[masab321]

I recently bought 2021 CPO X5 40i. The car drives like a new vehicle but I keep reading about transfer case issues. The vehicle has one year of manufacturer warranty and one additional year of CPO warranty. It’s at 39k miles at the moment.

I have heard some people getting the transfer case fluid serviced as a preventative measure around 40k miles. Is this something recommended or should I just wait and don’t think about it unless it actually fails and then get it replaced under warranty.

[Di3s3l_Power]

Originally Posted by masab321

I recently bought 2021 CPO X5 40i. The car drives like a new vehicle but I keep reading about transfer case issues. The vehicle has one year of manufacturer warranty and one additional year of CPO warranty. It’s at 39k miles at the moment.

I have heard some people getting the transfer case fluid serviced as a preventative measure around 40k miles. Is this something recommended or should I just wait and don’t think about it unless it actually fails and then get it replaced under warranty.

I could be wrong; some 2019 and 2020 had the wrong fluid in the transfer case thus higher rate of failures

[Chef FoodGuy]

No doubt this reply will stir up plenty of differing opinions, but here goes.

Based on the sage advice of long time BMW tech guru Mike Miller, owners of BMW automatic transmissions who wish to keep their vehicles well past 100K miles should consider periodic maintenance of drivetrain fluids, which in the case of X drive includes the transfer case (make sure tech resets transfer case adaptation).

I received similar advice from an experienced Atlanta BMW shop, who recommends drain/fill on ATF, transfer case and diffs every 65K - 75K miles. Not cheap service, and not a 100% guarantee of extended life for these components. But an ounce of prevention may be worth a pound of cure.

Have previously run an E53 and F15 over 150K each with a drivetrain fluid change at 75K without any problems.

YMMV.

Cheers.

[BlkGS]

Coming from the domestic world, the idea that making it to 150k miles is impressive is mind boggling to me, lol.

That said, I don't think it's a bad idea to change out high stress fluids.

[smyles]

Unless your X5 faces lots of heavy towing/mudding/deep snow driving, 99% you'll sell/rid of it before any issues with the transfer case caused by the unchanged fluid. Same with the differentials.

The only unit worth touching is the gearbox, and even then it's more for a peace of mind/OCD.

For the record, I change engine oil every 5k.

[X5MGuy]

If I'm not mistaken transfer case and rear diff service are recommended maintenance at 50k miles, at least on the M anyway. Only cost me about $400.

[TurtleBoy]

Originally Posted by X5MGuy

If I'm not mistaken transfer case and rear diff service are recommended maintenance at 50k miles, at least on the M anyway. Only cost me about $400.

It is not recommended to change the fluid in either of them for the non-M.

[F15_SGM]

I change my transfer case fluid every engine oil change. So every 5K. I don't do adaptation on ista+ anymore since I change it so frequently. We can all agree the transfer case needs a class action lawsuit sooner or later. My method keeps it fresh all the time as I'm a long term owner + I do have the 50i variant.

[maher]

Originally Posted by F15_SGM

I change my transfer case fluid every engine oil change. So every 5K. I don't do adaptation on ista+ anymore since I change it so frequently. We can all agree the transfer case needs a class action lawsuit sooner or later. My method keeps it fresh all the time as I'm a long term owner + I do have the 50i variant.

Is it easy to perform on the G05?

[Bolt1949]

Originally Posted by maher

Is it easy to perform on the G05?

No, it is not "easy" to do. There is only a single fill/empty plug. Used fluid must be pumped out and the new fluid pumped in. Changing this fluid every 5k miles is way, way too often, and likely introduces higher risk due to contamination, under/over fill, etc. than simply following BMW's policy.

[F15_SGM]

Originally Posted by Bolt1949

No, it is not "easy" to do. There is only a single fill/empty plug. Used fluid must be pumped out and the new fluid pumped in. Changing this fluid every 5k miles is way, way too often, and likely introduces higher risk due to contamination, under/over fill, etc. than simply following BMW's policy.

My friend is a bmw master tech at bmw dealer so he does it for me. I just watch him do it but it's pretty simple. First have to get a hoist to secure the transfer case and remove the transfer case bracket then you just siphon the old fluid with a thin hose and refill with new fluid until it starts to flow out. I don't see how it can be contaminated. Keeps the transfer case fresh and only takes about 30 min extra doing the engine oil change. Only cost associated is the dealer mark up on the dtf1 fluid. Really the procedure is the exact same for the previous gen aswell no difference. You can technically remove the fill plug without dropping the bracket but it's just easier that way if you have the equipment and skills. I do understand why some may think 5K is way to often but it doesn't hurt doing so in my opinion. What I do know is that the factory fluid was defective and I do believe the transfer case unit is just as trash in this car and prone to failure. Previously it was only the 50i guys with failures but as time goes on I have seen countless 40i X7 and X5 guys with transfer case failures. My unit was swapped at dealership at around 25K odo and I don't trust the new unit aswell. I think the solution will be a class action that may take many years before owners start to take action like every other class action bmw occurred. Just takes many years before something is done about it.

