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Discussion Starter #1 (Edited)
I've got a 525xi with 132k miles and I've only driven it 10k of those. I'm not sure if any service performed before I owned it as I bought it non running. I'll just assume nothing was done.

Generally it shifts pretty well. (After the computer learned that is. Since it had been sitting with no battery it seemed to have cleared adaptations because at first it shifted hard.)
However, here and there I'll get a over rev on a shift or just a general weird shift. I drive it pretty gently, honestly. If you put it in sport mode it's pretty jerky, but maybe that's by design? I digress.

I'm considering ordering the pan/filter along with the sleeves and plug adapter. Do you all think that would be a good improvement on shift quality, or at this mileage do I risk worsening the shifting?

Thanks!
 

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Definitely do it. There are no downsides apart from draining the trans only to find you can't remove the filler plug! Loosen the filler plug first.

There is a whole bunch of nonsense and misinformation out there about potential harm of "loosening up deposits". This was somewhat true of auto transmission designs of 50+ years ago but somehow this hooey has become the chinese whispers of the internet. Auto transmission design has changed completely.

I have done several of my own BMW trans fluids at 200,000km (120,000miles) and they have all come out dark, dark honey colour. Fluid change made them crisp & smooth.
 

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Btw, Normally you'd do 2 drain and fills as the service. I'd recommend another drain/fill in 6 months. Fluid is cheap.
 

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Fluid can be done now. When you dump the fluid into a clean container, check it. It should be translucent tea colored to brown/honey, meaning the tranny has been reasonably treated and you should have no issues. A few drops on white paper can give you some insights on its condition.

If it's black and smelly, the tranny has been treated harshly and the probability of crap settling in the orifices and passages of the valve body is higher. Tranny fluid is damaged by heat, and the black crap likely contains wear particles from excessive clutch wear. Doesn't mean it'll crap out, but probabilities increase as fluid gets worse. There's a big difference between old fluid and abused fluid.

Good idea to change the 5 rubber interfaces between the mecha and the turbine section at your mileage. They stiffen and crack in the heat.

Check the magnets in the pan. There will be a grey paste on them, which is normal metallic wear. Less is better, but there's no way to easily say what is "less" or not. If there are pieces of any kind, metal or plastic, again the probability is higher the tranny has been abused, and the higher the liklihood of later issues. You may be able to look at the date code on the pan plug (should be embedded in the plastic) to get an idea if its the one that came with the car. Some pans have it, some don't. If so, definitely change it. Replacing the pan will get another .5-1 L out as well.

Finally, after you change the fluid you should reset the adaptations and go through the re-learning procedure appropriate to your tranny.

Assuming the fluid isn't black and smelly, you shouldn't bother changing the pan on the second refresh. Post the condition here when you dump it.

So, should you change it? Absolutely, yes. Unless the tranny has been abused, it'll be fine.

Here's ZF's procedure: https://youtu.be/ZRrgmfM8VlQ
 
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