Attempt to start the engine of a car with an automatic transmission by towing another vehicle in most cases leads to expensive repair of the hydraulic transformer and frictions, since the design features DISTRIBUTION do not provide lubrication of the nodes with a non-functioning engine. Unlike mechanics, where the shafts are connected rigidly through a clutch, in the automatic torque is transmitted through the liquid, and the rotation of the wheels without running an oil pump causes dry friction and overheating of parts. If you find yourself in a situation where the starter does not turn, and the battery is discharged, you must clearly understand that the classic “light” cable does not work here and can become a fatal mistake for the transmission.
The main problem is that the oil pump automatic transmission It is driven by an internal combustion engine, not by wheels. When you tow a car with a idle motor, the wheels spin the output shaft, but the oil inside the box does not circulate, which instantly leads to bullies on rubbing surfaces. Therefore, the answer to the question of whether it is possible to pull another machine on the machine to start the engine is categorically negative for most modern models, although in rare exceptions for the old two- or three-speed boxes there were special modes.
Design features of automatic transmission and the risk of towing
To understand why the jerk method is dangerous, you need to consider the internal device of the automatic transmission. The key element here is hydrotransformerIt transfers energy from the engine to the transmission via the ATF fluid. When the engine is turned off, the pump does not create the necessary pressure, and the friction bags remain dry. If towing is started at this point, the mechanical connection between the wheels and the internal mechanisms causes the parts to rotate without lubrication, which is equivalent to the operation of the engine without oil.
Modern. 8-speed automatic transmissions and variators CVT They are more sensitive to the lack of pressure in the system. Even short-term towing at high speed can lead to irreversible changes in the structure of the metal and the destruction of Teflon rings. Owners often forget that the electronics of such boxes also require voltage to correctly switch solenoids, and with a fully loaded battery, the box can lock in emergency mode.
⚠️ Warning: Attempting to start the machine from the pusher or on the cable without prior heating of the transmission fluid (which is impossible without a working engine) is guaranteed to reduce the life of the box by 50-70% or disable it instantly.
There is a myth that if you quickly switch gears, you can turn the engine. However, in reality, the hydraulic resistance in the broken system is so great that the inertia of the accelerated car is not enough to create compression in the cylinders sufficient to ignite the mixture. Instead of starting, you will only get an overheated transmission and the need to evacuate on a tow truck.
Why the “push” method does not work for the machine
The method of starting the engine by accelerating the car, which works perfectly on the mechanics, is not physically applicable to a classic automatic machine due to the lack of a rigid connection between the input and output shafts. On a mechanical box, having squeezed out the clutch, you accelerate the mass of the car, throw the clutch, and the inertia of the wheels through the gearbox turns the crankshaft. In the case of DISTRIBUTION The connection is hydraulic, and to close it, you need pressure that is not present with a silenced motor.
Some drivers try to cheat the system, including high-speed transmission, but this only results in a sharp jerk that can damage the engine cushions or suspension elements, but will not start the engine. Hydrotransformer in this mode works as a viscosity clutch, extinguishing the impact loads, but not transmitting sufficient torque for the starter-generator. Moreover, electronic control units of modern cars in the absence of voltage simply will not open the fuel supply valves or sparks, making any physical manipulations pointless.
If you have a machine, always keep lighting wires or a portable starter (booster) in the trunk, as the towing method is closed for you.
The only theoretical option when the car will go from the rotation of the wheels is if the hydraulic transformer is already filled with oil under pressure, but the engine will stall. However, even in this case, the chances of a successful launch are minimal, and the risk of damage is minimal. friction It remains critical. Car manufacturers specifically design these units with the expectation of working only with an active pump.
Exceptions: When towing to launch is possible
Despite the general ban, there are rare exceptions to older models of cars produced decades ago. Some two- and three-stage automatic boxes installed on American cars of the 60s and 70s or early models VAZ and GAZAThey had a design that allows for towing to launch. In the instructions for such machines, there was often a special algorithm of actions that strictly regulated the speed and duration of the process.
There was a regime for such rare specimens Neutral, at which it was possible to accelerate the car to a certain speed (usually 30-40 km / h), and then sharply switch on Drive or Second. This created a hydraulic shock that could turn the engine around. However, relying on this method on a modern car, even if it looks old, is impossible without confirmation in the service book of a particular model.
It is important to note that even in permissible cases, the distance of the towing should not exceed 1 kilometer, and the speed should be the minimum necessary. Modern adaptive transmissions with a system SkyActiv or Tiptronic does not have such tolerances and when such intervention is attempted, they go into deep emergency mode, requiring computer diagnostics to reset errors.
Safe alternatives to engine start
Since it is impossible to pull a car with automatic transmission, owners need to know safe ways to resuscitate the car. The most reliable and common method is to use a start-up charger or “lighting” from a donor. This method is safe for transmission, as it does not require rotation of the wheels and creates the necessary conditions for the starter and pump immediately after start-up.
☑️ Right lighting
If there are no wires, you can use a portable lithium-polymer battery known as a booster. This compact device is placed in the glove compartment and allows you to start the engine even in severe frost, when the regular battery is lost. For vehicles with a system Start-Stop And complex electronics are often the only quick way to solve a problem without calling a tow truck.
