[jmciver]

Reviving this thread to ask a question about the transfer case drain/fill....

In order to get to the drain/fill plugs of the transfer case, the BMW TIS procedures say to remove the transmission brace. Did any of you do this? I can't see how you could get access to the drain/fill plugs if you don't. And if you did remove it, did you support the transmission?

I started to remove it, but since I did not have a transmission brace, and I saw quite a bit of movement of the transmission, I stopped. My car is a 2013 X3 xDrive28i if it matters. But looking at the BMW procedures it does not seem like it matters between my X3 and the xDrive35i variant.

Thanks!

[Barbera335]

Yes. I removed the brace. I did have to support the back of the transmission.

[jmciver]

I don't suppose you could elaborate a bit as to where you supported the transmission. It is very tight back there and putting a tranny jack (or some other type of support for the tranny) on the plastic transmission sump does not seem right....

I may be thinking about this too hard, but this is something I don't want to mess up with the car up on a lift.

Edit: So I was over thinking this a bit... I used a tranny jack with some wood to help protect the plastic transmission pan. While I doubt there was any damage done to the plastic tranny pan while supporting the weight of the transmission during the transfer box fluid change, I still decided to do the transmission fluid change AFTER the transfer box - just in case.

[jmciver]

So after doing all of my fluids in my X3 recently with the help of this thread, here is some additional info that may help others.....

1. For the transmission fill procedure using ISTA/D, it is best to do a dry run with the car BEOFRE you take everything apart. The procedure will not let you look ahead and there is no way to preview the entire procedure that I know of. The procedure does require you to prepare ahead for certain steps, and you have a narrow temperature window to get everything done. If the temperature goes out of the prescribed window, the procedure will not let you continue.

2. If possible, perform the transmission fill procedure when it is cold outside (i.e. fall or winter if possible). Even if you are very familiar with the procedure, as I recommended above, the temperature comes up pretty quick and it is really easy to blow past the required temperature window. Not that it can't be done when it is warm outside, but doing this procedure when the ambient temps in your garage are 85-90+ degrees could make getting the temperature timing more difficult.

3. For the transfer box oil change procedure, I could not find anything in the procedure that requires you to reset/recalibrate anything after the oil change. I did see a requirement for that for the previous model X3 (the E83) which I am assuming people are referring to. That said, ISTA does allow you to reset adaptations for the transfer box. Resetting adaptations is like clearing out historical data, so it doesn't usually hurt anything (I do it with my engine all of the time when changing tunes), so I went ahead and did it because I was in there - but I don't think it is required.

4. To get to the transmission oil fill procedure in ISTA was not very intuitive as the ISTA GUI is not very intuitive IMHO - it took me a while to find it inside ISTA after several internet searches came up short. Below is a screen shot of the tabs to get to it. It is after you have established a connection to your car. One note, when connecting to your car, make sure you connect w/running tests. There is an option to connect to the car without running the initial ECU tests, but if you do that, the procedures are greyed out for some reason and not available to run.

Vehicle Management -> Service Functions -> Power Train -> Transmission Control Unit 8HP -> Transmission Oil -> Oil Balancing -> ABL Transmission Control Unit: Oil Level Adjustment

[EndoDoc]

Saw somewhere on a different forum that the cold transmission fluid recaptured from the pan change can just simply be measured in new fluid and placed back in the new pans fill hole. I think that works great if you assume the level was correct before the transmission oil change but as long as everything is cold you could just fill until it begins to pour out. I have watched a video put on by ZF and still can not understand why the fluid has to be at a certain temp to refill, especially when all they do is put in cold fluid in the process of topping off. See it here:

My thoughts as I plan to do this on my X3 35i with 95K on the likely original trans oil.

[Wgosma]

Your idea of cold drain/fill makes sense, and as you said assuming the transmission has the correct volume of fluid to begin with.

My guess regards the checking of fluid level with transmission at elevated (operational) temperature would be that since all fluids expand when heated this method will eliminate the possibility of overfilling the transmission, along with insuring adequate fill volume. The total volume in the transmission system is somewhere in the range of 12+ quarts of fluid (transmission, torque converter, etc.) - so I can see how fluid expansion from increased temperature would affect the level by more than just a little.

(I don't believe a repair facility would ever consider doing a cold drain/fill as you've indicated- not good practice, too risky to assume initial fill level is 'correct'; they want to KNOW that the final fill level is spot on).
Good luck/Bill

[jmciver]

One other thing to consider is that there could be an internal thermostat (or something similar) that opens once the fluid is at normal operating temperature, which would affect the ability to completely fill the system - something similar to the engine coolant system. I don't know this for sure, this is just hunch after going through the fill procedure using ISTA.

