For disassembly, it is recommended to use the R-770 turntable, on which the engine has the ability to rotate around the vertical and horizontal axes

Before installing the engine on the stand, remove the oil filter with heat exchanger, fan, exhaust manifolds, front support brackets, starter;

  • - rubbing surfaces of parts, except as otherwise specified, lubricate with engine oil during assembly;
  • - when fastening parts using threaded connections, ensure the appropriate tightening torque;
  • - non-metallic gaskets for ease of assembly, if necessary, install with grease applied to one of the mating parts. Make sure that the gaskets evenly adjoin the mating surfaces, are tightly clamped and do not protrude beyond the contour of the mating surfaces;
  • - when installing, lubricate the rubber sealing rings and lead-in chamfers of mating parts with grease;
  • - do not bend the studs when putting parts on them.

Recommendations for the removal, installation and troubleshooting of engine parts and assemblies

To remove the fuel pump drive gear assembly with the shaft:

  • - unscrew the four compressor mounting bolts and remove the compressor;
  • - unscrew the three bolts securing the power steering pump and remove the pump;
  • - loosen the tightening bolt 10 (Fig. Setting the fuel injection advance angle of engine 740.13-260) or 6 (Fig. Setting the fuel injection advance angle of engines 740.11-240 and 740.14-300).
  • - remove the rear bearing housing assembly with the cuff;

Removing injection pump drive gear assembly with shaft

- remove the drive gear of the high pressure fuel pump assembly with the shaft (Fig. Removing the drive gear of the injection pump assembly with the shaft).

When assembling, align the marks on the ends of the drive gear and the camshaft gear.

To remove the cylinder liner with puller 801.05.000 (Fig. Removing the cylinder liner with a puller), fold the grip along screw 1 and insert it inside the liner in this form.

Removing a cylinder liner with a puller

Having hooked the grip on the lower end of the sleeve 5, set it perpendicular to the screw, then install the supports 4 in the hole on the mating plane of the block and, turning the handle 2, unscrew the screw until the sleeve is completely removed.

To remove the flywheel housing:

  • - uncompressor;
  • - remove the power steering pump;
  • - unscrew the three bolts and remove the rear eyelet;
  • - remove the brackets for fastening the fuel outlet pipe from the injectors;
  • - unscrew the oil dipstick mounting bolt; unscrew the flywheel mounting bolts and mounting bolts with M8 thread

Removing flywheel with mounting bolts

  • - remove the flywheel;
  • - unscrew the bolts of the flywheel housing, remove the housing.

Cuff driver for flywheel housing installation

When installing the flywheel housing, to protect the cuff of the crankshaft shank seal, use a mandrel (Fig. Mandrel of the cuff for installing the flywheel housing):

- at the same time, generously lubricate the cuff with engine oil.

To repair the crankshaft, block and connecting rod, there are seven repair sizes of liners. The designation of the inserts is printed on its back side.

To remove and disassemble the connecting rod and piston group:

  • - remove the cylinder head (see "Gas distribution mechanism");
  • - remove carbon deposits from the upper belt of the sleeve;

Removing the lower connecting rod head with a puller

  • - remove the cover of the lower head of the connecting rod with a puller (Fig. Removing the lower head of the connecting rod with a puller):
  • - remove the piston assembly with the connecting rod from the cylinder;

Removing piston rings with a puller

  • - remove the piston to rings with a tool (Fig. Removing the piston rings with a puller);
  • - remove the retaining rings from the piston bosses with pliers I801.23.000;
  • - heat the piston in an oil bath to a temperature of 80-100 ° C;
  • - remove the piston pin.

When assembling and installing the connecting rod and piston group:

  • - install the compression rings with a conical surface (with the TOP brand) to the piston bottom, on engines 740.13-260 and 740.14-300 the upper ring is installed so that the internal selection is located on the side of the bottom;
  • - install the oil scraper rings as follows: first, insert the spring expander into the groove, then put on the oil scraper ring so that the expander joint is diametrically opposite to the ring lock;
  • direct adjacent rings with locks in opposite directions;

Installing piston with connecting rod and rings assembly into cylinder liner

  • - during assembly, install the piston and connecting rod so that grooves A under the valves in the piston bottom and groove “B” in the connecting rod under the lock mustache of the liner are on the same side (see Fig. Installing the piston with the connecting rod and rings as an assembly into the sleeve cylinders):
  • - do not press your finger into a cold piston;
  • - when installing the piston into the cylinder, first insert it into the holder И801.00.000 (see Fig. Installing the piston with the connecting rod and rings as an assembly into the cylinder liner):
  • - the index stamped on the bottom of the piston must be the same as the index stamped on the end of the sleeve, if there was no piston replacement. Move the grooves for the valves on the piston bottom towards the collapse of the cylinder block.

The marks of pairing from the numbers on the connecting rod and the connecting rod cap must be the same.

