XC90 Lumpy rear end

[Martin Porter]

Hi Everyone, I am new to this forum and I am desperately in need of your collective minds! I have been the proud owner of a 2014 XC90 D5 for the last 5 years, she has been the most amazing family car to replace my Rover 75 Tourer (Please dont judge me the Rover was a gift!), aside from a few niggles, ordinary servicing and an engine mount freeing itself, we have had no major problems!! However this evening I ventured out into the cold ( France minus 2!) to help a friend about 2k from my house, the five minutes driving there with the aircon on max hot etc was fine, the tyres slipped a few times coming out of our driveway as the road was frosty, but I find with the camber out of the driveway she usually crabs a bit anyway.
Now to the problem, I parked up, at said mates house ,reversed up on a slight slope, and when I left the problem started. When I got back on to the main road it was as if i had a puncture, the back of the car was really lumpy almost like the rear wheel had turned into a large egg, I have double checked the tyres and they seem fine, obviously its dark so I cant see if there is a rhino stuck in the tread but my quick look with the torch suggests not. Any ideas? I apologise in advance if i have posted this in the wrong place as i am new to the forum. Any advice from you guys will be very gratefully received, Thanks in advance! Martin

[owenfackrell]

It could be possible that you have lost a corrective weight from one of the rear wheels.

[laundryman]

Last time i had something like that was on snow, It wa almost like the drive was snatching. Only thing i could think off was tires being different diameters and FWD cutting in and out. Checked and adjusted tyre pressures and problem went away. Only seems to happen on snow/ice.