Starter
The starter is a powerful DC electric motor. It can burn out for many reasons, for example, due to holding the key in the “start” position for a long time. If the starter does not turn or clicks are heard from it, you should not immediately buy a new one, you can try to repair it. Often, it is replacing the Bendix on the VAZ 2110 starter that helps solve everything. On a VAZ 2110, replacing the Bendix starter can be done with your own hands.
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.
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.
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.
Bendix replacement
Replacing the Bendix VAZ-2110 and other front-wheel drive models begins with dismantling the starter.
To do this you should:
- remove the “-” terminal from the battery;
- Using a 13 key, unscrew and remove the power terminal from the electric motor;
- unscrew the starter mounting bolts with a 13mm wrench (2 on top and 1 on bottom);
- remove the starter.
It is worth noting that the electric motor mounting bolts often become so sour that it becomes difficult to unscrew them. In this case, you should not try to unscrew the bolt by force. This may cause it to break. It is necessary to tap the heads with a hammer, fill them with WD-40 liquid and wait 15-12 minutes.
After this, you can try again. Another way to unscrew a soured bolt is to heat it with a gas burner.
With the electric motor removed, the retaining ring is removed from the shaft. To do this, you need to knock it out of its seat with a special mandrel (if you don’t have one, a high 15 socket will do) and remove it using pliers. After this, the part can be easily removed by hand.
The above procedure answers the question of how to remove the bendix from the starter. In general, at this point the main part of the repair can be considered complete, since replacing the bendix on the starter after the old element has been dismantled is a matter of one minute.
The new spare part is put on the shaft, after which the electric motor is assembled in the reverse order. They put on the retaining rings, install them on the car, secure the starter itself and the power terminal with bolts, and return the removed terminal to the battery.
Note: a new element must be checked for serviceability before installation, since the quality of spare parts for VAZ cars leaves much to be desired. To check the functionality of the new element, you should put it on the shaft and try to turn it in both directions. A working clutch rotates only counterclockwise.
How does this mechanism work?
Most models of overrunning clutches are a complex of several elements. So, among the components there is an outer ring or drive cage, inside which rollers and springs are installed. The device also has a driven holder.
The leading holder has wedge channels that are significantly wider on one side. Rollers rotate in them, which are pressed down by springs. In the narrow part of the cage channels, the rollers are locked between the driving cage and the driven one. Springs are necessary to drive the rollers into the narrow part of the channels.
Performance evaluation
After completing the work, you should check how the engine starts. The starting engine should run smoothly, without knocking and grinding noises characteristic of a faulty overrunning clutch. This is a sign of a high-quality replacement of the Bendix on VAZ-2109-2115 cars.
In some cases, changing the bendix is not enough. Prolonged operation of a faulty clutch leads to wear and damage to the flywheel teeth. In this case, the symptoms of failure that existed before replacing the gear may become weaker, but do not disappear completely. In such cases, it is necessary to replace the flywheel.
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.
Do-it-yourself Bendix repair (video)
What else is worth reading
Hall sensor in distributor
Starter operating principle
Windshield replacement
Spar
Charging a car battery without removing it
Causes of malfunctions
The gear should only rotate in one direction. This indicates a working mechanism. If it rotates in both directions, then this is a malfunction. Bendix needs replacement. There are several reasons for this node to work.
The diameter of the working rollers in the cage has decreased due to natural wear. You can get out of the situation inexpensively by selecting and purchasing balls of a suitable diameter. Sometimes car enthusiasts use pieces of drill bits instead of balls. But amateur performance in this case is undesirable. It's better not to even try to make repairs. For example, replacing a VAZ Bendix is a simple operation, and the price of a Bendix is a pittance.
There are flat surfaces on one side of the rollers. They are formed due to natural wear and tear. The repair is similar to the previous case. The working surfaces of the driving or driven holder are also ground down. It wears off especially actively in those places where the surfaces interact with the rollers. Repair is impossible, and it is also unprofitable - it will not be possible to remove the workings. The best and simplest solution is to replace the Bendix on the VAZ starter with a new one. A starter from a foreign car requires the same approach.
