BMW Front Differential Failing?

[m240.to]

I'm not going to dispute your data, but the LSDs are not the same. I've seen both off the car. They may be the same type of LSD but who knows what is different internally and I'm not even sure the vendor is the same. The M units are derivatives of the GKN that came on the F90 M5.

With your front diff, you have probably set yourself up for a tough situation. I'd make it look like you never changed fluids and drive until it fails unless you're good buddies with your SA. Unless you can demonstrate a problem like noises you'll just make them suspicious and think you're crazy if you tell them you had elevated wear metals.

The differential is absolutely the same as the M-cars; per BMW technician training documents (which I have spent hours before reading in the BMW TIS — technical information system) (no ///Marketing or other crap; these documents MUST be accurate or a technician could get hurt, and that opens up to lawsuits, etc). The only difference is 1 extra clutch in the pack. Even the servo motor and control module ("GHAS") is the same. Note: the GHAS only handles locking the differential. It doesn't directly control when it will lock, with regards to vehicle dynamics.My XDrive car is doing almost everything a RWD M2 would do (except for when the t case kicks in during a drift and it becomes a little sketchy - so this mostly applies to parking lot shenanigans). The diff for the most part, is almost the same.

I don't have access to the technical service documents to post here, but if you wanted to validate it, it can be found here: https://bmwtechinfo.bmwgroup.com/#/login

edit: there may have been a misunderstanding. When I said "they are the same diff" in the OP, I was referring to the rear. Front diff and the t case system is entirely different from AWD/RWD switchable M cars. I forgot what the difference is, but they are absolutely not the same.

 

[m240.to]

This car is a ‘22? Is it not still under warranty? If it is under warranty, I would stop monkeying with it and bring it to the dealer. My experience is that BMW and the dealer network behave honorably with warranty claims, and if there is an issue they will fix it. The more you do here, the more of a question you may raise as to whether it can be covered. Good luck with it.

PS: do yourself a favor and stay off of the BMW forums — I see you did some “research” — that generally means the Internet forums. ;-) I have driven BMWs since 1990. (Raced and auto crossed too.). They are great cars but like anything else there are issues. Internet forums, particularly the BMW ones, completely blow these issues out of proportion in my experience and wind up ruining your experience with what are generally great cars. Mike Miller of Roundel is another drama queen, albeit a knowledgeable drama queen. Are they expensive when they break? Yes, but those risks can be mitigated with a factory extended warranty and, not to sound like a jerk, if the money is that dear folks shouldn’t be messing with German luxury sport cars. Plus, if you are handy you can also keep the cost reasonable in that manner as well. Again good luck with the 240, it is a great car. If there is an issue, BMW will make it right, just don’t cloud the issue by messing with it further or not using factory fluid on any driveline component. Take care.

What do you mean by monkeying with it? By changing fluids preventatively? Huh?

"Do not mess with it further or not use factory fluid on any driveline component."

Brother, I have already said multiple times in this thread that I only use ORIGINAL BMW fluids in this car.

 

[wavinwayne]

@m240.to Have you taken the car to BMW yet? Curious to see what they say.

 

[m240.to]

@m240.to Have you taken the car to BMW yet? Curious to see what they say.

No, I am waiting for my dad to come back from his trip so he can help me with this.

I have had other issues with BMW in the past, and nothing seems to get done until he walks in there and makes things get done. Dunno, guess he's just better with people considering he's the best sales person I've ever met. God bless him, I would be lost without him as a kid, and even after all these years later.

I will update this thread when it goes to BMW. That won't be till September, because I want to heavily contaminate the fluid. Keep in mind, this is a "lifetime fluid" and this car has 12k kms on it. I don't want the fluid to look too "new" if you catch my drift. If the wear metals are too low, they might dismiss it even though in actuality, the sample they take might only have 1.5k on it.

 

[m240.to]

I'd buy new plugs if possible and change the fluid carefully .

New plugs have already been purchased. Fluid will be changed later this week and some time will be left to pass so the fluid contaminates, and then I will bring it to BMW.

 

[m240.to]

I still don't understand. Do you have any issues? Noise is just that, noise, and it might be coming from some different part of the vehicle. High elevated numbers might be actually normal. Depends on materials used. Some engines have normally high iron numbers, some very low. Same is with differentials.

