[VonKasta]

Hello all, new dude and first post, Im sure this is old news to most but I need some shitposting done to unlock pms so I figured might as well get right to it hah

How it started

So I was in the market for a f31 mainly looking for rwd 318/320d due to fuel efficiency as its going to be my daily commuter, plus the xdrive issues isnt exacly unknown.
Then this 320d xdrive popped up and it had a few perks I wanted, full leather, hifi and so on and the seller was letting it go for what I figured a good price. Jumped on a train to go pick it up. Nothing out of the ordinary so far.
It didnt take long for things to go south tho.
I was two hours into my ride home as I felt a little skip coming out of a roundabout. Could it really be.. I continued on. Soon after it took a turn for the worse, violently jerking on acceleration. I was at this point already comtemplating murder as the tpms light popped up, rear right low.
Pulled over at a service station, sure enough I had a slow leak. Adjusted tires and the jerkiness got much better but not gone by any means. Decided to push on home to evaluate options.

Research

Started looking into my options right away, got the leaky rear tire done and searched high and low for fixes.
Found this bulletin that kinda described the issue, alas not mentioning the ATC35L box: https://static.nhtsa.gov/odi/tsbs/20...76367-9999.pdf
Upon further looking into it turns out my -14 is factory filled with a different oil, the DTF1 made is debut at a later date.
Figured I didnt have much to lose at this point, if the box is shot oil wont fix it, plus I still had mechanical insurance cover for another 3000km. Bought a bottle of oem DTF1 and went ahead with my plan.

First and second oil change

Went for a drive to get things up to temperature before going at it, I decided that I would go with the suction method, allthough you only get about 50% of the oil out that way the time saved makes up for it. I had planned to do multiple oil changes anyway so that didnt bother me much.
Drained the first batch and not surprisingly it was very contaminated and had a burnt smell to it. Refilled the box and ran the car in gear for approx 15 minutes on the lift and drained the second batch. Again, not surprisingly, very contaminated. Refilled and put the car back on the ground.
At this point I ran a relearn of the transfer case actuator, while doing the relearn you get measuring values displayed on screen. My actuator moved 17 degrees til full stop, a differance of 0.2 degrees from previous learned values. Now Im not sure but I suppose this measurement can be used to estimate the wear of the clutch pack.
I performed a test drive, there was still a prominent judder but this didnt put me down as bulletin says to drive for a while to allow clutch discs to saturate.

Third oil change

After about 400km I decided it was time for another oil change. Didnt experience much improvement over this time but there was still oil left so why not go at it again.
Didnt bother to warm up the car this time around before pulling the third batch, this time oil looked a bit better but still dark with contamination.
New test drive, instant improvement! Drives way smoother, no judder until I provoke it, daily driving is pretty much a non issue at this point.
Drove another 500km, at around the 350-400km mark some more issues could be noticed.

Fourth oil change

Same procedure as third oil change, and again instant improvement! This time I could not even force any issues until about the 700km mark and even then it was not much of an issue. This is where I am today

My conclution/rambliings

I suspect much of the clutch slip is due to particles in the oil getting into the clutch pack and create uneven friction between clutch plates and friction discs, causing the electronics to go haywire.
Unless you take the transfer box apart to clean it, this takes time to do away with as you only get about half of the oil capacity each oil change. I also suspect the DTF1 oil losens buildup that stuck to the case walls over time, getting even more contamination running through the clutch pack.
I also suspect the DTF1 oil have additives that need to saturate the clutch discs over time, much like axle oils for limited slip differentials.
For daily driving my car is pretty much without issues today, but I will do another oil change as I still have oil left. After that I will leave it for maybe 10000km or so to evaluate over time.

Here is a shot of the batches I pulled (fourth is missing but it looks just like youd expect from the first three), as you can see they are all very contaminated but if you look at the top of the bottles you can spot the differance, all bottles are shaken before the pic was shot. First batch is burnt and thick with contamination, third is still pretty much the same viscosity as new oil but discolored. New oil has the same tone as a light lager.




Its still a bit early to call it, but Ive had people reach out that has had the same experience as me, the DTF1 oil solves a lot of the problems with clutch slip.
There seem to be are two main ways to go about it, either do a few oil changes in quick succession (like me) or do one total oil change (this call for transfer box removal) and eventually issues go away.
Of course this isnt a one fix for all issues, but I do suspect thare are a few transfer cases getting replaced a bit hasty. Time will tell I guess.

