[Gassy]

2019 F90 with 23,500 miles, in service for just shy of 4 years (December 2018). Dealer is pushing front & rear diff & transfer case oil based on length of service, not mileage, but I am reluctant based on recommendation for mileage being around 50K before these are done. I was thinking of doing it around 40,000 miles, but I need more learned advice from some experts in this forum. Help is much appreciated

[Eljeffrey13]

Originally Posted by Gassy

2019 F90 with 23,500 miles, in service for just shy of 4 years (December 2018). Dealer is pushing front & rear diff & transfer case oil based on length of service, not mileage, but I am reluctant based on recommendation for mileage being around 50K before these are done. I was thinking of doing it around 40,000 miles, but I need more learned advice from some experts in this forum. Help is much appreciated

I have a 19 and just hit 50k miles and it was covered since i have the maintenance plan, its always good to replace oils and it can only do good, if ur paying out of pocket thats on you, but in the owners manual it states those oils should be changed at 50k miles since u have 24k i eould say ur still good i doubt because the oil has been in the car acouple yrs it would go back, but u should try to get alittle more info before u make ur decision

[shawnhayes]

Originally Posted by Gassy

2019 F90 with 23,500 miles, in service for just shy of 4 years (December 2018). Dealer is pushing front & rear diff & transfer case oil based on length of service, not mileage, but I am reluctant based on recommendation for mileage being around 50K before these are done. I was thinking of doing it around 40,000 miles, but I need more learned advice from some experts in this forum. Help is much appreciated

Did yours get the front and rear diff change at 1800 miles?

Shawn

[Gassy]

Originally Posted by shawnhayes

Did yours get the front and rear diff change at 1800 miles?

Shawn

Yes, front & rear diff changed at 1200, not 1800. Dealer called while it is in for oil change to scare me into doing diffs & transfer oil by stating that "if the services aren't done by the recommended time it could affect your warranty on the parts." What warranty? I'm out of warranty. Is this just typical stealer BS?

[shawnhayes]

Originally Posted by Gassy

Yes, front & rear diff changed at 1200, not 1800. Dealer called while it is in for oil change to scare me into doing diffs & transfer oil by stating that "if the services aren't done by the recommended time it could affect your warranty on the parts." What warranty? I'm out of warranty. Is this just typical stealer BS?

It's a good thing to do if you're going to keep the car forever. If you're only going to 100,000 and letting it go, then meh. But, it should be done at least by 100,000. The little metal shards get into the oil and ruin its lubrication.

And yeah, he's blowing smoke on the warranty.

Shawn

[Maverik259]

Originally Posted by Gassy

Yes, front & rear diff changed at 1200, not 1800. Dealer called while it is in for oil change to scare me into doing diffs & transfer oil by stating that "if the services aren't done by the recommended time it could affect your warranty on the parts." What warranty? I'm out of warranty. Is this just typical stealer BS?

Oils do break down over time. The book should have a mileage or time but may not. Honestly it's not a horrible idea. Only extends the life of more expensive parts like a new transfer case. BMW won't even change the oil on the X5 transfer case. Call it a lifetime fluid for some reason and when it started acting up at 65k Miles they put in a new one for $6k that my extended warranty covered.

If I would have known at the time I would have changed it long before 65k miles.

[pbonsalb]

There is a schedule for every fluid but the trans. BMW says the trans fluid is lifetime but apparently ZF has a schedule. That trans is used in many vehicles by other manufacturers and I wonder whether they also use lifetime fluid.

[shawnhayes]

Originally Posted by pbonsalb

There is a schedule for every fluid but the trans. BMW says the trans fluid is lifetime but apparently ZF has a schedule. That trans is used in many vehicles by other manufacturers and I wonder whether they also use lifetime fluid.

Can you access the diff schedule?

And, as above, the center "transfer case" has been a weak part of the X-drive system for eons. Multiple "rebuild" videos on youtube.

BMW is one of the few that says "lifetime".

"In most, if not all other vehicles that have the 8 speed ZF transmission, the manufacturer recommends a transmission fluid and filter change at 70,000 to 80,000 miles. This is also the interval that ZF themselves recommend."

https://gearsmagazine.com/magazine/t...filter-change/

But, I have read some of the procedures to change this fluid. Especially in all wheel drive configuration, it appears to be a GIANT pain in the ass. You'd probably get away with a drain and refill if you did a mililiter for mililiter replacement, but I don't know.

Shawn

[pbonsalb]

I have seen this in a few places, but here is a link to pdfs at one of those places.

https://f90.bimmerpost.com/forums/sh....php?t=1605537

[LouK]

The app just pinged me for these services as well, I am at 32K so nowhere close on mileage but at the time mark.

[Ropes]

Those oils are not subject to combustion blow by, fuel or moisture in the air. They break down over use not time. You are supposed to change spark plugs every 30k/3 years with BMW. If you only drove 15k over 3 years, would you change them?

[pbonsalb]

People who are doing early oil changes are confused by the BMW service trigger that is based on the number of oil change resets done to the computer, which then signals another service is due. Read the service schedule and you should understand.

Nothing wrong with servicing early, however, and I sort of subscribe to the theory that age can be a substitute for mileage if the mileage spec is not reached but the number of years that might normally equate to that spec have passed. At least for some things.

[shawnhayes]

Originally Posted by Ropes

Those oils are not subject to combustion blow by, fuel or moisture in the air. They break down over use not time. You are supposed to change spark plugs every 30k/3 years with BMW. If you only drove 15k over 3 years, would you change them?

