DIY F85/86 Differential Fluid Change

[bmwx5er]

Originally Posted by Yuille36

Why do people fear changing their fluids in their vehicles. Forget what BMW is telling you and change the dam fluids, or don't. It's your choice.

Have to disagree with you, that's terrible advice IMO. This is not in the same category as "lifetime" fluids like transmission fluid that BMW dissuades from changing - you have the manufacturer ZF recommending replacing fluids at 60k miles. This is the rear differential service procedure if you choose to do it, and they explicitly warn not to remove the side chamber drain plugs. I don't know why they warn you, but ignoring the warning without understanding the reason behind it sounds risky.

[Yuille36]

Originally Posted by bmwx5er

Have to disagree with you, that's terrible advice IMO. This is not in the same category as "lifetime" fluids like transmission fluid that BMW dissuades from changing - you have the manufacturer ZF recommending replacing fluids at 60k miles. This is the rear differential service procedure if you choose to do it, and they explicitly warn not to remove the side chamber drain plugs. I don't know why they warn you, but ignoring the warning without understanding the reason behind it sounds risky.

I change my fluids in the entire rear diff, the rear diff is different as it has three distinct chambers. But regardless, at some point your fluids will require changing. You can either choose to change it or not, that's your choice.

This isn't some procedure that is difficult, anyone with simple tools can do.

The penalty for not changing it, is possibly an expensive repair bill in the future.

I'm trying to prevent expensive repairs in my future.

So, we can agree to disagree, but anyone that knows me, understands that I'm into preventative maintenance.

[SaNGRia]

Well, BMW tells too many thing that would cause issues in the future. They dont believe Rod Bearings are issue on S65s and S85s so keeping them stock will eventually cause issue since they do get worn. Fluid change is not a bad practice since we all know that moving parts always uses the life span of the oil. Does not matter which oil but they will eventually loose their protective function after being used that is 110% truth!

Plus every oil has a life span not based on usage but shelf time. SO if you do not use your car for 2 years doesn't mean that oil any good. Fresh oil always good for any equipment that runs with it. So changing the outer fluid is a good thing not a bad thing. The discussion here should be which fluid to use not "not to change the fluid" which we already done that. That will be a much better and smarter discussion since the required part needs sort of oil that supports its technology so it wont cause any sort of issue down the road!

[Yuille36]

That's a simply question to answer, 75W-140 for outer and 75W-90 for the inner.

[SaNGRia]

Originally Posted by Yuille36

That's a simply question to answer, 75W-140 for outer and 75W-90 for the inner.

i have mentioned "we already done that" but thanks for the reconfirmation

[Yuille36]

Originally Posted by SaNGRia

i have mentioned "we already done that" but thanks for the reconfirmation

Your welcome

[Abstracted]

Originally Posted by Yuille36

That's a simply question to answer, 75W-140 for outer and 75W-90 for the inner.

I'm confused.
I show up with my Castrol Syntrax SAF-XJ 75w140 for the rear left and right, and my indy shop says that I should be using 75W-85 instead.

Specifically this:
https://www.bimmerworld.com/Fluids/D...120445832.html

I had to back out of the service until it's clear what it needs.

[bmwx5er]

Originally Posted by Abstracted

I'm confused.
I show up with my Castrol Syntrax SAF-XJ 75w140 for the rear left and right, and my indy shop says that I should be using 75W-85 instead.

Specifically this:
https://www.bimmerworld.com/Fluids/D...120445832.html

I had to back out of the service until it's clear what it needs.

Your shop is correct per newtis.

[Abstracted]

Originally Posted by bmwx5er

Your shop is correct per newtis.

Thank you!

What does Newtis recommend for the front diff?

[bmwx5er]

Originally Posted by Abstracted

Thank you!

What does Newtis recommend for the front diff?

Here you go:

[Abstracted]

Originally Posted by bmwx5er

Here you go:

(Part number 83222413511)

Yep, that's the viscosity my shop recommended as well: 75w-85.

And I'm assuming that this one doesn't have the carbon modifier.

Questions:

1. Where did we get 75w-140 as the go-to for the front and rear sides?

2. Are there any aftermarket brands of 75w-85 that we can use for either the front or rear sides?
Both BMW's 75w-85 runs $100 per liter!

[MBoss_F86]

nishfish87 documented maintenance list. You can find diff fluids here
https://docs.google.com/spreadsheets...htmlview#gid=0

https://f15.bimmerpost.com/forums/sh....php?t=1851701

[Abstracted]

Originally Posted by MBoss_F86

nishfish87 documented maintenance list. You can find diff fluids here
https://docs.google.com/spreadsheets...htmlview#gid=0

https://f15.bimmerpost.com/forums/sh....php?t=1851701

Yeah, I got the "Castrol Syntrax SAF-XJ 75w140 - 0.5L" from the nishfish87 spreadsheet.

