[wesamjaber2004@gmail.com]

Sup guys, my f10 535i is approaching 120k miles and I don’t think the transmission has ever been serviced. I’m fbo and tuned engine and transmission. Should I be concerned with my adaptation values I currently have? Should I do the transmission service this high in mileage? I’m scared to do it as I get a lot of mixed opinions that it’ll be bad for the car if I change it. Let me know what you think.

FYI. The car shifts okay, not great but okay. It has its moments for being 120k miles.

[StradaRedlands]

I can't speak to the adaption values, but I say yes, change the fluid. Follow the ZF change guidelines and it's actually a pretty easy job.

[Surly73]

Opinions that are "mixed" are likely ignorant/misinformed (there's a lot of that on the Internet, you know, even among "professionals") . You should have done it at or before 60k miles, but the second best time is "now". No "flushes", no additives, no weird backflushing machines, but change the pan because the filter is incorporated. IMO use genuine ZF parts (that does not mean genuine BMW). You might consider a fluid only drain and refill without changing the pan after another 1000 miles to get a higher percentage of fluid swapped to fresh.

I have similar high adaptations on my C clutch, and have most of the time the car has been on the road. I have a couple of issues, also since the car was basically new, but not bad enough to qualify for a warranty replacement. This summer I am thinking of changing solenoids and possibly a ZIP kit to see if that permanently solves the issues I am having. Just relaying my journey, not suggesting you do the same.

[wesamjaber2004@gmail.com]

Originally Posted by Surly73

Opinions that are "mixed" are likely ignorant/misinformed (there's a lot of that on the Internet, you know, even among "professionals") . You should have done it at or before 60k miles, but the second best time is "now". No "flushes", no additives, no weird backflushing machines, but change the pan because the filter is incorporated. You might consider a fluid only drain and refill without changing the pan after another 1000 miles to get a higher percentage of fluid swapped to fresh.

I have similar high adaptations on my C clutch, and have most of the time the car has been on the road. I have a couple of issues, also since the car was basically new, but not bad enough to qualify for a warranty replacement. This summer I am thinking of changing solenoids and possibly a ZIP kit to see if that permanently solves the issues I am having. Just relaying my journey, not suggesting you do the same.

I know you said you’ve had a couple issues but after your first fluid change, did you notice it shifting better or did more problems occur ?

[Surly73]

Originally Posted by wesamjaber2004@gmail.com

I know you said you’ve had a couple issues but after your first fluid change, did you notice it shifting better or did more problems occur ?

My first fluid change was well before the 100k km / 60k mile ZF recommended interval. It was slightly better, but I think I have some solenoid issues. My fluid came out looking reasonably good. In theory, that's the way it should be (change it before it desperately needs changing, right?). I changed it well before the fluid had degraded and noticed some improvement, but not a revolutionary improvement.

I'm also running xHP stage 3 - it tightened up a few of my issues but not fixed.

Changing the fluid caused absolutely no additional issues. I did mine by the book - instructions are in quite a few places with the fill and final level set procedure. That's the only procedure I recommend. It seems like lots of folks are scared off by having the car running, running through the gears, and then being in the correct temp range and do a "measure what you take out and put exactly that amount back in" approach. Who says the level was correct before? Especially if you're having issues.

Now my "issues" might mostly go unnoticed by many. This is my first automatic, and I'd rather still be driving stick. Anything but the ZF8 would have probably driven me bonkers, but the ZF8 is pretty nice.

I'm hoping I can get it perfect with some extra TLC this spring. What I'm looking for a circle of experts on the 8HP (not necessarily BMW) to share ideas with and not embark on anything that isn't going to pay off.

EDIT: the fear you're probably getting is the "fresh fluid has too many cleaning agents and it will knock free some piece of crud that's holding everything together" rationale. If your transmission is held together by crud, it's dead anyways. A lot of the "it failed right after I serviced it stories" come from the use of flushes instead of just straight fluid changing. The fluid needs changing, ZF and even BMW have officially changed their "lifetime fluid" story. If it were mine, and you're planning to keep the car, I'd change it. And have done so on friends/family cars. It's only getting worse. Ultimately the decision is yours, however.

[Conserve]

^ +1 on post #3

[ctcarbonari]

+1 to everything that Surly73 has posted above. Especially the part about adhering to ZF recommended service procedure where you'll have the vehicle lifted-level-and running while you cycle thru gears and hold rpms. All while transmission is at the called for temperature range.
I'd stick with LG8 (can also use LG9) fluid although plenty of others have reported positive results with LM. For me, the few dollars savings is simply not worth it. I'm also a believer in doing at least 1 additional dump & fill in addition to the one you'll do when replacing the pan/filter.

Consider replacing the mechtronic sleeve. It's an inexpensive PM item "while you're there". They're plastic and have been known to leak, although not so much with the 8HP from what I gather.

To NEVER change your transmission oil & filter is absurd.

There's plenty of "it's too late" stories out there on the internet; however, imho, changing fluid & filter on an aged transmission will not cause any problems in and of itself but may bring to light existing problems earlier.

