[john_wick]

As some of you may know, BMW lists these fluids as "lifetime" and not needing change unless there is an underlying problem. For anyone looking to keep their X a long time, have any of you DIY changed these fluids?

I plan on doing it sometime this year around 30k. Can't find any guides on this model but hoping its a simple drain/fill.

[GCR]

Yes, I did both differentials and the transfer case at 25k miles. Glad I did, as the front diff fluid was very dark. Only reason I can think of is elevated operating temp due to very little airflow and proximity to the oil pan. Plan on doing it every 25k, and the trans at 50k intervals.

[Brendon]

Originally Posted by GCR

Yes, I did both differentials and the transfer case at 25k miles. Glad I did, as the front diff fluid was very dark. Only reason I can think of is elevated operating temp due to very little airflow and proximity to the oil pan. Plan on doing it every 25k, and the trans at 50k intervals.

Hard to believe that the fluid would be so dark after only 25k. It's a sealed design, correct? Definitely going to put this one on my radar for earlier than anticipated.

[GCR]

Originally Posted by Brendon

Hard to believe that the fluid would be so dark after only 25k. It's a sealed design, correct? Definitely going to put this one on my radar for earlier than anticipated.

The front differential, at least on the '19 6 cylinder has both a drain and a fill plug.

[john_wick]

Originally Posted by GCR

The front differential, at least on the '19 6 cylinder has both a drain and a fill plug.

Was it straightforward drain and fill? Or was there any surprises or anything to know going into it?

[GCR]

Originally Posted by john_wick

Was it straightforward drain and fill? Or was there any surprises or anything to know going into it?

Straight drain and fill. I used BMW fluid from the Dealer.

[ivinioX7]

Originally Posted by john_wick

Was it straightforward drain and fill? Or was there any surprises or anything to know going into it?

I just took my X7 in for an inspection with 37k miles on it. It turns out my car needs a new rear differential. The vehicle is in the shop waiting for the part to come in. I'm planning on replacing the fluid in the front differential before it's too late. I'm also planning on replacing the oil fluid in my TC this summer, and here is the right product for the X7s if you look for it.

https://www.ecstuning.com/b-genuine-...r/83222409710/

[lake x7]

What are the symptoms of a differential problem? I had the transfer case replaced recently at 43,000 miles. Since then I have felt, on two occasions, a sliding grinding sound and feeling, just momentary leaving a stop light. This is a 2020.

[john_wick]

Originally Posted by lake x7

What are the symptoms of a differential problem? I had the transfer case replaced recently at 43,000 miles. Since then I have felt, on two occasions, a sliding grinding sound and feeling, just momentary leaving a stop light. This is a 2020.

I believe I read you can test this by trying a slow speed turn in say a parking lot and if the drivetrain shudders/binds you have an issue.

[itiongo]

My 2020 M50i is at 60k miles with this issue. I've had this issue for about a month. Just FYI for anyone who has CPO, the fluid drain and refill is not covered under CPO, however the transfer case replacement is. Since the fluid drain and refill is not covered under CPO, the diagnosis is also not covered. So it's almost $700 for this service.

My M50i is currently being driven by the technician to achieve the 125 miles. I'm hoping it's the transfer case. I'd hate for my CPO to end later this year, and have this issue return, and transfer case needs replacement.

[mitch57]

Is there any consensus on whether the transfer case issue is more prevalent in the 50i vs the 40i? I have a 2020 40i with 56K miles and don't have this issue so far. Knock on wood.

I do have an extended warranty that covers the transfer case if it fails. I plan on keeping the vehicle and some say you should change out the transfer case fluid every 50K or so if you plan on keeping it for the long haul.

[arctic grey x7]

Does anyone know what is the oil capacity for the transfer case, front and rear differentials?

[Madsen203]

Originally Posted by arctic grey x7

Does anyone know what is the oil capacity for the transfer case, front and rear differentials?

My recent experience:
700 ml in front,
700 ml in tC
And 1L in rear.

[FSociety]

Originally Posted by ivinioX7

I just took my X7 in for an inspection with 37k miles on it. It turns out my car needs a new rear differential. The vehicle is in the shop waiting for the part to come in. I'm planning on replacing the fluid in the front differential before it's too late. I'm also planning on replacing the oil fluid in my TC this summer, and here is the right product for the X7s if you look for it.

https://www.ecstuning.com/b-genuine-...r/83222409710/

Any updates?

