A malfunction of the speedometer does not affect the overall performance of the vehicle and it can continue to move. However, the inability to control the speed limit can threaten not only with a fine for speeding or a problem with timely gear shifting, especially for novice drivers, but also with more serious consequences.
On a VAZ - 21099 car, the speedometer may not work for several reasons: a malfunction of the speedometer itself, a malfunction of the flexible shaft or a breakdown of the speedometer drive installed on the gearbox. The speedometer itself rarely fails, more often problems arise with the flexible shaft or with the drive unit, especially if an electronic speedometer is installed.
troubleshooting
To localize the malfunction, it is necessary to disconnect the flexible shaft from the gearbox. To do this, use the pliers to unscrew the round nut on the cable sheath and disconnect the shaft from the gearbox. Then clamp the shaft shank into the drill chuck and turn it on. If the arrow of the VAZ-21099 speedometer deviates, it means that the device is working properly, if not, the speedometer must be replaced.
If the speedometer works, you need to carefully inspect the tip of the flexible shaft. The tip should have a clear square section. If the edges are lapped and the tip is more round than square, then the flexible shaft must be replaced. When the edges are licked off, the shaft begins to slip in the drive, while the characteristic clicking is clearly audible and the speedometer needle will also twitch.
If the shaft tip is normal, then the speedometer shaft drive needs to be replaced. Also, if an electronic speedometer is installed, carefully inspect the wires connected to the sensor for fractures or breaks.
Replacing defective parts
To replace the flexible shaft of the speedometer with a VAZ - 21099, you need to disconnect it from the gearbox under the bottom of the car by unscrewing the round nut on the shaft shell with pliers. To disconnect the shaft from the speedometer, you will need to disassemble the dashboard and remove the instrument panel. To do this, use a Phillips screwdriver to unscrew the screws from the decorative pads on the steering column that cover the steering column switches.
In the two holes at the bottom of the dashboard, approximately at the level of the steering column, insert two flat screwdrivers and, pressing the latches, gently pull the dashboard towards you. The speedometer or flex shaft can now be replaced.
On old-style dashboards, to remove the instrument panel, gently pull out the right air deflector with a flat screwdriver. Through this hole, you need to squeeze the spring latch holding the instrument panel.
To replace the speedometer shaft drive, disconnect the flexible shaft from the gearbox drive. After that, unscrew one bolt and remove the drive by prying it with a flat screwdriver. If a new flexible shaft is installed, it is advisable to lubricate it along the entire length with Litol or CV joint grease, this will significantly increase its service life.