FWIW, the first time I filled the transmission, I did not follow the entire procedure (specifically the parts about getting it up to temp to do the last fill), I just essentially did a cold fill as described above. When I opened the system to drain it (I opened the fill plug before the drain plug), I had some oil come out. When I buttoned everything up, oil level was at the edge of the fill hole (similar to when I first opened the fill plug) - car seemed to run fine (with no error messages), but I still wanted to re-do the procedure again. I came back later (after the car was completely cool) to do the complete fill procedure, following all temperature requirements, and was able to get almost an additional quart into the transmission.

[EndoDoc]

Thank you for sharing those points. Did either of you use Rheingold software with a K+DCAN cable to monitor transmission temps? Also was curious to know if the hidden menu in the dash has transmission fluid temps?

I almost have everything to do the job, just not a scan tool and am debating on picking up the full Rheingold software with a K+DCAN cable from Bimmergeeks.

[Wgosma]

Hidden menu: no trans related data, only engine temp info.

[jmciver]

Originally Posted by EndoDoc

Thank you for sharing those points. Did either of you use Rheingold software with a K+DCAN cable to monitor transmission temps? Also was curious to know if the hidden menu in the dash has transmission fluid temps?

I almost have everything to do the job, just not a scan tool and am debating on picking up the full Rheingold software with a K+DCAN cable from Bimmergeeks.

I have a copy of ISTA/D (aka Rheingold) that I used (with a ENET cable - which is required for FXX series cars). You don't need to pay a 3rd party for the software (since it is all BMW proprietary anyway) if you are willing to do a bit of legwork - Google is your friend here.

Regarding the procedure, the temperature monitoring is built into the procedure in ISTA. I will not let you proceed unless you reach the required temperature at the appropriate step. The trick is to be familiar with the procedure and have everything pre-staged so that you can execute the procedure efficiently since it is really easy to blow past the very narrow temperature windows when the car is running. This happened to me initially.

To execute the procedure efficiently, I actually did a dry run (starting with the car cold) with my car in the driveway on the ground to ensure I could efficiently get through the procedure. Once I was comfortable with the procedure (and when the car was cold again), I had everything pre-staged to execute, to include my oil pumping assembly ready to go, all interference around the oil pan removed, and the fill plug loose. Another recommendation is to do this procedure when ambient temps are cooler (in the Fall/Winter vice Spring/Summer) as a cooler ambient temperature will slow down how fast the car warms up giving you a bit more time to execute the procedure.

[EndoDoc]

Jmciver would you mind directing me to where I can get the enet cable? Ill try google for the software and after a concerted effort I can PM you for more guidance on procurement of it.

[jmciver]

Originally Posted by EndoDoc

Jmciver would you mind directing me to where I can get the enet cable? Ill try google for the software and after a concerted effort I can PM you for more guidance on procurement of it.

Search: "BMW ENET cable" and you should have several options that show up..

[chrispitude]

Are the front and rear F25 diffs both "open" diffs? (We have an X3 28d if it matters.)

I'd like to add Liqui Moly's MoS2 gear oil additive when I do the fluid change, but not if there's any clutch pack stuff going on in there.

[EndoDoc]

Completed both differential oil changes today, again fill and drain plug on front and only drain plug on rear. The rear took a little over a 1L of fluid and the front a little over a half a liter. Front diff oil was darker and stronger smell, the rear was basically new. I have an X3 2014 35i with 95K. I did want to ask if the wetness I noted on the oil pan? near the front axles is of concern, see photos at link, too big to upload using my phone. This was on the right side.

https://photos.app.goo.gl/w5A3sdYuu9YvPqX58

[Wgosma]

That is the engine oil pan or ????

Looks like relatively minor gasket leak- no immediate attention needed, keep an eye on it periodically going forward.

[EndoDoc]

Yes, just to the rear of the drain bolt for the oil pan, the pan is not clearly defined.

I'll keep an eye on it.

Originally Posted by Wgosma

That is the engine oil pan or ????

Looks like relatively minor gasket leak- no immediate attention needed, keep an eye on it periodically going forward.

[Antfern]

Originally Posted by ThomasR

A word of advice. Change it.

My 2015 X3 has 70k. I'm changing all the drivetrain fluids for the first time. Front and Rear diffs, transfer case and transmission oil and pan. This weekend I started on the diffs.

