[EndOfAnEra]

Okay we're back again for another DIY!

The patient is a 2012 BMW X3 35i with 81K miles. I have chosen to go with Redline 75w-85, which is equivalent to OEM Part # 83222295532.

Link to fluid here -------> https://www.ecstuning.com/b-redline-...art/50104~red/

NOTE: This same fluid can also be used for the front differential!





Before you start this DIY make sure you have a nice fluid transfer pump. In addition to the pump, for this specific DIY, you'll also want to buy a 90 degree fitting to allow the hose to go into the differential at a downward angle to suck out all of the old fluid.



The one I used can be viewed here: https://www.ecstuning.com/b-schwaben.../022253sch01a/

Here is a parts list of everything you'll need for this DIY:

- 1 quart of rear differential fluid
- fluid transfer pump (plus a 90 degree angle fitting)
- ratchet
- 14mm hex socket

The two following pictures are the jacking points as described by BMW. The first picture shows the jacking points, and the second picture is the jack pads underneath the vehicle. Use these as a guide to properly raise and support your X3.

NOTE: Be sure to make sure the car is level once it's raised into the air. This will allow for the proper level of fluid to be put back into the vehicle.







Once the vehicle is in the air, go ahead and grab a drain pan to catch any fluid that may come out when the fill/drain bolt is removed.



Next you'll want to grab your 14mm hex socket and ratchet and remove the fill/drain bolt.



There will most likely be a little fluid that comes out, so be ready with something to catch it.



From here, you'll put your fluid pump hose into the fill/drain hole on the diff in a downward facing direction and suck all of the old fluid out. You should be able to remove roughly 9/10 or 90% of a quart. Once all of the fluid is out, go ahead and pump your new fluid back in until it starts to pour out of the fill/drain hole. At this point you'll want to thread the bolt back into place and torque that sucker to 60Nm. Congratulations! You've just changed your rear diff fluid! Clean everything up and then sit back and have a beer

[Marty in NY]

Originally Posted by EndOfAnEra

Okay we're back again for another DIY!

The patient is a 2012 BMW X3 35i with 81K miles. I have chosen to go with Redline 75w-85, which is equivalent to OEM Part # 83222295532.

Link to fluid here -------> https://www.ecstuning.com/b-redline-...art/50104~red/

NOTE: This same fluid can also be used for the front differential!

Why didn't you go with the 75W90? You have an F25 35i, right?

[EndOfAnEra]

Originally Posted by Marty in NY

Why didn't you go with the 75W90? You have an F25 35i, right?

The part number for the oil that is suggested for my vehicle is 75w-85 as per realoem.

[joshaguirre]

Much appreciated!

[lovebimmers]

Thank you so much!

[lovebimmers]

The pictures shown are for the rear. Where exactly is the front fill/drain bolt? Thanks so much for the DIY. Seems easy enough to do.

[Marty in NY]

Originally Posted by EndOfAnEra

The part number for the oil that is suggested for my vehicle is 75w-85 as per realoem.

Interesting, seems BMW changed from 85 to 90 just after my car was made, mines an 2011. Wonder why? Hmmmmm

[EndOfAnEra]

Originally Posted by lovebimmers

The pictures shown are for the rear. Where exactly is the front fill/drain bolt? Thanks so much for the DIY. Seems easy enough to do.

Are you referring to the front differential? This DIY is for the rear diff. I will be making a front diff fluid change DIY soon.

Originally Posted by Marty in NY

Interesting, seems BMW changed from 85 to 90 just after my car was made, mines an 2011. Wonder why? Hmmmmm

While I am not 100% sure, what I can tell you is when I changed diff fluid on my older 135i and 335i, they used 75w-90. I guess BMW updated its specifications around 2011?

[evilchargerfan]

is that 90 degree fitting crucial?

can someone sub in with a super crazy long hose instead?

[tracer bullet]

Originally Posted by evilchargerfan

is that 90 degree fitting crucial?

can someone sub in with a super crazy long hose instead?

It'd help a lot but in the end you just need to be able to get to the bottom. If you can manage it in another way go for it.

[383vett]

Nice write up.

[pungo]

I use a mityvac to suck the fluid out. Sure, I have to empty the small canister a few times, but the long small diameter hose can easily be fished around to get the bottom while the unit is holding a strong vacuum to extract most of the fluid.

[evilchargerfan]

I spent an hour saturday doing the fronts, and then another hour sunday doing the rears. EndOfAnEra, thanks again for such a nice detailed thread! I'll share how things went while I was under the car




big shiny drain plug staring right at you


break it loose


stick in hose and suck out old fluid


I tried my best to use various angles and hose lengths to suck up as much as possible


dump old fluid into container of your choice (I went with a clear one with measurements)


smells yucky as it looks. everyone else says their rears "look good" ... mine was nasty/dark


just about 946ml removed



per the op, drank a beer afterwards

(confession, I actually had 4)

[ClampThurst]

Has anyone used the Titan Sintopoid from Fuchs???? I was recommended this for both front and rear differential on 2017 X3 35I. I mentioned to them that BMW has two different oils for front and rear, but in their system, both part number correlate to Titan Sintopoid FE SAE 75W-85. Since Fuchs makes some of the original fill lubricants on the X3, I figured i'd give them a try. Similar to the RedLine used above, Titan is a GL-5, synthetic hypoid gear oil.

[evilchargerfan]

Chris, like the other UOA's I posted across our DIY's, I'm hoping its okay to share for Rear Diff as well

[sbacchus]

Curious why not the NS version of the Redline oil since the diff is non LSD?