To remove the crankshaft dismantle:

  • - connecting rod and piston group;
  • - flywheel housing;
  • - the front cover of the unit with a fluid coupling assembly;
  • - oil pump with oil pick-up assembly;
  • - covers of main supports;
  • - remove the crankshaft with a hoist or hoists, hooking the first and fourth connecting rod journals with brass hooks.

When installing the crankshaft on the engine:

  • - align the marks on the gears of the drive units;
  • - ensure that the dimensions of the liners correspond to the dimensions of the shaft journals;

Installing crankshaft thrust bearing half rings

  • - install the thrust bearing half rings so that the grooved sides are adjacent to the thrust ends of the shaft (see Fig. Installing the crankshaft thrust bearing half rings):

Installing main caps

  • - make sure that the numbers of the main bearing caps match the serial numbers of the supports on the cylinder block (see Fig. Installing the main bearing caps) - the numbers start from the front end;
  • - tighten the bolts of the main bearing caps and the block coupling bolts in the following sequence:

Clean the threads in the holes of the block and on the bolts from dirt, lubricate the threads on the bolts with engine oil, remove excess oil.

Install the seating surfaces tightly, without warping the main bearing caps.

Installing the 16x3 washers, screw in the bolts M 16 for fastening the covers, providing a preliminary tightening torque of 95 -120 Nm (9.6 - 12 kgf.m).

Finally tighten the cover bolts, providing a tightening torque of 275-295 Nm (28 - 30 kgf.m)

Install and tighten the block tie bolts to a torque of 147-167 Nm (15-17 kgf.m).

Main bearing cap bolt tightening

When tightening the bolts with a torque wrench, the resistance should increase smoothly, without jerking. Count the moment when the key moves.

At the end of the tightening, the crankshaft should turn freely from the force of the hand applied to the dowel pins of the flywheel, the axial clearance in the thrust bearing should be at least 0.05 mm.

Note: During the transitional period of mastering the production, the engine can be used with a cylinder block with screwed pusher guides, with oversized camshaft bushings, without enlarged oil channels, with the tightening torques of the main bearing cap bolts:

  • - pre-tightening - 95-120 Nm (9.6-12 kgf.m);
  • - final tightening - 206-230 Nm (21-23.5 kgf m).
  • - the tie bolts are tightened with a torque of 81-91 Nm (8.2-9.2 kgf m).

To disassemble and assemble the crankshaft:

  • - remove the front and rear counterweights, as well as the crankshaft drive gear and the oil pump drive gear with the I801.01.000 puller.

Removing the gear and rear crankshaft counterweight with a puller

To remove the crankshaft gear and the rear counterweight of the claws 1 (see Fig. Removing the gear and the rear counterweight of the crankshaft with a puller), slide the counterweight over the edge of the counterweight gear and fix it with stoppers 5.

Screw 3 through tip 2 rest against the end of the crankshaft and, turning handle 6. screw screw 3 into crosshead 4 until the gear is completely removed.

Removing oil pump drive gear and crankshaft rear weight

To remove the oil pump drive gear and the crankshaft front counterweight (Fig. Removing the oil pump drive gear and crankshaft rear counterweight), install tip 2 on tip 3 and remove the gear in the same way as removing the crankshaft gear;

  • - turn the screw inside out;
  • - before assembly, clean the oil supply holes from deposits;
  • - wash the shaft and blow the channels with compressed air;

Note: when using a new crankshaft, it is necessary to unscrew the screw, wash the shaft, blow out the channels with compressed air.

Assemble the crankshaft in the reverse order, before pressing onto the crankshaft, heat the front counterweight, oil pump drive gear, rear counterweight and crankshaft drive gear to a temperature of 105 ° C.

Dimensions of parts, mm

Piston rings

  • Gap in the lock of compression piston rings * 0.4-0.6
  • Gap in the lock of the oil scraper piston ring * 0.30-0.60
  • End clearance of the upper compression ring 0.12-0.17
  • Lower compression ring end clearance*. 0.09-0.14
  • Oil ring end clearance* 0.077-0.112


  • The diameter of the finger holes. 44.987 - 44.994
  • Clearance in the piston-sleeve interface (at the length of the piston 104 mm from the bottom) 0.119-0.162
  • * Piston ring clearance is measured in gauge 0 (120+0.03) mm


Internal diameter 120.0 0 - 120.021

Piston pin

Piston pin diameter 44.993-45.000

Clearance in mating piston pin - upper connecting rod head 0.017-0.031


Thickness of main bearing shells 2.440-2.452

Conrod journal bearing shell thickness. 2.453-2.465


  • Main journal diameter 94.989-95.011
  • Main journal bearing clearance 0.085-0.152
  • Crankpin diameter 79.9905-80.0095
  • Clearance in crankpin bearings 0.06-0.104
  • Axial clearance 0.100-0.195
  • Shaft journal diameter for front counterweight and oil pump drive gear: 125.080-125.110
  • Join diameter for rear counterweight and crankshaft rear gear: 105.070-105.096
  • Rear collar neck diameter: 104.86-105.00
  • Transmission input shaft bearing seat diameter: 51.977-52.008
  • Flywheel locating sleeve hole diameter: 51.977-52.008

