Diff fluid changes and transfer case
 

I subscribe to the theory that tranny changes should be done prior to recommended BMW intervals whatever they actually are and I have done that. What about diffs and transfer case? I assume there are two diffs and a transfer case but maybe the transfer case is part of the tranny? I had the auto tranny service done and didn't ask that question. I searched but could not find technical info on doing these changes.

Info on doing this on this site?

Jeff

Differentials are pretty straightforward. 60,000 miles is a pretty good interval.

As you have an x-drive model, the transfer case uses a special BMW fluid. When it is changed, there is a reset procedure for the transfer case control unit. A service computer is required to do that reset. 60,000 miles is a pretty good interval for this compartment as well.

Yes, there are lots of threads here about changing these fluids. A search will show them. Search on the full site, not just the E70 forum.

I assume diffs have a fill and drain plug or will they require removal of the case seal and resealing. Sounds like I have to have the dealer do the transfer case(if they will). Or I guess suck the diff fluid out of the fill plug?

Jeff

Differentials (and the transfer case) have both a drain and a fill. If you are doing them yourself, loosen the fill before draining.

The differentials use 75w-90 (from memory - check yourself). They are not limited slip differentials, and thus don't need LSD additives or special oil.

The dealer will do your transfer case fluid change, it is a straightforward job.

None of these compartments have the risks that are associated with transmission fluid changes, they are simple drain and fill procedures.

How many miles do you have on it? Seems early for a change.

55k. Lots of 1300 mile round trips to park city ut at 80 plus. I figure it is close to time.

Jeff

Funny you mention this. I was recently reading somewhere that some new BMW doesn't have either a differential or transmission drain plug anymore. I don't think that's the case with the X5.

I'd not do it without first seeing the BMW TIS for it.

But here are some pics:

RealOEM.com * BMW E70 X5 4.8i Transfer case, single parts ATC 700

Number 9?

and

RealOEM.com * BMW E70 X5 4.8i Final drive (front axle), parts, 4-wheel

Number 12.


I do get a kick out of the lablel, #15. Back in the day, a BMW could be expected to provide 200,000 miles of service. I want a BMW driveline engineer to look me in the eye and say "Yes, that fluid will last 250,000 miles and 20 years"

A

It is even more of a stretch to think he would look you in the eye and say "Yes, we will maintain all computerized service tooling and still be doing flash upgrades and providing new control modules 20 years after the date of production"

You really expect to own one of these 20 years in?

I don't disagree with you on the benefits of changing the differential oil prior to 20 years, but I just wonder how relevent it will be.

I just got rid of my 1992 Ford Explorer with 198,000 miles last week, and a guy down the road has a 1991 Ford Explorer with 236,000 miles that he still uses... I gave him all my service manuals. So some people keep 'em running that long.

But I agree that today's BMW's are unlikely to be financially viable to keep running nearly as long as today's GM, Ford, or Toyota products. BMW's part prices, lower reliability, and inherient design which requires more proprietary tools and computer programming simply make it too expensive to keep them running after things start to fail. I think people are figuring this out, and that BMW's historic good resale is beginning to suffer as a result, e.g., 7 series resale.

I had a 1990 Q45 with 245k when I sold it.

Computerized. ECU, ABS, bus-linked modules, all the bells and whistles that the BMW has (no nav)... I still see it around, it is still on the road- now 20 years later.

I have a 2001 MDX. Computer. All the above plus more. 207lk, kids beater- but every single module works.

I have every expectation these car will indeed last. I do not expect software updates, but why would you want/need any??? After 5-10 years the software is stable, no need for new code. If you lose a module, head to ebay or a junk yard for a replacement. Indeed, given the numbers of units made, I really don't expect cars being junked due to 'lack of electronic gizmos'

For the last 20 years people have been bemoaning the advent of "these newfangled computer based control systems will mean the end of [DIYers, lifetimes over 10 years, etc]" and it just hasn't happened.

Now, what really happens is (a) people tire of getting screwed over by dealerships and would rather have a monthly payment, (b) most people have no clue how to use a screwdriver, (c) consumers use failures as an excuse to buy new- they don't want to be seen in 'old cars'

Dunno if I'll be owing and driving the X in 10 years when it hits 200,000 miles- but I am figuring I will 'pay it forward' for them with my maintenance. SOMEBODY will benefit from it.

Ard's comment was specific to BMW, though.

I had two Explorers, and two Expeditions. All spent a good portion of their time with me on rough forestry and mining roads, in 4H. I have no doubt that those four vehicles I had could have gone that mileage without issue. I had to trade them due to an employment rule about maximum vehicle age, and I was incented to trade them every 2-3 years.

I agree that with the BMWs it will be a financial decision that causes many of them to be retired, not a mechanical wear issue.

Similar to my '92, '95, '97, and '98 Fords. They also had ECUs, ABS, etc. No communications bus that I ever came across, but they were simpler vehicles. I think a 2010 X5 is exponentially more complex, and that results in exponentially more failure modes.

I wasn't referring to software improvements as much as service diagnostics. No need for new features to be programmed in, but perhaps a need to use a computer to figure out why a transmission is jerking. Oh yeah, that's now, no need to wait 20 years.

I think there are parallels between BMW today and Jaguar in the '60s. Beautiful vehicles, but perhaps not the most reliable. Incredible engineering, but silly stuff broke, and that frustrated owners. People loved them regardless. After 20 years, people were taking mid sixties Jaguars and putting Chevy 350 engines in them, so they could have the looks and handling, but better mechanical reliability. This was even though the Jag straight six engine was an engineering marvel, and had no trouble going high mileages. You just had to stop it overheating, fix the electrical issues, fix the fuel system issues, fix the instrumentation issues, rebuild the suspension, etc. Damn, but there were a lot of parts in a Jag IRS. And all Jag parts were expensive, and you had to find a good independent mechanic to be able to afford to keep it running. Owners formed clubs to support that goal, helping each other solve problems with their cars. So what did we see recently on this site? A thread about putting a Chevy V8 in a BMW to build a more reliable vehicle. I found the parallels striking.

