In winter, many drivers face the fact that the automatic transmission behaves strangely: gears engage with a delay, shifts become harsher, and jerks are felt when starting to move. Most often, this is attributed to the cold and is considered a temporary feature of operation in frost. However, according to Yulia Trushkova, Service Director at Rolf, such behavior of the automatic transmission is not normal, but a sign of emerging or existing problems.
According to the expert, you should be alerted by delays when shifting immediately after starting to move, prolonged holding of the first gear, incorrect operation during acceleration, slight jolts when shifting from first to second gear or when engaging R and D modes. Vibrations, a feeling of slippage, and an uncertain start even after a short warm-up are also possible. If the gearbox starts to work adequately only after 10–15 minutes of driving, this is already a symptom of a malfunction, and not a harmless reaction to the cold.
One of the key reasons for problems in winter is the thickening of the transmission oil. Even modern synthetic fluids lose their fluidity noticeably at temperatures around −20 °C. The situation is aggravated if the oil has not been changed for a long time: oxidized and contaminated ATF thickens faster and is pumped worse through the hydraulic system, which directly affects the correctness of gear changes.
The second common reason is a clogged automatic transmission filter and a worn oil pump. When the filter is clogged, it is more difficult for the pump to pump cold and viscous oil. As a result, the pressure in the gearbox hydraulic system drops, which causes the electronics and valve body to work with errors, and the gear changes become late or abrupt.
Rubber elements of the transmission also play a role. In the cold, cuffs and oil seals lose their elasticity, become stiff and retain pressure worse. This can lead to internal oil leaks, unstable operation of the friction clutches and malfunctions when shifting gears, especially in the first minutes after starting the car.
A separate problem is the lack of full warm-up of the gearbox. On most cars, only the engine warms up, while the oil in the automatic transmission, even after 10 minutes of idling, can remain at a temperature of −20…−25 °C. In such conditions, the transmission is forced to work with cold and thick fluid, which dramatically increases the load on all components.
The expert recommends paying special attention to the correct winter operation of the automatic transmission. After starting the engine, you should wait 1–2 minutes in P or N mode without increasing the revs, then start moving smoothly, avoiding sudden accelerations in the first 5–10 minutes. The use of sports modes, Kick-Down or special winter algorithms until the gearbox is fully warmed up is undesirable.
It is equally important to monitor the condition and level of the oil. If the ATF has not been changed for more than 60,000 km, winter is a good reason to replace it. Fresh oil has a red or pink tint, while a darkened color and a burning smell indicate overheating and operation at the limit. During maintenance, it is necessary to change not only the fluid, but also the filter with the pan gasket. You should also use only oil with the manufacturer's approval and stable characteristics up to −40 °C, avoiding "universal" solutions without confirmed compatibility.
Ignoring winter symptoms, according to the specialist, can turn into serious consequences. Prolonged operation of the automatic transmission in adverse conditions leads to accelerated wear of the friction clutches, valve body and pump, and the result is often a major overhaul costing 150–300 thousand rubles.
