Shimmy / Vibration

my first thought is out-of-balance tires...have them removed, cleaned and harmonically balanced~

if its kinda high-milage would inspect the control arm bushings and the steering rack tie rods and wheel tie rods, Lower ball joint has a fussy alignment, if you went to your alignment shop they'd tell you that it cannot be aligned on account of it being too worn~ macpherson struts are not canceling out the vibrations...this also could cause the problems~

Thank you, judge_roy.

Around 90k miles, judge_roy.

the mileage could be HARD miles or like my wife who's got 147,000 on her Prius and looks and smells brand new yet~, on the other hand a TRUCK is driven like a truck~ Buick...is probably grampa's car, good choice~ 90k is some drivin' hopefully took the time for maintenance items in all those miles~

I've test driven 3 of these and they all shimmy in the rear to varying degrees.

2011 Buick Lucerne worst car I ever owned. It shakes above 50 MPH, had alignment shop check suspension, purchased new Firestone tires,, no help, , dealer tried to say it was tire balance problem, and with all complaints, they had to know it was defective, and sold me car anyway, only interested in my money. I am a senior citizen, veteran, and no way to afford to keep throwing good money after bad. Orleans is small town,.thought sure I could get honest deal, not so.. No wonder Americans give up on American products, we sell products knowing they are defective, but the " Bean counters" will say GM has great lawyers, so they proceed on volume, with no concern or care for those who buy their product., and they know average consumer cannot afford to fight them in court. My shirt I am wearing says I stand for the flag ( yes I believe in America) and I kneel for the cross, So as Christian I believe in doing right thing, seems to me only big companies can believe in is themselves and the almighty dollar/