Gonna resurrect this thread...it being Easter...ok that was bad.:D

Anyways, I have looked in the TIS and do not see where the transfer case unit has to be reset when changing the oil, only when the transfer case is being replaced. Any references?

Thanks

If a fault code is reset from the fluid being out of spec (as determined by measuring slip and engagement pressure) then that has to be reset.

If the fluid is changed prior to that code being logged, then it is just the adaptations.

What has to be done additionally when the transfer case is being replaced is that the vehicle needs coding related to the classification resistor.

Here are some sources.

http://www.xoutpost.com/bmw-sav-foru...intenance.html


http://www.xoutpost.com/bmw-sav-foru...available.html


This next one is about the X3 (which uses a different version of the same transfer case, same technology)


http://www.xoutpost.com/bmw-sav-forums/x3-e83-forum/67524-ecs-tuning-xdrive-x3-oem-bmw-transfer-case-fluid-now-available.html

Thanks for the sources. But there is just one thing, assuming the VTG module must be reset to purge intself of adaptation values even if a code has not been generated to properly calibrate the operation of the TC, why is this information only shown on an X-Drive training manual? I saw nothing of the sort on the TIS and mine is a version <1year old. I was under the impression that all service data was in the TIS, or at least a direction was given in the TIS if something else was required as part of the service procedure. Killcrap? Weasel?

P.S. I understand that people employed by BMW might not want to post from the TIS, but can I get a reference # or directory? TIA

I don't have a copy of the TIS, so I can't provide original references. However, the following are all posted on this site. Credit given to texmin, ripp222, and skeetjunkie:

Posted in response to where to find the TIS reference:

texmin wrote up a DIY, found the reference in the TIS, and reported that he never did do it. Not sure if he has done so since.

Posted in reference to how to cleare the VTG fault:

That refers specifically to the VTG fault when the fluid no longer meets spec, not the adaptation values that are to be reset whether or not the fault has been raised.

Posted in a discussion on why it matters:

It is that last information from Mike Miller that gives me pause to think. It makes sense that the adaptations are important for future transfer case clutch plate life, not just for a warning as to when the fluid is due to be replaced. Many have posted that they changed the fluid without resetting the adaptations, and it still drove fine. That is certainly possible, but IMO they won't be able to judge their success until they see if the transfer case lasts as long as expected without the adaptations being reset. Incorrect clutch pressures will lead to shortened clutch plate life if too low, and potentially to actuator motor failures if too high.

Jeff, I totally agree with your logic. My TC is a little newer than the ones you are referencing (ATC 700). I'm looking at 27 00 Repleneshing / Changing Transfer Case Oil (ATC 700). Nowhere in the document does it state that the BMW repair diagnostics should be consulted. It does say so in a different repair procedure regarding the TC replacement or the replacement of the TC servomotor that BMW Repair Diagnostics should be run.

I guess I'm still wondering if the newer TC software has been changed from the prevoius models or do I simply not have enough information?..

I just thought I would share a little info that I found recently in the newest 5-series Bentley Manual (E60). In the Transfer Case section, under clutch actuator (VTG) motor, it states:

“Because of mechanical tolerances in production, the characteristic curve of the multi-disc clutch locking torque varies slightly. At the factory, once the actual locking torque is measured on the clutch test bench, a resistor is attached to the clutch actuator. The resistor value (Classification) determines clutch locking torque characteristics.
1. Clutch actuator drive gear
2. Clutch actuator (servo motor)
3. Classification resistor
Each time the engine is started, the transfer case module measures the resistor value once and selects the optimum program map for transfer case engagement.”

Also, in the Transfer Case Fluid service section, the only mention of electronics is that the transfer case control module monitors oil life to determine when the oil is to be changed. There are no other caveats other than to use the correct BMW oil, filling to the bottom of the fill hole and torque the drain plug to spec. Although this TC is the ATC 300 rather than the 700 (X5), the procedure is consistent with my version of the TIS for the ATC 700.

So it seems there must have been a change in the software that required previous versions to have it reset with the dealer computer whereas now (>2009) it appears to reset itself upon startup.

If there is a change, it may be between the ATC 400 and ATC 500 vs the newer ATC 700 in the E70. We would likely need killcrap or weasel to advise specifically.

According to this training document, the transfer case control module has changed from the ATC400/500 (E83-E53) to the ATC700 (E70).

Also, referencing the June 2010 version of the SIB 27 01 07, there is a different procedure and allotted pay for the tech in the KSD for the E83&E53 than all other Xdrive models.

I've done about all the research I can do and short of having someone peer into their service computer, I would say with a good amount of certainty that no adaptations need resetting other than the E83 and E53 models.

Now for the fun. The transfer case on the X frequently do NOT have a magnetic drain or fill plug. You can buy them for a reasonable price from Cobratransmission.com in Miami.

The differential's also are lacking - the BEST are from a guy in North Carolina (http://www.drainplugmagnets.com) who sells them on the internet. Lifetime oil in a compartment with no filter, very scary.

LESS SCARY: Synthetic oil & magnetic drain plugs .... It's my holiday present to myself

Hey guys, I just finished uploading a new video to showcase how to drain and flush the transfercase (transfer case) for a 2005 E53 X5. At the end, I even show how to use GT1 / DIS to perform the adaptions reset.

https://youtu.be/Ol4PofF-fZY