I have a had a noise from the front of the car now which has got louder. It sounds like a wheel bearing droning and now audible at slow speeds as well as high. It is speed related but not obvious which side it is from which worries me it may be the front diif. I have jacked the front up and no bearing play evident or noise from either wheels when manually rotating. I realise there is no load on the bearings when jacked.
I changed the front diff oil and found no evidence of any metallic residue. Short of just changing the wheel bearings out to see if it cures it I am unsure how to confirm the issue as dont fancy the car in drive balanced on 4 axle stands
Not joined yet? Register for free and enjoy features such as alerts, private messaging and viewing latest posts and topics.
Drivetrain noise
Drivetrain noise
First check: tyres, are all four the same brand with a tread depth of less than 2mm between any? Are they either ‘
’ marked or a (premium) brand? BMWs are very sensitive to tyre choice on all but the very latest xDrive models.
Is there any jerkiness in the steering in full lock in either direction when moving at walking pace forwards or backwards? If yes, then your front diff is likely damaged. If no then wheel bearing most likely.
Replacing front wheel bearings requires specialist kit due to the bearings needing hydraulic pressing of the drive shaft into the flange in order to replace the bearings. The drive shaft has to come out of the flange.
’ marked or a (premium) brand? BMWs are very sensitive to tyre choice on all but the very latest xDrive models.Is there any jerkiness in the steering in full lock in either direction when moving at walking pace forwards or backwards? If yes, then your front diff is likely damaged. If no then wheel bearing most likely.
Replacing front wheel bearings requires specialist kit due to the bearings needing hydraulic pressing of the drive shaft into the flange in order to replace the bearings. The drive shaft has to come out of the flange.
Never anthropomorphise computers. They hate that.Drivetrain noise
Its not the tyres. The front bearings come as a complete hub unit and are bolt on
Drivetrain noise
OK. The driveshafts still need to be removed through them though?
Never anthropomorphise computers. They hate that.Drivetrain noise
Front bearings often grown into the housing with alloy corrosion it took 10 ton to press mine out so don't expect to just lift them out unless very lucky. The new ones however will just drop in after a cleanup. 
If you are spinning the bearing and it's smooth it's probably not the bearing, mine had roughness and it wasn't that noticeable on the road except coming over a long crest which verred left (right bearing) plus it was the side I had a dragging caliper on which creates heat.
If you are spinning the bearing and it's smooth it's probably not the bearing, mine had roughness and it wasn't that noticeable on the road except coming over a long crest which verred left (right bearing) plus it was the side I had a dragging caliper on which creates heat.
Drivetrain noise
it came as advisory on last MOT, the noise is more when you drive on concrete road, i have changed myself both on mine wasnt too hard with hub puller! looks like the water splashes from the inner side that causes the rust and noise.