[ssmith96]

Now before you bash, I did search, and the answers are very mixed.

Some say they have had a great experience chaining their automatic trans fluid, some say its bad and will cause gears to slip.

Right now my 07 328xi has 82k miles on it and the transmission doesn't seem nearly as smooth as it should be to me. Do you think its worth it to drain and fill (or flush, but some say flushing is bad) the ATF?

Can anyone with the same or similar car chime in if they've done it and what the results are?

Thanks!
Scott

[Titanium3er]

I've found the advice to be mixed as well. I have an 08 335 with 72k and am leaning towards changing the ATF before 75k. I should have done it already, but honestly just haven't gotten around to it. I've seen that before 100k you should be good, but there is no firm answer.

[Bimmer Barney]

I did mine at 80k and it looked pretty good, used but good, coming out. I used OEM Pentosin and had an Indy do the job, following the fill requirements getting the temp in range. It was like $80 to do a drain and refill and I watched it get done the right way.

[floydarogers]

I had mine done at 60K miles - seemed like that was a good mark to be more pro-active than the BMW 100K mark. Shifts were more "positive", although not significantly better.

Mechatronic was in good shape, filter replaced. Full flush, not drain-and-fill.
Cost was ~$450.

[bumere90]

It won't hurt, unless you have no idea what you're doing.
I have done several ATF and MT drain and refills and had no problems. One of my MT's had over 100k and the fluid was never changed.
Flushing is indeed bad. Do not flush! I would replace the filter as well.

[nycbr]

Originally Posted by bumere90

Flushing is indeed bad. Do not flush! I would replace the filter as well.

+1. I heard that a flush can force dirt into places and cause problems.

plan on doing it yourself or going to a shop?

[MyF15+F85]

I always have this argument.

Answer this for yourself.
If you will flush your transmission with FRESH NEW OIL, how BAD can it be for it....? What ! Is it going to have too much of goooood oil ?

In my opinion ( and I have done a few of those oil changes that did not have to be done ) there is no such thing as life time oil. It removes metal particulates, heat, lubrication ( that is why it changes color ).

There are many confusing oils out there as well, which will make your head spin. The only major difference on the trans oil out there, is the heat range, and the amount of additives in them, heavy metals ( for additional lubrication )

and there is lots of formulas.

I did some things to my transmissions before, things that I don't want to say, why... cause I would be crucified for it, but to my advantage my cars usually make 300,000 kms ( 200,000 miles ) without any incidents ( trans related ).

Here's my 5 cents
Hope this helps.

[ssmith96]

Thanks for the advice everyone, I'm going to ask my Indy about it. Anyone else please feel free to chime in, it would be nice to have a thread to gather opinions on this.

[floydarogers]

Originally Posted by bumere90

...Flushing is indeed bad. Do not flush! I would replace the filter as well.

Perhaps we're using "flush" for different things. I'm not talking about some detergent-like flush.

You have to use a pump to flush new fluid into the torque converter in order to replace all the fluid, else you'll be leaving around 1/3 old fluid in there.

And all the dirt/stuff will be in the filter, so there shouldn't be any to contaminate the new fluid.

FWIW: The "new" 10K oil-change interval for 2014+ cars also includes 50K manual-tranny/diff oil changes for M cars, and 60K AT changes for Active Hybrid trannys - Mike Miller's attitude is why not all other AT's, too. (This from the very latest Roundel.)

[ssmith96]

I'm just worried about people talking about gears slipping and being left with a useless tranny afterwords.

[ihc95]

I had mine done just recently at 80k and it shifts much smoother. I would highly recommend everyone with an AT to get it done sometime before 100k.

[nycbr]

Who is your indy? I am on the island and looking to get the AT fluid changed soon. PM if you dont want to post it. Thanks

[bumere90]

Originally Posted by floydarogers

Perhaps we're using "flush" for different things. I'm not talking about some detergent-like flush.

You have to use a pump to flush new fluid into the torque converter in order to replace all the fluid, else you'll be leaving around 1/3 old fluid in there.

And all the dirt/stuff will be in the filter, so there shouldn't be any to contaminate the new fluid.

FWIW: The "new" 10K oil-change interval for 2014+ cars also includes 50K manual-tranny/diff oil changes for M cars, and 60K AT changes for Active Hybrid trannys - Mike Miller's attitude is why not all other AT's, too. (This from the very latest Roundel.)

by flushing I mean using a power machine that works under pressure. Imagine your engine has sludge and that sludge starts breaking apart and will clog up the oil passages and motor oil pump/filter.

[F32Fleet]

What does the manufacturer of your transmission say? Tough call on a unit with 80k miles. A full fluid swap is going to remove a lot of clutch material. Will the transmission be able to compensate? Who knows.

Personally I would ask the manufacturer of the transmission.

For the record ZF has a "severe service" recommendation for a pan drop between 50-80k miles.

[mave198]

Bentley says between 60-80k, no more than 100k.

Planning a cross country run back to NY after Shift Sector next year so I'll be getting ALL fluids changed out. Gonna save some to analyze and I'll post the findings.

[WhiteFury]

I have 63k on my 2011 335i. Can I get away with a drain and fill. I am using redline ATF

[jmardinly]

Transmission service bulletin from AMSOIL says that ATF failure after a fluid change has been reported for ALL brands of transmission for all cars, and is related to the following: technician failed to change filter screens, clean magnets etc. New fluid had refreshed detergents, and blobs of crud that sat still with the old fluid get broken free with fresh detergent, and can block fluid passages.
Seems to me, that problem will be worse at 100,000 miles than at my present 65,000 miles. I just bought a used E93/N54 with a two month warranty, so I am getting mine changed while it is under warranty, but only at a GOOD place where they clean the insides, not just drain and fill.