Do-it-yourself repair and installation of the crankshaft in a VAZ 2106 car

01/26/2022 20 245 VAZ 2106

Author: Ivan Baranov

If the pressure in the lubrication system decreases or dull noises appear when the VAZ 2106 engine is running, the reason may be a faulty crankshaft. The article discusses the causes of malfunctions, as well as how to change the crankshaft of a VAZ 2106. In addition, a video is attached that demonstrates the partial assembly of a VAZ engine with the installation of the crankshaft.

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Symptoms of a problem

If you repair the crankshaft yourself, you can save a lot on car service costs. Therefore, it is worth understanding its diagnosis, repair and installation. If repairs are not carried out in a timely manner, the engine may seize, and this can lead to more serious repairs. The following are signs that serve to identify malfunctions:

• when the engine is running, the oil level control light does not go out, which indicates a decrease in oil pressure in the system;
• at medium and high speeds a metallic knock is heard in the engine, which increases with increasing speed;
• engine jams.

The cause of the first two malfunctions is the wear of the main and connecting rod journals. In this case, the distance between the neck and the liner increases, which leads to a decrease in oil pressure. If the distance is too large, the shaft may run out, causing metallic sounds in the engine. If the engine jams, it is better to replace the crankshaft. To diagnose the serviceability of the crankshaft, it should be dismantled and cleaned. It is better to remove the part together with the engine.

We remove the part from the VAZ 2106 for inspection

After removal, you need to perform a visual inspection of the necks and cheeks, according to which a decision is made on the need for grinding or replacement. No special instruments are needed for inspection; you can tell by touch. If scratches and burrs are found on the journals, the part is sent for boring. Boring can be done 4 times. Each boring increases the dimensions of the liners by 0.25 mm. After dismantling the crankshaft, you need to evaluate the size of the liners and whether they will allow boring. If grinding has never been performed, then the liners have an icon without any numbers.

Main bearings for VAZ 2106

If cracks are found, the crankshaft must be replaced. You can send it for welding, but usually restored parts last no more than 50 thousand kilometers. After boring, you need to polish the journals. Then the journals and crankshaft need to be washed with gasoline. The oil passages should also be thoroughly cleaned to prevent contamination from entering the bearings. After washing with gasoline, you need to blow out the oil channels using compressed air.

Crankshaft installation process

Before installing the crankshaft on the VAZ 2106, you need to wash, clean and dry the cylinder block. And only after that read the process.

Tools

To complete the installation you will need the following tools:

• a set of keys;
• Screwdriver Set;
• micrometer;
• consumables (liners, seals, half rings);
• torque wrench.

Set of repair tools

If defects in the form of scratches, burrs, or signs of wear are found on the surface of the liners, they must be replaced. The earbuds cannot be adjusted. When using the removed bearings further, you need to check the gap between them and the main and connecting rod journals of the crankshaft. For main shafts, the permissible size is 0.15 mm, for connecting rods - 0.10 mm. If the dimensions exceed the permissible limits, the liners are changed to a greater thickness after boring the necks. If the journals are properly ground and the appropriate bearings are selected, the crankshaft should rotate freely.

The oil seals that ensure the tightness of the crankshaft are replaced regardless of how long they have been standing. Half rings, like liners, cannot be adjusted. If burrs and scratches are found, the half rings are replaced. They are also changed if the axial clearance of the crankshaft is greater than the maximum permissible, which is 0.35 mm. The selection of new rings is carried out according to the nominal thickness or with a thickness increased by 0.127 so that the axial clearance is in the range of 0.06-0.26 mm.

Stages

Installation of the crankshaft on the VAZ 2106 is carried out in the following sequence:

1. First, the support bearing of the input shaft is pressed in.
2. Next you need to install new liners. The main liners are installed to the required repair size. The connecting rods are the same size, so they are interchangeable. When installing, you need to be careful not to mix up the bearings. The connecting rod bearings are smaller in diameter than the main bearings and do not have annular grooves.
3. Then you need to install the thrust half rings into the bed of the 5th main bearing. In this case, the grooves should be directed towards the crankshaft. Half rings are selected according to tolerances.

Replacing worn parts

• The main and connecting rod journals must be lubricated with engine oil.
• Now the crankshaft should be placed in the block.
• The bearing caps are installed according to the marks. The surface of the bearings and journals should be wiped well with a clean rag. When installing the covers, you need to ensure that the arrows marked on them are directed forward along the power unit. The fastening bolts must be lubricated with engine oil and tightened to a torque of 68-84 Nm.

