Jeep Grand Cherokee
+ Cars of the Jeep Grand Cherokee brand
+ Settings and routine maintenance
+ Line six-cylinder engine
+ V8 engine
- Procedures of the general and capital repairs of the engine
Capital repairs of the engine - the general information
Check of compression pressure in cylinders
The diagnostic checks made by means of the vacuum gage
Methods of removal of the engine and necessary precautionary measures
Removal and installation of the engine
Options 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
Assembly of a head of cylinders
Removal of conrod and piston assemblies
Removal of a bent shaft
Cleaning of the block of the engine
Check of a condition of the block of the engine
Honingovaniye of cylinders
Check of a condition of conrod and piston assemblies
Check of a condition of a bent shaft
Check of a condition of radical and conrod bearings
Engine assembly order after completion of its capital repairs
Installation of a bent shaft and check of gaps of radical bearings
Installation of piston rings
Installation of conrod and piston assemblies and check of gaps in conrod bearings
The first start of the engine after capital repairs
+ Cooling systems, heating and air conditioning
+ A power supply system and production of the fulfilled gases
+ System of electric equipment of the engine
+ Systems of decrease in toxicity of the fulfilled gases and engine management
+ Manual box of gear shifting
+ Automatic transmission
+ Transfer case
+ Coupling and transmission line
+ Brake system
+ Suspension bracket and steering
+ System of onboard electric equipment
+ Governing bodies and methods of operation
Installation of conrod and piston assemblies and check of gaps in conrod bearings
Before installation of conrod and piston assemblies of a wall of cylinders have to be carefully cleaned, the upper edge of cylinders it is chamfered, and the bent shaft - is installed in the engine.
Uncover the first (No. 1) rod (see the tags made in the course of dismantle). Take old inserts and wipe bearing surfaces in a rod and a cover pure неворсящейся with rags - they have to be absolutely pure.
Measurement of a gap in conrod bearings
- Wipe a back top of new inserts and put him to bed the bearing in a rod head. Track that the uvula of an insert entered reciprocal deepening in a rod. Do not try to begin to knock an insert in a bed the hammer at all and try not to damage a bearing surface, having left on it agnails and teases. Greasing at this stage should not be made!
- Wipe a back of the second insert and insert it into a rod cover. Again make sure of hit of a uvula in reciprocal deepening. Do not grease an insert. It is extremely important that at this stage the interfaced surfaces of inserts and from beds were absolutely pure and dry.
- Arrange locks of rings on the piston as it is shown on an accompanying illustration.
- Before installation in the engine of conrod and piston assembly place locks of piston rings as it is shown in the drawing.
- Pull pieces of a polyethylene or rubber hose on bolts of fastening of a cover of the conrod bearing.
- Grease pistons and piston rings with pure motive oil and put on the piston a tool mandrel for tightening of piston rings. Leave a skirt of the piston acting from a mandrel on height about 6.4 mm for introduction of the piston to the cylinder. Rings have to be compressed so that they appeared aflush with the surface of the piston.
- Turn a bent shaft so that the first conrod neck fell into a state of NMT and oil cylinder walls motive.
- Having focused the piston so that the arrow (or deepening) on its bottom was turned forward on the engine, carefully enter conrod and piston assembly into the first cylinder, having rested bottom edge of a mandrel of the tool for compression of piston rings against the surface of the block.
Deepening on the bottom of the piston has to be turned on the engine forward.
- Tap the upper edge of a mandrel of the tool for a guarantee of dense pressing of its bottom edge to the block on all the perimeter.
- Begin to tap carefully on the piston bottom with the wooden handle of the hammer, at the same time directing the lower head of a rod to a shaft neck. Piston rings tend to a vyskakivaniye from a tool mandrel before the calling the cylinder therefore provide a constant reliable clip of a mandrel to the block. Work without hurrying and at the first signs of emergence of resistance immediately stop introduction of assembly to the cylinder. Find out the reason of jamming and eliminate it before starting continuation of implementation of the procedure. Do not try to insert the rested piston into the cylinder by force at all - it is fraught with damage of rings and/or the piston!