If you do reset adaptations, make sure you check out the process for driving the vehicle for the re-learn procedure. I'm not sure of many public roads where that could ever be accomplished.

If you happen to come across a vendor that supplies a replacement drain plug [M18x1.0 w/10 mm hex head] for the ZF 8HP RWD that is OE/OEM or quality aftermarket then please PM me or post. I've recently been in search of that unicorn.

FWIW, here's a copy of the OA from Blackstone on my LG8 fluid from 8HP transmission after ~60k miles.

[ctcarbonari]

ZF Service Procedure Attached (for those that haven't seen it or could use in future)

[DementedF10]

Change it!! I did on mine when I got it at 120,000 and it was a great bit of difference. I did a fluid and pan swap, drove it 20mi and dumped and filled again, drove another 20-30mi and did another dump and fill, and fluid looked great and trans shifted much better afterwards.

[ctcarbonari]

Originally Posted by DementedF10

Change it!! I did on mine when I got it at 120,000 and it was a great bit of difference. I did a fluid and pan swap, drove it 20mi and dumped and filled again, drove another 20-30mi and did another dump and fill, and fluid looked great and trans shifted much better afterwards.

Nice! Imho, I think that is exactly the way to do it. That third "dump & fill" should get the transmission to be filled with 95%+ of new fluid.

[wesamjaber2004@gmail.com]

Originally Posted by ctcarbonari

Nice! Imho, I think that is exactly the way to do it. That third "dump & fill" should get the transmission to be filled with 95%+ of new fluid.

Originally Posted by DementedF10

Change it!! I did on mine when I got it at 120,000 and it was a great bit of difference. I did a fluid and pan swap, drove it 20mi and dumped and filled again, drove another 20-30mi and did another dump and fill, and fluid looked great and trans shifted much better afterwards.

Geez that seems like an expensive amount of fluid doesn’t it. My mechanic who I trust is only gonna charge total parts and labor around 500 for the job, doing it 3 times seems like a lot of money right now. But is the refill necessary? I know there is a procedure for it to refill but it should all be done within the job I believe correct?

[ctcarbonari]

Originally Posted by wesamjaber2004@gmail.com

Geez that seems like an expensive amount of fluid doesn’t it. My mechanic who I trust is only gonna charge total parts and labor around 500 for the job, doing it 3 times seems like a lot of money right now. But is the refill necessary? I know there is a procedure for it to refill but it should all be done within the job I believe correct?

It is a lot of fluid and at a price if you're sticking with LG8 (which I personally would, but plenty of people out there have reported good results with Liqui Moly too).

In fairness, ZF, the manufacturer of the transmission, only calls for service at 60k miles (a single pan/filter replace & fluid fill). The second & even third "dump & fills" shortly after that people do are in an effort to exchange out nearly all of the old oil. Each time you drain the fluid you'll end up getting about 1/2 to 2/3 of the old oil out. Is it absolutely necessary to do it a 2nd or 3rd time? Probably not so much. I think what's most important is to ensure that your transmission is being filled correctly as that process is a bit unique.

$500 is a very good price for parts & labor, especially if you're getting LG8 fluid & OEM pan/filter.

A short while after my initial service (Pan/filter) my mechanic let me bring in the LG8 oil then charged me an hour's worth of labor. I returned the old oil and picked up another 5 liters thru FCP's Lifetime Replacement Policy so that helped mitigate the cost.

[wesamjaber2004@gmail.com]

Originally Posted by ctcarbonari

It is a lot of fluid and at a price if you're sticking with LG8 (which I personally would, but plenty of people out there have reported good results with Liqui Moly too).

In fairness, ZF, the manufacturer of the transmission, only calls for service at 60k miles (a single pan/filter replace & fluid fill). The second & even third "dump & fills" shortly after that people do are in an effort to exchange out nearly all of the old oil. Each time you drain the fluid you'll end up getting about 1/2 to 2/3 of the old oil out. Is it absolutely necessary to do it a 2nd or 3rd time? Probably not so much. I think what's most important is to ensure that your transmission is being filled correctly as that process is a bit unique.

$500 is a very good price for parts & labor, especially if you're getting LG8 fluid & OEM pan/filter.

A short while after my initial service (Pan/filter) my mechanic let me bring in the LG8 oil then charged me an hour's worth of labor. I returned the old oil and picked up another 5 liters thru FCP's Lifetime Replacement Policy so that helped mitigate the cost.

500 is really good especially considering my friends a master tech at bmw dealership. But only thing scaring me is my mileage and the fact my transmission isn’t super smooth especially in first gear. I’m not sure but I feel like I’ll do more harm then good with the service. My mechanic recommended doing transfer case and rear differential fluid before the transmission service. I may do those and leave out my transmission due to the current state of it.

[ChiltiCoatl89]

Yes Change the Fluid my good man! then do another after 1k or so to get a nice exchange of fresh fluid inside the system, just ZF fluid only! nothing more!