No, the car has no issues apart from the tires appearing to have a decent amount of un-even wear on the front right tire that is not present on the rest of the car. My first thought was the actual alignment may have caused an issue because these x-drive systems are insanely sensitive, but the alignment of the car itself is perfect and there are no issues...

The noise is very minor, but after my track day when the car was pushed very hard, it became a little more apparent, but still minor. I understand that some components may have high iron numbers, but I've tried very hard to dispute this as exactly that, but I don't see how any of this is normal. I talked with Polaris, and they said they cannot see any form of possible lubrication issue, and they also believe there is very likely a gear alignment issue with the differential.

 

[edyvw]

No, the car has no issues apart from the tires appearing to have a decent amount of un-even wear on the front right tire that is not present on the rest of the car. My first thought was the actual alignment may have caused an issue because these x-drive systems are insanely sensitive, but the alignment of the car itself is perfect and there are no issues...

The noise is very minor, but after my track day when the car was pushed very hard, it became a little more apparent, but still minor. I understand that some components may have high iron numbers, but I've tried very hard to dispute this as exactly that, but I don't see how any of this is normal. I talked with Polaris, and they said they cannot see any form of possible lubrication issue, and they also believe there is very likely a gear alignment issue with the differential.

Do you drive spirited, or do you actually track cars?
The track will mess up your alignment, and if it does not, it is very easy to have uneven wear even if alignment is OK.
That is why I personally and a lot of other people use separate set of wheels and tires for a track.

Do you see any shavings in fluid? Also, you might install a magnetic drain plug to see how many shavings you have.

 

[RAVL]

What do you mean by monkeying with it? By changing fluids preventatively? Huh?

"Do not mess with it further or not use factory fluid on any driveline component."

Brother, I have already said multiple times in this thread that I only use ORIGINAL BMW fluids in this car.

I am trying to be helpful. Good luck with it.

 

[chris719]

The differential is absolutely the same as the M-cars; per BMW technician training documents (which I have spent hours before reading in the BMW TIS — technical information system) (no ///Marketing or other crap; these documents MUST be accurate or a technician could get hurt, and that opens up to lawsuits, etc). The only difference is 1 extra clutch in the pack.

Different part number, different housing, different fluid, different clutch pack... yeah, it's the same .

Back to the original issue - you should play dumb IMO. If you can make it look like you haven't changed the fluid I'd just tell them you have a noise. Dealerships are stupid, if you tell them you are bringing it in because you saw metal in a "lifetime" fluid that you aren't supposed to change who knows what they will say. They may try to blame you in a worst-case scenario. You will already know more than anyone but their master techs.

 

[m240.to]

Do you drive spirited, or do you actually track cars?
The track will mess up your alignment, and if it does not, it is very easy to have uneven wear even if alignment is OK.
That is why I personally and a lot of other people use separate set of wheels and tires for a track.

Do you see any shavings in fluid? Also, you might install a magnetic drain plug to see how many shavings you have.

I drive spirited and bring it occasionally to the track. It just went to the track, you can see the notes on the oil analysis.

The un-even wear was already present before it went to the track for the first time.

I do not change my own fluid, I send it out to a shop and call it a day. I would not be aware if there were shavings in the fluid or the magnetic plugs that I had installed. I did not slosh the fluid around in the vile before I sent it off to analysis to see if that was the case, and I would hope the shop I brought it to would inform me if that was true.

 

[edyvw]

I drive spirited and bring it occasionally to the track. It just went to the track, you can see the notes on the oil analysis.

The un-even wear was already present before it went to the track for the first time.

I do not change my own fluid, I send it out to a shop and call it a day. I would not be aware if there were shavings in the fluid or the magnetic plugs that I had installed. I did not slosh the fluid around in the vile before I sent it off to analysis to see if that was the case, and I would hope the shop I brought it to would inform me if that was true.

I highly doubt the shop will look for it.
Only thing I can think of is to try to get BMW to inspect it for warranty purposes.
Another is to run 75W140 and see if the noise will change. Then you will know if it is coming from there.

 

[m240.to]

Different part number, different housing, different fluid, different clutch pack... yeah, it's the same .