But according to my indy/bmwx5er/Newtis 75w140 is incorrect.

[Chilled]

So has anyone found a suitable alternative to the BMW SAF Carbon Mod 75w85 (83120445832). By this I mean non BMW logo version, whilst staying in the 75w85 with what ever the carbon mod is.

Which 75W90 is everyone running in the center?

[Chilled]

Was going to Edit, but figure enough time has passed to warrent a new post.


Is anyone able to comment on the PN# difference for the Synthetic Fluid. Just looking at 83222365987 (BMW synthetic OSP), but allot of sites bimmerworld, fcp euro all reference it as 07512293972 (SAF-XO GL-5). However in the notes it says that 972 was upto 2011 and 987 is for newer.

Based on RealOEM and BimmerCat, 83222365987 should be the current #. So how do you get the current 987 without the older pre 2011 oil?

*Edit*
found this thread.
https://www.e90post.com/forums/showthread.php?t=1442048

talks about this exact thing, with something along the lines of one been for bikes the other for cars at a higher price. Is this true?

Having 3 different chambers with 2x different types of oil is not confusing enough. Why can BMW keep their part numbers in order.

1 Week into F85 life, it does get better?

[Abstracted]

Originally Posted by Chilled

So has anyone found a suitable alternative to the BMW SAF Carbon Mod 75w85 (83120445832). By this I mean non BMW logo version, whilst staying in the 75w85 with what ever the carbon mod is.

Which 75W90 is everyone running in the center?

From my own research and from feedback from my BMW indy shop, what's listed in the Google Sheet, Red Line 75W90 NS GL-5 Gear Oil, seems to be OK for the rear middle diff.

At this point I'm confident enough to use it.

But for the rear sides, and the front diff, I'm still waiting for the thread veteran's input: Yuille36 nishfish87 Sophisticated Redneck
I'd really like to know how the conclusion was made that 75w140 is OK, especially without a carbon mod.

1 Week into F85 life, it does get better?

Yes, especially with all the help here. You just happened to stumble on a very tricky niche.

[Chilled]

Originally Posted by Abstracted

But for the rear sides, and the front diff, I'm still waiting for the thread veteran's input: Yuille36 nishfish87 Sophisticated Redneck
I'd really like to know how the conclusion was made that 75w140 is OK, especially without a carbon mod.

Same, all I see is guys saying that all is fine and they have been running the 75w140 for the last 5k,7k, but no long term. I would guess that even 5w35 engine oil would probably last 5k in a diff, but how would it go for 50k?

I'm surprised we don't have more info from the E70/71 guys, with 50k+ post change.

Is this diff/ style used anywhere else M5 or ML/GL63?

[bmwx5er]

My $0.02: The increase in $$ by going to 75w85 (vs 75w140) is probably $50-$75, for a 50k mile service item. I would just spend the additional $ if you aren't brave enough to take the plunge with 75w140.

[Chilled]

I don't have an issue with the $$ for a 50k interval. Its more a curiosity, as is there a better alternative or a non BMW logo version.

Ie, the ZF Transmission. There is a $$ difference between the BMW Logo and the ZF Lifeguard 8. So the question is why pay the extra for the same oil, just different package. Plus the availability/where to purchase of ZF vs OE.

[Chilled]

So i am going to ask a dumb question, with the ZF oil. Is there specific model# for the one we need.

Just looking for some Lifeguard 8, and have come across like 2x different model numbers, 3x different photos. Is this a regional thing? Castrol, Liqui, Redline, all seem to be the same across regions.


ie.
https://www.ebay.com.au/itm/29432799...cAAOSwTrdhEzhS

References it as "749800"

https://www.ebay.com/itm/13251566117...cAAOSwJXxcWdZu
as S671090312

and this one has the same # as above but has a different style label?
https://www.ebay.com/itm/26527542018...kAAOSwv91hHoOk

Does any of that matter or are they all the same?

[Blue By You]

I am really blown away by all of the information in this thread and other threads. To the point where I'm questioning whether a transmission service makes sense. Concerned about my indy's ability to flush and fill and recalibrate everything correctly, the plastic pan in the service kit voiding my warranty (because someone mentioned and showed pictures of the stock one being metal?), etc.

[///MCollection]

If you have the plastic pan in the kit it's the wrong kit and an expensive way of doing it. Just get the filter, gasket and ZF lifeguard 8 ( 7 litres to be safe) and keep your metal sump. Our metal sumps are the best thing BMW did for us!

Also only change the fluid and don't use a flushing machine, as far as I know ZF have not approved the use of a flushing machine so far.