[eelnoraa]

Originally Posted by F15_SGM

My friend is a bmw master tech at bmw dealer so he does it for me. I just watch him do it but it's pretty simple. First have to get a hoist to secure the transfer case and remove the transfer case bracket then you just siphon the old fluid with a thin hose and refill with new fluid until it starts to flow out. I don't see how it can be contaminated. Keeps the transfer case fresh and only takes about 30 min extra doing the engine oil change. Only cost associated is the dealer mark up on the dtf1 fluid. Really the procedure is the exact same for the previous gen aswell no difference. You can technically remove the fill plug without dropping the bracket but it's just easier that way if you have the equipment and skills. I do understand why some may think 5K is way to often but it doesn't hurt doing so in my opinion. What I do know is that the factory fluid was defective and I do believe the transfer case unit is just as trash in this car and prone to failure. Previously it was only the 50i guys with failures but as time goes on I have seen countless 40i X7 and X5 guys with transfer case failures. My unit was swapped at dealership at around 25K odo and I don't trust the new unit aswell. I think the solution will be a class action that may take many years before owners start to take action like every other class action bmw occurred. Just takes many years before something is done about it.

Wait, you change transfer case fluid every 5k and still need replacement at 25k?? Does it really prove changing too often isn’t great??

[BlkGS]

Originally Posted by Bolt1949

No, it is not "easy" to do. There is only a single fill/empty plug. Used fluid must be pumped out and the new fluid pumped in. Changing this fluid every 5k miles is way, way too often, and likely introduces higher risk due to contamination, under/over fill, etc. than simply following BMW's policy.

I'm not gonna disagree that 5k miles is too frequent (unless you're really abusing the 4x4 a LOT)...

But a single port to drain and fill is SUPER easy. Undo plug, use transfer pump to empty it of fluid. Turn pump around and use it to transfer new fluid in. I haven't checked, but usually those fill ports are designed to also be overflows, so you fill it to the port and then you've got the right amount of fluid in it when it starts to drip out (I would of course, verify this before completing the service). Worst case, you measure the correct amount out and transfer it in. Easy peasy. Heck id probably use my Mityvac extractor and just drain it that way, would be busting out a second tool, but it'd probably make it even faster and easier.

Unless access to the TC is total garbage, this is a job in the minutes range, super easy.

[F15_SGM]

Originally Posted by eelnoraa

Wait, you change transfer case fluid every 5k and still need replacement at 25k?? Does it really prove changing too often isn’t great??

Sorry for confusion. The replacement at 25K was with no fluid change and was whatever they had in it from factory. I do the changing fluid on the new unit never did anything on the old unit.

[BobsM3Coupe]

And here I'm reading in newtis that to completely drain the transfer case fluid, a connection to a software program is needed. This allows some valves inside the transfer case to open for completing the drain process.

[F15_SGM]

Originally Posted by BobsM3Coupe

And here I'm reading in newtis that to completely drain the transfer case fluid, a connection to a software program is needed. This allows some valves inside the transfer case to open for completing the drain process.

Yes you have to use ista+ to put it in service procedure mode. I have ista + if any one needs it.

[smyles]

Originally Posted by BobsM3Coupe

And here I'm reading in newtis that to completely drain the transfer case fluid, a connection to a software program is needed. This allows some valves inside the transfer case ...

what valves?

[TurtleBoy]

Originally Posted by smyles

what valves?

Perhaps someone who has taken it apart can say for sure, the procedures just say it needs to be in the service function for complete draining.

[915M]

How much do dealers charge for transfer case fluid change?

[bandersen]

Originally Posted by TurtleBoy

It is not recommended to change the fluid in either of them for the non-M.

TB - where can I find these fluid recommendations? Not in my manual, not where I can find online. If it wasn’t for the damn sunroof leak..hoping to keep it for 10+.

[TurtleBoy]

Originally Posted by bandersen

TB - where can I find these fluid recommendations? Not in my manual, not where I can find online. If it wasn’t for the damn sunroof leak..hoping to keep it for 10+.

They are in the Maintenance Guide. Unfortunately the resources site doesn't have it for all years. https://www.bmwusa.com/explore/bmw-v...nty-books.html

I have attached the one from MY20 which should also apply to yours.

[Aimster82]

Originally Posted by 915M

How much do dealers charge for transfer case fluid change?

$500 from what I've read here