[evilchargerfan]

The purpose of this post is to share my experience changing Transmission Fluid. Usual disclaimers apply ... break your car, not my fault.

I'm not sure if this thread will be considered as a good or poorly written DIY, but here goes! (NOTE: I am open to suggestions, editing where necessary, and those with talent feel free to help me annotate photos)




Our patient is a 2014 BMW i3 100K miles.



Original owner provided no service records, so we can assume its all original fluid.

Fluid was purchased from FCP Euro:
https://www.fcpeuro.com/products/bmw...ml-83222295532



I printed out the following to assist me throughout the day:














Parts list:

- two 500ml bottles of fluid
- fluid transfer pump
- torque wrench
- ratchet
- 8 hex socket
- 14 hex socket
- 13 socket
- 5/8 socket
- gloves
- shop towels
- an oil drain pan
- a means of keeping your floor clean (ie: tarp)


Pre Requisites:
-jack up car by preferred method




* * * to be continued * * *

[evilchargerfan]

A view of how things look from underneath / the rear end







First thing to remove is this Triangle thing



Next up is the brace. The manual calls to remove just one side, I opted to remove both sides so I could get a nice look while I'm down there





A bit filthy, but here it is, with all bracing removed







HERE is where all the action takes place



PRY the clip, then gently lift up the insulation



This is what you'll reveal



Drain plug is size 14 hex, Fill plug is size 8 hex





* * * to be continued * * *

[evilchargerfan]

I removed the Fill Plug first



Next, remove the drain plug



OEM magnetic drain plug caught allot of debris



Yuck



A little over 500ml drained



Pump in new fluid slowly, until it starts to overflow a bit



I used one full bottle, and a little bit from a second bottle
(note, I did spill some here and there)



Wait a little for the fluid to stop dripping ...


Torque specs for Drain and Fill plugs = 35 NM



DONE! Just reinstall everything in reverse order





Torque specs for the Bracing:
28NM for the smaller m8 bolts
56NM for the bigger m10 bolts




For kicks and giggles, I checked ... there appears to be no option to reset adaptations

[evilchargerfan]

EXTRA NOTES:


LATER models may or may not have drain/fill plugs ... please be aware of this

I was not able to determine what the proper trans "operating temp" should be

I cleaned off the plugs and re used

I did replaced the crush ring

I re used the clip that was pry'd off, near the insulation

I will more than likely send off the fluid to get tested by BlackStone Labs

[vreihen16]

I'm curious about what Blackstone has to say, especially with all of those scraps on the magnetic drain plug.....

[JoeCool88]

Many thanks for this awesome description of an oil replacement.
On my 2018 i3 I had a "lucky wheel" (clac-clac-clac) noise when driving real slow. You could only hear it with the pedestrian warning and all other fans / radio off. I decided to remove the mag plug an found what is depicted on the attachment. Compared to this and and i. a. w. my experience it's normal wear what you found on the a. m. mag plug.
My i3 had 22.000 km only, so I contacted BMW and got (praise the Lord) an XMSN on good will. On gearboxes w/o filler plug BMW says "oil is filled via input of output shaft into E-XMSN." But this means that you have to remove the RH driveshaft and check the cars geometry afterwards etc., just to fill in the oil?!? I used a syringe and filled in the oil through the upper vent port which is protected by a plastic cap which could be reused, no problem.
As you can hear the noise under the a. m. conditions, only, I'm pretty sure that hundreds of i3 are driving around with this. IMHO there will be no sudden catastrophic impact, but the question is what the long term consequences could be.

[ckspark]

I recently purchased my first BMW, a 2016 I3 rex 94ah. I was surprised to be told that there is no paper record of any service history only the I-drive memory record. So I have no idea if mine has ever been changed either. Do you know the recommended interval for changing the transmission oil?
Thanks.

[JoeCool88]

As far as I know the transmission is "filled for life" with the oil. Which makes sense, because the gearbox design is very simple. There's an input gear with two bearings 6307, an intermediate gear with bearings 6308, and the differential. That's it. The oil is fully or at least partly synthetic, a degradation is unlikely. Or, in other words, even if a degradation of the oil takes place over the years, it is unlikely that such a simple designed gearbox gets damaged by that.
However, it is important to understand that the XMSN has a centrifugal lubrication, only. When the car was stationed for a while all oil has flown back to the sump by gravity, and it takes some turns until the differential which is immersed in the oil has flinged it to the bearings of the input shaft. Consequently I find it beneficial to allow the car a "warm up" phase, with low to medium speeds and especially low torque, after start for some minutes. Instead of "spuring the horse" directly after leaving the garage.

[Stevefufu17]

The filling poses no problem by venting?
The manual says to drop the transmission.
And you will have some pictures thank you

[CnSky]

Where did you get the I3 shop manual I have been looking to buy one unsuccessfully?

[dansciol]

Just changed my diff oil in my 15 i3 rex. 58k miles. Lucky I had the fill plug. Tons of metal in the oil, magnet saturated in metal. Lifetime fill is bs. Running constant metal particles in the oil meshing in the gears is not good for longevity.
I used Mobil 1 75w90, should be just as good or better than the original oil.