Originally Posted by itiongo

My 2020 M50i is at 60k miles with this issue. I've had this issue for about a month. Just FYI for anyone who has CPO, the fluid drain and refill is not covered under CPO, however the transfer case replacement is. Since the fluid drain and refill is not covered under CPO, the diagnosis is also not covered. So it's almost $700 for this service.

My M50i is currently being driven by the technician to achieve the 125 miles. I'm hoping it's the transfer case. I'd hate for my CPO to end later this year, and have this issue return, and transfer case needs replacement.

Any updates?

I have a 2020 M50i CPO as well, Service Advisor said the same thing "The way CPO warranty works the tranfer case fluid needs to replaced first that is not covered by CPO and if the problem is still present then they can submit a case to replace the transfer case. But I can't just say to replace transfer case the transfer case has to fail the test"

[Madsen203]

Originally Posted by FSociety

Any updates?

I have a 2020 M50i CPO as well, Service Advisor said the same thing "The way CPO warranty works the tranfer case fluid needs to replaced first that is not covered by CPO and if the problem is still present then they can submit a case to replace the transfer case. But I can't just say to replace transfer case the transfer case has to fail the test"

Seems like the M50’s are killing these things. I wonder why? Too much power? Rare to see a 40i with same issue. I read somewhere that they use the same TC and front diff in all X drives which means your 3series sedan is the same hardware. Wild.

[kyoshozx]

I have a 2020 40i that just had its transfer case replaced. The car has 37k miles on it. Last year I had the shudder bind issue, and they replaced the fluid but the issue started again this year and they replaced the TC.

[Madsen203]

Originally Posted by kyoshozx

I have a 2020 40i that just had its transfer case replaced. The car has 37k miles on it. Last year I had the shudder bind issue, and they replaced the fluid but the issue started again this year and they replaced the TC.

I’m curious what the Root cause is for these issues. Maybe a downstream issue affecting the TC (binding diff, pinion angle, batches of solenoids that were faulty)?

2020’s seemed to have more issues. Not sure why other than just “new model” syndrome but these TC’s are used in a variety of models and have been in use since their revision in 2017(?) so it can’t be X7 specific.

It looks like a relatively easy part swap and a recond unit is $1-2k.

[ledphut]

I’ve heard that it was substandard fluid from the factory that did them in. Let’s hope so as I don’t have an appetite for replacing mine every 30K miles.

What another poster mentioned is true. Same parts on a 40i as my XB7 with 590ftlbs… crazy.

[Madsen203]

Originally Posted by ledphut

I’ve heard that it was substandard fluid from the factory that did them in. Let’s hope so as I don’t have an appetite for replacing mine every 30K miles.

What another poster mentioned is true. Same parts on a 40i as my XB7 with 590ftlbs… crazy.

Xb7 is the same as a 330xi.

I think there was a software update to address this as well.

Glad I changed (part of) my fluid at 24k. It’s easy to do for the most part.

[ledphut]

Originally Posted by Madsen203

Xb7 is the same as a 330xi.

I think there was a software update to address this as well.

Glad I changed (part of) my fluid at 24k. It’s easy to do for the most part.

My T-Case was replaced at 34k miles. I’m gonna be keeping a sharp eye on the fluid for sure.

[MSpeedX7]

Originally Posted by FSociety

Any updates?



Any updates?

I have a 2020 M50i CPO as well, Service Advisor said the same thing "The way CPO warranty works the tranfer case fluid needs to replaced first that is not covered by CPO and if the problem is still present then they can submit a case to replace the transfer case. But I can't just say to replace transfer case the transfer case has to fail the test"

The fluid change is covered by CPO. I just had mine done.

[Tinbad]

Originally Posted by MSpeedX7

The fluid change is covered by CPO. I just had mine done.

That’s great to hear. My CPO is about to kick in in 8 weeks and I’ve been hoping for mine to go out in the last year while under regular warranty (or not at all of course haha).

Did the dealer just do it or did you have to escalate? What were your symptoms?