First thing’s first – full disclosure
This post is NOT written by a car expert. Heck, it’s not even written by a mechanic. This post is instead written from the very basic perspective of someone who knows less about how an engine works than Trump does about fighting a pandemic – sweet FA. So it was my great surprise when I learned this fun fact: the transmission in a car is not necessarily even made by the car manufacturer – in fact the same transmission can be found in an Aston Martin DBS V12 and a Kia Mohave! For today’s example, we will talk about this very same transmission that can be found in a host of BMW’s, made by a company called ZF.
BMW owners cop enough flak from the wider community as it is. We don’t know where our indicators are. We like to park across two – sometimes three – spaces while getting our morning lattes. But we’ve had a sneaky smile on our faces all along because we’ve known that unlike every other car out there on the market, our transmission fluids will never need replacing. Lifetime transmission fluids – it’s genius from BMW, and we are all geniuses for buying one.
Here’s the kicker though – it turns out, yet another cruel BMW trick has been played on us. There’s a catch to this promise of eternal life, and that is that the guarantee only applies to the lifetime of the transmission itself – remember, the lifetime of a component is not the lifetime of the car! And at the end of the day, that’s just another mechanical component that experiences wear and tear like everything else and will one day cease to work. Sad face. Even ZF themselves state that to ensure proper operation, you need to service their transmission at 100,000km.
When life doesn’t mean life
Why have they done this to us?! Why, why, why! It was explained to me like this: BMW know that transmission unit is good for 100,000km. After 100,000km though…? Well, all bets are off – and the bets get pricy too, since a full transmission replacement can start to chew the thick end of $10,000. Yikes. Conversely, going against the Bible of BMW and getting your transmission serviced every 60,000km is going to not only save you a fortune, but also save the life of that car that you love so dear.
So what’s the science behind all this? It all seems relatively straightforward, even to me. To make your transmission work and keep the moving parts from grinding the living daylights out of each other, there’s this nifty little lubricant that everything swims in called transmission fluid. Any wear the transmission experiences from daily driving is caught in this fluid as well and after a while it starts to get pretty dirty. Not to worry though – there’s a filter to catch all the nasty contaminants (some really tiny, miniscule bits of metal and other sludge). But after a while, even this starts to get clogged up, and it just kinda stops doing it’s basic job – filtering. Bit by bit, the transmission has to work harder and harder, and then one day – BANG! Goodbye trans. If only you’d known to get it serviced – if only you hadn’t believed the lifetime tale you’d been told.
The service solution
And when it comes to the service itself? Naturally there’s two ways of doing that too. EuroSurgeon fall squarely in the camp that you should NOT, under any circumstances, pressure flush the transmission at service. This washes out every bit of the gunk that’s in the transmission, yes, but some of that could well have been holding things together in there. With 20+ years of transmission rebuilding experience, they’ve learned the hard way that it is usually these customers who will experience a full failure within 12 months of having their transmission pressure flushed.
The technique they opt for is simple – drain the contaminated fluid, replace the used filter, and top up the fluid with brand spanking new Motul ATF VI. And hey presto, just like that, you’ve extended the lifetime on your transmission. It seemed like common sense to me – hopefully it does to you, too.
If you want to talk to the experts about YOUR transmission service needs, you can get in touch with a EuroSurgeon here.