I know i get the shakes over speedhumps if my wheelbearings have come loose or are worn.
I have to keep an eye on them
Also could be wheel balance. I went from stockers with wobbles to 33's. I thought i was going to get mega wobbles. But smooooth as. Even with mud in the rims
Leafy's get worn suspension bushes too, but with a coily check your control arms etc.