Replacing the speedometer cable of a VAZ 2107 carburetor

You don't have to be a driver to know that every modern car has a speedometer. It is difficult to overestimate the role of the device, which is responsible for measuring the instantaneous speed of a vehicle. Over time, like any other mechanism, it can fail, so every vehicle owner must know what to do in this case. Most often, the reason for the incorrect operation of the device lies in a breakdown of its mechanism or a break in the speedometer cable. And if in the first case experts recommend replacing the damaged measuring device, then in the second case the way out is to replace the speedometer cable.

Drivers of foreign cars, when identifying a particular malfunction, prefer to contact service centers, so we will look at information on how to change the speedometer cable using the example of cars from the Volzhsky Automobile Plant. In the vast majority of cases, their owners carry out minor repairs and maintenance work themselves.

Characteristic

It should be noted that this element is used only in mechanical speedometers. All cars were equipped with these until the 90s.

Closer to the “zero” years, electronic speed sensors began to be installed on cars. The type of cable also depends on the type of instrument cluster. This element is located in the gearbox. The speedometer cable (including VAZ-2113) reads data from the transmission shaft and transmits information to the instrument panel. This way the driver can control the speed of the car in real time.

Device

The mechanism also includes an odometer.

Using it you can read information about the mileage of the car. There are two scales on the instrument panel. The one on top is responsible for the total mileage of the car, and the one below is responsible for the daily mileage (up to a thousand kilometers). All readings are taken from the cable. The speedometer and odometer are directly connected. The design of the element assumes the presence of high-speed magnetic units. Due to the rotational force of the magnet, a flow of eddy currents is formed. Passing through the coil, currents create a magnetic field. Thus, the speedometer needle on the instrument panel begins to move along the scale. The rotational force is proportional to the frequency at which the magnet rotates.

When reviewing the design of such an element as the speedometer cable, the question arises: how does the needle not fall if the gear ratio on the gearbox shafts is different? Everything is very simple. There is a small gearbox inside the element. On rear-wheel drive vehicles, it also serves as a secondary shaft. The position of the needle on the scale depends on the strength of the magnetic field in this gearbox itself. This way the driver receives accurate information about the mileage and current speed of the car.

Finding the cause of the breakdown

Cause of malfunction

Identifying the cause of a malfunction is not difficult. You need to twist the cable with your fingers, while observing the position of the speedometer needle. If it rotates smoothly and there are no jerks in its movement, then the problem is a broken cable. In this case, to fix the problem, it is necessary to replace the damaged cable.

The fact that the speedometer mechanism has deteriorated is indicated by jerky movement of the needle or a complete lack of response to the rotating cable of the device. In such a situation, you cannot do without a complete replacement of the device.

Is there any error

It is worth noting that the readings on the instrument panel (if it is a mechanical element) may differ slightly from the real ones. But often the error does not exceed five percent.

So, the speedometer readings are affected by the size of the rims, tire profile and gear ratio (if it is a rear-wheel drive car). Absolutely identical cars are supplied from the factory with different axles, with a different gear ratio (on average, it ranges from 3.9 to 4.4 for classic VAZs). Therefore, many manufacturers began to abandon cable speedometer technology. Nowadays, cars use an electronic sensor. Its error does not exceed one percent. And replacing it is much easier (you just need to disconnect one block with wires).

Basic faults

Such a part as the speedometer drive cable is highly reliable. But problems with this mechanism cannot be ruled out (especially since the technology is very outdated). So, during operation, the arrow on the instrument panel may twitch or even stop responding to changes in speed. What to do in such a situation? It is not necessary to replace the speedometer cable. The reason may be a simple loosening of the nut that secures the flexible shaft to the drive. In this situation, winding the speedometer, or rather, tightening that same nut, will help. In half of the cases the problem goes away on its own.

