes of components 6 cylinder engines located on a platform between the distributor and the coil of ignition.
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CODE
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COMPONENT
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THE SIZE WITH BELITTLING
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P |
One or more шатунных necks
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0,0254 MM (0,001 INCHES)
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M |
All radical necks
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0,0254 MM (0,001 INCHES)
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PM |
All radical necks of a cranked shaft and one or more шатунных
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0,0254 MM (0,001 INCHES)
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CODE
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COMPONENT
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THE SIZE WITH EXCESS
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B |
All cylinders
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0,0254 MM (0,001 INCHES)
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C |
All bearings of a camshaft
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0,0254 MM (0,001 INCHES)
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