Replacing the Bendix on the starter of a VAZ 2109 with your own hands

Bendix is a device without which you cannot start your VAZ-2109 or any other car. Its task is to transmit torque from the starter rotor to the flywheel crown. It includes only two parts: a gear necessary for transmitting torque, as well as an overrunning clutch that prevents the first element from rotating in the opposite direction. If any violation occurs in this system, you will no longer be able to start the car and you will need to replace the Bendix on the VAZ-2109. Today we will analyze the procedure for KZATE starters, which are used by AvtoVAZ.

Design and principle of operation

Most overrunning clutches (let's call them the more popular word among motorists - bendix) consist of a driving race (or outer ring) containing rollers and pressure springs, as well as a driven race. The leading holder has wedge channels, which on one side have a significant width. It is in them that the spring-loaded rollers rotate. In the narrow part of the channel, the rollers are locked between the driving and driven clips. As is clear from the above, the role of the springs is to drive the rollers into the narrow part of the channels.

The principle of Bendix operation is the inertial effect on the gear coupling that is part of it until it engages with the engine flywheel. While the starter is inoperative (the engine is turned off or running in constant mode), the Bendix clutch is not engaged with the flywheel crown.

Bendix works according to the following algorithm:

Bendix interior

The ignition key is turned and current from the battery is supplied to the starter motor, driving its armature.
Thanks to the helical grooves on the inside of the coupling and the rotational movement, the coupling, under its own weight, slides along the splines until it engages with the flywheel.
Under the action of the drive gear, the driven cage with the gear begins to rotate.
If the teeth of the clutch and the flywheel do not coincide, it rotates slightly until they are firmly engaged with each other.
The buffer spring included in the design serves to soften the starting moment of the engine. In addition, it is needed to prevent tooth breakage from impact when the gears engage.
When the engine starts, it begins to rotate the flywheel at a higher angular speed than the starter previously rotated. Therefore, the coupling twists in the opposite direction and slides along the splines of the armature or gearbox (in the case of using a geared bendix) and disengages with the flywheel. This saves the starter, which is not designed to operate at high speeds.

Definition

The VAZ-2109 starter bendix consists of an overrunning clutch, a gear and a mechanical element, the task of which is to protect the starter from the teeth of the rotating flywheel. The gear transmits a rotational impulse to the flywheel, while the clutch itself rotates this same gear in one direction. Bendix suppresses noise when starting the power plant and extends the life (service) of the starter.

How to check starter bendix

If the starter bendix does not turn, then you can check its operation in two ways - visually, by removing it from the car, and “by ear”. Let's start the description with the latter, as it is simpler.

As stated above, the main function of the bendix is to engage the flywheel and spin the engine. Therefore, if, at the moment of starting the engine, you hear that the starter motor is spinning, and characteristic metallic clanging sounds are heard from the place where it is located, this is the first sign of a Bendix malfunction.

So then it is necessary to dismantle the starter and disassemble the bendix in order to inspect it in detail and determine the damage. The removal and replacement procedure is described below.

And so, the bendix was removed, it is necessary to inspect it. In particular, check whether it rotates only in one direction (if it turns in both, it means it needs to be replaced) and whether the teeth are eaten. Also check to see if the spring has weakened. You should also remove the fork from the Bendix, check its integrity, signs of wear, and if necessary, replace it. In addition, be sure to check if there is any play on the armature shaft. If this occurs, then the bendix should be replaced.

Typical faults

It is better to start diagnosing the starter even before you remove it.

After dismantling, some signs of failure, by which the source of the problems can be determined, can no longer be determined.

Signs of a faulty element include:

An unusual noise occurs when the engine starts;
Complete absence or slow rotation of the starter;
Rotation occurs, but there is no gear engagement with the Bendix ring;
The unit rotates with the bendix, but then the clutch breaks;
Turning the key in the ignition, there is silence.

Possible causes of failure

As mentioned above, gear rotation is only possible in the direction of rotation of the starter armature. If rotation in the opposite direction is possible, this is an obvious malfunction, that is, the bendix must be repaired or replaced. There may be several reasons for this:

Reduction in the diameter of the working rollers in the cage due to natural wear. The way out is to select and purchase balls of a similar diameter. Some car enthusiasts use other metal objects, such as pieces of a drill, instead of balls. However, we still do not recommend doing it yourself, but buying balls of the required diameter.
The presence on one side of the roller of flat surfaces formed due to natural wear. Repair recommendations are similar to the previous paragraph.
Grinding the working surfaces of the driving or driven race in those places where they come into contact with the rollers. In this case, repair is hardly possible, since such excavation cannot be removed. That is, it is necessary to replace the bendix.

Note! It is often better to completely replace the bendix than to repair it. This is due to the fact that its individual parts wear out approximately equally. Therefore, if one part fails, the others will soon fail as well. Accordingly, the unit will have to be repaired again.

Another reason for failure is wear of the gear teeth. Since this happens for natural reasons, repair in this case is impossible. It is necessary to either replace the mentioned gear or the entire Bendix.

Since the starter not only experiences heavy loads, but also comes into contact with the external environment and is susceptible to irritants such as moisture, dust, dirt and oil, freewheeling can also occur due to deposits in its grooves and rollers. A sign of such a malfunction is the noise of the armature when the starter is started and the immobility of the crankshaft.

