Why does the first transfer turn bad? Driver's advice

One of the most common transmissions used on cars, including the VAZ brand, is mechanical. Although on many modern cars already in the design include an automatic gearshift. But they do not refuse to use mechanical boxes.

After all, the mechanical gearbox VAZ, like any other car brand, is very reliable, unpretentious and requires a minimum of maintenance. It is capable of withstanding significant loads without any harm to itself. Proof of this is the frequent use of this type of gearboxes on cars participating in various competitions.

But no matter how reliable and simple it was not a "mechanic", it also causes trouble. One of these malfunctions is that the first and back gear are badly turned on. And foreign cars are no exception.

But in order to understand why the first gear is turned on badly, it is necessary to first disassemble the design of this type of gearbox.

Transmission device

So, the gearbox layout is quite simple. There is a housing attached to the clutch housing. In this building are three shafts - leading, driven and intermediate. The peculiarity of the arrangement of the shafts is that the driving and driven shafts are on the same axis, with one end of which the driven shaft enters the leading shaft. Below them the intermediate shaft is installed.

On each of the shafts there are gears of different diameters and with a different number of teeth, while a part of these gears mounted on the driven shaft can move along it.

Principle of operation

The working diagram of the gearbox is as follows. The drive shaft receives rotation from the driven clutch plate and transfers it to the intermediate clutch . If the box has a neutral speed, the gears of the intermediate shaft are not meshed with the slave, the car is immobilized, as the rotation is not transmitted.

When a transmission is switched on, the driver engages the gear of the driven member with a certain intermediate gear. And the rotation begins to transfer from the driven shaft to the wheels. The car starts to move.

The gears are driven by a control unit consisting of three sliders and plugs. Each of the forks is wearing a special groove element. That is, the driver, using the gearshift lever and by means of a special link, acts on a certain slider, moving it to one side. In this case, the fork on the slider pushes the pinion, and it goes into engagement. The change in the speed of the gear shift is affected by the engagement of gears of different size and number of gears.

In order not to return the slider to the home position, the box control box is equipped with locks. The latter - spring-loaded balls that enter the grooves on the sliders. That is, there are grooves in certain places on the slider. When moving to the desired position, the ball retainer jumps into the groove, excluding the return of the slider. When switching the speed, the driver must press the slider higher than the spring of the lock so that the ball jumps out.

This is a simplified description of the design and operation of the mechanical transmission. Usually, according to this scheme, the VAZ gearbox of classic models works. On some cars, the circuit may be somewhat different, but the essence of the work is the same - the slider with the fork affects the gear.

In some cars in the CAT the slider, responsible for the inclusion of the first speed, also ensures the inclusion of the rear. At them also happens such, that the first and back transfer is badly included. Of course, one can not fail to pay attention to this breakdown.

At the other checkpoints, the first speed and the rear gear are separated and different sliders are responsible for their inclusion. In such auto problems with the inclusion of the first speed may not affect the inclusion of the rear.

Options, why the first transfer is turned on badly - a few. It also depends on how the reason is manifested - it is impossible to turn it on, while everything is accompanied by a metal screech on the side of the box, or the speed turns on, but immediately turns off on its own.

Bad inclusion due to the slider

First, let's look at why the first gear turns bad and the problem with the transmission is the fault.

Often, the problem with the inclusion of speed lies in the latch and the slider. The appearance of a hangnail near the groove for the catch on the slide can easily prevent the ball holder from entering the groove. When the slider moves, the latch rests against this barb and can not overcome it without significant effort on the part of the driver. In this case, the gears are very close, but do not enter into the gear, and the teeth of one gear are beating against the other. In the future such a run-out can lead to flaring of the teeth, and the impossibility of switching on will already be due to the fact that because of this rolling the teeth can no longer go into gear.

Knockout speed

If it turns on, but immediately turns off, it is possible to stick the latch in its squeezed position, so it no longer performs its work. It is also possible to destroy the spring, which presses the ball retainer. Without the force of the spring, it can not hold the slider in the desired position.

When making a significant effort, the power plug may bend during the power-up. If this happens, the gears will no longer fully engage, and the slider itself will not reach the stop, which will prevent the lock from entering the groove.

The cause of poor inclusion may be an incorrect installation of the handle of the gearshift knob. In this case, the link does not bring the gear for full engagement.

Troubleshooting the Transmission

Troubleshooting with the gearbox is done by removing it from the car, disassembling, defecting the parts, if it is found that some of them are badly worn. Particular attention should be paid to the condition of the sliders and retainers. If there are hangnails on the sliders, they need to be removed with the help of a file. Also it is necessary to check up a condition of springs and balls of a clamp. The springs must be intact, and the retainer can move without problems in its seat. If necessary, worn or damaged parts must be replaced.

Also, carefully inspect the plugs for bending. Even a slight bend can affect the ease of turning on the gear.

After the assembly, the shift adjustment must also be performed. To be precise, the position of the wings is set.

Malfunction of coupling

Often the reason why the first gear is turned on badly is not the box itself, but the clutch.

The modern transmission is equipped with synchronizers, which equalize the speed of rotation of the gears, ensuring ease of engagement.

However, the first speed synchronizer is not equipped. If the clutch "leads", then when the pedal is fully de-activated, torque transmission from the motor to the gearbox is not performed.

Because of this, there is a difference in the rotation of the shafts and gears of the first gear, in particular. In this case, it is difficult to put them into engagement, and all attempts to do so are accompanied by a strong metallic gnash.

It is possible that the rear speed will not turn on either, or it will be difficult to turn on. In this case, if you could still turn on the gear, the car starts to move even with the clutch pedal fully depressed. An additional sign of the problems with the clutch is that the car jerks when switching gears, especially if some of them are not equipped with synchronizers.

How to check the clutch?

To indicate the malfunction of the clutch, not the box, the engine of the car can help. If, with the engine stopped, all speeds are turned on easily, there are no problems, and when the engine is wound up, the first and rear gears are badly turned on, or it can not be turned on at all - you should pay attention to the clutch.

The reason that the clutch "leads" is often an incorrect adjustment. The squeeze bearing is too far from the squeeze diaphragm or cams. When the pedal is squeezed, this bearing is unable to fully squeeze the drive from the slave, and the torque continues to be transmitted. Affect the work of the clutch and its considerable wear and tear, because of which it and the beginning of the "lead".

Clutch adjustment and repair

The first thing to do in case of problems with the clutch, is to make adjustments. On different cars it is produced in different ways, but all operations are reduced to one - installation of a squeeze bearing at the necessary distance from the diaphragm or cams.

If the adjustment does not help, you will have to dismantle the clutch from the car, carry out the defect and replace the worn out items. Sometimes, over time, all parts of the system wear out. In this case, a complete replacement of the clutch - the driving and driven discs, the release bearing - is made.

Conclusion

The above are the main reasons for the fact that on the car it is difficult to switch gears. Although, as indicated in the beginning, if the mechanical transmission is very reliable, the more likely the fault of a bad inclusion is the grip, and not the box itself.