The rear diff oil was very clean and looked great. The front diff however looked dark and very used. There is no drain plug for the rear so you have to use a siphon like this one that I used:



And to pump it back in:



The front has a drain and fill plug. You do not have to remove the stiffening plate to change the front. I didn't. Make sure you break the fill plug loose first in case you find it is seized.

All fill and drain plugs are a 14mm allen. All fill plugs and drain should be torqued to 60nm.

Each require just under a quart. I used this for front and rear:



The manual calls for BMW 83 22 9 407 768 and this part number is listed as the direct replacement oil from Red Line for that part number.

The rear plug is on the top and there’s is no drain plug, is it because you don’t change it, just top off? It could be the reason why it is clean? Could be the only lifetime oil. Right now I have a transfer case oil leak, just a drip. I suspect the dealer loosen some bolts because I was there 3 times for different types of leak which they found initially, I did not see oil in my garage. I will try to put “Leak stop” mixed with the oil and by the way the transfer oil is not the same as the differential oil. The best thing to do is ask the dealer for part numbers, using your bin and you can buy cheaper from the web. Be sure they are reputable ones. Cause there might be companies that sell knock offs from China, cooking oil labeled as 75w90, you would t know ones it is inside. What I will do is mixed the old oil with stop leak put it back and top it off until the leak is gone and replace it with fresh one. These cars I bet you are easy to maintain if you are paying attention. The same with Mini Cooper, a pain in the ass but ones you know it’s intricacies, it can last longer.

[markslc1]

Originally Posted by ThomasR

Ok so I gave up on BMW and instead wrote to Fuchs oil who made the oil that's in our differentials from the factory:

Hello, I own a 2015 BMW X3 xDrive35i SUV. According to the latest BMW technical information, the rear differential gear oil BMW recommends is part number 83222413512 Hypoid Axle Oil G3 which they say is also Fuchs Titan EG 4218. The front differential gear oil they recommend is part number 83222413511, called Hypoid Axle Oil G2. Is that also produced by Fuchs? If so what is it? Could you provide more technical details regarding these oils? I have searched for days on the Internet, spoken to BMW dealers, etc and cannot determine what API service class (GL-5, GL-6, etc) or even what SAE Viscosity Grade (75w90) these oils are. All I could find on the Titan EG 4218 was an MSDS sheet.

Thank you,
Thomas Reynolds

His response:

Hi Thomas,

TITAN EG…. are a range of oils only for first fill applications. They are sold in bulk to BMW and other OEM’s. They are not made available for the service fill on the same names.

We produce service fill products under more consumer friendly names and packaging. TITAN SINTOPOID LS SAE 75W-90 (PI Sheet Attached) is the product for your BMW axles as per the following link to our oil chooser https://www.fuchs.com/de/en/products...s/oil-chooser/.

Please let me know if you have any other questions?

Best Regards,

John Anderson
Product Manager – Automotive & OEM Fluids
e-Mobility co-ordinator North America

FUCHS LUBRICANTS CO.

Using their oil chooser I did confirm what he wrote. I emailed Redline to ask if that oil is the same.

Did you ever receive a response from redline on the proper oil for you x3 xdrive35i?

[ThomasR]

Originally Posted by Antfern

The rear plug is on the top and there’s is no drain plug, is it because you don’t change it, just top off? It could be the reason why it is clean? Could be the only lifetime oil.

No. Just because there is no drain means nothing. Many transmissions, differentials, etc have no drains. Just like many reservoirs don't have drains like brake fluid reservoirs, power steering reservoirs, etc but still need to be drained and cleaned from time to time.

[Wgosma]

Originally Posted by ThomasR

No. Just because there is no drain means nothing. Many transmissions, differentials, etc have no drains. Just like many reservoirs don't have drains like brake fluid reservoirs, power steering reservoirs, etc but still need to be drained and cleaned from time to time.

In this day and age it's reasonable to conclude that since the differential (or other similar component) does not have a drain plug that the fluid will is a one time fill - i.e., a 'lifetime' fluid". I agree that one is better off draining/filling their 'lifetime fill' fluids but the reality is that many car manufacturers have moved in this direction, along with the concept of Condition-Based Maintenance - which is interestingly not not at all a recent concept for BMW.

My old 2000 528i's differential and (manual) transmission had drain plugs, however if one looked at the owners manual regarding service it was stated that the fluids did not require changing - i.e. lifetime fill. The car had rudimentary CBC that monitored/advised on oil/filter change also....that car was built 19 years ago.

[evilchargerfan]

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[wxm]

Thanks for the information. I am about to order the Foxwell and do the diff and transfer fluid change.