Starter VAZ 2106 how to remove and replace it

The scheme for dismantling the old device and connecting a new one does not require special forces from the car enthusiast. Anyone who is “armed” with the necessary tools (screwdrivers, a mandrel, several keys - 10, 8 and 13, a hammer, pliers), will be able to remove the gear starter and will carefully watch the video of this process (for many car enthusiasts it is enough to study the photo of the operation so that the disassembly of the mechanism will be “ without a hitch").

The diagram for such disassembly and connection of a working device is elementary. First, the air filter (or rather its housing) is removed. To do this, you need to use a 13mm wrench. Use it to disconnect all three bolts that secure the filter to the gearbox housing. After this, the wires are pulled away from the starter and dismantled. Now you can begin disassembling the mechanism in the following sequence.

How to change bendix on the starter

As a rule, in order to change the bendix, you need to remove the starter and disassemble it. Depending on the machine model, the procedure may have its own characteristics. We will describe the algorithm from the moment when the starter has already been removed and to replace the bendix it is necessary to disassemble its housing:

Bendix repair

Unscrew the tightening bolts and open the housing.
Unscrew the bolts securing the solenoid relay, and then remove the latter. When repairing, it is advisable to clean and wash all the insides.
Remove the bendix directly from the axle. To do this, you need to knock down the washer and pick out the restrictive ring.
Before installing a new bendix, the axle must be lubricated with temperature grease (but without excess).
Typically, the most difficult procedure involves installing the retaining ring and washer. To solve this problem, craftsmen use different methods - they open the ring with open-end wrenches, use special clamps, sliding pliers, and so on.
After the bendix is installed, lubricate all rubbing parts of the starter with high-temperature grease. However, do not overdo it with the amount, because excess will only interfere with the operation of the mechanism.
Check the starter before installation. To do this, use wires to “light” the car in winter. With their help, supply voltage directly from the battery. Connect the “minus” to the starter housing, and the “plus” to the control contact of the solenoid relay. If the system is working properly, you should hear a click and the bendix should move forward. If this does not happen, it is necessary to replace the retractor.

Some tips from experienced drivers

Here are some tips from experienced motorists that will help you avoid possible problems and inconveniences when repairing or replacing a Bendix:

Before installing a new or repaired bendix, always check its operation and the drive of the unit.
All plastic washers must be intact.
When buying a new Bendix, it is advisable to have the old one with you in order to verify their identity. Often similar parts have minor differences that are not visually memorable.
If you are disassembling a Bendix for the first time, it is advisable to write down the process on paper or put the individual parts in the order in which they are dismantled. Or use the manual with photographs, video instructions above, and so on.

Main stage

It is necessary to adhere to the following algorithm of actions:

Open the car hood.
Remove the “-” terminal from the battery. This is necessary to avoid electric shock, since the work will involve power wires.
Remove the “+” terminal from the top bolt of the starter solenoid relay using a size 13 wrench.
Disconnect the nearby thin wire - pull it to the left, towards the wing. The purpose of this wiring is to energize the relay winding when the ignition key is turned to the “Start” position.
Using a size 13 wrench, unscrew the nuts on the starter. Three nuts are located on the front of the part: bottom, middle, top.
Remove the starter.

Price issue

Finally, it’s worth adding that Bendix is an inexpensive spare part. For example, a Bendix VAZ 2101 (as well as other “classic” VAZs) costs about $5...6, catalog number is DR001C3. And the price of Bendix (no. 1006209923) for VAZ 2108-2110 cars is $12...15. The cost of Bendix for FORD cars of the Focus, Fiesta and Fusion brands is about 10...11 $. (cat. no. 1006209804). For TOYOTA Avensis and Corolla cars Bendix 1006209695 - $9...12.

Thus, repairs are often impractical for Bendix. It's easier to buy a new one and simply replace it. Moreover, when repairing individual parts, there is a high probability of rapid failure of others.

What is Bendix, and in what cases is it required to be replaced?

Bendix is a clutch used to engage the starting electric motor and flywheel when starting the engine. Externally, the element is an oblique gear and is located on the starter shaft. At the moment it is triggered, it moves forward with the help of a solenoid and connects to the flywheel.

When the power supply stops, the gear returns to its place, disconnecting from the flywheel. The amplitude of movement of the clutch is about 10 cm. The bendix is protected from excessive displacement by locking rings.

Signs of a malfunctioning clutch are clearly visible, so the question of how to check the starter bendix usually does not arise. The “symptoms” of a malfunction include:

a grinding noise in the flywheel area when trying to start the engine;
the starter rotates idle, without transmitting torque to the flywheel;
a characteristic knocking sound at the moment the solenoid relay is activated, after which the shaft does not rotate.

» alt=»»> A faulty gear is usually not repaired, but replaced. Repairing the element is possible, but such actions are not justified in terms of financial and time costs. Therefore, if the coupling breaks, it must be replaced. If you still want to repair it, a detailed video will be at the end of the article.

Note: if the part extends, but does not engage with the flywheel, proceed as follows: put the car in 2nd gear and manually shift it a couple of centimeters. The position of the flywheel and helical gear changes, after which starting the engine becomes possible. Before attempting to start, the car is removed from gear.

This method is not a repair method, but it allows you to start the engine and get to your home or auto repair shop.