In extreme cases, if the battery is completely dead and there are no launchers, only evacuation remains. You can call a specialized service or ask to tow the car to the garage or service, but strictly observing the rules for the transportation of cars with automatic transmission: either on a fully raised front axle (tow truck), or with a working engine (which is impossible when a failure occurs), or with a disconnected driveshaft, which is impossible in the field.
Comparison of Start Methods: Automatic vs. Mechanics
To understand the differences and risks, consider a comparative table of engine start-up capabilities in different ways for different types of transmission. This will help to finally see why the owners of machines should not even try the method of jerking.
| Parameter | Mechanical transmission (ICAT) | Automatic transmission (ACP) | CVT (CVT) |
|---|---|---|---|
| Launch from the pusher | Possible and safe. | categorically prohibited | categorically prohibited |
| Launch tow | Permitted (2-3 gears) | Inadmissible (risk of breakdown) | Inadmissible (chain breakage) |
| Dependence on ABC | I need a spark charge. | Need a charge for solenoids and pump | High dependence on electronics |
| Risk to the PPC | Minimum | Critical (dry friction) | Critical (cone bullies) |
As you can see from the table, gear-train Forgives many of the driver’s mistakes, allowing you to start “with a kick”. At the same time, box-box require careful care and the presence of voltage in the onboard network for any operation. The attempt to apply methods from mechanics to automaton is a direct way to replace expensive nodes.
It is also worth mentioning the robotic transmissions (DSG, PowerShift). They occupy an intermediate position, but on the principle of starting the engine closer to the mechanics, as they have a dry or wet grip. However, due to the complex actuator of gear shifting, starting from a pusher on robots is also not recommended by manufacturers, since electronics may not have time to properly close the clutch discs at the right time.
Rules of towing a faulty car with automatic transmission
If you can not start a car and it needs to be dragged for repairs or parking, it is important to observe strict restrictions. For most cars with automatic rifles, the rule “50 to 50” applies: the speed of towing is not more than 50 km / h and the distance is not more than 50 km. Exceeding these parameters without a working engine leads to overheating and jamming of the box.
Before starting the movement, it is necessary to transfer the selector lever to the position N (neutral) If the selector does not switch due to lack of power, you need to find the emergency unlock button (usually located next to the lever under the plastic plug) and press it to transfer the box to neutral. Without this step, moving the car from the spot will be impossible or extremely dangerous.
⚠️ Attention: Towing of all-wheel drive vehicles (4WD, AWD) with a cable automatic is often completely prohibited, regardless of distance. They can be transported only on a tow truck with full loading or with the disconnection of the driveshafts.
During the movement on the cable, try to avoid jerks and sharp braking. The automatic box in neutral mode still experiences loads, and any vibration is transmitted to the parts unprotected by oil. If you smell a burn or hear an extraneous noise from the transmission area, you should stop driving immediately.
How to unlock the selector without current
Find a hidden hole next to the automatic transmission lever. Remove the decorative pad. Press inside with a thin object (screwdriver, key) the emergency rod. Holding it, move the lever to the position N.
Diagnostics and prevention of launch problems
To avoid being in a situation where an emergency start is required, it is important to monitor the status of the battery and starter. Regular check of electrolyte density (for battery operated) and voltage under load will help to avoid surprises. For cars with automatic rifles, serviceable battery This is not just a source of current for the starter, but also a guarantee of the operation of the entire hydraulics of the box in the first seconds of launch.
If the starter starts to spin sluggishly or with a delay, this is the first signal to replace the battery or check the mass contacts. Ignoring these symptoms on a car with automatic transmission is fraught with the fact that the next time the engine may not start at all, and an attempt to pull the car will lead to breakage. It is also worth checking the tension of the generator belt, as its break will leave you without charge on the way.
Timely transmission maintenance, including oil replacement ATF The filters also reduce the risk. Pure oil better removes heat and ensures the valves work properly, which is critical for the longevity automatic box. Remember that automatic transmission repair costs many times more than a timely replacement of the battery or a call to the tow truck.
The main rule for the owner of the machine: never try to start the car by towing. Use wires, a booster or a tow truck.
Can you start on the machine if you push the car alone?
No, it's physically impossible. A person will not have the strength to accelerate a car weighing more than a ton to the speed necessary to create pressure in a hydraulic transformer (even if it theoretically worked). In addition, jump into the salon on the go and turn on the transmission without risking life will not work.
What happens if you accidentally pull the machine on the cable?
If the distance was short (several meters) and the speed was low, it may not be possible to do so. However, if you have traveled so for several kilometers, you need to check the transmission fluid for the presence of metal shavings and conduct computer diagnostics. The appearance of a hum or kicks when switching is a sign of damage to the frictions.
Is there a difference between a CVT and a classic towing machine?
Yeah, and it's substantial. Variator (CVT) is even more sensitive to the absence of lubrication, as the belt or chain works to compress cones under high pressure. Work "dry" for the variator is fatal in almost 100% of cases, requiring the replacement of the entire node part or box in the assembly.
How to tow a car with automatic transmission if the engine does not start?
The ideal option is a tow truck with full loading. If this is not possible, and the instructions for your car allow towing, then only in the position of the car. N, with speeds up to 40-50 km / h and a distance of up to 30-50 km. For all-wheel drive cars, towing on the cable is most often prohibited.