Apart from sloppy/poor steering and control, front end suspension issues will cause vibrations by magnifiying any slight unevenness in the road surface with harmonic vibrations varying by road speed (sweet spots of vibration). Steering alignment is where to start. At that time, the steering end link bushings should be checked for wear -there should be no discernable horizontal looseness and no sense of movement other than resistance to normal hub and steering rod play. Next is checking the radial control arm front bushings (the four conical bushings) and the sway bar end link bushings (the four cupped bushings), both are common wear points. Note carefully there are early and updated conical bushing depending on an updated control arm (to help prevent brake vibration) which can be determined by measing arm length. Note also the two kinds of sway bar end link rods listed, the common one is steel, but you may also see a very different aluminum one for an aluminum arm. The pressed-in rear radial control arm bushings (chassis) and lower sway bar linkage rod bushings are further down the wear list and in addition to being occasionally inspected for cracking or side play, when the other bushings are being replaced they should be bench checked that the rubber core isn't starting to detach. I had occasion to do that earlier this month and found one lower sway bar bushing starting to let go that had checked out during inspection.
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