Fifth crankshaft main bearing thrust bearing half rings

Thickness 4.010-4.050


  • Intermediate bearing journal diameter 59.895 - 59.915
  • Intermediate bearing journal bushing diameter 60.00 - 60.03
  • Rear support neck diameter. 41.930 - 41.950
  • Rear bearing journal bushing diameter. 42,000 -42,015
  • Clearance in mating bushing - intermediate bearing journals of the camshaft: 0.135 -0.085
  • Clearance in mating bushing - rear camshaft bearing journal: 0.085 - 0.050
  • Gap in mating end of rear bearing housing - gear hub: 0.15-0.30

Timing Parts

The diameter of the push rod. 21.993 -21.972

Pusher guide hole diameter 22.000 - 22.023

Gap between push rods and guide: nominal 0.007 - 0.051

Gap between stem and valve guide, mm:

  • - inlet 0.03 - 0.072
  • - release 0.07-0.112

Angle α of the chamfer of the seat (inlet, outlet) 45° - 45°15

Angle γ of the chamfer of the valve (inlet, outlet) 44°45 - 45°

To remove the cylinder head when replacing, as well as to troubleshoot the valve mechanism and the cylinder-piston group:

  • - drain the coolant from the engine cooling system;
  • - unscrew the bolts of the exhaust manifold and remove the manifold;
  • - unscrew the bolts for fastening the intake air duct and the water collection pipe from the removed head, loosen the fastenings of the same bolts

On other heads in order to obtain the necessary clearance for removal;

To remove the right row cylinder heads, first remove the compressor from the engine.

  • - remove the connecting pipe of the intake air ducts;
  • - disconnect all pipelines from the head and protect their cavities from dust and dirt;
  • - remove the nozzle, protecting the atomizer from impacts and clogging of holes, cylinder head cover, racks with rocker arms and rods;
  • - loosen the cylinder head bolts, following the same sequence as when tightening (Fig. Sequence of tightening the cylinder head bolts), then unscrew them;
  • - remove the cylinder head from the engine.

When installing the cylinder head, pay attention to the correct installation of gaskets.

Cylinder head bolt tightening sequence

Tighten the cylinder head bolts in three steps in the sequence shown in fig. Cylinder head bolt tightening sequence.

After tightening the bolts, check and, if necessary, adjust the thermal clearances between the valves and the rocker arms.

For disassembly and assembly of the valve mechanism using I801.06.000 tool (see Fig. Dismantling the cylinder head in tool I801.06.000):

Cylinder head disassembly in tool I801.06.000

  • - place the cylinder head on the base so that the pins fit into the pin holes of the head;
  • - turning the knob, screw in the screw and wring out the valve springs with a plate;
  • - remove crackers and bushings;
  • - unscrew the screw from the traverse, remove the plate and valve springs;
  • - remove the intake and exhaust valves.

When assembling the valve mechanism, lubricate the valve stems with diesel oil.

Valve sizes

The dimensions of the valves are given in the figure

For lapping valves:

  • - disassemble the valve mechanism as described above;
  • - Prepare a paste of 1.5 parts (by volume) green silicon carbide micropowder, one part diesel oil and 0.5 part diesel fuel. Stir the lapping paste before use (micropowder can precipitate);
  • - apply a thin, even layer of paste to the valve seat chamfer, lubricate the valve stem with engine oil. Lapping is done by the reciprocating rotational movement of the valve with a drill with a suction cup or a device.

While pressing the valve, turn it 1/3 turn, then 1/4 turn in the opposite direction. Do not rub the valves in a circular motion.

Frosted band location on valve seat

Continue lapping until a uniform matte belt with a width of at least 1.5 mm appears on the chamfers of the valve and the seat (Fig. Location of the matte belt on the valve seat);

- after grinding, wash the valves and cylinder head with diesel fuel and blow with air.

Assemble the valve train as above and determine the quality of the valve seating by checking for leaks:

- install the cylinder head alternately with the inlet and outlet ports up and fill them with diesel fuel. Well-lapped valves should not let it pass through the seals for 30 seconds.

When leaking, the top tap the end face of the valve with a rubber mallet. If leakage persists, lap the valves again.

If necessary, check the quality of lapping "by pencil", for which, across the chamfer of the valve with a soft graphite pencil, apply six to eight dashes at an equal distance.

Carefully insert the valve into the seat and. pressing hard, turn ¼ turn, all lines should be erased, otherwise repeat lapping.

When properly lapped, the matte band on the head seat should start at the larger base of the seat taper as shown