XC70 D5 Diff Whine?
 

Hello,

I have a 2011 XC70 D5 (205BHP) AWD Manual with about 117,000 miles on it. It has recently developed a whine from the rear end and I'm hoping someone might be able to point me in the right direction. I have read a number of other posts on similar problems but few seem to reach much of a conclusion.

The car has developed a whine/rumble from the rear end between about 45mph and 80mph, it is related to road speed rather than engine speed, and is getting progressively louder over time.

I assumed a wheel bearing at first as it sounds very much like this, however no change in sound when cornering and no wobble in either horizontal or vertical with wheels off the ground.

The car was in for it's MOT yesterday and I asked them to take a look at this noise too. They have suggested it maybe the rear diff, but are unsure without further investigation. Is there any known issues or common failure points with these, or could it be something else, Haldex, prop shaft etc?

I did have both rear tyres replaced a couple of weeks prior to the start of this noise, I have today swapped the rear wheels (8mm tread) to the front (5mm tread) and vice versa which has made no difference to the noise.

Thanks.

I have been a member on here for many years and have read about noise issues from the cars rear. Many have been wheel bearing related ( as you surmised). I don't remember that many being rear diff ( if any). Other causes have been poor quality tyres; ( road noise) prop shaft centre bearing, to name alternatives. I changed front off side drop link cos thats where I heard noise from...Turned out it was nearside that was chattering- old age deceived me :).
Cheers Bob.

I think the rear diff pinion bearing is a known failure point on the XC60 and XC90. My research suggests that the parts are shared with the Land Rover Freelander 2 and that independant repairers are doing repairs and upgrades to the bearings on these vehicles. The same repairers will often work on the Volvo failures too.

Has the Haldex fluid ever been changed?