2.2.8. Dismantling and assembly of shatunno-piston group

ATTENTION Arrange the removed details (rods, covers of rods, loose leaves of shatunny bearings) as their compliance to numbers of cylinders to provide the subsequent correct assembly.

Fig. 2.71. Piston and rod components

Unscrew bolts of fastening of a cover of a rod, then uncover a rod and the bottom loose leaf of the shatunny bearing.

To Vytolknita the piston and a rod assembled from the block of cylinders in the direction to a surface under laying of a head of cylinders.

Fig. 2.72. Knot dismantling piston rod

By means of special tools (09234-33001 and 09234-33002) execute dismantling and assembly of knot of the piston and a rod (fig. 2.72).

The piston finger is pressed in the top head of a rod, and the piston slides on it.

The set of special tools consists of the basis with a support and the inserts, directing, adapters, a rod pusher for removal and a rod pusher for installation. At removal or installation of a piston finger the piston keeps on the basis of the adaptation. Directing adaptations facilitate positioning of a piston finger at its removal and installation when the rod leans on support inserts.

Fig. 2.73. Finger extraction by means of a press

For removal of a piston finger lay the piston on the basis and arrange a rod on a support insert. Insert a rod pusher (for removal) through an arch of the top part of the basis into a piston finger and take a finger by means of a press (fig. 2.73).

At installation of a new finger it is necessary to establish the corresponding insert of a support for rod support.

Arrange the top head of a rod in the piston. On the one hand the piston insert corresponding directing via the piston and a rod, then slightly besiege directing by hand that it was kept by the piston. On the other side of the piston insert a piston finger and lay together the piston and a rod on the adaptation basis so that directing a finger was from below.

Fig. 2.74. Directing rod centerings

NOTE The directing is necessary for a rod centering concerning piston lugs. If assembly is executed correctly, directing a finger will precisely stand on the center of an opening of an arch of the top part of the basis and to concern a support insert. If it is used directing a finger of the wrong size, the piston (and a rod) and a piston finger will not be on one axis with a basis opening (fig. 2.74).

Fig. 2.75. The scheme of a press fitting of a finger in the piston and the top head of a rod

Insert a rod pusher (for installation) through an opening of an arch of the top part of the basis against the stop into an adapter on a piston finger and by means of a hydraulic press get a finger in the piston and the top head of a rod. Continue a press fitting till the moment when directing a finger will fall from below the bases and a rod pusher (fig. 2.75) will rest against an arch of the top part of the basis.

ATTENTION Do not exceed effort 12500±5000 N at a press fitting of a piston finger during the moment when the rod pusher will rest against an arch of the top part of the basis.

Check each piston on absence of scratches, задиров, wear and other defects. Replace the piston in the presence of defects.

Check each piston ring on lack of breaks, damages or considerable wear. Replace defective rings. In need of piston replacement at the same time it is necessary to replace its piston rings.

Be convinced that the piston finger enters into piston lugs. Replace the piston and a piston finger with a set in the presence of defects. At room temperature under hand pressing the piston finger should enter into a piston opening easily.

Fig. 2.76. Check of a face gap of a kompressionny ring

Measure a gap between a kompressionny ring and a piston flute (fig. 2.76).

If the measured gap exceeds maximum permissible value, establish a new piston ring and repeatedly measure a gap. If the measured gap again exceeds maximum permissible value, replace the piston and rings assembled. If the measured gap less maximum permissible value, replace only piston rings.

Values of a gap between a piston ring and a flute of the piston are given below.

Nominal rate:

kompressionny ring No. 1 – 0,04–0,085 mm;

kompressionny ring No. 2 – 0,04–0,085 mm.

Maximum permissible value:

kompressionny ring No. 1 – 0,1 mm;

kompressionny ring No. 2 – 0,1 mm.

Fig. 2.77. Gap check in the lock of a piston ring

For gap measurement in the lock of a piston ring establish a piston ring in a cylinder opening (fig. 2.77).

Arrange a ring at right angle to forming cylinder walls, carefully moving it down by means of the piston.

