4.4.6. Dismantling and assembly of the block of cylinders, service of components

Dismantle and installation of a bent shaft and conrod and piston assemblies can be made without removal of the engine from the car.


Design of the block of cylinders (see also illustration of the Detail of installation of a flywheel / a driving disk)

1 — the Cover of the lower head of a rod
2 — Inserts of the conrod bearing
3 — the Rod with the piston
4 — the Piston finger
5 — Piston rings

6 — the Cover of the radical bearing
7 — the Bent shaft
8 — the Directing bearing
9 — the Insert of the radical bearing
10 — Casting of the block
11 — the Lock ring


  1. Remove the engine (see the Section of System of electric equipment of the engine).
  2. Remove a head of cylinders (see the Section Service of a Head of Cylinders and Components of the Gas-distributing Mechanism).
  3. Remove the oil pump (see the Section Removal, installation and service of the oil pump).
  4. Remove the pallet of a case and a flywheel / a driving disk (see the Section Removal and installation of the pallet of a case).
  5. Remove a back epiploon with a cover (see the Section Replacement of Epiploons of a Bent Shaft).
  6. Turn out fixing bolts and uncover radical bearings with collecting with inserts.
  7. Turn out fixing bolts and uncover the lower head of the first rod assembled with an insert. Rest the handle of the hammer against a rod head and, pushing conrod and piston assembly up, take it from the cylinder.
  8. Working in a similar manner, take the remained assemblies.
  9. For the purpose of prevention of confusion when checking a condition of components at once establish on the former places covers of conrod and radical bearings of a bent shaft assembled with inserts and record them fixing bolts.
  10. By means of an inertial stripper dismantle the directing bearing installed in a back pin of a bent shaft (see an illustration).



  1. Attentively study a condition of casting of the block. Check each cylinder for existence of cracks, zadir and other mechanical damages.
  2. Working in the manner similar described in the Section Dismantling and assembly of the block of cylinders, service of components, estimate extent of violation of planeness of the surface of the block interfaced to a head of cylinders (see an illustration). In case of need replace the block.

Restoration of planeness of the interfaced surface of the block by its machining is not admissible at all!

  1. Teases of mirrors cylinders can be pierced to the corresponding repair size in case such processing is not represented possible, replace the block.
  1. Measure diameter of each of cylinders at three levels and in two directions that will allow to reveal such defects as conicity and ovality. If results of measurements exceed extreme admissible values (see Specifications of the Head Dvigatel), cylinders should be chiseled to the next repair size. In conclusion of a mirror of cylinders there have to be otkhoningovana, - act according to the instructions attached to special honingovochny sets.
  1. Remove with a special vertical drill the step wear of cylinders left by the top compression ring at the end of the course of pistons.
  1. Remove lock rings, take piston fingers and make dismantle of pistons from rods.
  2. Study a condition of pistons, in case of identification of cracks, zadir and other mechanical damages prepare replacement.
  1. Measure diameter of each piston in the direction, perpendicular axes of a piston finger and on removal in 18 mm from the lower cut of a flute under installation of an oil scraper ring. By comparison of result of measurement with the size of diameter of the corresponding cylinder determine the size of a landing side play. If the side play exceeds extreme admissible value, replace the piston, having pierced the cylinder to the next repair size.

Along with the piston it is necessary to replace also piston rings (on corresponding the repair size, - see Specifications of the Head Dvigatel).

  1. Check piston rings for existence of signs of excessive wear, cracks, chips and other mechanical damages. In case of need make replacement.
  2. Serially filling piston rings in the cylinder and pushing them the piston bottom in the lower part of the last (the provision of NMT of the piston), measure sizes of gaps in locks of rings (see an illustration). Compare results of measurements to requirements of Specifications of the Head Dvigatel, in case of need chisel locks, or replace rings.
  3. Measure the size of a side play of landing of rings in flutes of pistons (see an illustration), in case of need replace the ring/piston.

Measurement should be performed in several points of perimeter of a flute. From this point rings have to remain "tied" to the pistons / cylinders.

  1. At the special stand believe rods on existence of signs of a bend and twisting (see an illustration). At excess by results of measurements of extreme admissible values replace defective components.
  1. Measure diameters under landing of piston fingers in pistons. Write down results of measurements.
  1. Measure diameter of piston fingers in places from a press fitting in the piston.
  1. Determine by way of subtraction of results of the first measurements from results of the second a side play/tightness of landing of fingers in pistons.
  2. By measurement of the corresponding diameters of piston fingers and openings in the top heads of rods define side plays of landing of fingers in rods. At excess by results of calculations of extreme admissible value make replacement of rods.
  3. Attentively study a condition of a bent shaft. Check his root and conrod necks for existence of zadir, traces of an overheat and other mechanical damages. Make sure of lack of violations of passability of oil openings.
  4. Having laid a shaft in prisms, check it for existence of a bend by means of the DTI measuring instrument (see an illustration).
  5. Measure diameters of necks, estimate sizes of their conicity and ovality. If wear of necks exceeds extreme admissible value, pierce them under the next repair size (do not forget to pick up the corresponding size repair inserts), or replace a shaft.