- After assembly installation before finalizing a cover of the conrod bearing, it is necessary to perform measurement of a gap in it.
- Cut off a piece of the calibrated wire from the measuring Plastigage set, length width of the conrod bearing are slightly shorter and lay a piece on a conrod neck of a shaft, parallel to its axis.
- Lay a piece of the calibrated plastic wire from the measuring Plastigage set parallel to a neck axis.
- Wipe a bearing surface of a cover of a rod, remove protective hoses from bolts and establish a cover. Track that the adjusting tag on a cover was turned into the same party, as a tag on a rod.
- Screw nuts and, in three stages, tighten them with the required effort.
In order to avoid the wrong indications of a dynamometer key use a thin-walled replaceable head which will not get stuck between a nut and a surface of a cover. If nevertheless jamming happened, slightly raise a head, having released it and only then continue tightening. Do not allow a provorachivaniye of a bent shaft in the course of tightening of nuts of a cover of the conrod bearing.
- Give nuts and uncover, trying not to break integrity of the flattened-out calibrated wire.
- Measure width of the flattened-out wire on the scale printed on packing of measuring set. The scale is marked already in bearing gap sizes. Compare result of measurements to requirements of Specifications.
- Measure width of the flattened-out calibrated wire for definition of a gap in the conrod bearing (track using the correct scale - on packing both the metric scale, and a scale in terms of the American standard are printed (inch)).
- If the size of a gap does not meet requirements of Specifications, then, perhaps, inserts not of that size are established (that means need of their replacement). Before coming to final conclusion about need of replacement of inserts, make sure that under their backs dirt or oil were not in process of measurement of a gap. Besides, repeat measurement of diameter of a neck. If the flattened-out calibrated wire is wider from one of sides of a neck, then the last has conicity and the shaft needs a pro-point.
Final installation of a rod
- Carefully scratch out traces of plastic of the flattened-out wire from the surfaces of the bearing and a neck. Use a nail or an edge of a credit card.
- Make sure of perfect purity of bearing surfaces, then evenly grease them with a thin layer of molibdensoderzhashchy or assembly motive lubricant. For ensuring access to a bearing surface of a head of a rod and the piston it is necessary to push a little up the cylinder - do not forget to put on protective hoses bolts of fastening of a cover.
- Put on a rod back a neck, remove protective hoses from bolts, put on a cover bolts and tighten nuts with the required effort. Besides you make tightening in three stages.
- Repeat all procedure (including measurement of a gap) for the remained conrod and piston assemblies.
- Important points about which it is worth to remember at all is the following:
- Beds of bearings in rods and covers, and also backs of inserts have to be absolutely pure.
- In each of cylinders the conrod and piston assembly which is corresponding to it has to be established.
- Shooters (deepenings) on the bottoms of pistons have to specify on the engine forward.
- Locks of rings have to be oriented correctly (see
- Oil walls of cylinders pure motive.
- Do not forget to grease the surfaces of bearings at final installation of covers (after measurement of gaps).
- After completion of installation of all conrod and piston assemblies several times turn a bent shaft manually, checking it for lack of strong indications of jamming.
- In conclusion check an axial side play of rods (Section Removal of Conrod and Piston Assemblies).
- Compare results of measurement of an axial side play to requirements of Specifications. If the side play conformed to requirements before assembly and the former shaft and rods were established, the side play has to remain normal. In case of installation of a new shaft and rods the size of a side play can go beyond admissible limits. Then it is necessary to remove rods and to send them to a workshop of car service for machining.
- Continue installation of the remained components as it should be, the return to an order of their removal. Additional information it is necessary to look for Heads the Line six-cylinder engine (the 6-cylinder engine) and the V8 Engine (V8 engine).