• Next, the connecting rod bearings are mounted and the connecting rods are attached. The tightening torque should not exceed 54 Nm.
• We check the rotation of the crankshaft; it should rotate freely, easily, without play or jamming.
• Next you need to install the rear crankshaft oil seal.
• Next, the engine sump is installed on the block.
• When grinding, in any case, it is necessary to replace the front oil seal. It must be installed on the block along with the cover.
• After tightening the front cover, you can install the crankshaft pulley.
• Then the intermediate shaft, timing parts and cylinder head are installed on the power unit.
• Then you need to adjust the chain tension.
• Next, marks are installed on the camshaft and crankshaft.
• Then the remaining engine parts and components are installed.
• After installing the alternator belt, it is necessary to adjust its tension.
• At the last stage, the ignition is installed and adjusted.

When and why to change the front oil seal

The manufacturer recommends replacing the front crankshaft oil seal of VAZ 2101-2107 engines every 150,000 km. However, in practice such replacement has to be performed more often. Accelerated wear of the sealing element and the appearance of engine oil leaks are caused by:

• skewed oil seal during installation;
• loss of elasticity due to engine overheating;
• increased radial runout of the drive pulley of mounted units;
• use of low-quality motor oil;
• wear on the crankshaft pulley hub.

In addition, we cannot rule out hardening of the cuff due to natural aging and the possibility of a manufacturing defect - unfortunately, the quality of parts for rear-wheel drive VAZ models leaves much to be desired.

It is impossible not to notice damage to the sealing element - the rotating pulley scatters oil in the front of the engine and throughout the engine compartment. However, do not think that such a malfunction only leads to oiling of the units and a decrease in the lubricant level. If engine oil gets on the generator belt and other rubber parts, it can quickly render them unusable.

Keep in mind that the appearance of a leak through the engine seals is provoked by another factor - increased crankcase gas pressure. For this reason, be sure to check the cleanliness of the engine ventilation system.

Video “Assembling the engine of a classic VAZ car”

This video demonstrates the procedure for assembling an engine on a VAZ classic, including installing the crankshaft.

It is impossible to imagine an internal combustion engine without a crankshaft, since it is this part that allows the vehicle to move. The pistons are characterized only by translational movement, and the transmission requires torque, which can be obtained thanks to the crankshaft. Over time, the mechanism wears out and requires repair work. Therefore, it is important to know what needs to be done and in what order, and what tools to use.

The final stage

To secure, apply light blows with the handle of a hammer to the bottom of the piston, thereby pushing it into the cylinder. Screw on the second to fifth main bearing caps so as not to create a significant tightening. After this, purchase an odorless sealant from the store and apply a thin layer of it to the surface of the cylinder block in the place where it will come into contact with the first bearing cap.

After this, install a new sealing ring on the crankshaft and, after checking the location of the chain on the crankshaft sprocket, install the oil pump and pan. Also screw the removed cylinder head back into place, because only after this the structure can be completely assembled and the crankshaft considered replaced.

Why is a crankshaft needed in a VAZ 2106 engine?

The crankshaft (crankshaft) is an important part of the crank mechanism of any engine. The operation of the unit is aimed at converting the energy of combustion gases into mechanical energy.

Description of the VAZ 2106 crankshaft

The crankshaft has a rather complex design, with connecting rod journals located on the same axis, which are connected through special cheeks. The number of connecting rod journals on the VAZ 2106 engine is four, which corresponds to the number of cylinders. Connecting rods provide connection between the journals on the shaft and the pistons, resulting in reciprocating movements.

Let's look at the main elements of the crankshaft:

1. Main journals are the supporting part of the shaft and are installed on main bearings (located in the engine crankcase).
2. Crankpins. This part is designed to connect the crankshaft to the connecting rods. The connecting rod journals, unlike the main ones, have a constant displacement to the sides.
3. Cheeks are a part that provides connection between two types of shaft journals.
4. Counterweights are an element that balances the weight of connecting rods and pistons.
5. The front part of the shaft is the part on which the pulley and timing gear are mounted.
6. Rear end. The flywheel is attached to it.

Seals are installed in front and behind the crankshaft - oil seals, which prevent oil from escaping out. The entire crankshaft mechanism rotates thanks to special plain bearings (liners). This part is a thin steel plate that is coated with a low-friction material. To prevent the shaft from moving along the axis, a thrust bearing is used. The material used in the manufacture of the crankshaft is carbon or alloy steel, as well as modified cast iron, and the production process itself is carried out by casting or stamping.

The crankshaft of the power unit has a complex structure, but the principle of its operation is quite simple. In the engine cylinders, the fuel-air mixture ignites and burns, resulting in the release of gases. During expansion, the gases exert an impact on the pistons, which leads to translational movements. Mechanical energy from the piston elements is transferred to the connecting rods, which are connected to them through the bushing and piston pin.

