[bmwx32015]

Hey guys,
I have a 2015 X3 xDrive28i with about 68k miles. About 1k miles ago my rear differential failed. It is still running but making a humming noise. So I still can drive it but eventually I'd have to replace or repair it. The car was purchased new and besides the timing chain fix at about 50k miles (within warranty period), I didn't have any issues. The dealer offered to take care of it for around $4-5k. What are my options? I heard that I could just put a used one but I have no idea where to order stuff like that. Is Ebay a good place to buy it? Also does this part repairable - I read somewhere that it could be just inner bearings that needs to be replaced. Thanks.

[dtox9]

We bought ours (2017 xDrive) last year @ 65K miles....
Had the same humming on the test drive.

Dealer replaced the rear hub bearings, and all good since.

Purchased the car with different brand tires on it, and always was suspicious about the two tires that most likely were replaced before trading it in... very used Pirelli on the back, and fairly new Michelin on the front. (within 10 days it had the same Michelin tire all the way around with relatively the same tread depth)

[bmwx32015]

Originally Posted by dtox9

We bought ours (2017 xDrive) last year @ 65K miles....
Had the same humming on the test drive.

Dealer replaced the rear hub bearings, and all good since.

Purchased the car with different brand tires on it, and always was suspicious about the two tires that most likely were replaced before trading it in... very used Pirelli on the back, and fairly new Michelin on the front. (within 10 days it had the same Michelin tire all the way around with relatively the same tread depth)

Thanks, I'll check that, but in my case the noise comes up mostly under load, when I even slightly press the gas pedal. When I release it, it mostly disappears.

[andreigbs]

Is it at all speeds under load, or just at various speed ranges like 20-30 or 30-40?

[bmwx32015]

Originally Posted by andreigbs

Is it at all speeds under load, or just at various speed ranges like 20-30 or 30-40?

At all speeds

[andreigbs]

Interesting. My X3 has a bit of rumbling from the rear under load, but only in the 30-40mph range, and once more in the 80-90 range but only on max torque (as displayed in the Sport cluster) of 450 ft-lbs.

I was told that there may be a bit of sweating/seepage of both rear diff seals. I'll check that at the next service. The noise isn't getting worse, so at least there's that...

[383vett]

Has anyone checked the fluid level?

[bmwx32015]

Originally Posted by 383vett

Has anyone checked the fluid level?

Replaced oil recently, no leakage.