my 98 shakes at highway or on a rocky surface,low speeds .I did the bushings,all steering is good,,but I noticed something no on else has seen.THE STEERING SHAFT FROM THE COLUMN SHAKES A BIT IF YOU WIGGLE IT. what causes this.it wiggles from underneath where it meets the universal joint to the box.i think it could be all our problems on Toyota shake.i think they have bad bearings,bushings in the column.mine has always done this its less now that I did poly bushings.please check your 4 runner and reply what it takes to fix this bad joke.