Behind the Aurora* is the Dispute of the Transmission Rivers and Lakes

Although there may be such controversy, the influence and attention of CCTV's 315 party is beyond any doubt. From an ordinary audience's point of view, the automaker that was named for quality problems at the 315rd party this year was Land Rover, and the corresponding model was Aurora; however, from the perspective of the industry's audience, the most affected may be ZAF's 9AT. How big is the impact? See what you think. Really speaking, I am afraid that it can involve the “river” of the entire transmission.

Aurora problem is indeed ZF 9AT problem

At the 315 party, the aurora was said for a long time. In fact, the core issues were concentrated in its transmission. And there are problems, all are 9AT versions. If only Aurora is such a car, it can also be understood as what Land Rover has done in terms of matching. However, "people in the circle" all know that a similar problem is in the JEEP's new Cherokee equipped with the same transmission (ie domestic free light). JEEP even initiated two recalls in the United States. It can be seen that "the problem is indeed a bit troublesome." In fact, the ZF 9AT's trouble with free light began long before it went public – because of transmission shift problems, Cherokee had to postpone the listing.

Those who really care about this transmission can go to the forums of Aurora, Free Light (Higashi Aurora and Cherokee), and many news related to 9AT. They will find this transmission problem from the first time to the present. It never stopped. Only the influence of those forums and news can not be compared with the 315 party of China Central Television. In other words, it was a 315 party that completely exposed the 9AT problem to the sun.

The problem is unexpected on ZF

Where is the true problem of this 9AT still undecided? The official statement is a problem with software control programs that can be resolved by upgrading software. This possibility exists. After all, the more gears, the more difficult it is to control. This is like a good driver if you open a 9MT car, one and a half will be indispensable.

Whatever the reason, the reality is that ZF must admit that the transmission will indeed work abnormally and the probability of occurrence is not too low. The key is that there is no effective solution yet. This reality shows that this transmission is, in a sense, not a qualified quantity product.

This situation is not surprising if it appears on an ordinary, small supplier. New things, it's inevitable. However, ZF is not such a supplier. Before 9AT, its products have always been convincing. The vast majority of BMW transmissions, most of the world's 8AT, Porsche's PDK dual clutch transmissions, all come from ZF, and did not reveal any problems. In particular, PDK, although using a dual clutch that once was considered to be smooth and reliable, ZF's version performed surprisingly well. Then why on the 9AT, ZF's performance is so eye-popping?

The reason behind this is related to ZF's "quick success"

From an intuitive point of view, perhaps the technical engineer will give such or such an explanation, and it also makes sense. However, there is one thing that cannot be avoided. That is to say, this transmission is somewhat over-pursued in its development, and the launch time is a little anxious.

Many people who like technology should have seen more than one technical interpretation of this 9AT. From these articles, you can feel the near-perfect design of this transmission - 9 blocks, the ratio of the range of teeth to a terrible 9.81 (Aisin 8AT is also only 7.59, 6AT is only 6.05), weight 78 kg ( It is lighter than the 6AT and comparable to the dry dual clutch. Together with the extremely high shifting speed and transmission efficiency, it has become the most perfect transmission in the world. Because of the advantages of any kind of transmission, it is almost all available, and the disadvantages of other transmissions are theoretically non-existent.

The performance of this "artifact" is corresponding to the intention of supporting the mid-to-low-end models (horizontal, low-power version can only match the engine below 280 Nm). To know that this level of even the 7AT car has not yet, the world's high-end car still view 8AT as high-level goods, but it directly skip 7AT, 8AT, went straight to 9AT. This contrast, if not because this transmission was launched by ZF, I am afraid that many people would think that was a scam.

ZF is even more powerful. Its R&D team is also made up of people, not "god." So in such a short period of time to develop such an "artifact", the difficulty can be imagined, there are some flaws is also reasonable.

The question now is: Why does ZF have to do this? Can't you step by step?

Trying to wipe out the double-clutch camp and return to "AT unified rivers and lakes"

This will lead to the mention of "Jianghu" at the beginning of the article. The automatic transmission camp has always been safe in the past. Although there are CVT, AMT and other branches, but AT's boss status absolutely no one shakes. However, the situation has changed a lot since people hit the DSG. Although the dual-clutch in the high-end sector does not pose any threat to the AT camp, in the low-end camp, the dual-clutch market advantage has become increasingly evident. In particular, after the appearance of the dry double-clutch, the AT camp felt that “it must be taken as a defender and cannot wait for a fight”. Some people say that dry double-clutching is not the outbreak of the DSG crisis, why AT is still afraid? On the one hand, the DSG crisis is a matter of the past two years. AT cannot wait until its crisis erupts. On the other hand, look at the current public DSG, affected by the crisis? Do you still not sell well? Not only that, although there are also Ford and other manufacturers during the launch, but there are also many new players to join the camp.

Why has the reliability crisis erupted. Why is the vitality of dry double-clutch still so tenacious? The key is that its structure determines its performance advantage over non-traditional AT. The extremely high transmission efficiency can not only save fuel, it also greatly reduces the car's performance requirements on the engine. It is not only equal to the lifting performance, but also effectively reduces the manufacturing cost. The dry clutch structure also facilitates lighter weight and further improves performance and economy. In the past two years, what did the car fight in the powertrain? Isn't it these? What's more, dry dual-clutching also has cost advantages. Therefore, if the AT does not fight back, the small and medium-displacement fields are likely to be annexed by the dual clutch.

How to fight back? Naturally, it is necessary to introduce more competitive products than dry dual-clutch systems. The AT is inseparable from the hydraulic torque converter, so to increase the efficiency, it is necessary to increase the lock-up frequency and reduce the dependence on the "change torque function." This requires more transmission gear. Assuming that there are 7 blocks is enough, but the 7-block dual clutch has been popularized, and it will be even more to win. Then, in combination with the structural characteristics of the planetary gears, nine gears can be eliminated, and nine gears are eliminated. Then, in this case, the size of the transmission cannot be large and the weight cannot be heavy, limited to the field of competing models. At the end of the day, the ZF 9HP was completed.

It can be seen that the apparent damage of the 9AT is very large. The Cheung fungus had made predictions: If the 9AT is not loaded with big problems (or can be completely resolved immediately), and the production capacity can keep up, it is very likely to make the double-clutch camp seriously hurt, and thus become Similar to the CVT's marginal transmission variety. At the same time, AT can also "unified rivers and lakes" in the field of automatic transmissions.

Car cloud summary:

Jump too much (6AT straight to 9AT), the conditions are too harsh (small size, light weight, shift quickly and indispensable), coupled with the time and the heavy task, even if ZF such a master, and finally also Failed to be successful - problems inevitably arise after loading. Seemingly a little regrettable, but it is in line with the ecological law - from the perspective of competition, Cheung fungus is in fact not want to "unified."

Of course, the 9AT problem certainly will not lead to the defeat of the AT camp. Its role is mainly to prevent or at least delay the AT attack. It can be foreseen that this incident will inevitably lead to some manufacturers' hesitation and wait-and-see, which will greatly slow down the distribution of 9AT. At the same time, as a responsible manufacturer, ZF will not be able to roll out 9AT on a large scale until it really finds a solution to the problem. As a result, the double clutch has room for manoeuvre. Later, with the introduction of dual-clutch camp response products (such as the legendary 10-speed DSG), the demise of dual-clutch and AT in the low-end areas may actually begin. By then, I am afraid it will be the time for the good show to take place.