Back to the original issue - you should play dumb IMO. If you can make it look like you haven't changed the fluid I'd just tell them you have a noise. Dealerships are stupid, if you tell them you are bringing it in because you saw metal in a "lifetime" fluid that you aren't supposed to change who knows what they will say. They may try to blame you in a worst-case scenario. You will already know more than anyone but their master techs.

Part numbers are different, almost identical in design. You are missing my point. If they are that similar, there is no reason to dismiss that fluid and say its "lifetime" and not do a break in service the same way the M cars do.

The oil analysis in the rear diff and rest of the drivetrain (excluding the front) supports that this was the case and SHOULD be changed.

This is a pointless debate.

Also moving on,

That is what I am doing. I am trying to cover my tracks and make it look like I was never there, thus why I want to drive the car and track it for a bit, then bring it in. Also the same reason why I am changing the fluid and removing all the mag drain plugs this week.

I will not be showing them the oil analysis, because they will just be using it against me and 99% of the people who work there are far too ignorant to understand what I am telling them. They will just think I am insane and there is something wrong with me. If they choose to dismiss the noise, I will push for an oil analysis because this car has had other factory defects warrantied in the past. If they want to charge me accordingly for a front diff service to take that oil sample, that is fine. When the lab results come back, they will be forced to investigate further.

 

[m240.to]

I highly doubt the shop will look for it.
Only thing I can think of is to try to get BMW to inspect it for warranty purposes.
Another is to run 75W140 and see if the noise will change. Then you will know if it is coming from there.

To inspect the differential itself and open it up would cost a fortune at BMW labour rates.

My only option is to push for oil analysis, just like they would in order to void the warranty on my engine if it blew up today, and have them see in the report that there is something out of place with the diff. Correct me if I am wrong, but if they choose to further investigate at that point because they believe for there to be a fault present, I am safe from being charged anything labor wise?

I don't want them to say "ok, lets take apart the diff and if we don't find anything, or just say we didn't, we will now bill you thousands worth of labour."

 

[edyvw]

Part numbers are different, almost identical in design. You are missing my point. If they are that similar, there is no reason to dismiss that fluid and say its "lifetime" and not do a break in service the same way the M cars do.

The oil analysis in the rear diff and rest of the drivetrain (excluding the front) supports that this was the case and SHOULD be changed.

This is a pointless debate.

Also moving on,

That is what I am doing. I am trying to cover my tracks and make it look like I was never there, thus why I want to drive the car and track it for a bit, then bring it in. Also the same reason why I am changing the fluid and removing all the mag drain plugs this week.

I will not be showing them the oil analysis, because they will just be using it against me and 99% of the people who work there are far too ignorant to understand what I am telling them. They will just think I am insane and there is something wrong with me. If they choose to dismiss the noise, I will push for an oil analysis because this car has had other factory defects warrantied in the past. If they want to charge me accordingly for a front diff service to take that oil sample, that is fine. When the lab results come back, they will be forced to investigate further.

OK, here is the thing.
1. You did not change fluid, the mechanic did. Mechanic is I suppose, ASE certified? He used BMW fluid. YOU ARE COVERED! Warranty cannot be denied due to Magnusson-Moss Act.
2. The third analysis is after track day? And the previous two were not on track, right? Than don't track and see what happens at next analysis. Track will result in higher ppm.
3. Your differential is not the same. It is not the same as it has to work with active T case. M models don't not have T case, obviously. The ECU set upon is completely different. Turning off DSC is always a must on the track, BUT, your Ediff function is still active (in older BMW's can be turned off using INPA or ISTA, but not desirable). xDrive while fun, and I track mine, is not as suited for track as RWD model. Your ediff will exert a lot of force on front diff. due to understeer.

So, I would do UOA after the same mileage as the previous sample but without track time.

 

[m240.to]

OK, here is the thing.
1. You did not change fluid, the mechanic did. Mechanic is I suppose, ASE certified? He used BMW fluid. YOU ARE COVERED! Warranty cannot be denied due to Magnusson-Moss Act.
2. The third analysis is after track day? And the previous two were not on track, right? Than don't track and see what happens at next analysis. Track will result in higher ppm.
3. Your differential is not the same. It is not the same as it has to work with active T case. M models don't not have T case, obviously. The ECU set upon is completely different. Turning off DSC is always a must on the track, BUT, your Ediff function is still active (in older BMW's can be turned off using INPA or ISTA, but not desirable). xDrive while fun, and I track mine, is not as suited for track as RWD model. Your ediff will exert a lot of force on front diff. due to understeer.

