[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 # 83222413511.

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

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





Before you start this DIY make sure you have a nice fluid transfer pump. 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 front differential fluid
- fluid transfer pump
- ratchet
- extensions
- 8mm socket
- 10mm socket
- 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 up in the air, grab your 8mm and 10mm sockets and go to town on the lower engine cover underneath the vehicle.



From under the vehicle looking up, here is the front differential. You can easily see the drain bolt on the bottom.





It is a small window looking inboard from the LF wheel to locate the fill bolt.



Okay let's get to work! Grab your 14mm hex socket, a 6 inch extension (roughly) and your ratchet. Break loose the fill bolt FIRST before you do anything else. We would hate to remove the drain bolt first, and then have an issue removing the fill bolt. Know what I mean? Again, this view is looking inboard from the LF wheel. Make sure you have a drain pan ready to catch any fluid that may come out once the fill bolt is removed.



This view is from the ground looking up at the fill bolt with my socket already in place.



Once the fill bolt is removed, let's go ahead and remove the drain bolt on the bottom of the front differential. Again, make sure to have a drain pan ready to catch the old diff oil.



Old fluid on its way out after 81k miles!


From here it should be self explanatory. Once the old fluid is done draining, reinstall the drain bolt. You can also choose to buy new bolts if you wish. I just reused what was already there. Torque to 60Nm. After the drain bolt is torqued properly, go ahead and pump the new fluid in until it starts to come out of the fill hole. Since the wheels will be off of the ground, go ahead and spin the wheels a bit to get the new fluid into all the crevices of the front diff. That could give you a bit more room for new fluid. Then reinstall the fill bolt and torque to 60Nm. Clean up, and reinstall the lower engine cover and celebrate! Front diff fluid change complete!

[joshaguirre]

Will keep this in the bookmarks!

[tracer bullet]

Thanks for these! I'm a decent DIYer but it's so nice to have an example to look at first to know what you're getting into, get tools ready and see if I'm missing anything needed, give the wife an estimate of how long I'll be in the garage, and so on.

Really appreciate it!

[evilchargerfan]

Really Really Really appreciate these tutorials. prior to you making these, most of what i've looked up on the matter had no pictures, at all

Originally Posted by tracer bullet

give the wife an estimate of how long I'll be in the garage

I literally thought the same!

I looked at Chris's guide for the front diff, and I figured ... "okay I'll tell the mrs an hour this sat" and looking at Chris's guide (in another thread) for the rear diff, I can tell her another hour this sunday.

[6MT_Addict]

Fantastic DIY, thanks for posting!

[evilchargerfan]

Finally did my front diff, cant thank EndOfAnEra enough. I'll share some pics and my experience




my pump and extra hose for it. plan is to clean pump prior to doing another fluid, and trashing 12 inch section of hose and use new hose for the next fluid type


view from the front of car. per the op, will focus attn towards front/drivers side wheel


fill port (always a good idea to loosen this first)


drain port


loosening the fill port


loosening the drain port


about 500ml collected. yuck


replaced all my plugs. a little overkill, could easily skip this


torqued drain plug to 60 nm


mityvac pump could hold about 200 ml. so I had to do this 2 and a half times


pump in new fluid slowly. once excess flows out, stop pumping ... wait for overflow to stop. install plug and torque to 60 nm

[Bufalo]

I found tonight that with a decent bit of hose you can fill the front diff from the top, pouring slowly until fluid starts to run out of the plug. I have some fluid pumps, but man I hate using fluid pumps. I am doing the transmission, xfer case and rear diff this coming weekend, so I'll have plenty of time to use fluid pumps...

[one9kilo]

Nice write up. I just did my front, rear diff and transfer case fluids. Interesting though.. I used Redline 75w90 for both front and rear diff. From my research online, it doesn't seem to make a difference so I hope it's OK.

For the front diff, if you have the front left tire off you can actually sit in the pocket of the wheel well and pump fluid just sitting there. Makes it easier than laying on the ground.

I didn't think to rotate the wheels so make more room for fluids. Great advice there. I'll have to do that next time.

[AlexF25]

Very nice write up, thank you EndOfAnEra and Evilchargerfan for the effort of taken pics and posting, getting ready to do this along with Tranny/Transer case fluids and always gives more confidence to see photos of the DIY before hand.

[evilchargerfan]

Originally Posted by AlexF25

Very nice write up, thank you EndOfAnEra and Evilchargerfan for the effort of taken pics and posting, getting ready to do this along with Tranny/Transer case fluids and always gives more confidence to see photos of the DIY before hand.

YW!

I legit waited on Chris to do this, before I got anywhere near the car, lol!

But yea, his DIY made it so super crazy smooth. Going in with confidence was such a good feeling.

GL!

[Volkom]

Thanks for the write-up. Bought one quart for the front differential, had to drain it when i replaced my N20, a little bit was left over in the bottle. Really easy to do, old fluid was horrible looking. I appreciate the help.




Lifetime fluid? Questionable... 72k miles and it looked like this

[romero1990]

it looks like FCP recommends 75W90 Redline or Limo. What's your take on 75W90 vs 75W85? What's the difference going from hypoid vs full synthetic? (it seems RealOEM is saying OE using hypoid instead of full synthetic)

[evilchargerfan]

EndOfAnEra , I hope its okay to share a UOA of what our diff fluid looks like



(if not, lmk I can take it down)