Do not cut off a rounding off of necks at all, - the minimum admissible radius of a rounding off makes 2.6 ÷ 3 mm.

Radius of roundings off of necks has to make not less than 2.6 ÷ of 3.0 mm.
  1. Study a condition of inserts of bearings. In case of detection of defects prepare a replaceable set. Spread out inserts as installation them to the engine.



  1. Before assembly make sure of absoluteness of purity of all components.
  1. Arrange the correct image the piston concerning a rod.
  1. Oil pure motive openings in the piston and the top head of a rod.
  2. By means of special nippers put a lock ring in a flute in one of piston openings, then fill in the last the top head of a rod.
  1. Through a suitable mandrel accurately begin to knock a piston finger, having fixed the piston on a rod. Record a finger the second lock ring.
  1. Working in a similar manner, mount the remained conrod and piston assemblies.
  2. Put the picked-up earlier piston rings on pistons: at first in the lower flute of the piston previously oiled dilator of an oil scraper ring is established, then its working sections (scrapers) are got.
Landing of the top scraper of an oil scraper ring.
Scheme of installation of components of an oil scraper ring.

Scrapers of an oil scraper ring are identical on a design and do not demand unambiguity of landing at installation.

  1. Further, in the remained flutes also plentifully greased lower and top compression rings (do not mix a ring - they differ in a section form) refuel, - track correctness of placement of rings, - they have to be established by the party marked with a letter of "R" up.
  1. Develop the rings put on pistons locks in the specified directions.
  1. Put in the block of cylinders masloraspylitel and tighten bolts of their fastening with the required effort (12 ÷ 18 Nanometers).
  1. Carefully wipe necks of a bent shaft, a back of inserts of radical bearings and their bed in the block, having completely removed from them oil traces. Enclose inserts and establish a shaft.

The central radical bearing is persistent.

  1. Once again wipe radical necks of a shaft, lay along them the calibrated plastic wire from the Plastigage set for definition of working gaps in sliding bearings.

Watch that the wire did not keep within over oil openings of necks!

  1. Wipe backs of inserts of bearings and their bed in covers, then establish the last, having tracked correctness of placement and, working strictly in a certain order, tighten bolts of their fastening with the required effort.
  1. Release fixture, uncover and, measuring width of the flattened-out wire on the scale applied on packing of the Plastigage set, determine sizes of gaps in radical bearings.

During check do not turn a bent shaft! If the result of measurement exceeds extreme admissible value, make selection of new inserts, in case of need pierce a shaft to the corresponding repair size and establish repair inserts.

  1. Having finished check, grease working surfaces of the picked-up inserts and radical necks of a shaft with pure motive oil, lay a shaft in the block.
  2. Establish covers of radical bearings, push a shaft forward against the stop, then return back it and tighten bolts of fastening of covers with the required effort.
  1. Check the size of an axial side play of a bent shaft and freedom of its provorachivaniye. Compare result of measurement to requirements of Specifications of the Head Dvigatel, in case of need pick up the new persistent bearing.
  1. By means of a suitable mandrel, put on a back pin of a shaft the directing bearing (see an illustration), - do not forget to oil previously the bearing and a pin motive. After installation fill the bearing jellied lubricant.
  2. Accurately fill conrod and piston assemblies in the cylinders: walls of pistons and a mirror of cylinders before installation should be oiled pure motive, to press out piston rings a special mandrel; it is the best of all to make pushing through of pistons in cylinders the hammer handle. Track that pistons were installed by tags in the form of letters of "F" on the engine forward.

At emergence of resistance it is necessary to stop immediately pushing through of the piston, to take assembly and to make sure of completeness of removal of step wear in the top part of the cylinder!

  1. Having put the lower heads of rods on conrod necks of a shaft, make measurement of working gaps in conrod bearings, - act in the manner similar described above for radical bearings. Remember that inserts of bearings when checking have to be established on dry, track correctness of an arrangement of covers.
  2. By means of the probe of lezviyny type make measurement of sizes of axial side plays of rods (see an illustration). Compare results of measurements to requirements of Specifications of the Head Dvigatel, in case of need replace the corresponding rods.
  3. Finalize conrod covers (having oiled the working surfaces of bearings), - track correctness of combination of landing tags and tighten bolts of their fastening with the required effort.

Carving parts of bolts and nuts before tightening also should be oiled pure motive.

  1. You make further installation as it should be, the return to an order of dismantle of components.