The legendary and proverbial reliability of the Japanese automobile giant Toyota, which for decades was synonymous with peace of mind for buyers, is starting to seriously crack under the pressure of modern environmental regulations. In the race for lower fuel consumption and cleaner emissions, even the biggest players on the market are forced to rush the implementation of complex technologies. Unfortunately, this engineering sprint is already bearing bitter fruit, and the modern 8-speed automatic transmissions with product codes UA80 and UB80 have come under the sights of experienced auto mechanics. It turns out that these gearboxes hide factory defects that can turn driving into a real nightmare and dig deep into the owner's pocket even before the car has reached the modest 100,000 kilometers.
How do we actually understand that the transmission is "passenger"?
Experienced experts warn that while rough gear shifting is a software feature of modern cars, a specific, progressive howling under the hood is not to be ignored at all. The first symptom of an impending disaster is a barely perceptible whistling sound during acceleration, resembling a miniature jet engine. The strange thing is that this noise comes and goes - it disappears as soon as you release the gas pedal and changes dramatically depending on the temperature. When the box is cold, it is silent as a fish, but once it warms up well - the howling becomes intrusive. If you ignore this clear signal, things quickly get worse: the howling grows into an ominous metallic creak, the box begins to slip, jerk convulsively, and finally leads to complete mechanical damage.
The most at risk from this fiasco is the UA80 model, designed for the more powerful 3.5-liter naturally aspirated V6 units. Although the brand's official service documents diplomatically limit the defect mainly to V6 modifications of the Camry and Lexus ES from 2021, the reality in the service centers is much darker. Mechanics have literally given up on Toyota Highlanders manufactured between 2020 and 2022 (excluding hybrids), with complaints from owners of this model pouring in several times a week.
With the smaller UB80 transmission, which partners with the 2.5-liter four-cylinder engines, the drama has a slightly different flavor and is often the result of driver naivety. A huge number of owners blindly believe the urban myth that the oil in the automatic transmission is “eternal“ and does not need to be replaced. Well, no! In order to avoid costly repairs, the oil must be changed without compromise every 100,000 km or at most every 6 years. The problem is exacerbated by the fact that the internal filter of the box is screwed into the exhaust, is extremely difficult to service, and in some cases is not intended for separate replacement at all. That is why regular refreshing of the original transmission fluid is the only lifeline for the long life of this unit.
However, to reassure drivers, not every strange behavior of these 8-speed boxes means automatic failure. Many people complain that the automatic constantly “wonders“, shakes and shifts up and down like crazy. In fact, there is no failure here – it is just that the engineers have set extremely short gears from first to fifth for the purpose of economy. First gear has a gear ratio of 5.5:1 and serves only to slightly lift the car off the ground, after which the electronics immediately engages second in search of optimal emissions. This constant “search“ in the ideal gear creates a feeling of slight pulling, which is completely normal. Therefore, every driver should learn to clearly distinguish between the factory eco-settings and the real symptoms of a technical defect, so as not to be unpleasantly surprised on the road.