Since I bought my 2019 S60 every now and then when driving on a bumpy highway the front of the cars starts shaking. The only way for it to stop shaking is by stepping hard on the brake and then it stops.
Recently it is repeating more and more, the car now has 80K miles, the brakes were replaced with 60K, the tires were replaced with 40K and the alignment is checked every 10K miles.
The mechanics say the brakes are good, routers are good, but no one can explain why the car shakes when driving occasionally, also this usually only happens when driving 60-80 mph.
Any recommendations or suggestions is greatly appreciated.
Thank you,
John

 

I mean when driving on a bumpy road, I would expect the vehicle to shake a little.

Tires properly balanced? If you think it's only the front, swap the front tires to the back and see if the problem changes.

 

The bumpy road is the instigator, the shaking begins on the bumpy road and when its a smooth road the shaking continues until braking and then this releases shaking or what feels like the brakes that have been stuck.
It is not the balancing or alignment, example, last week I drove for 700 miles 12 hours straight and this only happened 3 times during the trip.

 

have you had the car inspected for worn suspension bushings, checked rotors for premature wear (ie a stuck caliper), torn axle boots, strut/shock leaks?

curious what would happen if the next time you coasted to a stop, turn the car off/on and restarted without touching the brakes. Wondering if there could be something amis with the ABS controller or a wheel sensor that triggered one of the wheel's to brake when it gets jostled. Did your tech do a full scan for ABS codes?

 

In regards to the inspection, yes, everything has been checked when they replaced the pads in November. I can try to coast and see what happens like you suggested. I did just have the ABS and auto hold error message cleared as something triggered it, but they didn't say anything about other codes. They didn't do any updates to the system and even when I took it to the dealer for the 60K servicing I specifically asked to see if there where any updates and I just found out that the dealer never did any updates for the past two years. I'm going to another dealer next week to just do any update as online it shows there have been multiple updates in the past few months. I'm hoping this may be the fix. Thank you for the information above.

 

The whole idea of "death wobble" type dynamics requires you to have worn front end parts. If it's not that, then I have no idea.