Measure a gap in the ring lock flat shchupy (fig. 2. 78).

If the measured gap exceeds maximum permissible value, replace a piston ring.

Values of a gap are given in the lock of a piston ring below.

Nominal rate:

kompressionny ring No. 1 – 0,20–0,35 mm;

kompressionny ring No. 2 – 0,30–0,45 mm;

maslosjemny ring – 0,2–0,7 mm.

Maximum permissible value:

kompressionny rings No. 1 and No. 2 – 1,0 mm;

maslosjemny ring – 1,0 mm.

At replacement of piston rings without boring of cylinders in the repair size check a gap in the ring lock in a point located in the lower part of the cylinder (a zone of the smallest wear).

Fig. 2.78. Gap measurement in the lock of a piston ring

NOTE The identification label of the repair size is located on the top part of a piston ring about the ring lock.

Fig. 2.79. Grooves of loose leaves in a cover of a rod and a rod

At installation of a cover of a rod be convinced that labels of number of the cylinder (made when dismantling) on a rod and a cover of a rod coincided. At installation of a new rod be convinced that fixing grooves of loose leaves in a cover of a rod and a rod are located on the one hand (fig. 2.79).

Replace a rod in the presence of damage of a face surface of the top or bottom heads. If there is a bend or twisting of a rod or an opening surface under a piston finger at the top head of a rod is considerably worn-out, replace a rod.

Fig. 2.80. Installation of a dilator of a maslosjemny ring

Establish a dilator of a maslosjemny ring (fig. 2.80).

Fig. 2.81. Scheme of installation of the top scraper of a maslosjemny ring

Establish the top scraper of a maslosjemny ring. For scraper installation at first establish one end of a scraper between a dilator and a piston flute, then, holding the scraper end, press a finger a scraper to get it in a flute, as is shown in drawing 2.81.

ATTENTION Do not apply an ekspander of piston rings at installation of scrapers of a maslosjemny ring.

Fig. 2.82. Installation of the bottom scraper of a maslosjemny ring

Establish the bottom scraper of a maslosjemny ring according to the previous procedure (fig. 2.82).

Put engine oil on the piston and piston flutes under rings on all circle.

By means of an ekspander of piston rings establish a kompressionny ring No. 2.

Fig. 2.83. Scheme of installation of a kompressionny ring No. 1

Establish a kompressionny ring No. 1 (fig. 2.83).

Fig. 2.84. Scheme of locks of kompressionny rings

Arrange locks of rings as it is possible further from each other. Be convinced that the lock of any ring is not on an axis of a piston finger or perpendicular this axis the direction (fig. 2.84).

By means of the special adaptation reliably fix piston rings on the piston before piston installation assembled in the cylinder.

Establish the top loose leaves of radical bearings in the block of cylinders.

Fig. 2.85. Installation of the bottom loose leaf of the radical bearing in a rod cover

Establish the bottom loose leaves of radical bearings in covers of rods (fig. 2.85).

At installation be convinced that a "forward" label on the piston and a "forward" identification label on a rod are directed to a forward part of the engine (to a belt of a drive of GRM).

At installation of a new rod be convinced that fixing grooves of loose leaves on a rod and a cover of a rod are located on the one hand.

At assembly bolts of fastening of covers of rods should be tightened, using an angular method of an inhaling, as follows:

– put oil on a carving of nuts of fastening and a place of contact of a rod of nuts and bolts;

– tighten bolts of fastening of covers of rods the nominal moment of an inhaling.

Moment of an inhaling of nuts of fastening of covers of rods: 32–35 N · m.

ATTENTION Do not establish repeatedly former in operation (removed when dismantling) bolts of fastening of covers of rods. At installation of new bolts of fastening of covers of rods do not tighten them more than three times.

Check a lateral gap between the bottom head of a rod and the corresponding cheek of a cranked shaft.

Lateral gap of the bottom head of a rod:

nominal rate – 0,1–0,25 mm;

maximum permissible value – 0,4 mm.

Establish a maslozabornik.

Establish the oil pallet.

Establish a head of cylinders.