So, I would do UOA after the same mileage as the previous sample but without track time.

1. The first sample is 10k without track time.
2. The second sample is 1.6k with 450kms ish of track time + distance driven to the track
3. I have all the receipts from BMW as I provide the parts to my ASE certified mechanic. All of those parts except for the plugs are all genuine bmw. The act however, is irrelevant. I am not suing BMW when they decide to void my warranty even though they can't find reasonable cause. BMW here voided one of my friends engine warranties because after market exhaust tips which weren't even connected to the actual exhaust caused "excess back pressure." I am only listing one case. My area is terrible when it comes to dealerships, especially dealerships and warranties. In terms of BMW having proof that I purchased those diff fluids and other items, as I feel you might bring that up, I don't think so because I would be bringing it to a different dealer. It is not VIN connected, and unlike some BMW dealers, the dealership working on the warranty claim does not use the same system as the dealership that the parts were purchased from.
4. Third analysis will come in the next week when I drain the fluid again. Looking at my absolutely massive binder of receipts and service records and referencing the milage, the car should have roughly 250kms on the upcoming non tracked sample. It is impossible for me to match the milage of 1.6k with how little I drive this car. This car will also be brought to various different BMW events across the country in the coming weeks, where it will be tracked multiple times. I cannot cancel those, I have a couple thousand or more of dollars in registration and tickets.

 

[RAVL]

Obviously keep quiet about track use. Track use, even if it is just HPDE and not wheel to wheel racing, is generally not covered by your insurance policy or your car's warranty. Bear in mind BMW (like everyone now) can pull down engine log data.

 

[m240.to]

Obviously keep quiet about track use. Track use, even if it is just HPDE and not wheel to wheel racing, is generally not covered by your insurance policy or your car's warranty. Bear in mind BMW (like everyone now) can pull down engine log data.

I would expect BMW to pull engine log data on an extreme failure like my engine, not a front differential. That would be a bit extra, no?

 

[BMWTurboDzl]

OK, here is the thing.
1. You did not change fluid, the mechanic did. Mechanic is I suppose, ASE certified? He used BMW fluid. YOU ARE COVERED! Warranty cannot be denied due to Magnusson-Moss Act.

He's in Canada

 

[edyvw]

He's in Canada

They should still have similar law.

 

[RAVL]

I would expect BMW to pull engine log data on an extreme failure like my engine, not a front differential. That would be a bit extra, no?

It depends on whether the car has signs of track use - alignment, tire wear, etc. My experience with BMW is out of date to some degree so
I don’t know the cost of a front differential, but I am sure they aren’t cheap, particularly when you factor in labor, and so it would not surprise me that they might look at the service records in the BMW network and pull the engine log. In my experience, BMW gives the customer the benefit of the doubt, but they make a quality product so driveline failures are uncommon and I would not be shocked if they look over the car. I haven’t seen your car so I really don’t know. Some idiots leave the window numbers and inspection stickers on because they think it looks cool . . . .

You may not want to hear this, but if you were interested in a lot of track use, a new BMW is not really a good choice. Too much power and capability will hide the defects in your techniques, and the cost / risk of totaling or significantly damaging a new car is significant. If I were starting today, I would buy a cosmetically ugly E36 or E46, strip the interior, put in at least a roll hoop (can add a cage later if you want to go wheel to wheel in a series like Lemons or AER) and go through the suspension, cooling system, and other wear items. A good seat with proper harness will allow you to properly feel the car and focus on driving instead of restraining yourself with the weak factory / street belts. Keep the power under 200hp and leave the brakes stock, suspension too. This will make you learn. Learn to drive that car at the limit, and if you put it into a tire wall or have another agricultural excursion that is a little
Ugly, it won’t really matter. The car is fixed pretty easily and you don’t have to worry too much about the cosmetics. The new cars, and the new BMWs are so capable that it is difficult to really learn and the reality is that they are road cars - the service intervals and some of the more finicky hardware on the car isn’t designed for true track use, particularly if we aren’t talking about parade laps.

Good luck with it.