Why is the gearbox of Mercedes-Benz BMW maintenance-free for life? Don’t listen to them if you don’t want to fail

What would you think if 4S told you that your car does not need to change the gearbox oil for life, because the gearbox is maintenance-free for life? Recently, a BMW owner in the group of friends raised this question. In fact, the same question applies to Mercedes-Benz, Volkswagen, Audi, and Porsche owners.

“Lifetime maintenance free” statement,

How exactly do we understand it?

Here’s the thing: BMW’s manual says “the gearbox is maintenance-free for life”, so I think changing the gearbox oil for BMW is a stupid act of “more money has no place to spend”. Moreover, at present, the domestic BMW 4S shop does not have the service of changing the transmission oil, and even the technicians are not allowed to change the transmission oil of any BMW car.

But there are also friends who know cars reminded: The standard gearboxes of BMW cars are basically derived from ZF in Germany, and ZF is the second largest gearbox manufacturer in the world (the largest production capacity is currently Toyota Aisin). BMW uses the most classic “8AT” (8HP gearbox) from ZF, but ZF never seems to dare to say that it is “maintenance-free for life”!

The simplest truth: The car manufacturer asked the gearbox manufacturer to buy the gearbox and installed the car. Then car manufacturers “know more about gearboxes” than gearbox manufacturers? ——Obviously, this most basic logical thinking tells us: this high probability does not hold! So how exactly does BMW understand the “lifetime maintenance-free” statement?

The gearbox manufacturer will tell you

What is “lifetime maintenance free”

By reading the manufacturer’s documentation of ZF gearbox (List of lubricants TE-ML file), it can be found that before 2021, ZF requires car owners to “change the gearbox oil every 8 years or 100,000 kilometers”, if the long-term driving is smooth and gentle , the oil change interval can be extended according to the situation.

After 2021, ZF revised relevant documents, requiring car owners to “change the transmission oil every 150,000 kilometers. If the use environment is harsh, or there are often intense driving conditions, it is necessary to shorten the maintenance cycle as appropriate.” As for the change in the content of the documentation, ZF also made it very clear: the original gearbox after 2021 is canned with maintenance-free gearbox oil (which can be understood as oil with enhanced performance).

Here we will mention Volkswagen and Audi with a crooked mouth. The gearboxes of the Golf 6 and Audi Q3 are both “DQ200 gearboxes”, but the Golf 6’s manual says “recommended oil changes every 60,000 kilometers” and the Audi A3’s manual says “lifetime maintenance-free”. Also related to changes in transmission oil.

What is the industry default definition of “lifetime”?

8 years or 100,000 miles (160,000 km)

Back to BMW, in fact there is a key figure here – every 160,000 kilometers. Because the “160,000 kilometers” of the ZF pipe is called “lifetime maintenance-free”. So everyone couldn’t sit still. They said it was a lifetime. Why did they come up with a figure of 160,000 kilometers? ——In fact, this is the default definition of “lifetime” in the EU auto industry.

In fact, we can also see a similar definition in the original German document of Mercedes-Benz: the full service life of a private car is 8 years or 100,000 miles (equivalent to 160,000 kilometers, which is almost 20,000 kilometers per year). This is based on the actual situation of European car owners (in fact, many car companies in my country stipulate a warranty period of 8 years or 150,000 kilometers, which is also based on this).

The location is transferred to my country. In fact, students who are familiar with the used car market must have heard the phrase “Your car has more than 20,000 kilometers in one year, so it’s a bit hard to drive”. It’s true that in our country’s private car (non-operating, not part-time running DiDi), there are not many riders who exceed 20,000 kilometers in one year according to the proportion (most car owners basically have between 10,000 and 20,000 kilometers in one year).

If the driving is intense and the road conditions are bad

Even shorter maintenance intervals!

Therefore, few car owners have accumulated more than 160,000 kilometers in the past 8 years (take Brother Hu’s own situation as an example: my car was licensed in January 2016, and it has been just 6 years, with a total of 95,000 kilometers). So if I am a BMW owner, and I usually drive on flat roads, and I drive very gently, I can indeed achieve “regardless of the gearbox in 8 years” (assuming I don’t want this car after 8 years of driving).

But if I want to keep driving, or some other friends take a fancy to my car and buy it home (used car), do you think I dare not ignore the gearbox? Or if I have been used to driving violently and violently in these 8 years, or the road conditions are not good, would I dare to ignore the gearbox for 8 years? The answer is obvious!

After all, when the gearbox is working, no matter how well the lubrication and protection are in place, it is impossible for the general rule to achieve true “zero wear”. As long as there is wear and tear, iron filings will inevitably be produced. The accumulation of iron filings to a certain extent will cause the clutch disc to slip, so a major failure of the gearbox “lost gear” occurs. Of course, if you are unlucky, if the iron filings enter the valve body, causing the valve body to get stuck… The maintenance cost of tens of thousands is not a joke. Finally, the definition of “lifetime maintenance-free” also applies to other brands of vehicles.