But there are also more significant faults for which only repairing the speedometer or replacing it completely will help. So, the drive shaft itself fails. He is interrupted. The malfunction is accompanied by a characteristic knocking sound. The arrow stops showing reliable information. What could be the reason for this phenomenon? A drive breakage occurs due to the presence of contaminants inside it. The counter spring also breaks. In any case, the speedometer cable needs to be replaced (if tightening the nut did not help). Below we will look at how to change this element with your own hands.

About the speedometer drive on the VAZ 2107 and its replacement

In order for the driver to be able to control the speed of the vehicle, a speedometer or speed indicator is provided in the design of the instrument panel. Few people think about how it works until it malfunctions. The drive mechanism is responsible for its operation, for which the VAZ 2107 uses a cable. This speedometer cable on the VAZ 2107 is far from eternal, so if a malfunction occurs, it will need to be replaced.

Basic malfunctions of the speedometer drive mechanism

Structurally, the VAZ 2107 speedometer drive is a flexible steel cable, which is in an armored braid. This braid serves as a fixed base, since the main task of the cable is rotation. When it rotates inside the braid, torque is transmitted, which is removed from the gearbox and transmitted to the speedometer sensor. The braided cable design also uses connecting elements to transmit torque. One of these devices connects the drive to the gearbox gearbox, and the second to the speed indicator mechanism.

Knowing the structure of the drive mechanism, it is necessary to analyze its malfunctions. These malfunctions can be divided into two types:

• The main ones are when the speedometer completely stops functioning and displaying information about the current speed of the car.
• Secondary - when the speed indicator works, but at the same time makes extraneous noise.

The causes of the main types of breakdowns of the speedometer drive of the seven are as follows:

1. Malfunction of the speed dial indicator. It happens rarely, but such a breakdown is not excluded.
2. The flexible shaft has broken, which means the integrity of the steel cable is being compromised. To correct the situation, you need to change the cable.
3. Self-unscrewing of the fastening nuts that secure the ends of the drive mechanism. This damage can be eliminated by tightening the fixing nuts.
4. If the tips of the flexible drive are damaged - the driven and drive gears. When the speedometer on a VAZ-2107 does not work, the reasons for the breakdown may be hidden in a violation of the integrity of the tips, so in case of such a breakdown, you will need to replace the cable. If the speed indicator mechanism is damaged, the last part must be replaced, but the cable may still be in good condition.

5. Flexible shaft drive malfunction. This is one of the most difficult breakdowns, when the breakdown concerns not the drive, but the gearbox. If the gearbox mating socket breaks down, the device will need to be repaired.

Also, during the operation of the seven, a type of breakdown may occur such as the occurrence of extraneous noise emanating from the speed indicator. The reasons for this phenomenon are:

• The bending radius of the cable is small, so it begins to rub strongly against the braid and creak. The damage can be corrected by leveling. If the device is not damaged, then it must be reinstalled.
• When the braid is damaged. The cause of damage is a violation of the integrity of the protective layer of the armored base. If the protective base is damaged, the drive must be replaced.

Only after a breakdown has been identified can a decision be made to fix it. Most often, the cause of speedometer malfunction is the cable, so let's look at the process of replacing it.

Tools for replacing the VAZ 2107 speedometer drive

To replace the speed indicator drive of the seven, you will need a minimum set of tools, as well as half an hour of time. The only tools you need are a screwdriver and pliers. To simplify the replacement work, it is recommended to use steel wire, the diameter of which should be in the range from 0.3 to 0.5 mm. A mandatory condition for the wire is its length, which is at least 2 meters.

It is better to carry out replacement work from the inspection hole, since the cable mount in the gearbox is located in the lower part of the car. The replacement process is not difficult, so it is enough to do everything once in accordance with the instructions in order to do the work yourself the next time you replace it.

This is interesting! The question often arises: how many teeth does the speedometer drive gear have? This is important to consider because if you install a gear with the wrong number of teeth, the indicator will display incorrect information about speed and mileage. The number of teeth on the drive gear of the flexible speedometer drive is 13. This must be taken into account if the tip in the gearbox is changed.