[wesamjaber2004@gmail.com]

Originally Posted by ChiltiCoatl89

Yes Change the Fluid my good man! then do another after 1k or so to get a nice exchange of fresh fluid inside the system, just ZF fluid only! nothing more!

If I do I gotta pray I didn’t destroy the transmission 🤣

[ChiltiCoatl89]

Originally Posted by wesamjaber2004@gmail.com

If I do I gotta pray I didn’t destroy the transmission 🤣

If that happens, well? replace? and get it done right with normal fluid drain and fills lol.

[StradaRedlands]

Originally Posted by wesamjaber2004@gmail.com

If I do I gotta pray I didn’t destroy the transmission 🤣

Chances are you'll be fine!

[wesamjaber2004@gmail.com]

Originally Posted by ChiltiCoatl89

If that happens, well? replace? and get it done right with normal fluid drain and fills lol.

Lol true. I think I’ll do transfer case and differential first and then once I feel comfortable to have a transmission replacement, I’ll then service it. Not the worst idea in my opinion

[ctcarbonari]

Originally Posted by wesamjaber2004@gmail.com

500 is really good especially considering my friends a master tech at bmw dealership. But only thing scaring me is my mileage and the fact my transmission isn’t super smooth especially in first gear. I’m not sure but I feel like I’ll do more harm then good with the service. My mechanic recommended doing transfer case and rear differential fluid before the transmission service. I may do those and leave out my transmission due to the current state of it.

+1 to everything that everyone has been saying above.

If nothing changes.....well.....then nothing changes. Your transmission shifts will only get worse over time. Change the fluid & filter/pan and, as others have mentioned, I'd recommend at least a second "dump & fill" shortly after. That'll leave you with about 85%+ fresh fluid. Doubtful if you'll see any sort of significant & immediate improvement but it will extend the life of your transmission. Once completed, see how it goes. You may end up needing to replace mechtronic sleeve, tube sleeves, & solenoids. Tough to say, but ZF rebuild kits are available out there and it sounds like something your mechanic can definitely handle.

Yes, Transfer Case & Differentials at the same time as transmission fluid is an excellent schedule (They all should be replaced around the 60k mile mark, if not a bit sooner).

You're RWD, no? If so, then you'll only need to replace fluid in the one differential. There is no transfer case or front differential. If you're AWD then yeah, Transfer + (2) Differential.

Take a deep breath. Everything will be just fine. Don't buy into the "it's too late to change my transmission oil" hype.

And, if you don't do any servicing, then I can guarantee that nothing will change and your transmission will only continue to get worse.

[wesamjaber2004@gmail.com]

Originally Posted by ctcarbonari

+1 to everything that everyone has been saying above.

If nothing changes.....well.....then nothing changes. Your transmission shifts will only get worse over time. Change the fluid & filter/pan and, as others have mentioned, I'd recommend at least a second "dump & fill" shortly after. That'll leave you with about 85%+ fresh fluid. Doubtful if you'll see any sort of significant & immediate improvement but it will extend the life of your transmission. Once completed, see how it goes. You may end up needing to replace mechtronic sleeve, tube sleeves, & solenoids. Tough to say, but ZF rebuild kits are available out there and it sounds like something your mechanic can definitely handle.

Yes, Transfer Case & Differentials at the same time as transmission fluid is an excellent schedule (They all should be replaced around the 60k mile mark, if not a bit sooner).

You're RWD, no? If so, then you'll only need to replace fluid in the one differential. There is no transfer case or front differential. If you're AWD then yeah, Transfer + (2) Differential.

Take a deep breath. Everything will be just fine. Don't buy into the "it's too late to change my transmission oil" hype.

And, if you don't do any servicing, then I can guarantee that nothing will change and your transmission will only continue to get worse.

Tbh you may have just convinced me to do it. You’re right about the part that it’ll only get worse if not serviced. Idk how good or bad it could be due to my 116k miles currently on the trans. I know that my clutch A is worn down so I’m not sure if new fluid can help at all but I guess we shall see.

[ezaircon4jc]

Originally Posted by wesamjaber2004@gmail.com

If I do I gotta pray I didn’t destroy the transmission 🤣

Wife's tale from the early days of automatics and loose tolerances. A transmission expert (worked for Ford/Lincoln in Wixom, MI) told me a few years ago that a fluid change won't damage the transmission, in and of itself. He said if a trans fails after a fluid change, it was already failing and on its way out.

[wesamjaber2004@gmail.com]

Originally Posted by ChiltiCoatl89

Yes Change the Fluid my good man! then do another after 1k or so to get a nice exchange of fresh fluid inside the system, just ZF fluid only! nothing more!

Hey I wanted your thoughts, so I’m pulling through front and rear differential service as well as Guibo and transfer case for this week, is there a break in procedure after the fluid change ? I know I’m going to reset the TC adaptations after but i dont know if I can drive hard for a certain amount of mileage and what not. I may open a new thread on this but wanted to see what you thought