Repairing Bendix is completely unprofitable. The fact is that during the operation of the starter, all elements inside the overrunning clutch wear out almost equally. Therefore, if something does not work, then the rest of the elements will soon fail. Replacing one or two rollers will not solve the problem - something else will break, and the unit will have to be repaired again.
Another reason for the failure and subsequent replacement of the VAZ-2109 Bendix, for example, is wear or breakage of the gear teeth. Wear and tear is usually natural, and repair again does not make sense. You can replace only the gear, but you still need to find it on sale, and this is difficult. It is much faster to replace the entire overrunning clutch.
Since the starter not only experiences heavy loads, but also has contact with an aggressive external environment, dust, dirt, oil, and moisture constantly enter it. Bendix often slips due to various deposits in the rollers and grooves. This can be determined by the noise of the armature and the stationary crankshaft of the engine.
Self-repair of starter on VAZ 2110, 2112, 2111 cars
Starter repair usually occurs on old cars, since this unit is quite reliable and lasts for many years without breakdowns, but no one is immune from low-quality parts and assembly. The most common malfunction is burning of the contacts on the retractor; there may also be a malfunction in the drive overrunning clutch or wear of the contact brushes. Disassembling the starter is not a difficult task and requires a small set of standard tools. The first thing to do is remove the starter from the car.
Next we will repair the traction relay. Repair may involve cleaning the contacts or replacing them completely, but first you need to remove it.
After removing the retractor, check whether the bolts are closed by the contact plate. To do this, push the armature in as far as it will go and measure the resistance on the contact bolts with an ohmmeter. If it is missing, then we replace the relay or repair it.
If you had a breakdown of the traction relay, then the disassembly ends here, but if everything is more serious, then we proceed to the next stage. To replace the brushes, armature, bendix, and starter gearbox parts, you will need complete disassembly.
The starter doesn't turn over
There are many reasons why the starter does not work, but first of all you need to check the most common reasons why the engine will not start.
Checking contacts on the battery
Often the reason when the starter does not turn is due to loose terminals on the battery or their oxidation. It is enough just to clean the oxidized terminals from chemical reactions and tighten them with a force that will ensure reliable contact.
Battery discharge
Quite often, especially in winter, after a period of inactivity, the car’s battery may discharge, and thickened oil during parking will not allow the weak battery to rotate the crankshaft with the starter. You can check the battery with a regular multimeter; in winter its voltage should not be less than 12V, in summer not less than 11V. This voltage is not an indicator of the battery charge; at such values it is better to charge the battery.
Egnition lock
In some cases, the contact part of the ignition switch may fail. This is due to aging or poor quality parts. In this case, when turning the key, the contacts will not close to turn on the starter.
Winding break
If the winding on the stator or rotor of the starter breaks, the magnetic field that rotates the armature will not appear and the starter armature will not move.
Repair of starter gearbox VAZ 2110, 2112, 2111
The gears that are inside wear out over time, metal shavings appear and the lubrication properties deteriorate. The gearbox must be well lubricated to reduce wear on parts.
The brush holder is easiest to change as an assembly.
When installing the brush holder, bend the clamps and remove the springs.
In order to check the anchor for possible defects, remove it from the housing.
We check the condition of the winding using a 220 V lamp. When we apply voltage to the collector plate and the armature core, the lamp should not light. If it lights up, then the armature needs to be replaced.
Useful tips
It is worth noting that when buying a new Bendix you need to have an old copy with you. Very often, different couplings differ from each other in small details that are not visually memorable. In the worst case scenario, you may end up purchasing the wrong mechanism.
Note! A cracked or worn plastic washer located on the starter cover can be replaced. If there is damage to the insulation on the mechanism pin, it can be repaired using electrical tape.
Today, any car repair can be performed at a service station, but in some cases you can do without this service. As a rule, this concerns minor repairs or replacement of components in mechanisms. Thus, with the help of video and photos, you can replace the bendix on the starter with your own hands. When disassembling the VAZ starter repeatedly, instructions are not needed, since everything can be done from memory. Self-repair is considered a profitable business, since the price of car service services is far from affordable.
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