Removing the speed indicator cable on the seven

Step-by-step instructions on how to replace the speedometer cable on a VAZ 2107 are as follows:

1. Place the vehicle on the inspection hole and remove the negative terminal from the battery.
2. To get to the flexible drive mount where it connects to the speedometer, you will need to remove the instrument panel.
3. Find the connection of the device to the speedometer, and unscrew the fastening nut of the element.

4. After this, tie a steel wire to the device, which will tighten instead of the cable when it is pulled down.
5. Move to the inspection hole and find the point of attachment of the device to the gearbox.
6. Using pliers, unscrew the fastening nut and then slowly dismantle the flexible element.
7. The cable must be pulled from below so that the steel wire is pulled into its place.
8. Once the device is removed, you will have the end of the wire in your hands. It must be disconnected and then proceed to install a new device.

If you do everything according to the instructions, you won’t have to worry about inserting a new cable into its location. The cable should be pulled exclusively from bottom to top, but not vice versa. This is due to the fact that the tip in the area where it connects to the gearbox has thickenings, so the cable simply will not pull out of the passenger compartment.

Installing the cable

The installation process is similar to the principle of dismantling and is performed in reverse order. Initially, experts recommend removing the steel core and lubricating it with Litol. This will increase the service life of the device. After these manipulations, the core is installed back, secured to the wire at the bottom of the car, and tightened into the interior.

As soon as it is tightened into the cabin, you should screw the fastening nut to the mount on the instrument panel, and then move down again and secure the device to the gearbox. When attaching the device to the tip on the gearbox, it is necessary to take into account that the cable has a protective cover. It is for this case that it is necessary to focus on the correct installation of the device in place. At this point, the replacement of the speedometer cable has been successfully completed.

This is interesting! When tightening the new drive unit, the rubber seal between the passenger compartment and the engine compartment will be displaced. It should be installed back, otherwise dust, dirt, moisture and cold air will enter the interior.

How to check the mechanism for functionality

After changing the cable yourself, you need to make sure that everything was done correctly. To do this, you need to carry out a visual check and make sure that the cable is not damaged anywhere and is not bent. Only after this can you start the engine and check the serviceability of the device. The correct operation is checked by driving the vehicle.

I drove 100 meters and it will be clear whether the problem was fixed or not. On VAZs the replacement process is not difficult; sometimes it is more difficult to find a good new flexible drive than to change it. When purchasing, keep in mind that a good cable will not cost a penny, and its estimated cost is 300-500 rubles.

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Dismantling

First of all, you need to remove the old mechanism. To do this, you need to de-energize the vehicle's on-board network by removing the negative terminal from the battery. Next, disconnect the old element. How to remove the speedometer cable with your own hands? To do this, you need to find the connection point of the mechanism and unscrew the fastening bolt that secures it. Regardless of whether the car is front- or rear-wheel drive, the end of the cable is located on the gearbox. For convenience, it is better to use a viewing hole. So, unscrew the fastening bolt and remove the clamping nut that connects the cable to the speedometer in the cabin.

Next we move on to the second part of the dismantling. To completely remove the element, you need to partially disassemble the instrument panel. From the reverse side, remove the second end of the cable.

When dismantling, try not to damage the rubber sealing gasket.

Replacing the speedometer cable on Niva

Once I turned to auto repairmen I knew a couple of times with a request to replace the speedometer cable on my Niva, but I didn’t meet with enthusiasm or understanding, apparently it was cheap and tedious, and after living for half a year without a speedometer, I came to the disappointing conclusion - I’ll have to change it myself.

It turned out that it’s okay, and now I’ll show you how it’s done.

The speedometer cable on the Niva is attached at one end to the dashboard and the other to the transfer case, so replacing it will require a pit, overpass, or lift.

You can jack up the car on blocks of wood, which is what I did.

We start from the bottom, otherwise it will be impossible to pull out the dashboard (I unknowingly started from the top, but this is no longer in danger for you).