An element such as a connecting rod is connected to the crankshaft journal using a liner. As a result, the translational movement of the piston is converted into rotation of the crankshaft. When the shaft makes a half revolution (turns 180˚), the connecting rod journal moves back, thereby ensuring the return of the piston. Subsequently, the cycles are repeated.

No less important in the operation of the crankshaft is the process of lubrication of rubbing surfaces, which include the connecting rod and main journals. It is important to know and remember that lubricant is supplied to the shaft under pressure created by the oil pump. Oil is supplied to each main journal separately from the general lubrication system. Lubricant is supplied to the connecting rod journals through special channels located in the main journals.

Neck sizes

The main and connecting rod journals wear out as the engine operates, which leads to disruption of the proper operation of the power unit. In addition, wear can be associated with various types of engine problems. These include:

The listed nuances lead to damage to the surface of the shaft journals, which indicates the need for repair or replacement of the unit. To assess the wear of the journals, you need to know their dimensions, which are shown in the table.

Table: crankshaft journal diameters

What to do when necks wear out

What are the steps to take if the crankshaft journals are worn out on a VAZ 2106? First, the defectiveness is carried out, measurements are taken using a micrometer, after which the crankshaft journals are polished using special equipment to the repair size. This procedure cannot be done in a garage environment. The necks are ground to the closest size (based on the tables provided). After processing, thickened liners (repair) are installed in accordance with the new size of the necks.

If a major overhaul of the engine is being carried out, it would not be superfluous to inspect the oil pump, blow out the oil passages of the cylinder block, as well as the crankshaft itself. Attention should be paid to the cooling system. If there are signs of wear or damage on the engine elements or its systems, the parts and mechanisms need to be repaired or replaced.

How to replace crankshaft bearings without removing the engine? A few tips

Sometimes, car enthusiasts and novice mechanics wonder how to replace crankshaft bearings without removing the engine.
There are several reasons for this interest. In many cases, it is simply not possible to remove the motor from the car. This unit is quite heavy, so you will need a hoist or the help of several strong men. If these conditions for removing the engine do not exist, then you will have to get rid of it and do the work directly on the car. But keep in mind that repairs without removing the engine somewhat resemble a perversion, which means you will have to tinker thoroughly. Therefore, still try to get helpers to remove the motor. How to replace crankshaft bearings without removing the engine? Before answering this question, let's figure out what earbuds are and why they should be changed. Everyone knows that bearings are used to ensure long-term operation of all rotating parts. They can be very different; in the engine, sleeve bearings are installed on the crankshaft - liners. They are a steel sheet of a certain shape, which is installed in the engine bed (main) or in the lower connecting rod heads. They have fasteners in the form of a tendril, which allows you to avoid bearing displacement during operation. There is also a special groove or hole for supplying lubricant. The inner surface has an anti-friction coating

, which significantly reduces the level of wear of the part

Please note that different coatings are used for different engine models; when selecting replacement liners, pay attention to this factor

Inserts are changed for several reasons, the initial one being wear, but the consequences can be different:

• Backlash
  . In this case, the crankshaft will knock. It is recommended to carry out repairs as soon as possible. In this case, replacement can be done even without removing and disassembling the engine;
• Cranking
  . As a result of excessive wear, the bearing tendril pops out of it and turns around the crankshaft journal. Sometimes this happens due to insufficient lubrication. Here, scuffs can form on the journal; the only option is to remove the crankshaft and grind it.

As you can see, the reasons for such repairs can be different. When the bearings rotate, further use of the car is impossible; the engine simply jams.

Crankshaft pulley

The generator and water pump on the VAZ 2106 are driven by a belt from the crankshaft pulley. When carrying out repair work on the engine, attention should also be paid to the condition of the pulley: is there any visible damage (cracks, scuffs, dents). If defects are found, the part should be replaced.

During the installation process, the pulley should sit smoothly on the crankshaft, without distortion. Despite the fact that the pulley fits quite tightly on the shaft, a key is used to prevent rotation, which can also be damaged. A defective part must be replaced.

Crankshaft marks

In order for the engine to work flawlessly, after installing the crankshaft, the correct ignition setting is necessary. There is a special casting on the crankshaft pulley, and on the cylinder block there are three marks (two short and one long) corresponding to the ignition timing. The first two indicate an angle of 5˚ and 10˚, and the long one - 0˚ (TDC).

The mark on the crankshaft pulley is located opposite the length of the marks on the cylinder block. There is also a mark on the camshaft sprocket that must be aligned with the casting on the bearing housing. To rotate the crankshaft, use a special wrench of the appropriate size. According to the marked marks, the piston of the first cylinder is at top dead center, while the slider on the ignition distributor must be installed opposite the contact of the first cylinder.