[aaroncoppen19]

So I’ve been hearing sort of a humming noise coming from my car the past couple weeks when I go higher speeds then when I start to slow down it gets more quite so I took it to the garage today assuming it would be one of the wheel bearings starting to fail, so I get the car back and they said all my wheel bearings are fine but they said it sounds like the sounds coming from the bearings in differential, so is it worth trying to replace the bearings in the differential or just replace the whole thing? Also I’ve been having a problem with the traction flashing at 60-70mph cutting power unless I just turn the traction control off it’s fine could the bearings in the differential be causing this to happen?

I’ve got a 2008 bmw 320i e90

[Gemini562]

about the traction control problem, any codes or warning lights?

[aaroncoppen19]

Originally Posted by Gemini562

about the traction control problem, any codes or warning lights?

No codes or warning lights no, I’ve replaced abs rings and sensors. Just flashes traction at about 60/70 and won’t let me go any faster unless I just turn traction off. Got a vid of it happening but can’t add it on here.

[Gemini562]

Originally Posted by aaroncoppen19

No codes or warning lights no, I’ve replaced abs rings and sensors. Just flashes traction at about 60/70 and won’t let me go any faster unless I just turn traction off. Got a vid of it happening but can’t add it on here.

yea, it's quite possible that the differential problems could be messing with the traction, if no codes are popping up.

[Cloverdale]

Curious what your mileage is to reach that repair requirement? I have 07's but fortunately at lower mileage. You'll want to ensure bearings have been done if you go with a replacement diff and replace bushings while you're in there.

[aaroncoppen19]

Originally Posted by Cloverdale

Curious what your mileage is to reach that repair requirement? I have 07's but fortunately at lower mileage. You'll want to ensure bearings have been done if you go with a replacement diff and replace bushings while you're in there.

My car has about 108k miles

[Bims328i]

I had mine go out at some point (replaced at 99k mi), creeped up on me slowly. One way to tell if you diff is going bad is you'll hear a hum like grinding sound but it will change depending on load.

You get one grinding tone under acceleration, another tone on deceleration and usually will kill the grinding noise when you hover the throttle so there is no load on the bearing. I had all of these symptoms along with flakes in my diff fluid.

In my case it was the input shaft bearing. Replaced with a used one which has been good since.

[aaroncoppen19]

Originally Posted by Bims328i

I had mine go out at some point (replaced at 99k mi), creeped up on me slowly. One way to tell if you diff is going bad is you'll hear a hum like grinding sound but it will change depending on load.

You get one grinding tone under acceleration, another tone on deceleration and usually will kill the grinding noise when you hover the throttle so there is no load on the bearing. I had all of these symptoms along with flakes in my diff fluid.

In my case it was the input shaft bearing. Replaced with a used one which has been good since.

How much did that cost mate ?

[Bims328i]

$479 with tax on ebay with free shipping. Add extra for the 3 replacement bushings and toolkit.

Was a decent assembly. Also had both output flanges.

Picked up an MMR magnetic diff plug as well.