x3 28i Rear differential possible leak? anyone elses?

pungo · 03-27-2021, 02:33 PM

Quote:

Originally Posted by slowblackx3f25

So I got the transmission fluid drained and re-filled earlier last week, and it is night and day difference! It drives really smooth, and the power output is there at the wheels.

The trans filter is built into the trans pan and if all they did was drain and re-fill without replacing the pan, that's not good. If you noticed that much of a difference after replacing the fluid, it was in there way too long, wearing away at the trans parts. You shouldn't really notice much difference or no difference at all when the fluid is changed at the proper intervals. That interval depends on the service duty, that's why the trans manufacturer provides a range for fluid changes.

Blacktemplar · 09-30-2021, 05:19 AM

My M40i is 22 months old with 8,000 miles on the clock and I noticed a high-pitched whine at all speeds about a year ago. At that point it was very faint and not all that noticeable most of the time so I dismissed it as background exhaust drone.

The noise has become more noticeable in recent weeks, so when it was in for service I had them look at it. Seems the diff seals have gone, which at low miles on a $63K car is not good enough.....

slowblackx3f25 · 09-30-2021, 06:12 AM

Blacktemplar that is not good at all... low mileage with a diff leak doesn't make any sense. If you have warranty, ask the dealership to fix it (get both left and right seals replaced all at once).

My x3 is Out of warranty, so I paid out of pocket, and a BMW M specialist in Ontario replaced the rear diff seals within the hour (actually), he's highly experienced on BMW's and BMW M vehicles. RMP Motors... the owner worked at a BMW dealership for 10 years, then decided to open up his own private BMW specialist shop.

I originally knew about the diff leak, but I ignored it (as it was just oil sweat on the diff), but as I drove the x3, there was a whine noise coming from the rear end, and at the time I knew I had to get the diff seals fixed, or else it'll get louder and the diff will lock up...

so I found RMP motors and got it done there as they are BMW specialized, and the BMW dealership told me it's 'normal'.... for diff to have sweat spots of oil... (that just means they are being lazy and don't want to fix a diff leak). I did't argue or dispute with them because I bought my x3 at a third party non-bmw dealership, but it had BMW original warranty. I just didn't want to dispute with the BMW dealership... talk is cheap.

If you can, get the dealership to fix it, or find a good BMW specialized shop to do it for you at a lower cost, AND make sure you replace the diff fluid as well!!!

Blacktemplar · 10-14-2021, 12:27 PM

The dealership replaced the seals under warranty, and the whine has disappeared. Hopefully no permanent damage, but will monitor it over the coming months.

Have to say the transmission feels smoother, though that may just be placebo effect.

slowblackx3f25 · 10-30-2021, 05:58 AM

That's good to hear!

The drive will be a lot smoother. I experienced the same when I got my x3 diff seals replaced at a BMW specialized shop. The dealer wouldn't replace under warranty.

09-30-2021, 05:19 AM	#24
Blacktemplar Brigadier General 3481 Rep 3,691 Posts Drives: X3 M40i Join Date: Aug 2016 Location: Scotland iTrader: (0)	My M40i is 22 months old with 8,000 miles on the clock and I noticed a high-pitched whine at all speeds about a year ago. At that point it was very faint and not all that noticeable most of the time so I dismissed it as background exhaust drone. The noise has become more noticeable in recent weeks, so when it was in for service I had them look at it. Seems the diff seals have gone, which at low miles on a $63K car is not good enough.....
	Appreciate 0 Quote

09-30-2021, 06:12 AM	#25
slowblackx3f25 xdriv33 69 Rep 218 Posts Drives: 17' BMW x3 F25 xDrive28i xLine Join Date: Aug 2019 Location: Toronto, Ontario, Canada iTrader: (0) Garage List 2017 BMW x3 [0.00]	Blacktemplar that is not good at all... low mileage with a diff leak doesn't make any sense. If you have warranty, ask the dealership to fix it (get both left and right seals replaced all at once). My x3 is Out of warranty, so I paid out of pocket, and a BMW M specialist in Ontario replaced the rear diff seals within the hour (actually), he's highly experienced on BMW's and BMW M vehicles. RMP Motors... the owner worked at a BMW dealership for 10 years, then decided to open up his own private BMW specialist shop. I originally knew about the diff leak, but I ignored it (as it was just oil sweat on the diff), but as I drove the x3, there was a whine noise coming from the rear end, and at the time I knew I had to get the diff seals fixed, or else it'll get louder and the diff will lock up... so I found RMP motors and got it done there as they are BMW specialized, and the BMW dealership told me it's 'normal'.... for diff to have sweat spots of oil... (that just means they are being lazy and don't want to fix a diff leak). I did't argue or dispute with them because I bought my x3 at a third party non-bmw dealership, but it had BMW original warranty. I just didn't want to dispute with the BMW dealership... talk is cheap. If you can, get the dealership to fix it, or find a good BMW specialized shop to do it for you at a lower cost, AND make sure you replace the diff fluid as well!!!
	Appreciate 0 Quote

10-14-2021, 12:27 PM	#26
Blacktemplar Brigadier General 3481 Rep 3,691 Posts Drives: X3 M40i Join Date: Aug 2016 Location: Scotland iTrader: (0)	The dealership replaced the seals under warranty, and the whine has disappeared. Hopefully no permanent damage, but will monitor it over the coming months. Have to say the transmission feels smoother, though that may just be placebo effect.
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10-30-2021, 05:58 AM	#27
slowblackx3f25 xdriv33 69 Rep 218 Posts Drives: 17' BMW x3 F25 xDrive28i xLine Join Date: Aug 2019 Location: Toronto, Ontario, Canada iTrader: (0) Garage List 2017 BMW x3 [0.00]	That's good to hear! The drive will be a lot smoother. I experienced the same when I got my x3 diff seals replaced at a BMW specialized shop. The dealer wouldn't replace under warranty.
	Appreciate 0 Quote