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Transmission jerks when shifting — why and what to do?

Started to feel unpleasant jerking in the drivetrain? You should determine the reasons and find out whether it is harmful to the car.

First, divide the problem into two components. First we put such a box design, in which a gear shift controls the driver. The second — the various robots, machines and variable speed. It should be noted that jerks while driving is not only unpleasant for the driver and passengers, but also extremely harmful to the drivetrain of the car.

If the transmission began to twitch, she not only rapidly wears out itself, but also causes destructive torsional vibrations in the drive wheels, transfer boxes, driveshafts and rear axles.If the transmission began to twitch, she not only rapidly wears out itself, but also causes destructive torsional vibrations in the drive wheels, transfer boxes, driveshafts and rear axles.

Just need to cut off the problems caused by jerking of the engine. To do is sometimes difficult. It is not always at the same time on the instrument the symbol illuminates the “Check engine” (“Check engine”). Most often, the uneven operation of the engine cause a misfire in individual cylinders. The reasons may be different — a leak of unaccounted air, and the malfunction of candlesticks with nozzles, and leaky valves, and lower compression. To confuse the electronic engine control unit can malfunction of the speed sensor and defects in the idling speed controller coupled with the sensor fault throttle position. Well, the quality of fuel can not be discounted, as well as the water enters the cylinder through the entire fuel system.

In other words, one cannot argue that it pulls the gearbox. The engine also could contribute, so without a thoughtful diagnosis of the motor you start to repair the gearbox is not advised.

Another reason for the jerking of the entire power unit, not associated with transmission operation, is the failure of supports. With shattered legs even under normal loads, the entire unit will twitch, transmitting these vibrations to the body.

Manual transmission

In the case of mechanics most often twitches occur when a cold engine. A defect is considered not to be, but you need to try to avoid riding in these conditions.

Manual transmission simple in design and it is unlikely that she will provoke leaps in the transmission of torque from the engine to the drive wheels. But may suffer from malfunctions of the engine and clutch.Manual transmission simple in design and it is unlikely that she will provoke leaps in the transmission of torque from the engine to the drive wheels. But may suffer from malfunctions of the engine and clutch.

Jerks when shifting create shock loads on gears, couplings, shafts, bearings gear boxes. Possible gouges and other damage to these expensive and difficult to repair parts of the gear box. It often happens that the jerks caused by wear on the clutch mechanism, which when operated in a city or, on the contrary, quite broken poor rural roads feels overly heavy loads.

The educated driver good grip to pull the gearbox will not, but worn out, and even with inexperienced “driver,” can quickly cause damage.The educated driver good grip to pull the gearbox will not, but worn out, and even with inexperienced “driver,” can quickly cause damage.

Jerks possible due to the following error the driver when the transmission control and clutch:

  • not properly coordinated squeezing and releasing the clutch pedal with the gear change;
  • switching at too high engine rpm;
  • shock the throttle after the shift;
  • the movement is too high for the speed gear when the tachometer is less than 1200-1500 rpm and attempt to accelerate to this speed in the same gear.

Automatic transmission

Automatic transmission of different types is very complex in a constructive manner mechanisms. Reliable and trouble-free operation of such boxes can be provided if you constantly monitor the serviceability of the unit, regular preventive inspections and ensure quality service. Keep in mind that even a minor failure that the owner has ignored and not addressed to the specialists in time, may be the cause of the complete failure of this expensive device.

Let’s start with robotized gearboxes with single clutch. Suffer from all the defects described for manual transmissions. Plus suboptimal algorithms written in the software. And they, in my opinion, and may not be optimal: too many external and internal factors affecting the operation of this unit. Modern electronics are simply unable to accommodate all and to adapt the operation of the transmission.

The design of the robot with one coupling is not perfect, and jerks almost inevitable.The design of the robot with one coupling is not perfect, and jerks almost inevitable.

Active driver in the city nothing but white hair, such a transmission does not add. Believe that it is better to manually shift the transmission on the conventional mechanics than this, so to speak, automatic.

Robots with two clutch is the song: a modern box with the stuffing fast, convenient, economical. Until… that’s right, twitch. And here already it turns out that possible defects in the clutch, mechanical parts and electronics. If a robot with two clutches began to twitch, you need a professional diagnosis. The repair at this stage will be cheaper than if you make it to the moment when the car is not able to move independently.

Now consider the variators. This transmission, which has essentially no transmission and no twitching. Almost never happens. The principle of operation of CVT is the completely smooth, stepless transmission of torque and the same smooth and inextricably change. The jerks? Jerks — this is a disaster. Pressure of the friction elements of the variator has decreased so much that there is a periodic slippage. While there are unavoidable scuffing of rubbing surfaces, after that you need a complete disassembly and overhaul of the CVT. And the reasons for reducing the contact force can be insufficient fluid pressure, and in the failures of e-governance.

In the transmission with the CVT jerks shouldn’t be at all. While all properly.In the transmission with the CVT jerks shouldn’t be at all. While all properly.

We now turn to the classical hydromechanical automatic. Most manufacturers of this is brought to mind, reliable and durable device. Nevertheless, there are a number of situations where jerks when shifting will pester the owner. So, the jerks are possible:

  • At very low temperature “overboard”. Hydraulic fluid thickens, which leads to insufficient pressure to the actuators, and the movement becomes Jumpy as if the box is “entangled in the gear”. The solution is simple — warm up engine and automatic transmission at idle before driving. This will prolong the life of both. It is possible the vehicle is stationary several times to translate the selector in position D and R, so it is better to “disperse” the fluid in the box and only after that start moving.
  • “Old fluid”. Only the wine more expensive, the more endurance it has. The hydraulic fluid should be changed no less frequently than prescribed in the instructions. And usually better, if you constantly stand on the car in traffic. Sometimes to escape from the snow captivity on the Park is not easy. This process may require the machine and its transmission of all possible forces, which does not extend the life of both fluid and the whole Assembly.
  • “Underfill”. When there is insufficient fluid level in the automatic box fluid pressure may be insufficient to clear the operating mechanisms of the device. You should periodically check the fluid level in the gearbox and in a noticeable decline not just topped up, and immediately repair the leakage. “A minor” flow may damage the insides of the gearbox.
  • “Phantom” jerking. Until you get used to your car, it can take the manifestation of the adaptability of the gearbox for some jerking. The fact that the control electronics after a few trips in the same style, such as aggressive, then when smooth drive feels a little strange. But over time the owner realizes the algorithm of this behavior and getting used to it.

Classic hydro-mechanical multi-step automatic, being completely normal, not annoying the driver with unnecessary jerks.Classic hydro-mechanical multi-step automatic, being completely normal, not annoying the driver with unnecessary jerks.

All the jerking, in addition to an easy “adaptive” jerking of hydromechanics and unavoidable “kozlenev” robot with one grip, should not be ignored. Perhaps they are symptoms of the beginning of destruction of the box-machine, which saves you a lot of strength and nerves of mirror traffic. Take care you do not delay a visit to the service.

Suggest in the comments to share what jerks you’ve encountered in the operation of their automatic and manual transmissions.

Transmission jerks when shifting — why and what to do?Transmission jerks when shifting — why and what to do?Photo: “Behind the wheel.Of the Russian Federation”

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