My uncle has a 1998 toyota tacoma prerunner (the one that is tall) and when I recently drove his car, when I drive on the freeway it shakes really hard and when I apply the brakes it shakes violently what might be the problem?
These are the symptoms of tires in serious need of rebalancing, and/or defective tires, and/or severely worn suspension components, and/or brake rotors in need of replacement.
Ball joints and/or tie rod ends and/or wheel bearings. Put it up on a hoist and start wiggling the wheels side to side while looking for the slack.