Heavily modified oils age over time. There is SOME consideration for fluid replacement when they are old, even with little use. They change fluids in museum pieces if they are ever driven (Leno).

Shawn

[Gassy]

Originally Posted by Ropes

Those oils are not subject to combustion blow by, fuel or moisture in the air. They break down over use not time. You are supposed to change spark plugs every 30k/3 years with BMW. If you only drove 15k over 3 years, would you change them?

Excellent point. I don't think that anyone here thinks that the overly aggressive app-driven diff oil change recs are driven by anything but profit by those lovely people at BMW. Thank goodness for the indy mechanics for those of us who lack the DIY skill-set.

[shawnhayes]

Originally Posted by Gassy

Excellent point. I don't think that anyone here thinks that the overly aggressive app-driven diff oil change recs are driven by anything but profit by those lovely people at BMW. Thank goodness for the indy mechanics for those of us who lack the DIY skill-set.

In an oil thread, the point is being made that the tranny is a "lifetime" fluid so the tranny dies and costs the owners money by needing replacement.

In this thread, the oil change interval is said to be overly aggressive to make a profit.

Both points are unlikely to be true together. Likely one is and one is not, or they are both true.

Agree or disagree?

Shawn

[Demon Barber]

Just crossed 33k miles and got the same app alert for diff fluid change. I had already changed them myself back in April around 30k miles, along with the transfer case fluid and the transmission. The manufacturer of the transmission recommends changing the fluid, so that's what I will be doing. Changing earlier is always better.

[Maverik259]

Originally Posted by shawnhayes

In an oil thread, the point is being made that the tranny is a "lifetime" fluid so the tranny dies and costs the owners money by needing replacement.

In this thread, the oil change interval is said to be overly aggressive to make a profit.

Both points are unlikely to be true together. Likely one is and one is not, or they are both true.

Agree or disagree?

Shawn

I mean. BMW calls the transfer case fluid in the X5 lifetime but not in other models. Yet give them fill and drain ports. And then when they fail prematurely they replace. Luckily I paid for an extended warranty and the cost to replace the case covered the entire initial warranty cost.

I think bmw service recommendations are 90% financial based and 10% engineering based. Plus or minus. Haha.

[shawnhayes]

Originally Posted by Maverik259

I mean. BMW calls the transfer case fluid in the X5 lifetime but not in other models. Yet give them fill and drain ports. And then when they fail prematurely they replace. Luckily I paid for an extended warranty and the cost to replace the case covered the entire initial warranty cost.

I think bmw service recommendations are 90% financial based and 10% engineering based. Plus or minus. Haha.

A very interesting thought.

A 75,000 mile interval for our ZF-8hp transmissions might help make them A LOT of money. But, leaving them might result in a destroyed transmission and a full replacement. Doubt that 75,000 mile and up M5's are getting this done at BMW though. And, that transmission is "off the shelf" from ZF and can be gotten from other "recycled" cars.

Not sure I agree with you. But, it's just a thought.

Shawn

[shawnhayes]

Originally Posted by Demon Barber

Just crossed 33k miles and got the same app alert for diff fluid change. I had already changed them myself back in April around 30k miles, along with the transfer case fluid and the transmission. The manufacturer of the transmission recommends changing the fluid, so that's what I will be doing. Changing earlier is always better.

I think I'll be following you. I think I can manage the front and rear diff.

The tranny SOUNDS hard if you follow the BMW service procedure.

Any recommendations? Old fashioned knowledge is to drain, measure, and replace. But with the replaceable pan (which supposedly contains a filter), that sounds even more troublesome.

Interested in your procedure. (or did you have the dealer do it?)

Shawn

[pbonsalb]

I don’t think the pan has to be replaced. On my E61 535xi it was plastic with integrated filter and I drain plug. I replaced it. I think my 2018 M5 has an aluminum pan with drain plug but I would have to put it back on the lift to check. The transfer case looked like it had easier service access than the one on the 535.

I have all fluids but trans and will do them sometime in the next year. 41k on 2018. The trans can wait until 60k miles.

[Demon Barber]

Originally Posted by shawnhayes

I think I'll be following you. I think I can manage the front and rear diff.

The tranny SOUNDS hard if you follow the BMW service procedure.

Any recommendations? Old fashioned knowledge is to drain, measure, and replace. But with the replaceable pan (which supposedly contains a filter), that sounds even more troublesome.

Interested in your procedure. (or did you have the dealer do it?)

Shawn

I did it myself, and I bought the ZF Lifeguard 8 fluid from FCP Euro (8 liters to make sure I had plenty). I also bought the replacement pan, filter, and bolts from BMW parts of South Atlanta. It was easy to locate the drain and fill plugs, and the procedure for changing the fluid is from ZF. You have to have the car level, drain the fluid, remove the pan and replace it with a new filter and new bolts, torques in a specific pattern and to a defined torque value. Very easy access after removing the skid plates. Once done, I used a foxwell scanner to monitor temperature of the transmission. You initially refill to overflowing the fill hole, start the car and let warm up, do a specific shifting procedure, then top off to the fill plug once the scanner states you've reached temperature. Then torque the fill bolt, replace the skid plate, and you're done. I'll try to post the procedure PDF from ZF.

[Demon Barber]

Here's the info from ZF. To fill with the new fluid, you will need a manual pneumatic fluid transfer pump (go to ECS tuning). And you will need a scanner that can read the transmission temperature, and a low range torque wrench and I think torx head sockets for the bolts. You have to jack up the car on all four corners in a way that it is level.