I had a noticeable vibration on my 2018 S90 T6 Inscription. The car was shuttering and vibrating heavily under acceleration or coasting at different speed (at 30K miles).
After inspecting and balancing the tires and wheels twice, as advised by the dealer, as usual. It turned out the axle shaft in the front right was the cause of the vibration. Easy to inspect by any qualified technician. The right side was moving while the other side wasn't. Check the below video and you will see the play in the axle.
The car was making the vibration since 24k miles and it was intermittent. I found the source of the vibration at around 30K miles, after it got worse & became permanent.
One thing that I tried is to tight the axle bolt (13mm-half turn max if the bolt was really loose), however, not advisable at all as this will create stress on the bearing in the inner axle boot. That actually helped a little to treat the vibration but for sure the axle was defective.
I hope this will be all the cause of all my vibration and the not another thing else.
Anyway, hope this help anyone having the same issue. It's really frustrating to see such axle go bad at this very low mileage. It seems the axle is too weak for the engine torque But who knows?!
The dealer diagnosed the car and found two issues:
1- The right drive axle had a play and needed to be replaced as expected
2- Front Prob drive shaft CV Joint is defective: The dealer showed me the new redesigned version where it is marked with a green line. If you don't see the green line on your prob shaft, this means you might have the old design one and will probably be defective.
Item#2 in the picture CV JOINT
Only for front CV joints. For rear CV joints the entire propeller shaft must be replaced. front.