The speedometer cable cap can be unscrewed and removed manually, but if it gets stuck, you can use pliers, but without pressing hard.

All that remains is to cut the ties that attach the electric cable to the cable. connecting the speed sensor, and you can move to the top, since the cable is freed, and in fact, if you wish, you can pull it out into the cabin, but let’s wait for now.

In the cabin, we look under the steering column and unscrew the two screws that secure the dashboard trim

The cladding is fastened on top with metal clips, so that without self-tapping screws it is simply pulled out with force, after which the long plastic nuts of the bolts securing the panel itself are unscrewed, and the entire panel is pulled out.

If the panel does not want to be removed, then you need to tighten the cable from below, since only it can hold it.

Installation

The procedure for installing the element is the reverse of removal. To do this, we lay a new speedometer cable through the panel in the cabin and “pull” it to the transmission. Try to secure the element in the same way as the old one. If it is a front-wheel drive car, where the gearbox is installed in the engine compartment, the mechanism is routed through a special hole in the partition between the passenger compartment and the engine compartment. All rubber seals are installed in their places. Depending on the make of the car, there may be a different number of them (but in any case at least two).

Removing the dashboard and speedometer

New cable

It is impossible to identify the cause of the speedometer failure without dismantling it. The round-shaped speedometers produced these days can be removed from the seat after the instrument panel has been disassembled. It can be removed after dismantling the decorative linings of the steering column and removing the rubber seal, which is located near the ignition switch. In the opened opening there are fastening elements in the form of brackets. They are easy to remove using slotted screwdrivers. At the last stage, the panel is removed from its seat.

The old-style measuring device is also easy to dismantle. First of all, the ventilation grille is removed. This is done in order to gain free access to the fastening elements that secure the dashboard. After pressing the latches, the panel can be easily removed.

Useful tips

When performing operations with this mechanism, pay attention to the following points:

• When purchasing a new element, be sure to check the length of the cable. On identical car models, its size may be different. It is unacceptable to use elements shorter or longer than the standard size.
• Before installing a new speedometer cable, it is recommended to apply a layer of lubricant to it. This will prevent premature failure of the mechanism. You can use regular mining or Nigrol.
• When installing, try to lay it as it was from the factory. It is unacceptable for the cable to come into contact with moving parts. Also, do not use tight loops when laying. This will increase the load on the cable core, and it will quickly fail even with a good layer of oil.

Causes of speedometer malfunction

Speedometer malfunction

There are two reasons why the speedometer may fail:

• malfunction of the device mechanism;
• breakage of the speedometer drive cable.

Broken cable

We will dwell in more detail on the second option, because in the first case it is best not to repair the device yourself, but to buy a new speedometer.

Rewinding the speedometer

Let's tell you a few words about such a device as a “twist” for the speedometer. The element is designed to rewind odometer readings. It is connected via the OBD diagnostic connector. The device interferes with the control unit and independently increases the mileage readings. The device is based on a CAN bus. Mileage is adjusted not only on the instrument panel, but also in all duplicate blocks. It is quite difficult to determine cheating using such a device. Who uses such devices? They are used on owner's cars in order to “get rich” on fuel. So, the car travels 100 kilometers, and the dashboard and ECU display a mileage of 110. The cost of such a device is 3.5 thousand rubles.

Signs of problems with the speedometer

Symptoms of a problem

The following describes typical needle behavior typical for an unstable device:

• the arrow freezes in one place and remains in this position both while driving and while parking;
• the arrow “lies” at zero;
• the process of measuring speed is accompanied by trembling or significant oscillations of the needle in different directions.

Settings

To ensure that the speedometer readings have a minimum error, experts recommend making additional adjustments. To do this, measure the distance from the beginning of the damper to the clutch fork. The parameter should be 86 (+5) millimeters.

Next, measure the gap between the end of the damper and the tip of the cable. The normal parameter is 65 millimeters with a margin of 5 mm. If your readings differ from the factory ones, you should adjust the cable tension with a wrench using a lock nut. After this, you can start operating the car.