[Eddamoo]

Can you share what tyres you're running?

We had this shudder/judder problem on our old F20 1 series - it was very common on the BabyBMW forum seemingly thanks to the 18" 225/40 & 255/35 tyre sizes and using non star-marked tyres pushing the XDrive past its tolerance.

You can measure the % circumference easily by marking the bottom of each tyre - use a plumb line from the roundel. Then roll the car forward several revolutions until the front wheels lines are plumb again. Finally measure the circumference of the rear tyres back to the plumb line. If you're more than 1% out, that will be the cause of the shuddering.

On an 18" staggered setup the rears will be smaller - you could try running the fronts at 30psi and rears at 40psi which may help with the shudder also.

[VonKasta]

Originally Posted by Eddamoo

Can you share what tyres you're running?

We had this shudder/judder problem on our old F20 1 series - it was very common on the BabyBMW forum seemingly thanks to the 18" 225/40 & 255/35 tyre sizes and using non star-marked tyres pushing the XDrive past its tolerance.

You can measure the % circumference easily by marking the bottom of each tyre - use a plumb line from the roundel. Then roll the car forward several revolutions until the front wheels lines are plumb again. Finally measure the circumference of the rear tyres back to the plumb line. If you're more than 1% out, that will be the cause of the shuddering.

On an 18" staggered setup the rears will be smaller - you could try running the fronts at 30psi and rears at 40psi which may help with the shudder also.

Thanks for the information, I run non staggered Hankook 225/45 -18 on 397 style rims, evenly worn within spec.
They are on their way out tho so I will prob get a new set next season.

[anom3]

Thanks for posting this.

I just finished doing front / rear diff and oil and am about to tackle this. Everything is in the garage ready to go. I did not think that I would need to do multiple changes but I guess that makes sense seeing as we only get about 50% of what ever is in the transfer case.

I experience no judder except very occasionally at very very high load but I just hit 100K km so I figure its time to swap the oil as I am planning on keeping the vehicle for another 50K at least.

[anom3]

btw... how much were you getting out of the tcase every time? those bottles are 500 or 750 ml? hard to tell just from the pic.

Originally Posted by VonKasta

Hello all, new dude and first post, Im sure this is old news to most but I need some shitposting done to unlock pms so I figured might as well get right to it hah

How it started

So I was in the market for a f31 mainly looking for rwd 318/320d due to fuel efficiency as its going to be my daily commuter, plus the xdrive issues isnt exacly unknown.
Then this 320d xdrive popped up and it had a few perks I wanted, full leather, hifi and so on and the seller was letting it go for what I figured a good price. Jumped on a train to go pick it up. Nothing out of the ordinary so far.
It didnt take long for things to go south tho.
I was two hours into my ride home as I felt a little skip coming out of a roundabout. Could it really be.. I continued on. Soon after it took a turn for the worse, violently jerking on acceleration. I was at this point already comtemplating murder as the tpms light popped up, rear right low.
Pulled over at a service station, sure enough I had a slow leak. Adjusted tires and the jerkiness got much better but not gone by any means. Decided to push on home to evaluate options.

Research

Started looking into my options right away, got the leaky rear tire done and searched high and low for fixes.
Found this bulletin that kinda described the issue, alas not mentioning the ATC35L box: https://static.nhtsa.gov/odi/tsbs/20...76367-9999.pdf
Upon further looking into it turns out my -14 is factory filled with a different oil, the DTF1 made is debut at a later date.
Figured I didnt have much to lose at this point, if the box is shot oil wont fix it, plus I still had mechanical insurance cover for another 3000km. Bought a bottle of oem DTF1 and went ahead with my plan.

First and second oil change

Went for a drive to get things up to temperature before going at it, I decided that I would go with the suction method, allthough you only get about 50% of the oil out that way the time saved makes up for it. I had planned to do multiple oil changes anyway so that didnt bother me much.
Drained the first batch and not surprisingly it was very contaminated and had a burnt smell to it. Refilled the box and ran the car in gear for approx 15 minutes on the lift and drained the second batch. Again, not surprisingly, very contaminated. Refilled and put the car back on the ground.
At this point I ran a relearn of the transfer case actuator, while doing the relearn you get measuring values displayed on screen. My actuator moved 17 degrees til full stop, a differance of 0.2 degrees from previous learned values. Now Im not sure but I suppose this measurement can be used to estimate the wear of the clutch pack.
I performed a test drive, there was still a prominent judder but this didnt put me down as bulletin says to drive for a while to allow clutch discs to saturate.

