Replacing the bendix on the car starter with your own hands

2024 Author: Erin Ralphs | [email protected]. Last modified: 2024-02-19 11:41

Bendix (aka overrunning clutch) is a mechanism designed to transmit torque from the starter rotor to the engine flywheel, as well as to protect the starter from high engine speeds. The element is highly reliable and fails quite rarely, but breakdowns do occur. A common cause of failure of the mechanism is the natural wear of the internal elements of the mechanism and springs. Let's see how the Bendix is replaced on a car with your own hands if it is broken.

How does this mechanism work?

Most freewheel models are a complex of several elements. So, among the components there is an outer ring or a leading cage, inside of which rollers and springs are installed. The device also has a driven clip.

On the leading cage there are wedge channels that differ significantlywidth 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 needed in order to drive the rollers into the narrow part of the channels.

Operation principle

The principle of operation of the bendix is an inertial effect on the gear coupling until it engages with the flywheel. When the driver turns the ignition key, current from the battery is supplied to the solenoid relay, and from it to the windings and the starter armature. Thus, the anchor is set in motion. Due to the presence of helical grooves on the inside of the bendix and the rotational movement of the armature, the clutch has the ability to slide along the splines until it engages with the flywheel crown.

Under the influence of the drive gear, the driven cage and gear are driven. If the teeth on the flywheel and on the clutch gear do not match, then the clutch turns to get a hard engagement. The design of the bendix has a buffer spring - it serves to soften the start of the engine. It also helps to avoid breakage of the gear teeth on the freewheel during engagement.

When the internal combustion engine has already started, the angular velocity of the flywheel is much higher than that with which the flywheel rotated the starter. Therefore, the clutch rotates in the opposite direction and slides along the splines in the opposite direction, disengaging from the flywheel.

How to check the mechanism?

Before the bendix is replaced, it is necessary to check the operation of the mechanism. This can be done likevisually as well as aurally. The last way is easier.

As already discussed above, the main task of the bendix is to enter into a rigid engagement with the engine flywheel ring and spin it up to a speed sufficient to start it. Therefore, if in the process of starting the engine you can hear that the starter has started and is spinning, and a clanking sound is heard from the engine itself, this is a signal that the bendix is faulty.

If there is a clanging sound, then you need to remove the starter. It is necessary to disassemble it, and then carefully inspect the bendix and its damage. To remove the starter, unscrew two or three mounting bolts.

So, the bendix has been removed and its revision is needed. You should check whether it rotates in one or two directions. If it rotates easily in each direction, then the bendix needs to be replaced. The mechanism is defective. After that, look at the gear teeth (whether they are intact). Then the spring is checked. It is important here that she not be relaxed. After that, remove the plug and study its integrity, wear. Be sure to check the backlash of the bendix on the armature shaft. If there is even minimal play, the bendix needs to be replaced.

Causes of malfunctions

The gear should only rotate in one direction. This speaks of a working mechanism. If it rotates in both directions, then this is a malfunction. Need to replace the bendix. There are several reasons for this operation of the node.

The diameter of the working rollers in the holder has decreased due to natural wear. You can inexpensively get out of the situation by selecting and acquiring balls of a suitable diameter. Sometimesmotorists use drill bits instead of balls. But self-activity in this case is undesirable. It's better not to even try to fix it. For example, replacing a VAZ bendix is a simple operation, and the price of a bendix is cheap.

There are flat surfaces on one side of the rollers. They are formed due to natural wear and tear. Repair is similar to the previous case. The working surfaces of the driving or driven cage are also ground off. It grinds especially actively in those places where the surfaces interact with the rollers. Repair is impossible, and unprofitable - it will not be possible to remove the development. The best and easiest 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 the 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 assembly will have to be repaired again.

Another reason for the failure and subsequent replacement of the VAZ-2109 bendix, for example, is the wear or breakage of the gear teeth. Wear and tear is usually natural and repairs again make no sense. You can only replace the gear, but it still needs to be found for sale, and this is difficult. Much faster to replace the entire freewheel.

Since the starter not only experiences heavy loads, but also hascontact with an aggressive external environment, it constantly gets dust, dirt, oil, moisture. Often, the bendix slips due to various deposits in the rollers and grooves. You can determine this by the noise of the armature and the stationary crankshaft of the engine.

How to replace the bendix with a VAZ-2110?

It will be much cheaper and faster for car owners to replace the Bendix with 2110. Let's see how it's done. First of all, unscrew the two upper bolts and one lower one, which attach the starter to the gearbox housing. Then the starter itself is removed. It is better to change the bolts to new ones - they get very sour over time, and when you try to unscrew them, they can easily break.

After that, the starter is dismantled. On the removed shaft, the retaining ring is removed - you can knock it down with a mandrel, and also knock it down using a high head by 15. The ring will be removed with pliers. Then the old bendix is removed.

A new spare part is put on the shaft, the retaining ring is installed in place. The replacement can be considered complete. After that, the starter is assembled, installed on the engine, the bolts are tightened, and the electrical part is connected. It is important to check the mechanism for serviceability before replacing the VAZ-2114 bendix and on other models, including foreign cars - now they often sell defective spare parts.

How to replace the mechanism on rear wheel drive vehicles?

Here the work algorithm is simple and accessible to everyone. Unscrew the bolts that secure the starter to the gearbox housing. The starter is attached with three bolts. If it has never been filmed, then you will have to work underby car. The last bolt from under the hood cannot be unscrewed.

Then, turning the starter to the right, remove the terminal on the retractor relay and a thin wire. After that, the starter can be removed. They clean it, unscrew the solenoid relay, unscrew the bolts that tighten the starter. Take out the back cover, winding and middle part. Also pull out the cotter pin, knock out the stopper. Now you can get the anchor and overrunning clutch. Immediately check the brushes, change worn parts. The new bendix is installed in its place at anchor. After that, the stopper is clogged, the cotter pin is installed, and the assembly is assembled. This completes the replacement of the VAZ-2107 bendix. You can install the starter and check it already on the car.

VAZ-2106

On the Soviet "six" the replacement process is carried out in a similar way. But only after the clamp is removed, you should remember the position. Then, the reverse part is pushed out from the back of the starter. Only then is the fork removed from the overrunning clutch.

Conclusion

Many people are afraid of the starter, but repairing it yourself will save a lot of money. Auto electricians perform simple starter repairs, and anyone can do it themselves.