The short answer for the modern BMWs with “lifetime fill” ATF: Change it and the filter
at least every 60,000 miles using ONLY the factory BMW proprietary ATF.
Here is the long answer:
At various production dates in the mid-1990s, which vary according to model, BMW
switched to their so-called “lifetime fill” ATF in automatic transmissions, as well as
manual gearbox lubricant and differential oil. The reason for this, as far as anyone can
tell, is marketing and not engineering – the idea being to foster the notion of the lowmaintenance
BMW.
There was no explanation of what “lifetime” meant, i.e., lifetime of the car, the
component, or for that matter the driver. If it was the component, then obviously anything
could be “lifetime fill”. The factory’s initial position is that these lubricants never need to
be changed. Then, some time later, it came out that “lifetime” means 100,000 miles.
Many dealerships are now recommending manual gearbox and differential oil changes be
done at customer expense every 60,000 miles. Every independent BMW technician I
know recommends a 30,000-60,000-mile interval, and many recommend Red Line
synthetic oils, but not for automatics with “lifetime fill” – you need the factory
proprietary ATF for “lifetime fill” automatics.
Older automatic
transmission models, which do not have “lifetime fill” should have ATF
and filter services every 15,000 miles if using petroleum ATF; every 30,000 miles with
synthetic.
However, the modern automatic transmissions are different. No one knows exactly what
BMW’s proprietary ATF is, so no one knows if there are viable alternatives. We do know
that BMW dealerships charge about $500 for an ATF and filter service, due to the price
of the ATF. And that’s assuming you can get them to do the job, which is not often the
case.
Bavarian Autosport (
www.bavauto.com), Pelican Parts (
www.pelicanparts.com), and
perhaps others are now importing the proprietary “lifetime fill” ATF at reasonable prices,
which they sell along with filter kits, for independent BMW shops and do-it-yourselfers.
It is risky to drain a previously un-maintained automatic
transmission with high mileage,
even though if it were my car I would probably chance it. Still, I have seen it happen too
many times, where a well-meaning owner or technician performs an ATF and filter
service on a neglected but well-shifting automatic, and then all of the sudden it starts
slipping. I can’t explain it, but my feeling is the fresh ATF flushes a bit of sludge from a
place where it was doing no harm to a place where it does do harm. Overfilling, underfilling,
and cleanliness are also issues in ATF and filter servicing, but these should not be
problematic for a professional BMW technician, dealer or independent.
Copyright © 2011 by Mike Miller, all rights reserved.
Copyright © 2011 by Mike Miller, all rights reserved.
20
BMW has backed off its lifetime fill mantra for automatic transmissions, currently
recommending an ATF and filter change every 100,000 miles for the current BMW
models.
My inclination is to tell people to change “lifetime” ATF and filter every 60,000 miles.
However I have seen BMW automatic transmissions that were maintained break anyway.
In that event, say it happens at 90,000 miles, you would like to have the money you spent
on the ATF and filter change to put toward your new automatic
transmission. And if I
told you to spend it on maintenance you’re probably not going to be very happy with me.
On the other hand, I have seen maintained automatics last 200,000 miles. I have also seen
un-maintained automatics last 200,000 miles, although both are very rare. There's just no
predicting with these transmissions. When you choose to buy an automatic transmission,
you also buy into the vagaries of the darn things, which is one reason technicians hate
them. Whether to maintain a modern BMW automatic is up to you.
At automatic transmission replacement time, we are confronted with the reality that the
local transmission shop cannot rebuild BMW automatic transmissions, even those built
by GM (BMW’s GM transmissions bear no resemblance to GM transmission in domestic
cars). There are some domestic specialists who concentrate in BMW automatic
transmission rebuilding, and you’ll see their ads in Roundel and Bimmer. However, I
have no current experience with domestic rebuilders. My experience in the past is…well,
the owner wound up buying a BMW factory rebuilt automatic transmission every time,
and this is the course I recommend to readers – “back to the dealer.”