Third oil change

After about 400km I decided it was time for another oil change. Didnt experience much improvement over this time but there was still oil left so why not go at it again.
Didnt bother to warm up the car this time around before pulling the third batch, this time oil looked a bit better but still dark with contamination.
New test drive, instant improvement! Drives way smoother, no judder until I provoke it, daily driving is pretty much a non issue at this point.
Drove another 500km, at around the 350-400km mark some more issues could be noticed.

Fourth oil change

Same procedure as third oil change, and again instant improvement! This time I could not even force any issues until about the 700km mark and even then it was not much of an issue. This is where I am today

My conclution/rambliings

I suspect much of the clutch slip is due to particles in the oil getting into the clutch pack and create uneven friction between clutch plates and friction discs, causing the electronics to go haywire.
Unless you take the transfer box apart to clean it, this takes time to do away with as you only get about half of the oil capacity each oil change. I also suspect the DTF1 oil losens buildup that stuck to the case walls over time, getting even more contamination running through the clutch pack.
I also suspect the DTF1 oil have additives that need to saturate the clutch discs over time, much like axle oils for limited slip differentials.
For daily driving my car is pretty much without issues today, but I will do another oil change as I still have oil left. After that I will leave it for maybe 10000km or so to evaluate over time.

Here is a shot of the batches I pulled (fourth is missing but it looks just like youd expect from the first three), as you can see they are all very contaminated but if you look at the top of the bottles you can spot the differance, all bottles are shaken before the pic was shot. First batch is burnt and thick with contamination, third is still pretty much the same viscosity as new oil but discolored. New oil has the same tone as a light lager.




Its still a bit early to call it, but Ive had people reach out that has had the same experience as me, the DTF1 oil solves a lot of the problems with clutch slip.
There seem to be are two main ways to go about it, either do a few oil changes in quick succession (like me) or do one total oil change (this call for transfer box removal) and eventually issues go away.
Of course this isnt a one fix for all issues, but I do suspect thare are a few transfer cases getting replaced a bit hasty. Time will tell I guess.

[afn19]

Hi all, first post, had the same problem when I had mine at only 18mth old still under warranty, BMW had to change the transfer box, apparently a very common problem on all xDrive of that age.

[HowardP998]

I have had my my 320d x-drive (2014) since 1 year old and 18k miles. The supplying dealer fitted a new front tyre due to sidewall damage. At about 22k miles I was warned about tyre wear asymmetry and replaced the other three tyres so all were within less than 1mm of wear. Maintained tyre symmetry ever since. At about 60k miles I noticed judder under intermediate to hard acceleration and immediately thought it was an injector fault. A fuel injection specialist thought the same. The judder was hard to replicate to order but, with practice, was most reliably recreated when holding in a gear (say, 3rd) and accelerated under half throttle from about 3k rpm. No faults found on injectors. Eventually found to be the transfer case. The problem was probably caused by the 4k miles when I had one new and three worn tyres.
I had the transfer case fitted by Bloor BMW in Bolton. Good price. The car has driven like new since. Very smooth.

[VonKasta]

Originally Posted by anom3

btw... how much were you getting out of the tcase every time? those bottles are 500 or 750 ml? hard to tell just from the pic.

Those are 500ml bottles, you get about 300-350ml out doing the quick change, so a bottle of Dtf1 will give you at least two changes most likely three.

[robert58]

After reading this I have to do this to my 120000km x-drive.

[anom3]

So I just did the first round.

Mega pain in the ass, especially since I did it on race ramps. Not too concerned about the tilt of the car during refill as when I popped the fill plug off just a tiny bit came out. I caught it all.

Overall I drained / filled just over 400ml.

Have not had a chance to take it for a spin as its midnight so it'll wait until tomorrow.

In a week or two I'll do it again.

[anom3]

I just did the 2nd drain / fill.

The transfer case is behaving perfectly now. After the first drain / fill there was still a tiny bit of judder here and there. After the 2nd drain / fill its completely gone.

I recommend doing at least 2 drain / fill cycles, if not 3.

[M27]

VonKasta
Can you please tell me what is relearning of the transfer case actuator? How did you do it?
Thanks